AudioNervosa

Specialists => Audiologists => Topic started by: rollo on August 13, 2017, 10:15:01 AM

Title: SENERGY What really is It ??
Post by: rollo on August 13, 2017, 10:15:01 AM
   Character of components ? Electrical characteristics of components ? All of the above ? They like each other? :duh :rofl: My ears tell me so ? :roll:


charles


Title: Re: SENERGY What really is It ??
Post by: steve on August 13, 2017, 05:50:43 PM
   Character of components ? Electrical characteristics of components ? All of the above ? They like each other? :duh :rofl: My ears tell me so ? :roll:

charles

Here is my explanation in this string, as in the phase splitter string.

All synergy is, is an attempt to combine separate elements to obtain maximum sonic quality. Synergy is variable as it depends upon how the combination sonic quality compares to perfect entities that are combined. (Let's leave out the room and speakers for now.)
The main culprits are lack of correct designing, and lack of understanding how sensitive the "ear" is.

Virtually every part is critical to the sonic properties of a component. That includes parts in the power supply (and number of stages), parts quality in the rest of the circuit, harmonic distortion properties, frequency response etc.

The "ear" is incredibly sensitive to tonal abnormalities etc based upon Olson, Rane, Fletcher, Jensen, RCA Radiotron Designers Handbook etc, and I have confirmed before and after reading these sources over the years. 

If we are dealing with a preamplifier to amplifier combination, we look for enough signal voltage to drive the amplifier. This is usually not any problem. What could be a problem though, is output signal current capability of the preamplifier. Is that signal current enough to drive the output capacitance, IC capacitance, and amplifier input capacitance?

With not enough signal current, as the frequency rises, the HD distortion rises. I have seen sine waves become triangular waves as the frequency rises. But one does not need a buffer stage. A 12au7/6sn7/6dj8 type tubes generally provide plenty without any buffer. If a buffer is needed, there is one more stage to degrade the music.

As a very simple example of synergy; if a preamplifier is full sounding, we tend to find an amplifier that is thin sounding to compensate. Unfortunately, there is usually more than one flaw in a component, unless we are dealing with superb pieces of equipment. 
And some flaws one cannot cancel out. For instance, how does one cancel smearing caused by a component? If a component is so full it loses detail, how can that inner detail be recreated? Some of the biggest problems I see in components are;

1. Insufficient power supply filtering stages
2. Insufficient size and quality of coupling capacitors in tube components

My philosophy is to perform listening tests over months for each part, if possible, and each component for accuracy in absolute terms. With proper design, there will be less signal degradation, thus higher synergy can be achieved. Then I would design the speaker.

A couple of reasons why speaker sound so different are:

1. Different frequency responses and price range.
2. Different venue testing the speaker
3. Different quality components in the speaker.
4. Different quality active components in the test system. If a designer is using components that lack sufficient high frequency response, then the speaker will probably be bright sounding.
Etc.

Based upon these reasons, I would provide variable adjustments so the customer can create the best synergy possible. I have three adjustments on my speakers alone.

One could go on and on, but I hope this is not too complicated nor simplistic.

Cheers
Steve
Title: Re: SENERGY What really is It ??
Post by: Nick B on August 13, 2017, 07:22:49 PM
Steve,
Not too simple nor too complicated... it's just right imo. I have mixed feelings about synergy. I would not want "synergy" to be the solution for equipment that has design flaws. I'd rather just get components to produce the sound that I enjoy, whether colored to some extent or not. That's why I'm a fan of cable looms...wires that show a consistency in design and execution. I'm sure many of you have much more experience in this area and have tried many more products, but that's my .02 c
Nick
Title: Re: SENERGY What really is It ??
Post by: tmazz on August 13, 2017, 08:22:50 PM
Steve, I have mentioned this before, but I am not sure if you were part of that thread. I understand and appreciate all of the points made in your post, but I do have one problem with what you wrote and that is your references to design "flaws." I am just not comfortable with you referring to some of the things you describe as flaws, a word which carries a very negative connotation when taking about a design. I prefer to call them design limitations. Using the word flaw implies that the piece of equipment sounds the way it does because of some error made by the engineer. Most times this is not the case at all.  In a perfect world amn engineer would have an unlimited budget and not restrictions in terms of size, weight. heat dissipation etc and a customer base that would be willing to pay whatever it took to make a perfect sounding amp. But this is rarely, if ever the case. I am sure there is not an audio designer out there that wouldn't love to put together an amp made with all top of the line Dueland caps, but the reality is that in most case, the cost of those caps could exceed the entire parts budget for the amp.
Engineers do not undersize power suppliers or coupling caps because they don't know any better, they do so because they have to make compromises to make the amp work within the restrictions that they are given to work with and quite often produce a very good amp given those restrictions. To refer to a $1k amp as flawed because it does not sound as good as one that sells for $25k IMO is doing a great disservice to the company that sells it and the engineer who designed it.

That said, given that an amp at any given price point will have to have some kind of design limitations and that the improvement of any of the sonic characteristics will have a price tag associated with it, it is up to the engineer, guided by his personal taste and perhaps the "house sound" of the company that is producing the amp, the engineer has to which parameters he wants to improve so that he can stay within his budget and produce an amp with a sonic signature that will make it successful in the market place. (Sorry if this sound like a rant, but as a degreed engineer I get very defensive when I get told that something is flawed because because it doesn't performs as well as something that costs significantly more. I have had numerous arguments with marketing types that come in and say wee need you to build us a box that we can sell for $1k and then they see then prototype complain I am proposing a poor design because that our competitors model XYZ has 15 more feature than ours. To which I told them that they competitors box also sells for $7k. Duh! Give me $7k to work with and I can deliver all of those features as well.)

I do agree with the points you are trying to get across, but as a fellow EE I think you can understand why the choice of vocabulary gets under my skin.

Anyway, back to synergy. In my mind synergy is simply the selection of various pieces of equipment whose sonic signature complement each other and add up to a better sound when used together as oppose to pieces whose sonic signature class and sound worse as a pair.
Title: Re: SENERGY What really is It ??
Post by: rollo on August 14, 2017, 07:02:46 AM
it's the misspelling of the word "synergy"   :rofl:

doug s.

   Got me there Doug. What an idiot I am.


charles
Title: Re: SENERGY What really is It ??
Post by: rollo on August 14, 2017, 07:15:24 AM
Tom in essence the design is flawed. I could see using a less expensive part however you alluded to a poor design choice of ntimproper values due to cost/direction.
If one amp sounds better than another the lesser is "not" flawed unless it has been compromised in design. A good EE should be able to get a good circuit design and sound using less than exotic parts. That is their job.
I leave it to the engineers to design a good sounding component. Then as a consumer I insert component in my system. If it sounds better to me than removed component it stays. if not NEXT.
I would say synergy is inherent to one's system. If it all comes together after a component change its SYNERGY !


charles
Title: Re: SENERGY What really is It ??
Post by: steve on August 14, 2017, 08:11:37 AM
I have to respectfully disagree with some of your post. This is not about bashing you Tmazz, but about the culture marketing has created.

