AudioNervosa
Self Medicating => General DIY => Topic started by: richidoo on July 16, 2011, 07:07:36 PM
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(http://www.audionervosa.com/MGalleryItem.php?id=905)
Rough draft is up and running on a test board.
Unbelievable!
Believe it! If you come to hear this, wear your Depends. Even though my new horn speakers are not stuffed correctly I can listen right through the ringing horn, enraptured, totally swept away by music. Dense, textured, alive, natural, resolved, powerful, extended.
Very special thanks to my friend Sol for diagnosing a hum during dinner, over the phone and prescribing fix from parts I have on hand, all within 5 minutes. I wouldn't even try this without you. A source is no good without an amp, so credit must also go to Sol's i60 for this incredible sound!
Thanks to topround for lighting my fuse on transformers. It took a while to pull the trigger but now it is ON.
Still some adjustments to do, correct parts values, connectors, box, PS etc. That and some break in time, better hookup wire, local caps, there's still more to be had.
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Thank Karl he was the one who got me hooked.
Transformers can do wonders...as well as chokes..
Get the caps out and watch what can happen :thumb:
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Rich,
Are those separate transformer's one for the digital and one for the analog?
http://www.audionervosa.com/index.php?topic=3187.0
Please excuse the self promotion. :lol:
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Hi Bill! They are analog output transformers, left and right
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Yeah, love transformers on the DAC. That is nearly exactly what I'm running, buffalo into Lundahl's with a little forest of PH regs hanging on the board. :thumb: :thumb:
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Thank Karl he was the one who got me hooked.
Transformers can do wonders...as well as chokes..
Get the caps out and watch what can happen :thumb:
The best cap is no cap.
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Agreed, even the best cap can't compete with no cap. Unfortunately the industry is cap oriented.
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Um...feeling stupid here. Can you explain in English what I'm looking at in the picture?
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English: It is a printed circuit board with some smaller printer circuit boards sticking up out of it, with a mess of tangled wires coming out of it and 2 shiny metal things on each side. All sitting on a raw wood surface.
Audioese: It is a DAC, based around this DIY kit:
http://www.twistedpearaudio.com/digital/buffalo.aspx
I added special ultra high speed voltage regulators, and output transformers instead of the usual powered active buffer stage that follows most DACs.
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Ah. I see. It's a DAC. cool.
I kinda figured out the circuit board with wires stickin' out of it on my own.
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I would REALLY like to hear this DAC at my house...
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I kinda figured out the circuit board with wires stickin' out of it on my own.
:D
I would REALLY like to hear this DAC at my house...
I'll get it into a box soon.
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I put the DAC in a box tonight, so it would be safer to handle with the crowd on hand. I ran into a little problem though, maybe somebody can help...
I designed a simple power supply to feed the local regulators on the DAC. I used a Hammond 5V center tapped transformer, #166L5, using the outer taps, not using the center tap. I made a full wave bridge rectifier with fast diodes, filtered it with a 4700uF Nichicon 16V cap and a 5k bleeder resistor. Blimey to hell I am getting 7.4 volts out of it. :x
My wall voltage is 123V as always. Tranny is rated 115, so there wil be a bit of a bump from that, but not 3 volts! I double checked the wiring, looks good. Duncans power supply simulator predicts 5.6VDC with 30mV ripple with this power supply, which is adequate for the regulators I am using.
I measured 6.4VAC where the secondary connects to the bridge, so might it be a mislabelled transformer, or must I measure it without the bridge connected?
The part that really has me baffled, is why am I not getting the .7 voltage drop through the rectifier? Crazy! :lmc:
I rigged up a power inlet to I can use the DAC with the 5V external regulated power supply that I have been using since I first ran the DAC, have it playing now. I can also use the external power supply to power the TT, with a different plug making 12V. I do need to label them so the 12V doesn't go into the DAC.
