Hi all! As a first time poster I would just like to say I have done moderate amounts of soldering with decent skill. I have some electronics knowledge, currently researching/reading material to gain more. As for audio based electronics I am not very experienced, I am considering some low cost projects to get my skills up to scratch. This project will be a skill builder in aim of the USB DAC I am searching for below!
I have been researching USB DAC's for a bit over a week now and have believe I have a fair understanding of the principles behind them, however I do have some questions.
I am constructing this post as I am having trouble refining my search to a good quality DIY build for no more than 3-400.
I am after something simple, I have no use for digital inputs/outputs or analogue for that matter bar RCA L+R. I assume less inputs / outputs will mean more money to spend on other components
What I am after
Input/Output:
+ USB
+ Power
- RCA L+R
- 2 ChannelD)
- Non Upsampling (done on PC)
- Non Oversampling (Better quality I have read)
- Separate USB transport and DAC. Connected via I2S (Better quality no translation)
- Ability to process upsampled computer source 24/96
- Would prefer mains power for constant usage as the unit will not be leaving my PC
Any suggestions on some models to have a poke at would be great.
The DDDAC1543 with USB module looks good, but I can’t seem to find any user impressions of the quality.
I am finding it hard to get a direct comparison of any units or individuals for that matter. Even a nudge in the right direction would be a great help. Thanks!
I have been researching USB DAC's for a bit over a week now and have believe I have a fair understanding of the principles behind them, however I do have some questions.
I am constructing this post as I am having trouble refining my search to a good quality DIY build for no more than 3-400.
I am after something simple, I have no use for digital inputs/outputs or analogue for that matter bar RCA L+R. I assume less inputs / outputs will mean more money to spend on other components
What I am after
Input/Output:
+ USB
+ Power
- RCA L+R
- 2 Channel
D)- Non Upsampling (done on PC)
- Non Oversampling (Better quality I have read)
- Separate USB transport and DAC. Connected via I2S (Better quality no translation)
- Ability to process upsampled computer source 24/96
- Would prefer mains power for constant usage as the unit will not be leaving my PC
Any suggestions on some models to have a poke at would be great.
The DDDAC1543 with USB module looks good, but I can’t seem to find any user impressions of the quality.
I am finding it hard to get a direct comparison of any units or individuals for that matter. Even a nudge in the right direction would be a great help. Thanks!
leggi said:
Hi there.
I am running a modded DDDAC1543 with 24DACs and battery supply.
If you want to go for a 16bit DAC I can strongly recommend this DAC.
The Tent-clock upgrade I'd consider a must and get yourself decent
coupling caps. Though I've thrown out my coupling caps, since I connect
the DAC directly to the AMP ( I am running a modded Charlize module).
Now I got a spare pair of 100$ Mundorf Caps.
You'll be happy with this DAC. Sound, soundstage, dynamics and transients
are really great. I love this DAC. I am running the DAC over USB. This just works great.
If you find the right PC setup, which is not that easy, you'll have a hard time to find any CDP out there able to beat this little thingy.
Be careful with DACs, where USB is converted the SPDIF. You'll be catching
more jitter.
Cheers
Hello,
DDAC1543MK2 is in my audio system from a year now, and i'm very happy with it.
I have builded also a standalone audio player based on it.
At the following links I've posted my impressions:
http://www.simonecapretti.eu/Audio/DDDAC1543MK2/DDDAC1543MK2.htm
and here there is the standalone audio player:
http://www.simonecapretti.eu/Audio/MoSAP2/MoSAP2.htm
Ciao!
Simone.
DDAC1543MK2 is in my audio system from a year now, and i'm very happy with it.
I have builded also a standalone audio player based on it.
At the following links I've posted my impressions:
http://www.simonecapretti.eu/Audio/DDDAC1543MK2/DDDAC1543MK2.htm
and here there is the standalone audio player:
http://www.simonecapretti.eu/Audio/MoSAP2/MoSAP2.htm
Ciao!
Simone.
Another very happy DDDac user here -- 2 DAC boards (2x 12 chips) and the USB board. Unlike soundcheck, I don't have the tentlabs clock on the USB board yet (they are still out of stock), but can't wait to get it.
Even without this, I'm 100% happy with it. It has replaced my Benchmark DAC1, which I was feeding from the PC with SPDIF. It may have been this inferior interface that was making the DAC1 sound a bit grating, but to my ears the DDDac is more enjoyable and loses nothing when it comes to detail.
Simone -- thanks for your site -- it was a big help for me wiring up my DAC and playing with various PSU's.
Leggi -- do a search for DDDac here and on google and you'll find some impressions. Mostly very good, although others argue that NOS dacs and 1543 chips in general are 'junk'.
Even without this, I'm 100% happy with it. It has replaced my Benchmark DAC1, which I was feeding from the PC with SPDIF. It may have been this inferior interface that was making the DAC1 sound a bit grating, but to my ears the DDDac is more enjoyable and loses nothing when it comes to detail.