Quote
Steve, I have mentioned this before, but I am not sure if you were part of that thread. I understand and appreciate all of the points made in your post, but I do have one problem with what you wrote and that is your references to design "flaws." I am just not comfortable with you referring to some of the things you describe as flaws, a word which carries a very negative connotation when taking about a design. I prefer to call them design limitations. Using the word flaw implies that the piece of equipment sounds the way it does because of some error made by the engineer. Most times this is not the case at all.

Actually, in many cases it is errors that engineers do make in designing. Insufficient power supply (even in expensive components),  number of filter sections used. Checking parts quality throughout, many are not necessarily associated with price at all. More as I follow through in response.

Quote
In a perfect world amn engineer would have an unlimited budget and not restrictions in terms of size, weight. heat dissipation etc and a customer base that would be willing to pay whatever it took to make a perfect sounding amp. But this is rarely, if ever the case.


Size, weight, heat dissipation are terms for power output, maybe the power or output transformer in an amplifier. Those terms do not define what it takes to make a perfect sounding amp or preamplifier. Who needs an unlimited budget, except for high power out? I designed a perfect sounding preamplifier which marketed for only $3,000. This is certainly not the 10 grand, 20 grand, 30 grand nonsense. Sure if one wishes huge amounts of output, the cost would be more, but we are discussing quality, not quantity.

By the way, I think we both agree that designing is more than solving a few equations. Please correct me if you feel differently.
 
Quote
I am sure there is not an audio designer out there that wouldn't love to put together an amp made with all top of the line Dueland caps, but the reality is that in most case, the cost of those caps could exceed the entire parts budget for the amp.

And how would one know how good/accurate a Dueland capacitor is (not just picking on Dueland)? By some string in some forum “comparing” capacitors? By the cost? DIYers? Those hardly qualify as defining how good/accurate a capacitor is. In fact, different physical shapes, sizes, voltage ratings from the same manufacturer can affect accuracy.
 
Secondly, by using the wrong values in coupling, the accurate capacitors are deemed poorer in quality, relegating the good capacitors to actual extinction. How many times has one seen schematics/diyers/capacitor comparisons that use .1, .22, .47, .82uf coupling capacitors in their designs.

Guess what, those smallish accurate capacitors will sound thin/sterile, while the fuller, less accurate capacitors will actually sound better. More will choose smooth over sterile. Unless the capacitors are properly tested, with the correct value ufd, the wrong brands will be claimed as superior. By the way, I found some much much less expensive that tested accurate, that I used in my preamplifiers and amplifiers, but they have become extinct due to the marketers and unqualified “testers”. I guess one wishes to pay more for the same sonic quality product, be my guest. That assumes the more expensive product is actually accurate.

Quote
Engineers do not undersize power suppliers or coupling caps because they don't know any better, they do so because they have to make compromises to make the amp work within the restrictions that they are given to work with and quite often produce a very good amp given those restrictions. To refer to a $1k amp as flawed because it does not sound as good as one that sells for $25k IMO is doing a great disservice to the company that sells it and the engineer who designed it.

Three comments. First engineers do undersize power supplies all the time. I can’t remember the last time I saw a power supply that was designed properly; for example with the proper number of filtering stages. This included both inexpensive and very expensive components.

Secondly, with respect to price, you are correct in that there are price points, so $1k would necessitate a lesser quality. However, $25k is nonsense, unless one is dealing with super high power output, thus special ordered parts, and in appearance.

Quote
I do agree with the points you are trying to get across, but as a fellow EE I think you can understand why the choice of vocabulary gets under my skin.

There is a difference, as I am an electronics engineer, you an electrical engineer. Back in my day we concentrated on linear electronics, while your curriculum is much more generalized. I think we both understand that classes/books only give us the tools for further investigating. Frankly, I have found very few engineers who fully understand designing audio, even the very expensive components.

As one simple example, on another forum I know of one with a Masters Degree in EE from MIT who did not understand how an inductor worked in an electronic circuit. He stated twice he would flunk me for breakfast. Turned out he could only quote a narrow book definition; he understood nothing more. I proved otherwise by actual experiment/photo of results. He voluntarily left the forum never to return.

Quote
Anyway, back to synergy. In my mind synergy is simply the selection of various pieces of equipment whose sonic signature complement each other and add up to a better sound when used together as oppose to pieces whose sonic signature class and sound worse as a pair.

I agree. I would add that when designing, I dig deeper, thoroughly testing individual parts and dividing components into sections.

In conclusion, as I believe we both agree, that classes and books only provide a foundation for further investigation. This is not unique, as this also occurs in mechanical engineering and other disciplines.

Cheers
Steve
Title: Re: SENERGY What really is It ??
Post by: tmazz on August 14, 2017, 11:40:41 AM
First off Steve, your post didn't even come close to bashing, no explanation needed and no offense was taken. I think one of the things we pride ourselves on here at AN is the ability to have these kind of discussions on an intellectual and civil basis, as opposed to other places that shall remain nameless where things like this quickly lead to name calling, hurt feelings and people getting voted off the island. I for one welcome your opinions and input, even if they don't agree with mine. I am 36 years out of engineering school and still learning new things every day.

That aside I think we do agree more than disagree on when point I was trying to get across. The disagreements you had were really just with the examples I used rather than the point I was trying to get to. My use of Dueland caps was just to throw out the concept that in general you can solve many engineering problems by throwing money at it, although I do agree that this is not always the best way to improve something,and sometimes it does not even work at all (Large $ do not always lead to better performance. Likewise, the dollar figures I tossed out were just off the top of my head to make a point. But using your examples you said you could built a perfect sounding preamp for $3k and that if you had to build one for $1k it would be of lesser quality. The point that I was trying to get across was that it would be a disservice to you to say that the $1k model was "flawed", it would be simply the best you could do for $1k, and there's nothing wrong with that.

I am surprised at how much sub par design work is out there, but I will have to take your word for it as you have eyes on a lot more equipment than I do.  But do agree with you that many, and probably most EEs just do not "get" audio. The problem is that it is not all to tough to design an audio circuit from a large signal viewpoint. it is fairly easy to get something that sounds fairly good and will satisfy most consumers. However when you get down to the small and micro signal views where the details that we as audiophile crave can be found things can get very strange. I had a professor in engineering scholl that told us audio circuits, while often viewed as very simplistic are some of the toughest to get right. His reasoning was that circuit non-linearities are usually expressed in terms of change per octave. The audio band although it is only 2khz wide spans 10 octaves. . Compare that to the FM broadcast band which spans less than 1/4 of an octave and within that 1/4 there are 100 separate channels. So the the bandwidth of an FM carrier signal spans in the area of .0025 octaves maiking it infinitely easier to design a linear circuit for it as compared to a 10 octave wide audio signal. (granted there are other problems that occur in high frequency circuits, but let's put them aside for now.) So yes I do agree that while there are many many talented EEs out there, very few of them thoroughly understand audio circuits, especially high end ones.

 Well, time to get down off my soapbox. but again feel free to challenge my ideas any time. I don't take it personally and rather enjoy the mental stimulation.