Rich
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The NL transformer voltage is 5.5 volts AC. When you turn AC into DC you multiply your AC voltage by 1.414 . If your transformer sags a little bit lower towards the 5 volt full load spec you could easily get 7.4 volts DC. If you divide 7.4 by 1.414 you get about 5.23volts AC which sounds about right. You should be able to drop 2.4 volts across the regulator just fine. In fact you have to have a minimum amount of voltage above above the 5 volts the regulator is supposed to put out so that your regulator doesn't drop out. The minimum voltage the regulator wants to see before dropout occurs should be stated in the specs on the regulator data sheet.
Scotty
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Thanks a lot Scotty. Someone said use 6.3VAC transformer and it will drop .7, after rect, but that was incorrect. It should have been 5V * .7 for a 3.5V transformer. In addition, the Duncan simulator was way off also, predicting 5.6V from 5V transformer. Not sure why that is, I assume I am doing something wrong with the simulation.
When I designed a PS for hypex UcD400 I used a 40-0-40 which made 56V after rectification and filtering. I should have remembered that before.
The DAC has 3.3VDC regulators, so the 5VDC is the desired overhead, so I'll need a different transformer.
Thanks again,
Rich
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You could build a little perf-board with a 5volt 3pin regulator and then regulate down to 3.3 volts.
That way you still use the same transformer and maybe have some potential benefit from cascading your regulation. I am cheap enough to try to get out of buying another transformer if I can make what I already have work for the cost of a 5volt regulator.
Scotty
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Good idea. The Belleson regulator designer prefers not to have any preregulation, but I'll try it. For the cost of a 7805 and a couple caps might as well. Thanks
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The Belleson regulators can take 35V input, so I'll just use my 7.4V supply. Peak current is only 50ma each regulator, so the extra overhead is no problem. These are series regs based on Jung, not shunts. They remain cool to the touch with the 1.7V overhead I have now.
http://www.belleson.com/
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The PS actually puts only 6.6vdc to the Buffalo under load. The one regulator that Belleson doesn't make yet is the 1.2vdc voltage for Sabre's core. Voltage still comes from the Buffalo's onboard LT chip reg which can take 20V input. I got the DAC up and running on its own power now, and it sounds significantly better without the pre-regulator. More bass kick, denser tone, stronger everything.
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Mike and I compared this DAC to his Oracle DAC1000 last Friday. We used Mike's Oracle transport and Black Cat Veloce digital interconnect, DNA500 and Aerial10s. Both DAC piped directly to the amp, with Oracle using its own analog IC volume attenuator chip and the Buffalo using its internal 32 bit digital volume control. The DAC1000 is also a preamp, so it has extra voltage to spare, but the Buffalo transformer was over the halfway mark with lowish volume levels. Low sensitivity speakers with an amp that needs 2V to play loud might want more voltage. I think Mike used my SC3 ICs for both DACs.
The Oracle DAC had a little less resolution than the Buffalo, but denser tone which I expected, because line transformers don't usually fatten things the way a active circuit can. But the transformer had a more realistic, natural tone. The Oracle has an excitement which is fun to listen on all kinds of music. I think the transformer might have been slightly more microdynamic, but we did not calibrate volume levels so that's hard to tell except for feel. We did not try the Buffalo through the DAC1000 as preamp, but that would have made them sound more alike, and fattened up the transformer sound. I was thrilled that my DAC was able to stand next to it without being embarrassed.
I have an older Twisted Pear Legato discreet active output stage kit on hand, and plan to also try a 6n6p tube/transformer output when funds allow. But with my 95dB speakers the DAC is more than enough for me, and I like the transformer's seemingly unlimited detail and perfectly natural tone. With the regulators the bass is full and powerful, no thinness, so it is a nice combination.
Thanks for the visit Mike.
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Rich, glad you could make it over. It was great to hear your DAC! A couple observations on my part...
-- the tonal quality of Rich's DAC was exceptional and far removed from any digititis. Smooth, engaging and highly musical.
-- Interestingly, I think the bass from Rich's DAC was a bit more defined and pronounced than the Oracle. Hard to say for sure because deep bass in my room suffers a bit - minimal room treatments.
