Author Topic: I think my System is virtually, finally finished  (Read 33800 times)

Offline steve

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Re: I think my System is finally finished
« Reply #75 on: October 26, 2021, 11:11:26 AM »
This is great stuff  :thumb:  To what extent I could determine some of the very small changes being described here, I don’t know, but it sure would be fun trying to find out…

What would also be fun is to have is a CD of recorded music/sounds that would allow comparison of different caps, resistors, types and purity of wire, etc. Don’t know if that’s doable or that I’ve seen something like that, but it would be a great companion disc to have.

The brighness, the clarity, attack times seem easily discernable to those who visit. However, hearing fatigue will set in that will affect one's ability to discern if listening to the same selections over and over at one sitting. The quality of the recordings vary quite considerably as well. Some mask the musical information much more than others.

Others have attempted and written capacitor comparison articles, but I am not sure if that is what you mean. Anyway, those articles are less than worthless when it comes to how accurate is the capacitor itself. That is because they either don't know, or they don't do the work necessary to perform those experiments.

Actual, accurate testing requires multiple sources, multiple setups, highest quality selections, more than one testing  method, and takes a long time if one wishes to be spot on, (may wish to quit, sick of recordings) to make sure one's conclusions are absolutely correct in absolute terms.

When I was young I performed the research from scratch, but today I don't think I could. Just very complicated, time consuming, and fatiguing.

I am sorry to report Nick, that there is no way of easily scientifically test a capacitor, or resistor. I wish I could be more positive.

cheers and great week my friend.

steve






« Last Edit: June 20, 2022, 08:09:56 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline Nick B

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Re: I think my System is finally finished
« Reply #76 on: October 26, 2021, 05:39:47 PM »
This is great stuff  :thumb:  To what extent I could determine some of the very small changes being described here, I don’t know, but it sure would be fun trying to find out…

What would also be fun is to have is a CD of recorded music/sounds that would allow comparison of different caps, resistors, types and purity of wire, etc. Don’t know if that’s doable or that I’ve seen something like that, but it would be a great companion disc to have.

The brighness, the clarity, attack times seem easily discernable. However, hearing fatigue will set in, that will affect your ability to discern, if listening to the same selections over and over at one sitting. The quality of the recordings vary quite considerably.

Others have attempted and written capacitor comparison articles, but I am not sure if that is what you mean. Anyway, those articles are less than worthless when it comes to how accurate is the capacitor itself. That is because they either don't know, or they don't do the work necessary to perform those experiments.

Actual, accurate testing requires multiple sources, multiple setups, highest quality selections, more than one testing  method, takes a long long long long time, (may wish to quit, sick of recordings) to make sure one's conclusions are correct in absolute terms.

When I was young I performed the research from scratch, but today I don't think I could. Just very complicated, time consuming, and fatiguing.

I am sorry to report Nick, that there is no way of easily scientifically test a capacitor, or resistor. I wish I could be more positive.

cheers and great week my friend.

steve

Thanks for the explanation, Steve. I was just wondering if there was a different/easier methodology to accomplish the testing. My recollection about the Van Alstine ABX Comparator got me thinking.. 
Ultimately, I will just continue to rely on the opinions of members here and reviewers whose opinions I’ve come to trust and rely on.
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline steve

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Re: I think my System is finally finished
« Reply #77 on: October 26, 2021, 08:31:56 PM »
This is great stuff  :thumb:  To what extent I could determine some of the very small changes being described here, I don’t know, but it sure would be fun trying to find out…

What would also be fun is to have is a CD of recorded music/sounds that would allow comparison of different caps, resistors, types and purity of wire, etc. Don’t know if that’s doable or that I’ve seen something like that, but it would be a great companion disc to have.

The brighness, the clarity, attack times seem easily discernable. However, hearing fatigue will set in, that will affect your ability to discern, if listening to the same selections over and over at one sitting. The quality of the recordings vary quite considerably.

Others have attempted and written capacitor comparison articles, but I am not sure if that is what you mean. Anyway, those articles are less than worthless when it comes to how accurate is the capacitor itself. That is because they either don't know, or they don't do the work necessary to perform those experiments.