Tom






Title: Re: SENERGY What really is It ??
Post by: tmazz on August 14, 2017, 12:01:57 PM
Tom in essence the design is flawed. I could see using a less expensive part however you alluded to a poor design choice of ntimproper values due to cost/direction.

I think you are missing my point here. I never said that they were making poor design choices  due to cost, what I was saying was that given cost constraints they are forced to make design decisions that could result in a lower quality sound. And that this is not a flaw per se, but just the nature of , but rather the nature of then design process. Remember When Andrew Jones came to our meeting last year and he was saying that he was excited about the prospect of designing a $2500 speaker for ELAC, because the parts budget he would have for a $2500 speaker would allow him to do things that he could not do with the limited budget he had for the Uni-Fi series.  And the fact that the new $2500 speaker is significantly better does not make the Uni-Fi a flawed design, it is still a great $500 that is just more limited because of it's price point. the same line of thinking applies to electronics.


If one amp sounds better than another the lesser is "not" flawed unless it has been compromised in design. A good EE should be able to get a good circuit design and sound using less than exotic parts. That is their job.


Correct, but even a good EE is limited by the amount of money he can put into the build. Of course the better ones find ways to squeeze more performance out of a limited budget and those pieces end up being the better products on the market. But lets keep in mind that we are talking high end audio here, so good sound it a base requirement to play in the game to start. It is been a long time since I have heard a high end product that actually sounded bad. I have heard plenty that I did not feel sounded as good as the should of given their asking price, but nothing that I would consider bad.

Besides, putting in exotic parts is our job after we buy them.  :lol:
Title: Re: SENERGY What really is It ??
Post by: steve on August 14, 2017, 02:29:48 PM
Thanks for the kind words Tom. I appreciate the civility of this forum vs some others.

Just in the past month, on another major forum, I saw a computer scientist with an "audio backround", argue for 20 literal pages, claiming  the other "B" misunderstood concepts. Turned out the "expert" did not understand basic ohms law, I = E/R. This, even after the other poster "B" gave an example right out of an EE textbook. I have had my fill of computer scientists hyping themselves as experts.

First off Steve, your post didn't even come close to bashing, no explanation needed and no offense was taken. I think one of the things we pride ourselves on here at AN is the ability to have these kind of discussions on an intellectual and civil basis, as opposed to other places that shall remain nameless where things like this quickly lead to name calling, hurt feelings and people getting voted off the island. I for one welcome your opinions and input, even if they don't agree with mine. I am 36 years out of engineering school and still learning new things every day.

I agree with you. I started when I was 7 or 8, got back into audio design around 1979, and for the past several years have discovered just how sensitive our "ears" are, especially when it comes to frequency response/tonal balance. More than I ever thought. +/- 0,1db means virtually nothing in my book.

Quote
That aside I think we do agree more than disagree on when point I was trying to get across. The disagreements you had were really just with the examples I used rather than the point I was trying to get to. My use of Dueland caps was just to throw out the concept that in general you can solve many engineering problems by throwing money at it, although I do agree that this is not always the best way to improve something,and sometimes it does not even work at all (Large $ do not always lead to better performance. Likewise, the dollar figures I tossed out were just off the top of my head to make a point. But using your examples you said you could built a perfect sounding preamp for $3k and that if you had to build one for $1k it would be of lesser quality. The point that I was trying to get across was that it would be a disservice to you to say that the $1k model was "flawed", it would be simply the best you could do for $1k, and there's nothing wrong with that.

I figured you were using examples. I was attempting to make a more generalized statement, similar to yours, that money does not necessarily mean better. The other points are that most diyers, designers, and strings on comparing capacitors, do not test capacitors properly, and at least some designers believe all parts "sound" the same. I have to test a part properly before I use it.

Quote
I am surprised at how much sub par design work is out there, but I will have to take your word for it as you have eyes on a lot more equipment than I do.

I have viewed hundreds of schematics if not more, and as just one example, am continually surprised how the designers can use 0.47uf or smaller coupling capacitors and claiming high fidelity. No global feedback used. I mean in just one component the frequency response (FR) might be -3db at 20hz, and I have seen -7db at 20hz (not counting OPTs, input filters etc) and calling the component high quality sound, no subs/filters used. Really amazes me. (By the way, -3db at 20hz might be -0,6db at 80hz, -0,25db at 160hz and even -0,1db at 320hz. No wonder some like low order high distortion figure components, to give some flesh to the music.

Quote
But do agree with you that many, and probably most EEs just do not "get" audio. The problem is that it is not all to tough to design an audio circuit from a large signal viewpoint. it is fairly easy to get something that sounds fairly good and will satisfy most consumers. However when you get down to the small and micro signal views where the details that we as audiophile crave can be found things can get very strange.

I agree. +1. I look at audio having different issues. Instead of reading a meter, digital etc, we use "ears". Auditory vs sight.
Our "ears" have different and multiple issues than sight, smell, feel. How does one measure smearing, depth, width with measurements?

Quote
I had a professor in engineering scholl that told us audio circuits, while often viewed as very simplistic are some of the toughest to get right.

I agree. Check out Walter Jung/Richard Marsh on "picking capacitors" and check out how poor electrolytic capacitors are VS frequency.
Compare typical wirewound power resistors to Mills non inductive resistors. Amazes me.

Quote
His reasoning was that circuit non-linearities are usually expressed in terms of change per octave. The audio band although it is only 2khz wide spans 10 octaves.

I am assuming you meant 20khz. I am going to guess that the professor had studied Olson, Rane etc, as they demonstrated the importance of  bandwidth, and harmonics and bandwidth etc.

Quote
Compare that to the FM broadcast band which spans less than 1/4 of an octave and within that 1/4 there are 100 separate channels. So the the bandwidth of an FM carrier signal spans in the area of .0025 octaves maiking it infinitely easier to design a linear circuit for it as compared to a 10 octave wide audio signal. (granted there are other problems that occur in high frequency circuits, but let's put them aside for now.) So yes I do agree that while there are many many talented EEs out there, very few of them thoroughly understand audio circuits, especially high end ones.

I agree Tom.

Quote
Well, time to get down off my soapbox. but again feel free to challenge my ideas any time. I don't take it personally and rather enjoy the mental stimulation.

Tom

Don't worry about it Tom. I have been on mine a couple of times as well.

Cheers
Steve
Title: SQ be damned.
Post by: P.I. on August 14, 2017, 02:47:14 PM
I have to respectfully disagree with some of your post. This is not about bashing you Tmazz, but about the culture marketing has created.

Quote
Steve, I have mentioned this before, but I am not sure if you were part of that thread. I understand and appreciate all of the points made in your post, but I do have one problem with what you wrote and that is your references to design "flaws." I am just not comfortable with you referring to some of the things you describe as flaws, a word which carries a very negative connotation when taking about a design. I prefer to call them design limitations. Using the word flaw implies that the piece of equipment sounds the way it does because of some error made by the engineer. Most times this is not the case at all.