-- To my ears, the Oracle provided a more defined soundstage with quicker transient response and a more defined decay. I don't think I can agree that the Oracle had less resolution but it was denser.
A couple potentially unfair points to note:
-- The JPS SC3 RCA ICs were used between Rich's DAC and my amp but JPS SC3 XLR balanced ICs were used between Oracle and amp.
-- The Oracle DAC/Pre was powered thru my UberBUSS but Rich's DAC was straight to the wall.
As I've said before - I think our systems adjust our hearing and much as we strive to adjust our systems. I've lived with my rig as it currently is for probably the longest period of my audioholic years and, to be honest, I'm really happy with it. For Rich's DAC to sit in for the Oracle and perform as well as it did was quite impressive! I'd love to hear it in other systems and compared to other DACs like the new EE Minimax+
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Belleson has a 1.2V regulator in development, I have been selected as beta tester. :thumb: I don't expect it to make much difference, but Hynes has a 1.2 as part of his Buffalo kit. 1.2v powers the DAC core (it's own internal microprocessor.)
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Is there a way to eliminate the analog output all together ? Meaning going from the DAC chip to a trannie then to a standard preamp ?? Would gain be the only issue. Why not just use the preamps analog instead of both CD and Preamp.
BTW Bill cannot wait to hear the new DAC.
charles
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Thanks Charles. I hope you can hear it sometime soon. I think you'll like it.
This DAC has only a super high quality 1:1 transformer between the DAC chip and the output jack. I think it makes about 1+Vrms at the output, but not measured yet. It is a strong DAC chip.
After reading about the Lampizator DAC I'm curious to try that tube 6N6P, but I know it will smear transients and warm things up, but there may be a special magic distortion with that tube that I'd like to hear. But powering the tube with Belleson regulated high voltage PS will not be a cheap experiment so it won't happen soon, unless someone wants to commission a custom richi-dooDAC?
There is no harshness at all right now with just the transformer, despite a feeling of unlimited resolution, so it doesn't need any warming or smoothing. It also doesn't need a tube for current buffer. Carl and I played it last week driving his 10kOhm McIntosh MC402 directly and it made awesome bass. It sounded great through his Belles 21a preamp also, which he preferred due to the zooming out effect. The direct connection felt like the music was all around us, while the preamp held the music as a whole in front of us. I liked the direct connection sound better on my test tracks and the preamp better on his stuff. Thanks to Shane for the USB/spdif adapter.
Carl said it was the first DAC he's heard besides his Nixon TubeDAC that didn't have his dreaded "oversampling" sound. We both preferred it to his TubeDAC.
I think it got better after breaking in a couple hundred hours. I don't know why that still surprises me. I don't expect things to get better but they do.
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Yes, this was the first DAC I've heard that I wanted to actually buy in a very long time. It is musical and detailed without the hard brittle fake upper registers. No digititus at all! No fatigue. Just music with all the details intact and unadulterated. :)
Excellent and satisfying, thanks for opening my ears, Rich.
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So Richadoo you are hereby commissioned to make one for me. :drool: Pretty please. :lol:. With sugar on top :-P,
charles
SMA
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Awesome!! Buffalo is DIY only, so you must buy your own Buffalo 3 DAC ($300) from Twisted Pear Audio and send it to me with a $1700 check, and I'll assemble it for you with all the goodies.
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Awesome!! Buffalo is DIY only, so you must buy your own Buffalo 3 DAC ($300) from Twisted Pear Audio and send it to me with a $1700 check, and I'll assemble it for you with all the goodies.
:shock: Hmm, gotta think about it, now. $2000 for a piece not heard first is a gamble. I trust your ears to a point. :-P
Gotta think this one out.
charles
SMA
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I wouldn't trust my ears if I were you. You already have a great DAC.
