Choosing a DAC

[muel]

I’m trying to find that elusive synergy with my setup and
would like your advice and to hear about what you
are using, especially if you have a similar setup. I’m looking for a
nice USB connected DAC that will make my ears happy. I’ve had a Musical
Fidelity V-Dac and a Cambridge Audio DacMagic that I have been rotating for the
last few months. I graduated to these after using various computer sound cards
such as various built-ins, the Creative
Audigy 2zs and the old Creative external Extigy. I picked up the DacMagic first and when those first notes poured out it made all the old
sound cards I had heard before sound like mud in comparison!

I apologize that I
might not be good at giving a clear description of what I am hearing but I will
do my best. The DacMagic has a very clear sound that reminded me much of
listening straight from the Oppo. It had a better sound stage than I am used
to experiencing. As clear and nice as it was there was a harshness or brightness that appears on some recordings
that I found annoying. After enabling the
equalizer in Foobar I found that I could reduce the harshess by lowering 5kHz a
notch. DacMagic has 3 filters available which do nothing about the harshness
but changing this can improve or worsen some recordings to my ear. I
also used the DacMagic as the DAC (via toslink)
for the Oppo to compare. With some music it was similar enough that I
forgot which way I had it switched… then with other recordings I could hear some
of that harshness when it was switched to the DacMagic.

The V-Dac also sounded nice but the soundstage wasn’t quite
as precise and I couldn’t place the musicians and
instruments as easily. It has a bit of a grainy sound (very
slight). Still, it was nice enough that I am
using it in another setup for now.

Some of the DACs I am
considering include: Grant Fidelity Tube DAC-09, Scott Nixon's DACs, Bryston
BDA-1 ($$ have to find used at those prices), MHDT Labs Havana, Music Hall 25.3, Benchmark DAC1,
wyred 4 sound dac 2 ($$). I
would like to keep my budget under 1k but I might go over that for the right
DAC. If I find myself listening to the DAC instead of the music then I know I
have a problem. So, what do you think?

System:
Scott 299B w/Telefunken 12ax7
Oppo DV-980H
1967 Cornwall CWO with ALK xovers

[DrWho]

If you're going from a computer to your stereo, then the weakest link is actually going to be the windows audio kernel which forces everything to resample to 48kHz with a rather crappy (but fast) algorithm. For critical applications, I try to stick to ASIO devices since it sends an unfiltered bitstream to the device (basically it bypasses the windows kernel). The only downside to this route is that I've yet to find a good media streaming program that is completely quirk free with ASIO.

For $1k, you could get into some rather nice studio quality gear too...especially if you only need 2 channels.

[Hajj]

As mentioned by the Doc, your limiting factor is the Windows kernel.

Since you're running foobar, just a few tips to get the best out of it:

Install Asio4all, I found it to be quite easy to install and setup, and once you're done with the preliminary setup, you'll forget there's an interface for it, it blends perfectly with foobar.

When using foobar:

Disable the equalizer and play your music directly through Asio (in foobar, file -> preferences -> playback -> output -> choose Asio4all) , if you use the equalizer you'll be losing most (if not all) of the advantages offered by Asio.

Reduce buffer to a minimum, until you start hearing the music breaking up.

Avoid using the volume control in foobar, it defeats the purpose of Asio.

Set your volume control in windows to 100%

There's an option in windows (i don't remember where exactly, i'm sure someone it'll show up on a quick google) where you defeat sampling to 48khz.

Try to close all others programs running in windows when listening to music.

These are the main things that would make the biggest difference (i'm sure there's more, but i can't remember them right now)

I'm using HRT music streamer II+ and it's so far the best sounding DAC i've heard under the 1,5-2k$. Yes, it's that good, crystal clear, super fast, great seperation and extracts the tiniest of details, but i'm guessing this also has to do with the synergy between it and my system since i'm using very transparent gear, a Decware integrated 7wpc EL34 tube amp, and a Decware preamp using 6922 tubes, and getting the music out of full-range speakers.

If most of your listening is through PC playback, I couldn't stress more on trying out the HRT musicstreamer, even the regular version (musicstreamer II) is great sounding, and considering the price of 150$, there's very little to be lost in the process....

Just my 2 cents.

Nick

[pzannucci]

muel,

You have the Dac Magic and the usb intput to that is not nearly as good as tos-link or standard digital cable.

Have you tried them with the Dac Magic. You might be very surprised.

[jcmusic]

I have a MHDT Labs Renaissance II if you are interested, pretty cheap as well.

Jay

[bliss53]

I have a piece of studio type gear who's dac performed well enough for me to sell my wavelength brick. It is a $400 TC Electric Impact Twin. It is a 24/192 output and input. I use the input for raw vinyl recordings that run through a program called Pure Vinyl on a Apple Mac Mini.