Actually, in many cases it is errors that engineers do make in designing. Insufficient power supply (even in expensive components),  number of filter sections used. Checking parts quality throughout, many are not necessarily associated with price at all. More as I follow through in response.

Quote
In a perfect world amn engineer would have an unlimited budget and not restrictions in terms of size, weight. heat dissipation etc and a customer base that would be willing to pay whatever it took to make a perfect sounding amp. But this is rarely, if ever the case.


Size, weight, heat dissipation are terms for power output, maybe the power or output transformer in an amplifier. Those terms do not define what it takes to make a perfect sounding amp or preamplifier. Who needs an unlimited budget, except for high power out? I designed a perfect sounding preamplifier which marketed for only $3,000. This is certainly not the 10 grand, 20 grand, 30 grand nonsense. Sure if one wishes huge amounts of output, the cost would be more, but we are discussing quality, not quantity.

By the way, I think we both agree that designing is more than solving a few equations. Please correct me if you feel differently.
 
Quote
I am sure there is not an audio designer out there that wouldn't love to put together an amp made with all top of the line Dueland caps, but the reality is that in most case, the cost of those caps could exceed the entire parts budget for the amp.

And how would one know how good/accurate a Dueland capacitor is (not just picking on Dueland)? By some string in some forum “comparing” capacitors? By the cost? DIYers? Those hardly qualify as defining how good/accurate a capacitor is. In fact, different physical shapes, sizes, voltage ratings from the same manufacturer can affect accuracy.
 
Secondly, by using the wrong values in coupling, the accurate capacitors are deemed poorer in quality, relegating the good capacitors to actual extinction. How many times has one seen schematics/diyers/capacitor comparisons that use .1, .22, .47, .82uf coupling capacitors in their designs.

Guess what, those smallish accurate capacitors will sound thin/sterile, while the fuller, less accurate capacitors will actually sound better. More will choose smooth over sterile. Unless the capacitors are properly tested, with the correct value ufd, the wrong brands will be claimed as superior. By the way, I found some much much less expensive that tested accurate, that I used in my preamplifiers and amplifiers, but they have become extinct due to the marketers and unqualified “testers”. I guess one wishes to pay more for the same sonic quality product, be my guest. That assumes the more expensive product is actually accurate.

Quote
Engineers do not undersize power suppliers or coupling caps because they don't know any better, they do so because they have to make compromises to make the amp work within the restrictions that they are given to work with and quite often produce a very good amp given those restrictions. To refer to a $1k amp as flawed because it does not sound as good as one that sells for $25k IMO is doing a great disservice to the company that sells it and the engineer who designed it.

Three comments. First engineers do undersize power supplies all the time. I can’t remember the last time I saw a power supply that was designed properly; for example with the proper number of filtering stages. This included both inexpensive and very expensive components.

Secondly, with respect to price, you are correct in that there are price points, so $1k would necessitate a lesser quality. However, $25k is nonsense, unless one is dealing with super high power output, thus special ordered parts, and in appearance.

Quote
I do agree with the points you are trying to get across, but as a fellow EE I think you can understand why the choice of vocabulary gets under my skin.

There is a difference, as I am an electronics engineer, you an electrical engineer. Back in my day we concentrated on linear electronics, while your curriculum is much more generalized. I think we both understand that classes/books only give us the tools for further investigating. Frankly, I have found very few engineers who fully understand designing audio, even the very expensive components.

As one simple example, on another forum I know of one with a Masters Degree in EE from MIT who did not understand how an inductor worked in an electronic circuit. He stated twice he would flunk me for breakfast. Turned out he could only quote a narrow book definition; he understood nothing more. I proved otherwise by actual experiment/photo of results. He voluntarily left the forum never to return.

Quote
Anyway, back to synergy. In my mind synergy is simply the selection of various pieces of equipment whose sonic signature complement each other and add up to a better sound when used together as oppose to pieces whose sonic signature class and sound worse as a pair.

I agree. I would add that when designing, I dig deeper, thoroughly testing individual parts and dividing components into sections.

In conclusion, as I believe we both agree, that classes and books only provide a foundation for further investigation. This is not unique, as this also occurs in mechanical engineering and other disciplines.

Cheers
Steve
Steve, great post.  Since I am a power guy I am in total agreement with what you have to say especially when it comes to power supplies and capacitors in general.  I have seldom seen what I considered to be a well designed power supply, as you stated.  I know for a fact that often the PS is compromised, not in the design phase, but when it hits the bean counters in the accounting office.  They generaly demand the minimum in performance to get the job done, SQ be damned.  I have seen many PS that the topology was great, but the implementation in component quality and sizing was just stupid.  That is why guys like us have made a living at out craft.  Fixing other's junk for better SQ.

Capacitors suck. All of them.  That being said, many caps sound better than DC servo circuits implemented to "fix"  offset at the input or output.  Gate delay, crappy parts, more tiny little bugs to pass the signal... all of these are culprits.  With that is consideration a cap, carefully chosen for SQ for that particular application is the least of many evils that are inherent in component design.  Since I am a tube guy I am a minimalist by nature.  The proper capacitors and resistors for the application may take a while to find, but absolutely essential for stellar SQ with tubes.  Also, the proper tube fed the proper way with signal and, more importantly, silent power is what it takes to get "there".

Low noise incoming power is obviously a consideration.  That is why I do what I do.  Can't feed the heart of the system poison and expect pristine audio quality.

In the end for me, a music lover first and gear lover second... on a budget, I have to choose ancillary pieces of gear that overcome the shortcomings of the SQ before the gear I am choosing.  Bright > darkish is better than bright > neutral in that equation.  I hate having to do that, but sometimes it must be done.  Typically I use pieces of gear that are essentially as neutral as I can afford and then choose cabling as the spice necessary to get "there"  There is that "there" again.  It takes years of experience to make these judgements or an experience mentor to lead us through the quagmire that is great audio SQ.

Buying the "best gear" (often deemed as most expensive) is an absolute road to lousy sound.  Expensive does not = good.  There were several BIG NAMES that offered $20K each amps that used the same ICE module that I could buy for $150.00 all day long, but in a gorgeous case.  In the power treatment end of the business I have been inside of $5K-$6K conditioners that frankly sounded and measured bad, but sold because of marketing and industry whores that printed a bunch of drivel about those pieces.

There is a reason why cottage audio is booming and the Big Boys are struggling along with the storefronts that sell their wares.  I can and have built systems that sell for less (sometimes much less) than 10% of the Big Boys that sound infinitely better.

One case in point: several years ago Gayle and I were invited to a showcase of gear in a local doctors home that retailed for almost $200K.  After it was all over I asked her what she thought.  Her reply was: "Let's go home and listen to MUSIC not excessive marketing".  I love that woman (for almost 50 years)!

Just sayin...
Title: Re: SENERGY What really is It ??
Post by: djdube525 on August 14, 2017, 03:16:35 PM
Steve, I have mentioned this before, but I am not sure if you were part of that thread. I understand and appreciate all of the points made in your post, but I do have one problem with what you wrote and that is your references to design "flaws." I am just not comfortable with you referring to some of the things you describe as flaws, a word which carries a very negative connotation when taking about a design. I prefer to call them design limitations.