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ROAD TRIP! :lol:
Scotty
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ROAD TRIP! :lol:
Scotty
I call shotgun! :D
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I installed a beta test Belleson 1.2VDC regulator this week. 1.2V supplies the DAC chip's internal processing core. I don't know if it sounds different, but now every supply is Belleson Superpower regulated. Good stuff. Next up is installing the balanced output jacks, and fine tuning the grounding scheme as there is a slight buzz when used with my tube amps, but silent on my SS amps.
One new thing I ran across on AC, thanks to mgalusha's post, was this USB 'transport' for Buffalo DAC: http://www.exadevices.com/exaU2I/Overview.aspx
It allows using the 8 separate channels of the ESS 9018 individually, which would be cool for a PC based active crossover setup.
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My exaDevices board arrived this week, initial test plugging into a PC works, so hopefully this weekend I can integrate it into Mr. Buffalo. Lot of coin for a little board, so hopefully a big step up. :shock:
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How do you plan to use it, Mike? Stereo at first?
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Almost certainly it will never be used for multi channel. The DAC has only two output transformers and I don't see buying more but more importantly I have no plans to actively bi-amp my speakers or change to a multi channel system. I do want to try playing DSD/DXD though, some samples are out there so it will interesting. :)
How do you plan to use it, Mike? Stereo at first?
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Today I finished upgrading my Buffalo2 DAC by adding the Legato active output stage powered by the Placid-BP bipolar shunt power supply. These DIY kit modules are offered by Twisted Pear Audio to compliment the Buffalo DAC. I am using the earliest versions from several years ago. There are newer updated kit versions and newer user manuals available now.
Although it seemed to sound good in a few other systems, especially those with active preamps to buffer the DAC, I started to think that the DAC with only passive transformer output was sounding a bit thin in my system, and comparing it to my old Buffalo32 DAC with its built-in opamp buffers proved this to be true, although the Buff32 sounds a bit less open and refined than the passive transformers.
I assumed the thin sound was due to the lack of output buffer, but it could also have been due to the Buffalo32 running the DAC in current mode while the passive was voltage mode. The legato also runs the DAC chip in current mode by offering a very low load impedance, like 1 ohm. Then the current signal is converted into voltage signal and buffered. Legato has a true balanced signal path with discreet transistors, 5 per channel, running deep in class A and no caps in signal path. :thumb: There are a lot of happy Legato reviewers over the years since. But I've hear that song before... Audio hope is dope! But I already owned the Legato and Placid kits, so I'd might as well try them. But I was thinking that if it didn't work out I would throw in the DIY DAC towel and get a high value, high end commercial DAC like the new stereo exasound DAC, or Zodiac, etc.
By using the discreet active Legato in combination with the transformer outputs in place of the Legato's output caps I was hoping I could keep the refined, open and natural sound of the passive transformers plus gain the bass solidity and tonal fullness of the active buffer, while also avoiding the somewhat closed-in sound of the "IVY" output stage on the Buffalo32 DAC which uses all opamps for I/V and buffer. The LM4562 used as buffer on the Buff32 is one that I particularly dislike. Legato also optionally uses LM4562 as BAL/SE output buffer so I enjoyed leaving that part of the board unpopulated.
I used only the core of the Legato without the optional discreet balanced current buffers, and with no BAL/SE (balanced to single ended) conversion stage. I replaced the Legato's large electrolytic output coupling caps with the super-awesome 80% nickle core, ultra-low distortion, wide bandwidth, professional line-out transformers that I used before as passive outputs. They eliminate the DC offset on the Legato's output and provide choice of balanced or single ended output. I am just using SE output now, but Sol has designed a simple circuit that can switch between BAL and SE jacks that I will employ eventually.
Well it was a good gamble, the DAC sounds awesome! I couldn't be happier to hear it come to life and sound so good. There is great body and presence along with with excellent space and ambiance. No closed in sound at all, and excellent tone, every bit as good as the transformers alone, probably better. Time will tell.