Actual, accurate testing requires multiple sources, multiple setups, highest quality selections, more than one testing  method, takes a long long long long time, (may wish to quit, sick of recordings) to make sure one's conclusions are correct in absolute terms.

When I was young I performed the research from scratch, but today I don't think I could. Just very complicated, time consuming, and fatiguing.

I am sorry to report Nick, that there is no way of easily scientifically test a capacitor, or resistor. I wish I could be more positive.

cheers and great week my friend.

steve

Thanks for the explanation, Steve. I was just wondering if there was a different/easier methodology to accomplish the testing. My recollection about the Van Alstine ABX Comparator got me thinking.. 
Ultimately, I will just continue to rely on the opinions of members here and reviewers whose opinions I’ve come to trust and rely on.

Please be careful as abx (along with typical dbt testing addressing only sight as a confound variable) is clearly unreliable. If all the confound variables are not properly addressed, the input data will be compromised, thus the
calculated confidence test result is unreliable.

Others can claim the testing is repeatable over and over with the same results/conclusions, thus accurate. Making mistake after mistake with the input data does not produce honest conclusions. Unreliable times repeated unreliable equals unreliable, not reliable.

A quick question for the general public if I may. In a typical room, there are bass increasing modes and bass decreasing modes. How does one obtain a 95% confidence conclusion when statistically one half of a group is in the bass increasing modes while the other half of the group is in the bass decreasing modes?

There is a second and third abx tester that I am aware of. They both use ordinary (often cheap) parts and at least one uses solder, switch(es), an ic chip, low pass filter (blocks higher frequencies) directly in the signal path. As an example, price differential is often a few cents to over ten dollars for one resistor.

An interesting paradox indeed. The abx/dbt promoters claim/assume (a bias) that all parts, including the ordinary, questionable parts, sound the same and don't deteriorate the sonic quality. The question is, how can one use the questionable parts in abx comparators to "prove" the questionable parts are accurate. Questionable parts to test the questionable part(s). Does anyone not see a problem? Yet abx comparitors are advertised as being scientific.

Does just one part interfere with the sonic quality? As an example, when I was designing my monoblocks, I soldered a capacitor in a circuit to increase the fullness. I then decided to install a silver coin contact switch to add or subtract this capacitor to the circuit. This gave some versatility in the real world.

However, when I used the silver contact switch and connected the capacitor, the sound actually got leaner/thinner, just the opposite of it being soldered in. The listening testing occurred over months. Obviously I exchanged out the silver contact switch and the sound got fuller, which it was designed for and the circuit worked properly. Physics and other data are important.

cheers and all the best.

steve

ps. I hope my modified post is simpler and easier to understand.
« Last Edit: February 08, 2022, 06:09:23 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
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Offline steve

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Re: I think my System is finally finished
« Reply #78 on: March 06, 2022, 09:33:35 AM »
The latest update to my system; I am checking to see if I can tweak my upgraded dac
for just a touch more realism, naturalness, focus in the backround. I was able to
get a touch more out of it, and still continuing research. To put so far into perspective; I have not
experienced this level of “live experience” in any other system in all the decades of shows,
homes etc, at any price.

The journey is much more difficult than one might think. Designing a limited range
system with “magic midrange” might seem good and simple. I have to ask the question, if it
were that easy, why have the seemingly unlimited number of brands?

So what do we have with a limited bandwidth system? Well, let’s go to a concert and minimize
some of the bass, the highs, if classical then high violins, piccolos, and manipulate the hall
backround as well. So we are not really at the venue are we.

Talk to the higher level manufacturers, and they will tell you it is those lowest and highest
octaves that are so difficult to properly design and execute. With the "magic midrange" and
both extremes, we can make breath taking, jaw dropping music.

This experiment is about, recreating the live experience. However, there is a second
reason, as I have stated in an earlier post.

That second reason is to see if it is possible to design perfection using newly manufactured
tubes, tubes at a reasonable price. (Forget solid state with the inherent limitations.) The answer
is a resounding YES. In fact, many if not most NOS or new tubes won’t work properly. I was able to use
all JJ tubes for the project as well as bin stocked Wing C KT88s and 6550 output tubes. But one cannot just
throw a circuit together and expect the tubes to sound great.