Not to put words in your mouth... but can I offer an alternative? How about design "compromises".

What do they say about design... you can have Fast, Cheap, or Good... pick two. :)

Title: Re: SENERGY What really is It ??
Post by: tmazz on August 14, 2017, 05:56:13 PM
Steve, I have mentioned this before, but I am not sure if you were part of that thread. I understand and appreciate all of the points made in your post, but I do have one problem with what you wrote and that is your references to design "flaws." I am just not comfortable with you referring to some of the things you describe as flaws, a word which carries a very negative connotation when taking about a design. I prefer to call them design limitations.

Not to put words in your mouth... but can I offer an alternative? How about design "compromises".

What do they say about design... you can have Fast, Cheap, or Good... pick two. :)

 :thumb:
Title: Re: SENERGY What really is It ??
Post by: tmazz on August 14, 2017, 06:55:33 PM
Quote
His reasoning was that circuit non-linearities are usually expressed in terms of change per octave. The audio band although it is only 2khz wide spans 10 octaves.

I am assuming you meant 20khz. I am going to guess that the professor had studied Olson, Rane etc, as they demonstrated the importance of  bandwidth, and harmonics and bandwidth etc.



yup, 20 khz  :duh :lol:

You are right While human hearing can theoretically detect fundamental tones up to 20khz, music is not made up pure sine wave but rather very complex waveforms that as Dr Fourier taught us contain spectral energy at frequencies far above their fundamental tones. Also it is the harmonic content of an instruments tone that lead to its distinct character. it is the different mix of harmonics that make middle C on a cello sound different from middle C on an oboe even though the notes from both have the same fundamental frequency. So the preservation of the harmonic structure even about the hearing threshold it vital to making recorded music sound similar to a live performance instead of like a reasonable facsimile. which makes designing equipment for high end reproduction even more difficult than the just good enough reproduction of most  mass market audio equipment.
Title: Re: SENERGY What really is It ??
Post by: steve on August 15, 2017, 07:25:17 AM
Quote
His reasoning was that circuit non-linearities are usually expressed in terms of change per octave. The audio band although it is only 2khz wide spans 10 octaves.

I am assuming you meant 20khz. I am going to guess that the professor had studied Olson, Rane etc, as they demonstrated the importance of  bandwidth, and harmonics and bandwidth etc.


You are right While human hearing can theoretically detect fundamental tones up to 20khz, music is not made up pure sine wave but rather very complex waveforms that as Dr Fourier taught us contain spectral energy at frequencies far above their fundamental tones. Also it is the harmonic content of an instruments tone that lead to its distinct character. it is the different mix of harmonics that make middle C on a cello sound different from middle C on an oboe even though the notes from both have the same fundamental frequency. So the preservation of the harmonic structure even about the hearing threshold it vital to making recorded music sound similar to a live performance instead of like a reasonable facsimile. which makes designing equipment for high end reproduction even more difficult than the just good enough reproduction of most  mass market audio equipment.

Nice explanation Tom. If I can expand a little from Olson (keeping it simple) there is a weighting factor for harmonics. Higher harmonics are perceived much easier than low harmonics. In otherwards it takes much less change in, say, the 14th harmonic to be perceived VS a change in the 2nd harmonic. Below are just some figures based upon a pentode.

Harmonic               Weighting factor

2nd                               1
3rd                                1.5
4th                                2
5th                                2.5
6th                                3
7th                                3.5
8th                                4
9th                                4.5
10th                              5
etc.
14th                              7

According to Olson's work, higher orders would be even more sensitive to amplitude changes. (Cymbals come to mind.) As such, if the frequency response varies in the highs or lows, such as +/- 0,1db, a variation would occur in several harmonics, thus a instrument or voice change would be perceived. In my testing, I have consistently found, along with others, that altering an ~9k resistor, parallel, across a 4 ohm driver, by less than 0,1 ohms is perceivable. Pretty amazing to me.

Since same model drivers have fairly large spec differences, adjustments will be different for each driver, both electrically and placement wise in the room.

Cheers

Steve
Title: Re: SENERGY What really is It ??
Post by: rollo on August 15, 2017, 08:00:50 AM
   Very informative explanation of the science. Exactly what I look for in a component. Harmonic structure and tonality.  I put this question out there to hear the engineering or scientific reasons for component synergy.
  My subjective synergy combos are just that. You know a tubed pre with SS amp. DCs and tubes and so on. however if I'm choosing a speaker cable should I be aware of the capt ? Inductance, impedance as a guide to select contenders. When matching a Pre to amp output and input impedance of each is important.
  So what I'm looking for is a guide to help select the right stuff to audition.


charles
Title: Re: SENERGY What really is It ??
Post by: Nick B on August 15, 2017, 08:37:09 AM
Good posts. More harmonic structure is the missing ingredient  right now. As I've broken in the four receptacles on the Uber, I may plug the dac in soon with that in mind
Nick
Title: Re: SENERGY What really is It ??
Post by: Nick B on August 15, 2017, 10:13:03 AM
hi nick,

in the electrocoompaniet thread, i mentioned the stellar melos ma333r preamp f/s on agon and audiomart; and you said it was too spendy.  but, that's what you need in your system, imo, if you want "more harmonic structure".  you don't have to spend that much.  i saw three melos sha-1's sell recently on ebay, for $325 to $450.  (also one of the best headfone amps ever, according to the headfone freaks.)  this is a simple low-frills unit w/three line inputs.

and, there's one f/a now, w/discolored faceplate; a not uncommon feature of vintage black melos gear:
http://www.ebay.com/itm/253093887794
 (http://www.ebay.com/itm/253093887794)
and another more traditional unit:
http://www.ebay.com/itm/172816881914 (http://www.ebay.com/itm/172816881914)

yes, i am partial to the melos preamps; mine was fabulous before i upgraded it.  i only had it upgraded because i could!  but, you don't have to get a melos just cuz i like it; there's other preamps out there as well, that garner good reviews.

also, i am curious - you mentioned in the ec thread about wanting to upgrade your speakers, possibly to sp tech.  what speakers do you have now; unless i am missing it, there's none listed in your signature, w/the rest of your stuff.

doug s.
Good posts. More harmonic structure is the missing ingredient  right now. As I've broken in the four receptacles on the Uber, I may plug the dac in soon with that in mind
Nick