Today Sol and I were playing the DAC with my I-15 amp and he put on a Telarc Fanfare for the Common Man. I think it was the best sounding recorded trumpet I have ever heard. Such subtle tonal details and the exquisite comb filtering acoustic effects of the two trumpets playing in unison in the large hall plus perfectly natural and biting brass edge was an eye opener for me. I can see why you hard core audiophile types fall hard for this... Sol's amps deserve credit for allowing that kind of detail and power to get to the speakers intact, but I'm sure that this is the best source I've owned so far.
Usually it's a bit of a let-down after a day like today because some of the great sounding gear usually goes home with its owners, but today the good stuff stayed behind because it's mine! I'm pretty happy with the way my new system is coming together!
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Congrats, Rich! :thumb:
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Took the new DAC over to Carl's this morning for a quick comparison. His is identical to mine, except without the Legato output stage. We listened to his for a long while, it was sounding so nice, good overall balance. I wasn't sure the output stage would make much of a difference when a preamp is in the mix. His is hybrid tube input/gain with discreet SS output buffer. So if ever there was a perfect load for the passive DAC chip, this was it.
But, when we switched to the new DAC, playing the same song from a minute before I literally didn't recognize it. Dynamics, punch, texture, lyric intelligibility, everything was drastically stronger. It could play much louder without distorting. Bass was clearer and some loose mid bass we attributed to room mode seemed to tighten up. We both liked it liked it a lot, but it is very much 'stronger' presentation than the gentler passive output DAC. But the treble is still perfectly natural, like any Sabre DAC, even on brass and strings, just stronger and more thrilling now.
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So did the Buffalo roam or still at home ?? :roll:
charles
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Still goin... still sounds great.
Now I'd like an 8 ch version.
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Looks good, I'd like to hear it! Why did you with multichannel kit and not the dual mono stereo?
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Better Call Sol!!! :lol: :lol:
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Better Call Sol!!! :lol: :lol:
:) I do almost every day!
Looks good, I'd like to hear it! Why did you with multichannel kit and not the dual mono stereo?
Mine is stereo Buffalo2. Only the Buffalo3 has the multichannel option. I want multichannel DAC so I can run active crossover filters on the PC.
I am using a pro audio multichannel audio interface for the purpose now, with JRiver DSP. It sounds bad compared to Buffalo so I'm doing some mods to it, upgrading the nest of "Chang" brand electrolytic caps to Nichicons. Later maybe eliminate those caps altogether. If I were smart I would stop messing around with DIY crap and just buy Exasound e28 balanced. I would listen to more music and save money in the long run. But it's been fun to do these DAC projects.
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Does you dac have a dual mono option? I am only asking but you might get more power output with dual dacs in mono. Don't know what do you think?
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Yeah, you're right. The more DACs in parallel, the more current you can source. But an active output stage buffers current so no shortage of power to the load. So a Buffalo uses ESS 9018 DAC chip which has 8 separate DAC channels in it, so Buffalo PCB can do either 4+4 stereo, or 8 in parallel for a mono channel per board, but then you need two Buffalos, for left and right. I guess a few peeps have done that. The ESS DAC can source 3mA per DAC, or 12mA stereo, or 24mA mono, so I was able to drive stereo 10kOhm loads with only a 1:1 tranny, non active output. I lived with that for 2 years. When i sold my old Buffalo32 to Nick I tested it and heard awesome bass and solidness that I missed with my tranny version, so I added the active output to mine and it is much better than the trannies. Now I use an active output stage which provides a nearly dead short load to the DAC to keep it in current mode where it sounds best, and then the output stage provides gigantic current to any load, like 150mA iirc. But the active output stage is unity gain, so the DAC is a little shy for voltage, only 1.4Vrms. There is a way to up the gain on the output stage, but I haven't done that yet. I have a preamp so no biggie.
The trannies runthe DAC in voltage mode, it sounds better in current mode, so you need an active I/V converter to show the dac a low impedance load, then change the current to a voltage output. That's what makes it sound good. Not all ESS9018 DACs do this.