Think of all the money one would save using new tubes in a design, vs nos tubes costing $xxx.99
 
I am still testing and performing very minor tweaking of outside components in my system,
DAC, Wire, my test Speakers, and might even test some other outside components.
 
Some time ago I was able to compare a 4 grand lampizator to my upgraded dac and the
lampizator sounded just slightly wider, but the same in other respects. I have compared an
entry level Denafrips and although it sounded good, my upgraded dac was clearly superior.

I can adjust my speakers (2 controls) for using youtube premium, redbook, or hi rez.

Stay tuned for more.

steve
« Last Edit: June 20, 2022, 08:19:46 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline Nick B

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Re: I think my System is finally finished
« Reply #79 on: March 06, 2022, 01:33:57 PM »
The latest update to my system; I am checking to see if I can tweak my upgraded dac
for just a touch more realism, naturalness, focus in the backround. I was able to
get a touch more out of it, and still continuing research. To put so far into perspective; I have not
experienced this level of “live experience” in any other system in all the decades of shows,
homes etc, at any price.

The journey is much more difficult than one might think. Designing a limited range
system with “magic midrange” might seem good and simple. I have to ask the question, if it
were that easy, why have the seemingly unlimited number of brands?

So what do we have with a limited bandwidth system? Well, let’s go to a concert and minimize
some of the bass, the highs, if classical then high violins, piccolos, and manipulate the hall
backround as well. So we are not really at the venue are we.

Talk to the higher level manufacturers, and they will tell you it is those lowest and highest
octaves that are so difficult to properly design and execute. With the "magic midrange" and
both extremes, we can make breath taking, jaw dropping music. (Actually, the magic midrange is
not accurate.)

This experiment is about, recreating the live experience. However, there is a second
reason, as I have stated in an earlier post.

That second reason is to see if it is possible to design perfection using newly manufactured
tubes, tubes at a reasonable price. (Forget solid state with the inherent limitations.) The answer
is a resounding YES. In fact, many if not most NOS or new tubes won’t work properly. I was able to use
the JJ tubes for the project as well as bin stocked Wing C KT88s and 6550s. But one cannot just throw a
circuit together and expect the tubes to sound great.
 
I am still testing and performing very minor tweaking of outside components in my system,
and might even test some other outside components.
 
Some time ago I was able to compare a 4 grand lampizator to my upgraded dac and the
lampizator sounded just slightly wider, but no better in any other aspect. I have compared an
entry level Denafrips and although it sounded good, my upgraded dac was clearly superior.

I can adjust my speakers (2 controls) for using youtube premium, redbook, or hi rez. I generally setup
for youtube pre since there are so many many selections, and  the music is better than any other
system I have auditioned, whether using redbook, high rez, or turntable.

Stay tuned for more.

steve

Steve,
You are trying to squeeze even more out of your $99? Modi??  I’m glad you are! Very interesting if you can do it. I believe you have spent maybe $400 to $500  in this dac  project. It would be rather amazing to get better performance than a $4000 Lampi.
Pls keep us posted
Nick
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline dflee

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Re: I think my System is finally finished
« Reply #80 on: March 06, 2022, 04:26:02 PM »
Steve:
You are one amazing dude.  I am amazed at what you do. It would drive me crazy to attempt to do the work you do on the equipment. Really enjoy reading about it.
"Enjoy pleasure, not because it is fleeting, but because it exists at all." Sacrament, Clive Barker.

Offline rollo

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Re: I think my System is finally finished
« Reply #81 on: March 09, 2022, 01:18:37 PM »
  Steve Youtube has better sonics ?? That is very interesting to hear that.

charles
contact me  at rollo14@verizon.net or visit us on Facebook
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Offline steve

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Re: I think my System is finally finished
« Reply #82 on: March 09, 2022, 08:15:08 PM »
I think I can answer Nick's, Don's, and Charles's comments and questions in this post.

A few things most already know. But some do not.

1. It has a DAC chip.

2. It  has a following analog chip for gain of about 2 times, or about 6db.

3. The analog chip has no markings/labels.

4. There is no re clocking in this little dac, thus a good usb cable is necessary. (The supra usb cable turned out to be pretty descent.)

5. The DAC chip includes both digital and analog circuitry with two power inputs, one for digital and the other for the analog sections. The one for analog handles both channels. I have no idea of how many transistors are incorporated
in the analog section of the chip. We also have X number of solid state resistors and capacitors (silicon types) within the analog section.