Doug,
Can't believe I left the speakers out  :duh They are SP Tech 2.0 upgraded to 2.1 or 3.0 status. Where is that paperwork from 2008 ??? As I've seen your posts since you came on AN,  I'm comfortable trusting your judgment. But getting a Melos is kinda like shooting in the dark for me. It's also a bit difficult to comprehend that I'd be getting the excellent sq that I'm getting now from an older,  unmodded unit.
I'd be a bit more inclined to try a Tortuga LDR  and my Buddy Gary has one. If I'm extra nice, he may bring it from Vegas. At one time, I had thought of getting a McCormack unit, but the upgrade was more than I wanted to spend. I am going to read up more on the EC though as I've always thought favorably of the company.
Nick
Title: Re: SENERGY What really is It ??
Post by: Nick B on August 15, 2017, 12:06:39 PM
Hi Doug,
I believe you're right and a tube buffer may be the way to go for what I'm trying to achieve. I was on the Tortuga site and the cost of the buffer is way more than I want to spend right now. I checked out the Zman ASE and part of the description mentions a reduction in noise..lessening the harsh sound of CDs. Well that's fine, but the Uber already does a great job at lowering the noise floor with all the resultant benefits. But I'm trying to reproduce the harmonic structure of violins, guitars etc. or at least what they should sound like imo. All my components are capable of excellent resolution, so why am I not getting that right now and why would a tube buffer be able to do/create that? None of my audio buddies even use one afaik. I haven't checked out the Kaitlin yet. If any of your units are for sale, send me a pm if you'd like.
As a side note, I plugged in my dacs Voltikus power supply into the P and S polished receptacle. It's a fuller, seemingly more accurate sound. Very nice and an apparent improvement in "harmonic structure", but not there yet. More listening tonight in the later hours
Nick
Title: Re: SENERGY What really is It ??
Post by: Nick B on August 15, 2017, 01:06:05 PM
Ok, Doug. Thanks for the "sound" advice:thumb:
Nick

nick, the kailin mu-1 and the z-man have both been out of production for a long time; good luck finding one used.  mine are keepers; i find them useful in 2nd systems, and sometimes even w/a tubed preamp, in front of particularly dry sounding gear.

i am a firm believer in tubed preamps; they seem to me to provide that "je ne sais quoi" to a system that makes it sound more like real music instead of a recording.  (at least tube preamps that i like anyway!  :D)

a tube buffer (like the yaqin) is an inexpensive way to see what you think.  w/the particular yaqin i linked, i'd recommend some quality nos tubes; you still won't be out a ton of cash, and could always recoup most of the investment if it's not your cuppa.  and, i'd ask that seller if he would consider including the tubes he used in it - he obviously has other tubes or the ones he's including w/it would not be "unused"   8)

doug s.

Hi Doug,
I believe you're right and a tube buffer may be the way to go for what I'm trying to achieve. I was on the Tortuga site and the cost of the buffer is way more than I want to spend right now. I checked out the Zman ASE and part of the description mentions a reduction in noise..lessening the harsh sound of CDs. Well that's fine, but the Uber already does a great job at lowering the noise floor with all the resultant benefits. But I'm trying to reproduce the harmonic structure of violins, guitars etc. or at least what they should sound like imo. All my components are capable of excellent resolution, so why am I not getting that right now and why would a tube buffer be able to do/create that? None of my audio buddies even use one afaik. I haven't checked out the Kaitlin yet. If any of your units are for sale, send me a pm if you'd like.
As a side note, I plugged in my dacs Voltikus power supply into the P and S polished receptacle. It's a fuller, seemingly more accurate sound. Very nice and an apparent improvement in "harmonic structure", but not there yet. More listening tonight in the later hours
Nick
Title: Re: SENERGY What really is It ??
Post by: topround on August 15, 2017, 02:03:24 PM
I agree
a good tubed preamp would work wonders, the amp you have is very good I had a DNA 0.5 deluxe and loved it.
Also those speakers might be a little problem, I had the 2.0 for a while and while they play loud very cleanly they do not impart any great amount of love.
They are very neutral and fast, they really benefit from tubes, not trying to knock them just being honest in their sonic signature.

Tmazz has Nola Boxers. you might LOVE those, very musical speakers.

what is your budget for a preamp?
Title: Re: SENERGY What really is It ??
Post by: steve on August 15, 2017, 04:05:34 PM
Things are a little more complicated than what might appear. There are several other factors to consider, this is not exhaustive. For general consumption.

Quote
and yes, impedance matching between pre and amp is important, as i mentioned. 

Not so much as one normally thinks. RCA Radiotron Designers Handbook suggests a 5:1 ratio, amp input Z to preamplifier output Z. I suggest, as you have heard, 10:1 to be safe. But that is normally calculated at midband. What is really important is across the entire audio band.

My Preamplifiers are approximately 1.9k output Z, and works fine to 20k amp input Z. So a buffer stage is not necessary. Why not? What is the scoop.

1) Let's examine high frequency first. Example: we have an IC capacitance of 100pf and amplifier input capacitance of 50pf, so 150pf in parallel with the 100k input resistor (100k input Z at 1khz).

The reactance of 150pf at 20khz is ~53k ohms. So at 20khz, we actually have 100k ohm in paralleled with 53k ohms of capacitive reactance (called "I").

However, the preamplifier output Z is in parallel with "I" and 100K resistor, so not that bad. With 1.9k output Z, the high frequency response exceeds half a mhz (550khz) before -3db. 

Believe it or not, the major limit on high frequency response is the volume control to tube grid input capacitance (including Miller effect). Not only that, the minimum frequency response (FR) occurs at mid resistance setting of the volume control. Using a 100k volume pot limits the HF more than a 50k or 25k pot.

2) Let's examine the low frequency response. Pretty easy as a coupling capacitor and following grid resistor. Here is some data.
Frequency 10hz. Grid resistor 100k ohms.

Coupling Capacitor          -db

1uf                                 .114
.82                                 .162
.68                                 .235
.47                                 .47
.33                                 .883
.22                                1.76
.1                                  5.5 db

With 50k grid resistor.

1uf                                 .38db
.1                                 10.

That is just one stage coupling. With multiple stages, dbs add. By the way, the 1uf coupling capacitor, - 0.116db at 10hz may seem small enough to not be perceived, but when additional stages and/or the OPT are considered, don't be so sure. By the way, bloated bass in tube amps is not so much damping factor, but more likely a power supply design problem.

Quote
my first foray into a tube preamp was the arc sp-9mkll.  in a word - it totally sucked.  it was worse than the adcom gfp-1a i was using at the time.  reading this thread, and seeing that tmazz uses an sp-9 in his system made me go and read a lot of articles on it, and what folks thought, good and/or bad.  one thing i gleaned was that the sp9 wants to see an amp w/minimum 60k ohm input impedance.  i knew nothing about that back then.  the amp i was using at the time has an input impedance of 22k ohms.  maybe that was why everything sounded like it had molasses poured over it; the sound was so thick, heavy and lifeless.

With a smaller 22k ohms, the sound should have been thinner than using 60k ohms minimum, not heavier. This leaves several possibilities.
One, the room is quite bass resonant.
Two, the speakers are not correctly matched for the venue,
Three, the speakers are bass heavy to begin with, due to either their venue or electronic components they used
Four, the other electronic components in your system are not designed properly, thus bass heavy

The proper way I have found is to design the electronics first, since the preamplifier and amplifier can be listening tested for accuracy. After that, then I worked teeter/totter with speaker/venue.