Simone -- thanks for your site -- it was a big help for me wiring up my DAC and playing with various PSU's.
Leggi -- do a search for DDDac here and on google and you'll find some impressions. Mostly very good, although others argue that NOS dacs and 1543 chips in general are 'junk'.
dublin78 said:
I think a guy called John Svensson at audiocircle or AA took some measurements. He measured double the jitter, if I recall it right. The jitter on each single interface was pretty much the same. When cascaded it doubled.
That might not be the case, if you do a proper reclocking in front of the DAC
I don't have the link at hand anymore. Just google it.
Cheers
ssmith said:
I think that's pretty much what Doede experienced and measured, before he applied his biasing setup and DAC-stacking.
However - I'd love to get a similar, but 24bit, DAC with just a resistor I/V output stage.
Perhaps one day BurrBrown also comes up with a 24bit USB2I2S interface chip.
Cheers
soundcheck said:
I think that's pretty much what Doede experienced and measured, before he applied his biasing setup and DAC-stacking.
However - I'd love to get a similar, but 24bit, DAC with just a resistor I/V output stage.
Perhaps one day BurrBrown also comes up with a 24bit USB2I2S interface chip.
Cheers
Is there any way I can build a setup with 24bit output? I was thinking that upsapling to 24bit on the PC would produce better sound...
Sorry for the late reply, I have been out of town.
Just FYI, talking a bit about 1543 perfomance potential with a single chip.
http://www.enjoythemusic.com/magazine/equipment/0506/zero_oversampling_dac.htm
Have a look what Charles Altmann squeezed out of a single
1543 DAC. (over SPDIF)
Altmans homepage is a quite interesting read too!
Cheers
http://www.enjoythemusic.com/magazine/equipment/0506/zero_oversampling_dac.htm
Have a look what Charles Altmann squeezed out of a single
1543 DAC. (over SPDIF)
Altmans homepage is a quite interesting read too!
Cheers
Simcap
I like your system very much - well done.
Newbie question: Please can you explain the function and advantages of the two capacitors connected to the analogue outputs?
I am about to build a similar sytem, but with a cdp transport, a NOS DAC, and a charlize amp with pot, all in one housing. I may add a USB input as well, but probably not at this time, as this will be a secondary system.
I am pleased that you had success with your "off the shelf" power supply. I had decided to use this method also, although I was not planning on spending as much. I was going to choose a TFT monitor supply 12v DC 5A @ about £20 (switched and regulated)
Best wishes.
Michael
I like your system very much - well done.
Newbie question: Please can you explain the function and advantages of the two capacitors connected to the analogue outputs?
I am about to build a similar sytem, but with a cdp transport, a NOS DAC, and a charlize amp with pot, all in one housing. I may add a USB input as well, but probably not at this time, as this will be a secondary system.
I am pleased that you had success with your "off the shelf" power supply. I had decided to use this method also, although I was not planning on spending as much. I was going to choose a TFT monitor supply 12v DC 5A @ about £20 (switched and regulated)
Best wishes.
Michael
The jitter coming out of the USB chip is the same whether it is I2S or S/PDIF. The difference occurs in the S/PDIF receiver that you have to add. That's where the extra jitter is added.
As the I2S isn't perfect either (nothing is jitter-free), it still helps to re-clock. That's what I do.
So I figured, I'm re-clocking anyway, it's not going to hurt too much to use the S/PDIF output. The benefit of choosing this approach is that it is much easier to isolate grounds. Most of the I2S implementations you see tie the ground of the computer directly to your audio system. To me, that was actually the worse of two evils. So I use the S/PDIF output from USB chip, and run it through a tranny for complete isolation of supplies and grounds. This method has the side benefit of making an input selector switch easy. Only one 75-ohm signal per input. Much simpler than trying to mux several I2S inputs (which ties together even more grounds).
jh
hagtech said:
Why not taking an I2S output of an Envy-chip based soundcard and reclocking this I2S signal with a precision clock!
Is anybody aware of a reclocking module for I2S?
The Envy chip on such as soundcard can even be driven as clock slave, if the I2S reclocker runs as master! That's most probably
even better.
(Do I mix up things here?)
I am wondering in general if the ground issue is such a big issue.
Lynx managed to come up with an internal PCI solution, where
a noisy PC environment doesn't seem to be an issue at all.
I think the ground issue is becoming a real issue the more (independend powered) stages you connect togehter.
My idea: Limit the involved stages!
Cheers
Depends on how it is done. I would not power the USB chip with any of the supplies in the DAC. Better to make an independent supply. The reason again is to prevent coupling from a computer system ground to the audio ground.
There are two ways to power the USB chip. Easy method is to use the 5V bus power supplied by the computer. The problem here is that this is a noisy supply. It is powered from a dc-dc converter that has both HF and LF noise. It is not low impedance and varies with other loads within the PC such as when a hard drive kicks in or a fan. Some PCs are better than others. This is NOT the best raw 5V power you can get. The other approach is to add a supply running from AC mains. However, that power line is just as noisy and full of garbage as the PC power.