Fortunately, Schiit did a wonderful job with the digital part or I would not have gotten the resultant superior quality of my upgrade. However, the analog section is a quite different matter. But then for the $99.00 price point set, what should one expect, not faulting the company at all; they wanted to reach a certain market. Nothing wrong with that.

There is nothing to be done with the analog section of the DAC chip. I have not spent a ton of time on this DAC, no schematic. So I have left the analog chip connected.

One of the faults I often see in players/dacs is the power supply simply using electrolytic capacitors and typical solid state voltage regulators. Both degrade the sound. However, using poly caps takes a huge amount of room. I used a 17" by 10" by 3" chassis for all the parts in my upgrade. I used a variety from my parts bin from yesteryear. Is it possible to improve further? Maybe, but I need to investigate not assume for that possible ounce.

Maybe I will tweak a little more on the DAC if I can get a schematic. But right now I don't see why.

---------

Charles, I rewrote the last paragraph of my last post to be clearer. What I am saying is that even though I mainly use Youtube premium (many more selections), the sound is more natural, transparent, dynamic etc etc than any other audio system I have ever auditioned over the decades, and those systems used redbook/high rez, or turntable and cost xxxx. (I can use redbook or high rez, even turntable as well, but you tube has so many more selections.)

What I found, as a result of my decades of research is how far off my initial designs were 40 years ago (and other stereo designs to this day) are from accurate. I initially fell into the same trap as others, that solving a few
equations is enough, but it is far from true. From 1980 on I learned a lot.

Another major factor is the distorted history of ancient designs becoming so propagated, as to become "law".
The problem is one never sees and understands the inherent flaws of those ancient designs. How many times
has one seen the inherent flaws of any design explained? The next question becomes how does one overcome
decades of misinformation by those not understanding all the science required, yet claiming expertise. Of course,
there are obvious conflicts of interest involved.

I have mentioned that solving a few equations won't produce an accurate/truly natural sounding component..
The paradigm of what is considered "superior" sound quality was based on inherently flawed designs across the decades, with little understanding of the science.

-------

Here is another question I have. If the older electronic designs/systems are so good, then why are small speaker enclosures being pushed with high power SS amps, instead of sticking with large speaker enclosures? (My large enclosures are only 11" wide but still ~4.5 cubic feet total volume.) Is space the only answer?

I hope this has helped in understanding.

Cheers

steve

« Last Edit: November 15, 2022, 07:38:00 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline rollo

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Re: I think my System is finally finished
« Reply #83 on: March 10, 2022, 12:13:30 PM »
  Always a pleasure learning from you.
charles
contact me  at rollo14@verizon.net or visit us on Facebook
Lamm Industries - Aqua Acoustic, Formula & La Scala DAC- INNUOS  - Rethm - Kuzma - QLN - Audio Hungary Qualiton - Fritz speakers -Gigawatt -Vinnie Rossi,TWL, Swiss Cables, Merason DAC.

Offline steve

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Re: I think my System is finally finished
« Reply #84 on: April 06, 2022, 07:23:12 PM »
Thanks Charles. I try to pass important information on, as long as it does not reveal classified company secrets. (I learned that from all the politicians and company execs over the decades.  :rofl:)

I have found that as I improve the system using redbook, tidal, that YouTube premium also improves. Got to
give the public some selections that the public can test, adjust, and hopefully help their systems.

Yes, there can be "touch ups" when switching to YT Premium, but there are so many selections that the others just don't have available but the public loves to listen to. I am hoping that the public sees what is possible in the lab and that stereo improvement is still possible in this day and age.

By the way, my preamplifiers and monoblock amplifier design were manufactured in the real world,
and did not use NOS tubes, just modern tubes. The speaker was too cumbersome to move around
or test at other venues.

Anyone wish to come by for an audition, just give a shout.

cheers and thanks again.

steve
« Last Edit: November 15, 2022, 07:40:49 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline steve

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Re: I think my System is finally finished
« Reply #85 on: April 28, 2022, 12:13:05 PM »
A tidbit (for diyers) on your audio quest is the elimination of electrolytic capacitors as decoupling capacitors. Decoupling
capacitors are capacitors that connect to the plate resistor (or collector/drain resistor in solid state
devices) and ground.