Quote
even so, i wonder, as the sp-9 mkll's output impedance is 250 ohms, and the standard rule of thumb is the amp's input impedance should be at least 10 times greater.  and tho arc recommends 60k ohm amp input, it also says "min 20k ohms".  but, in any event, preamp-amp impedance matching is definitely something to consider.

Although the rule of thumb 10:1 is good, as shown above, the real culprit is the output capacitor size and quality, and also the power supply, which I did not address.
 
There are some weird "rules of thumb", such as concerning the -3db point, way out of line.

Cheers

Steve

Title: Re: SENERGY What really is It ??
Post by: steve on August 15, 2017, 06:06:29 PM
steve, it could simply be that i think the sp-9 sucks!   :D  i was just trying to figure out a possible reason, as i know others are fond of it.  looking at the sp-9's specs, i suspect it's less likely any impedance mismatch, and more likely that i just don't like that preamp.

regarding the speakers and venue, i seriously doubt either was an issue.  the room was quite huge - ~20x40, w/ceiling vaulted to a 2nd story balcony along the 40' length.  and, tho i don't know the design specifics, i do know, just from my ears, that items 3 & 4 also don't apply.  nothing at all bass heavy was going on.  (and it wasn't bass heavy w/the sp-9 either - just dull lifeless sound.)  speakers were on the short wall, about 4' from the back wall.  there were some short walls in the room splitting it up, but it was basically one big open space.  speakers were thiel 3.5's, (flat to 20hz w/factory eq), amp was original series adcom gfa555 (smooth faceplate w/rack handles.)  the adcom gfp-1a was adequate, the sp-9 was not.  if anything the preamp should have been a good match, due to the sonic characteristics that have been attributed to the speakers and the amp. (at least according to the audio press.)  next preamp was an arcam delta 110 preamp; it was most excellent.  (a bud of mine still uses one; bought after he heard mine.)  that was followed by the electrocompaniet ec-1a; even better.  it was several years later before i tried another tube preamp; the melos ma333r completely thrashed the rogue magnum 99 and the cary spl98 that i was auditioning.  at that point, i stopped investigating preamps; the melos was that good.  (different venue, by then, and various speakers were now being actively crossed over to subs.)  i was really wanting to like the cary because it looked so nice, but it was not to be..

doug s.

Thanks for the info Doug. I hope you did not think I was simply addressing you, but for the audience in general. Your info was quite helpful, good logical way to address the problem. I too would estimate the SP9 was the culprit.

I find that components in general can be syrupy, "lifeless sound" and yet not overly bass because of undersized ufd while terminated improperly. The Orange Drop 716 copper lead polypropylene capacitors are known for this characteristic. Other brands as well.

I have mentioned that I am adjusting an ~ 9k ohm resistor by 0,05 ohms or less. That is one part in ~200,000. That is incredibly touchy. Adjust 0,05 ohms too much, and too much bass. Same the opposite. My work has demonstrated just how tough it is to get a system right.

Aside from our conversation, who knows what associated electronics or speakers are part of the manufacturer's test system. If their associated components are not accurate/natural, that has to be considered. Now back to our conversation.

There are a very few manufacturers who can design a great preamplifier. Glad the Melos worked out great.

One other thing. It has become apparent to me that the future will be those whose company can become "vertical" in nature. By that I mean that all the components, phono, preamp, amp, speakers are all designed together almost as one piece so to speak. I use separate components simply because it takes separate power supplies to optimize each stage of electronics.

I find the "audio press" to be questionable at best ever since, when I opened for business, one reviewer literally hammered my 10A and shipped it back to me destroyed because I would not sell it to them for $300.00. They, and friends, have attempted to destroy me several more times over the years.

Cheers

Steve
Title: Re: SENERGY What really is It ??
Post by: topround on August 15, 2017, 06:21:19 PM
I've never owned an SP9 but aren't they sort of known for a warmish vintage tone?
I think the magic started to happen at the SP10
Title: Re: SENERGY What really is It ??
Post by: steve on August 15, 2017, 08:32:04 PM
Doug, you and anyone else are always welcome to visit if you get to central Illinois and see how my experiments are coming along. Just give me a shout/email before hand so I can warm the system up.

Getting ready for the eclipse. Tomorrow morning a shipment of special approved glasses is coming into town. This after every single pair has been sold a week ago. None to be had. Neighboring Peoria museum had 1000 pairs come in this morning, but by 1 pm were sold out. See if I can get some tomorrow, get in line early and hope the proper ISO is printed on them.

Cheers
Steve


steve, no problem - there's plenty here for everyone.  as i can't design equipment, i can only read what others say, and then use my best judgement as to what i might want to try, and then trust my ears.  you go into details as to why the sp9 may sound the way it does; could be; i have no way of knowing that.  those more technically inclined, that own this gear, might want to consider parts upgrades.   8)  me, personally, i am good at parts swapping, but someone needs to tell me what parts to swap!   :rofl:  i still have a wintage art di/o dac that i modded, and it's still competitive w/dacs costing a wee bit more...

everything i've read about what you have said over the years, and about what others have said about sas gear leads me to believe i'd enjoy sas products, tho i have never sampled...

there's something to be said about a mfr making gear that fits well with its other gear.  especially if people like the sonic signature of that mfr.  i know i'd love to hear the powered kef ls50 monitors, as i own a pair of the passives, and they are simply astounding, considering their size and cost.  and for me, personally, especially when it comes to speakers, i now believe that, even w/multi-driver speakers, separate amplification and active x-overs for each driver will give far more accuracy than will passive x-overs, even if the speakers are not by themselves, active.

doug s.
steve, it could simply be that i think the sp-9 sucks!   :D  i was just trying to figure out a possible reason, as i know others are fond of it.  looking at the sp-9's specs, i suspect it's less likely any impedance mismatch, and more likely that i just don't like that preamp.

regarding the speakers and venue, i seriously doubt either was an issue.  the room was quite huge - ~20x40, w/ceiling vaulted to a 2nd story balcony along the 40' length.  and, tho i don't know the design specifics, i do know, just from my ears, that items 3 & 4 also don't apply.  nothing at all bass heavy was going on.  (and it wasn't bass heavy w/the sp-9 either - just dull lifeless sound.)  speakers were on the short wall, about 4' from the back wall.  there were some short walls in the room splitting it up, but it was basically one big open space.  speakers were thiel 3.5's, (flat to 20hz w/factory eq), amp was original series adcom gfa555 (smooth faceplate w/rack handles.)  the adcom gfp-1a was adequate, the sp-9 was not.  if anything the preamp should have been a good match, due to the sonic characteristics that have been attributed to the speakers and the amp. (at least according to the audio press.)  next preamp was an arcam delta 110 preamp; it was most excellent.  (a bud of mine still uses one; bought after he heard mine.)  that was followed by the electrocompaniet ec-1a; even better.  it was several years later before i tried another tube preamp; the melos ma333r completely thrashed the rogue magnum 99 and the cary spl98 that i was auditioning.  at that point, i stopped investigating preamps; the melos was that good.  (different venue, by then, and various speakers were now being actively crossed over to subs.)  i was really wanting to like the cary because it looked so nice, but it was not to be..

doug s.