So what to do? Use dirty dc power or dirty ac power?
The answer is that you can use either. It's just a matter of addressing the problems proactively. For dc, you use passive filtering to clean up the HF noise on the 5V bus. Since the USB chip runs at 3.3V, you have quite a bit of voltage headroom to play with for the filtering. I use a ferrite bead and low impedance electrolytic. That cleans the HF. Then use the built-in linear voltage regulators on the USB chip. That cleans up the LF. You end up with pretty decent clean supplies. Most importantly, there are four separate linear regulators, which you keep separate. This helps to decouple noise between the analog, digital, PLL, and other circuit sections within the USB chip.
Using an ac supply can be better. The reason is that you can clean up the dirty input and create a nice dc output. In fact, a regulated and already clean 5V dc output is best. This is in comparison to the dirty 5V dc from the USB bus. So obviously, it can be an improvement. Then the rest is the same. What you have to watch out for with the ac supply, is that it remains grounded to the PC side, not the audo side. And then you still use a transformer output. You see, if you had borrowed 5V from the DAC, then you would have to tie the PC and audio grounds together. That would introduce noise back into the system.
The other mistake you can make here is by supplying a common regulated 3.3V to the USB chip. The reason that is not good is because it ties together the internal sections. You don't want to do that. Keep the digital supply off the PLL off the analog. You can, however, use 3 or 4 separate 3.3V supplies. In fact, you can improve a notch further by running these at 3.6V. Just be careful that if you try this, sequence the outputs to make sure they all come up at the same time.
jh
imperfectcircle said:
The DDDAC, especially the USB variant, needs proper source material, a highly optimised PC setup and some tweaking to sound best. I think a lot of people just miss this out.
If you manage to get this done, all the NONOS DAC incl. passive output stage advantages will apply!
The DDDAC is loosing, IMO, at least 30% of its potential on the way from PC to PCM2707. If you manage to improve the front-end of the DAC, Lynx will have a hard time.
E.g. Just feeding the DAC with 48kHz material (offline upsampled with Shibatch ssrc under Linux) lifts it up in a different league!
Cheers
dublin78 said:
Hello dublin78,
They are the output capacitors.
In this picture of the dac scheme:
http://www.simonecapretti.eu/Temp/Image1.jpg
you can view that output capacitors are not on the circuit board.
In the kit are already included the 100uF + 100nF but it's so funny to try other values and brand
So actually I'm using the Mundorf MCap Supreme Silver Oil.
Ciao!
Simone
Re: DDDAC->Charlize capping?
Correct.
Charlize input caps are sufficiant.
If you don't catch DC on the DAC output, forget about the output caps. The best cap is no Cap!
I used small value input caps, running as low-cut in conjunction with the 20k input resistor, on the Charlize input.
I just run my mids and highs over Charlize, crossed over at
250Hz. That way you take off low freqeuncy load from Charlize.
I use BG non polars as coupling Cs. They sound as good as my Mundorf Silver/Gold I used before. The small values do make a
huge difference.
This tweak heavily speeds up the whole chain.
Further mods on Charlize: All BG caps and Mundorf Air Coils and some other minor things.
Cheers
goon-heaven said:
Correct.
Charlize input caps are sufficiant.
If you don't catch DC on the DAC output, forget about the output caps. The best cap is no Cap!
I used small value input caps, running as low-cut in conjunction with the 20k input resistor, on the Charlize input.
I just run my mids and highs over Charlize, crossed over at
250Hz. That way you take off low freqeuncy load from Charlize.
I use BG non polars as coupling Cs. They sound as good as my Mundorf Silver/Gold I used before. The small values do make a
huge difference.
This tweak heavily speeds up the whole chain.
Further mods on Charlize: All BG caps and Mundorf Air Coils and some other minor things.
Cheers
Thanks Klaus.
I'm running foobar into RME96 SPDIF into DDDAC Mk1 into Gilmore Headamp. I have (only) this one pair of Auricaps, at the output of the DDDAC, that I wish were not there (for all those reasons you give). Looks like they will survive just a little longer.
Different to your USB input: I would like to know how to build a clock output circuit from the Tent clock in the DDDAC that the RME would slave to. Who can spell it out to me?
I am also considering how to do a Mk2 PC audio, so I read all this with much interest.
I'm running foobar into RME96 SPDIF into DDDAC Mk1 into Gilmore Headamp. I have (only) this one pair of Auricaps, at the output of the DDDAC, that I wish were not there (for all those reasons you give). Looks like they will survive just a little longer.
Different to your USB input: I would like to know how to build a clock output circuit from the Tent clock in the DDDAC that the RME would slave to. Who can spell it out to me?
I am also considering how to do a Mk2 PC audio, so I read all this with much interest.
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