In the schematic below, the C1 capacitor connected between RL plate resistor and ground. Decoupling capacitors are
in nearly every stage of the source, preamp, and amplifier.

Even one electrolytic capacitor in your system will cause loss of audio quality, the realism, naturalness of the music.
If all the electrolytic decoupling capacitors were eliminated, that last one makes the most difference. As one adds more electrolytic decoupling capacitors, the effect is less but still perceived. A typical audio system could have up to a dozen or more. That is a lot of degradation to the musical quality.

Unfortunately, electrolytics are generally necessary in the main high voltage power supply for output stages due to the high capacitance (ufd) needed; especially in solid stage amps.

The one obvious hang up is a polypropylene cap's physical size.

But if realism, naturalness is your goal, ridding of electrolytic decoupling capacitors is a positive.

cheers

steve


« Last Edit: July 01, 2022, 01:10:23 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline steve

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Re: I think my System is finally finished
« Reply #86 on: June 30, 2022, 09:42:31 AM »
Doing a little cleaning out my favorites, I found this string from AC forum.

https://www.audiocircle.com/index.php?topic=114637.0

I found a tiny tweak in the up graded DAC's power supply, just a little cleaner in the upper bass, lower midrange.

I know, I know, I performed a tweak. Well, all I can say is that it was extremely minor.

cheers

steve
« Last Edit: June 30, 2022, 09:44:33 AM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline Nick B

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Re: I think my System is finally finished
« Reply #87 on: June 30, 2022, 04:24:15 PM »
Doing a little cleaning out my favorites, I found this string from AC forum.

https://www.audiocircle.com/index.php?topic=114637.0

I found a tiny tweak in the up graded DAC's power supply, just a little cleaner in the upper bass, lower midrange.

I know, I know, I performed a tweak. Well, all I can say is that it was extremely minor.

cheers

steve

Hi Steve,

Audiophiles  don’t forget great products. I imagine you occasionally get in an 11a or a 10a to replace caps or do some other maintenance. As to your dac, I’m assuming you are still using the Schiit Modi 2?
Orchard Starkrimson Ultra amp
Hattor Big preamp
JMR Voce Grande speakers
Holo Cyan2 dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline steve

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Re: I think my System is almost finally finished
« Reply #88 on: July 01, 2022, 12:56:27 PM »
Doing a little cleaning out my favorites, I found this string from AC forum.

https://www.audiocircle.com/index.php?topic=114637.0

I found a tiny tweak in the up graded DAC's power supply, just a little cleaner in the upper bass, lower midrange.

I know, I know, I performed a tweak. Well, all I can say is that it was extremely minor.

cheers

steve

Hi Steve,

Audiophiles  don’t forget great products. I imagine you occasionally get in an 11a or a 10a to replace caps or do some other maintenance. As to your dac, I’m assuming you are still using the Schiit Modi 2?

Hi Nick,

To answer your last question first, yes I am still using the hugely upgrade Modi 2. I adjusted the
power supply uf total just a hair as well as the voltage rating for one cap. What is sometimes irking
is that the shape and voltage rating of a cap affects the sonics. Of course higher voltage rating,
more conductor area, more resistance involved.

I have 16 smaller poly caps in parallel in the power supply for the analog chip gain stage. For
another tweak, I could change the other analog supply, with 5 caps, and go with a bunch of smaller
and see what happens.

I just can't stop tinkering for that final gram of improvement, and I thought I could go no farther when I
started this string. The title of this string makes me a hypocrite, so I changed the title to almost finally
finished.

Concerning your first comment, actually no 10As have come for at least a decade or more. The last one I
recall working on had the gold plating of a tube socket filament pin separate, causing an intermittent tube
filament from heating.

I have had two 11As that needed repair a very long time ago. The first was on the initial tour
(~17 years ago?), when a Mills military grade resistor became noisy. The second 11A, in Europe,
an intermittent audio output relay (in parallel) that sometimes refused to open after 45 seconds.

I have tinkered around, on my own 11A, with switching the initial electrolytic capacitor to poly, so it will
last forever (except for lightning strike). This does not affect the sonics because I use a hefty 5 filter
stages after it. I attribute the longevity for two reasons.