Thanks for the info Doug. I hope you did not think I was simply addressing you, but for the audience in general. Your info was quite helpful, good logical way to address the problem. I too would estimate the SP9 was the culprit.

I find that components in general can be syrupy, "lifeless sound" and yet not overly bass because of undersized ufd while terminated improperly. The Orange Drop 716 copper lead polypropylene capacitors are known for this characteristic. Other brands as well.

I have mentioned that I am adjusting an ~ 9k ohm resistor by 0,05 ohms or less. That is one part in ~200,000. That is incredibly touchy. Adjust 0,05 ohms too much, and too much bass. Same the opposite. My work has demonstrated just how tough it is to get a system right.

Aside from our conversation, who knows what associated electronics or speakers are part of the manufacturer's test system. If their associated components are not accurate/natural, that has to be considered. Now back to our conversation.

There are a very few manufacturers who can design a great preamplifier. Glad the Melos worked out great.

One other thing. It has become apparent to me that the future will be those whose company can become "vertical" in nature. By that I mean that all the components, phono, preamp, amp, speakers are all designed together almost as one piece so to speak. I use separate components simply because it takes separate power supplies to optimize each stage of electronics.

I find the "audio press" to be questionable at best ever since, when I opened for business, one reviewer literally hammered my 10A and shipped it back to me destroyed because I would not sell it to them for $300.00. They, and friends, have attempted to destroy me several more times over the years.

Cheers

Steve
Title: Re: SENERGY What really is It ??
Post by: tmazz on August 15, 2017, 09:34:24 PM
steve, it could simply be that i think the sp-9 sucks!   :D  i was just trying to figure out a possible reason, as i know others are fond of it.  looking at the sp-9's specs, i suspect it's less likely any impedance mismatch, and more likely that i just don't like that preamp.

regarding the speakers and venue, i seriously doubt either was an issue.  the room was quite huge - ~20x40, w/ceiling vaulted to a 2nd story balcony along the 40' length.  and, tho i don't know the design specifics, i do know, just from my ears, that items 3 & 4 also don't apply.  nothing at all bass heavy was going on.  (and it wasn't bass heavy w/the sp-9 either - just dull lifeless sound.)  speakers were on the short wall, about 4' from the back wall.  there were some short walls in the room splitting it up, but it was basically one big open space.  speakers were thiel 3.5's, (flat to 20hz w/factory eq), amp was original series adcom gfa555 (smooth faceplate w/rack handles.)  the adcom gfp-1a was adequate, the sp-9 was not.  if anything the preamp should have been a good match, due to the sonic characteristics that have been attributed to the speakers and the amp. (at least according to the audio press.)  next preamp was an arcam delta 110 preamp; it was most excellent.  (a bud of mine still uses one; bought after he heard mine.)  that was followed by the electrocompaniet ec-1a; even better.  it was several years later before i tried another tube preamp; the melos ma333r completely thrashed the rogue magnum 99 and the cary spl98 that i was auditioning.  at that point, i stopped investigating preamps; the melos was that good.  (different venue, by then, and various speakers were now being actively crossed over to subs.)  i was really wanting to like the cary because it looked so nice, but it was not to be..

doug s.

Wow, I find that interesting. I have had an SP-9 Mk1 since 1988 and never found it to be anything near lifeless.  And as a matter of fact I got the SP-9 not long after I replaced my Dahlquist DQ-10s with a pair of Theil 3.5s. The CJ Premier 2 that sounded so nice with the DQ-10s did not mate well with the Thiels, so out it went. I have compared the SP-9 with many preamps over the years and while so were somewhat better, I never felt the amount of SQ increased justified the $s I would have needed to spend to get it.The SP-9 has been used to drive a Moscode 600, a Classe Twenty Five, an ARC VT-200 an ARC D-130 and currently a pair of Quicksilver Mid Monos. In addition to the Thiel 3.5s it was used with Thiel CS-6s and now Nola Boxers. Throughout all of these combination I have always felt it performed like a champ.

I'm just curious, did you ever swap out the tubes while you had it? Perhaps and under-performing tube may have caused the sound you didn't like (of a bad passive part somewhere in the unit.

Or perhaps I just like it and you just don't. And that is a matter of personal opinion, which means neither is right or wrong, and that's perfectly OK.

I have often wondered if differences in personal taste might in some part  be driven by differences in the frequency response of our own ears, as opposed to those of other audiophiles. In reality what we hear out of our systems is a combination of the sound put out by the system and our own ears sensitivity to sound as a function of frequency. Could it be that we all have the same idea of what is good sound and our personal preferences are simply a way of finding equipment that is more compatible with the response of our own ears? Hmmmm.... but that is a topic for another discussion.
Title: Re: SENERGY What really is It ??
Post by: _Scotty_ on August 16, 2017, 01:57:43 PM
While the amount of distortion a piece of gear has seldom tells the whole story, the SP 9 couldn't be described as having a low distortion circuit design as it does no better than 0.1 THD and by 10kHz this has deteriorated to 0.25THD. Looking at the specifications I initially thought it was a non-negative feedback design which is not the case.
 The ARC SP3A measured better than 0.005 THD using an all tube design with 12AX7s. I don't think there is any reason that circuit with 6DJ8s in it should intrinsically have as much distortion as the SP 9 has.
Scotty
Title: Re: SENERGY What really is It ??
Post by: steve on August 16, 2017, 02:22:33 PM
While the amount of distortion a piece of gear has seldom tells the whole story, the SP 9 couldn't be described as having a low distortion circuit design as it does no better than 0.1 THD and by 10kHz this has deteriorated to 0.25THD. Looking at the specifications I initially thought it was a non-negative feedback design which is not the case.
 The ARC SP3A measured better than 0.005 THD using an all tube design with 12AX7s. I don't think there is any reason that circuit with 6DJ8s in it should intrinsically have as much distortion as the SP 9 has.
Scotty

With the JJs or new Telefunkens no way. I listed the 11A as 0,015%, had trouble measuring lower, and wanted a cushion due to possible tube variations.

I agree as parts quality and design makes a difference.

Cheers

Steve
Title: Re: SENERGY What really is It ??
Post by: steve on August 16, 2017, 09:27:30 PM
While the amount of distortion a piece of gear has seldom tells the whole story, the SP 9 couldn't be described as having a low distortion circuit design as it does no better than 0.1 THD and by 10kHz this has deteriorated to 0.25THD. Looking at the specifications I initially thought it was a non-negative feedback design which is not the case.
 The ARC SP3A measured better than 0.005 THD using an all tube design with 12AX7s. I don't think there is any reason that circuit with 6DJ8s in it should intrinsically have as much distortion as the SP 9 has.
Scotty

With the JJs or new Telefunkens no way. I listed the 11A as 0,015%, had trouble measuring lower, and wanted a cushion due to possible tube variations.

I agree as parts quality and design makes a difference.

Cheers

Steve

Meant to say Scott, that with the JJs or new Telefunkens, that the distortion was way below 0,1%. I used my preamp as an example, which agrees with your assessment.

Cheers
Steve