The Buffalo 3SE is a great DAC. With Legato output stage, and Placid bipolar power supply, plus a USB input like Amenero or diyinhk makes a really great stereo DAC for <$1000
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32bit dac at 1.4v unity? Something wrong here. Where is the 2 volt line level? What am I missing here?
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32bit dac at 1.4v unity? Something wrong here. Where is the 2 volt line level? What am I missing here?
You're not missing anything. 2V isn't mandatory. Bit depth is not related to output voltage. The designer aims for best SQ and specs rather than obeying convention. The instructions describe how to make more gain if needed in the out put stage, but it has been enough for me with the standard build. Many designers are easing off the traditional gain standards to avoid having too much gain which equals too much noise. It would be nice to have the full 2V sometimes. :D
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Awe, this is a single bit dac no MSB. Supports up to 32 bit but is not a 32 bit dac. I get it now
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Their trademark is "Sabre32" because it is a 32 bit DAC. It can also render single bit DSD directly.
Fact Sheet:
http://www.esstech.com/PDF/ES9018%20ES9012%20Product%20Brief.pdf
White paper with all the technical details:
http://www.esstech.com/PDF/sabrewp.pdf
Nope, it's not MSB (http://www.msbtech.com/).
Twisted Pear Audio has just released a new master clock product called Cronus (http://www.twistedpearaudio.com/digital/cronus.aspx). It provides master clock to digital source, then reclocks the stream directly, then sends the clean I2S to Buffalo 2 and 3, and any I2S input DAC.
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I think it modulates a 32 bit signal into a single bit output. If there is no MSB than its a pulse modulator or single bit output. The advertising is deceptive.
Or I could be completely wrong.
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Hell if I know :-P
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Hell if I know :-P
😂 it is I took digital in college with my technician course. Nonetheless what you've done achieving zero gain output using transformers is more than I've ever done or thought of.
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Capacitor-phobia is a good motivator!
The ESS9018 DAC has some DC offset so cap or tranny is needed to stop that. The new Legato uses trim pots to null out the DC so no caps or trannies needed.
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Yeah, you're right. The more DACs in parallel, the more current you can source. But an active output stage buffers current so no shortage of power to the load. So a Buffalo uses ESS 9018 DAC chip which has 8 separate DAC channels in it, so Buffalo PCB can do either 4+4 stereo, or 8 in parallel for a mono channel per board, but then you need two Buffalos, for left and right. I guess a few peeps have done that. The ESS DAC can source 3mA per DAC, or 12mA stereo, or 24mA mono, so I was able to drive stereo 10kOhm loads with only a 1:1 tranny, non active output. I lived with that for 2 years. When i sold my old Buffalo32 to Nick I tested it and heard awesome bass and solidness that I missed with my tranny version, so I added the active output to mine and it is much better than the trannies. Now I use an active output stage which provides a nearly dead short load to the DAC to keep it in current mode where it sounds best, and then the output stage provides gigantic current to any load, like 150mA iirc. But the active output stage is unity gain, so the DAC is a little shy for voltage, only 1.4Vrms. There is a way to up the gain on the output stage, but I haven't done that yet. I have a preamp so no biggie.
The trannies runthe DAC in voltage mode, it sounds better in current mode, so you need an active I/V converter to show the dac a low impedance load, then change the current to a voltage output. That's what makes it sound good. Not all ESS9018 DACs do this.
The Buffalo 3SE is a great DAC. With Legato output stage, and Placid bipolar power supply, plus a USB input like Amenero or diyinhk makes a really great stereo DAC for <$1000
Rich,
That Buffalo dac you sold to me is a great dac. I was shocked at the performance. Being a McCormack enthusiast, I bought their DAC 1 recently and put a $1,000 in as a beginning upgrade. It would cost another $1,500 to $2,000 to bring it to their Platinum level. Right now I'm on hold with everything audio as we have medical bills to pay. But I am seriously considering just putting your TPA dac in a nicer box and just enjoying it
Nick