1. The caps have very little surge and repetitive peak currents; far far below max rated. Just a few ma.
(milliamps).

2. The operational temperature is just a few degrees F above room temp. I believe the general rule of
thumb is that for every 20 degrees F below max rated temperature by the manufacturer, one can double
the hours of useful life. By the way, the hours rating by manufacturer is at both maximum temperature and
maximum ripple current. Peak current is also minimal.

Just calculating by temperature, I arrived at 90,000 hours. Since the ripple current in the 10A/11A is just
a few ma., the life should be much longer.

One customer, I replaced a couple of resistors to Vishay naked Bulk foil after I tested them in my 11A.
Vishays have at least 20db less noise than other metal film resistors.

If I have missed something, please correct me, but I don't think so.

Cheers and happy 4th Nick and Gents.

steve


« Last Edit: November 15, 2022, 07:47:26 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers

Offline Nick B

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Re: I think my System is almost finally finished
« Reply #89 on: July 01, 2022, 10:29:50 PM »
Doing a little cleaning out my favorites, I found this string from AC forum.

https://www.audiocircle.com/index.php?topic=114637.0

I found a tiny tweak in the up graded DAC's power supply, just a little cleaner in the upper bass, lower midrange.

I know, I know, I performed a tweak. Well, all I can say is that it was extremely minor.

cheers

steve

Hi Steve,

Audiophiles  don’t forget great products. I imagine you occasionally get in an 11a or a 10a to replace caps or do some other maintenance. As to your dac, I’m assuming you are still using the Schiit Modi 2?

Hi Nick,

To answer your last question first, yes I am still using it. I adjusted the power supply uf total just a hair
as well as the voltage rating for one cap. What is sometimes irking is that the shape and voltage rating
of a cap affects the sonics. Of course higher voltage rating, more conductor area, more resistance involved.

I have 16 smaller poly caps in parallel in the power supply for the analog chip gain stage. For
another tweak, I could change the other analog supply, with 5 caps, and go with a bunch of smaller
and see what happens.

I just can't stop tinkering for that final gram of improvement, and I thought I could go no farther when I
started this string. The title of this string makes me a hypocrite. I will change the title to almost finally finished.

Concerning your first comment, actually no 10As have come for a decade or more. The last one I recall
working on had the gold plating of a tube socket filament pin separate, causing an intermittent tube
filament heating.

I have had two 11As that needed repair. The first was on the initial tour (~17 years ago?), when a Mills military
grade resistor became noisy. The second 11A, in Europe, an intermittent audio output relay (in parallel) that
sometimes refused to open after 45 seconds, thus the output remained shorted to ground. I believe that was
a decade, give or take, ago.?

I have tinkered around, on my own 11A, with switching the initial electrolytic capacitor to poly, so it will
last forever. This does not affect the sonics because I use a hefty 5 filter stages after it. I checked the
caps in the drawer, and in use, and after 20 years they are still measuring near perfect. I can only
attribute such to two reasons.

1. The caps have very little surge and repetitive peak currents; far far below max rated. Just a few ma.

2. The operational temperature is just a few degrees F above room temp. I believe the general rule of
thumb is that for every 20 degrees F below max rated temperature by the manufacturer, one can double
the hours of useful life. The hours rating by manufacturer is at max temperature and ripple current.

Just calculating by temperature, I arrived at 90,000 hours. Since the ripple current in the 10A/11A is just
a few ma., the life should be much higher.

One customer, I replaced a couple of resistors to Vishay naked Bulk foil after I tested them in my 11A.
I think they are a little bit better than originals. No one else has contacted me for the Vishays.

If I have missed something, please correct me, but I don't think so.

Cheers and happy 4th Nick and Gents.

steve


Hi Steve,

Glad that Modi is sounding excellent. I remember when Jeff at Sonic Craft on AC was raving about the performance of a Bifrost after some mods. I’m surprised you didn’t have a number of customers asking you to make changes over the years.  We all get curious over time if a piece of equipment can be made to sound better. I am also curious if a 10a unit can be brought up to the specs of an 11a and has anyone requested that.

As to the yearning to keep tinkering and improving, that’s what this hobby is all about!  :thumb:
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