[muel]

Thanks for the replies!

I've spent some time playing with the settings in ASIO4ALL and my settings are pretty much where you were describing. There is a checkbox you can check to Always Resample to 48kHz. I leave this unchecked now... on the DacMagic it has lights telling you the incoming sample rate so you can see if it is working right. I can't hear any difference with the ASIO Buffer Size setting... it doesn't seem to matter on playback but it might actually keep my CPU percentage down a little. The Kernel Buffers are working fine set at 2. I didn't know what to do with the latency compensation settings (in and out number of samples?). I mentioned enabling the equalizer temporarily because I found it interesting that lowering the gain on 5kHz helped the harshness. Of course, it also took some music with it.

I haven't done enough comparison with the toslink and USB. From the computer I only have USB available. I did compare the same music from the Oppo via toslink and the computer via USB. It still has the slight harshness or brightness from both sources. I wasn't doing a very good job keeping the levels equal so I couldn't say if toslink sounded better than USB. The Oppo DAC straight to analog is smoother sounding but very close otherwise to the DacMagic.

I am stuck with USB for my computer source so any digital connections would be reserved for other less used sources. Half of my listening is via Foobar but I also spend a lot of time on Pandora (paid version with 192Kbps) which is great for the variety and hearing music I don't have but certainly lacking in quality compared to Foobar. I'm just hoping to do the best I can with it. I like "detail" but perhaps I need to lean more towards what I hear people refer to as more "musical" DACs. Actually, both detailed and musical would be nice! What do you think of the "1 bit" DACs? or the NOS DACs? Any other Scott owners using a USB DAC they are particularly happy with? I'm swimming in a sea of choices and I'm trying to narrow it down some.

[DrWho]

Do you think any of the harshness you're hearing could be related to your speakers instead of the DAC? Differences between DAC's are going to be in low level details like the noise floor, anti-aliasing filters, and maybe zero crossing distortions. Are you controlling your volume on the computer, or is there a volume knob between your DAC and the amps?

[muel]

Do you think any of the harshness you're hearing could be related to your speakers instead of the DAC? Differences between DAC's are going to be in low level details like the noise floor, anti-aliasing filters, and maybe zero crossing distortions. Are you controlling your volume on the computer, or is there a volume knob between your DAC and the amps?

You are giving me some things to think about. I understand noise floor but I don't know what I would hear with the other two things you mention. There is no volume control between the DAC and the Scott amp and I've started leaving the Foobar volume at maximum. I thought about swapping out the Cornwalls for some old Bostons just to listen for the differences but that might just confuse things for now. I thought I eliminated the speakers as being related to the harshness because the same recording via the Oppo CDP sounds better. I can say for sure that I am hearing a slight harshness with the DacMagic that I didn't hear with the V-Dac. Could that be because the DacMagic is a little more revealing and I am just hearing more of what is in the recording? hmmm... perhaps. I'm certain that some of my recordings are just not that great to begin with.

I'm getting a little confused about where I should go from here. I've been concentrating on the DAC but maybe I should be listening for other causes... different amp etc..? Thanks for the comments!

[DrWho]

Btw, nice avatar, muel [Y]

Poor anti-aliasing filters, and I should probably include dither in this as well, will cause random frequencies (spurs) to pop up out of the noise floor that are not at all tonally related to the music being played. The worse the filters, the louder these spurs become. Even in bad systems, these spurs are usually relatively quiet, but with poor gain structure and/or very quiet passages they can become audible. I think most people would describe this as sounding "grainy" or "digital harshness"...

Zero crossing distortions, or crossover distortions happen when amplification stages don't behave well at very very low voltages. Here's a picture demonstrating very very dramatic crossover distortion:

Ideally you would have a flat line, but as you can see, at low voltages the line flattens out a bit. This will create odd-order harmonic distortion at very low levels, but again it's something that can crop up with poor gain structure and/or very quiet passages. Most opamps have anything but class A output stages so there's always some built-in level of crossover distortion that mostly gets tracked out by the negative feedback. However, there are limits to the effectiveness of the feedback, so at very low levels you might notice higher orders of harmonic distortion creeping into the signal.

I should have also mentioned that you have to be very careful when combining digital and analog circuitry together (which is required for a DAC) since the digital stuff operates at very high frequencies, and if those frequencies get into the analog stages, then they can create all sorts of "interesting" sounding artifacts. They can also inject frequencies that cause amplifier stages to become non-linear, which can in turn cause frequencies to mix down into the audible band....and these will be as bad as the poor anti-aliasing/dithering filters since these new distortions will not be tonally related to the music. If your DAC is powered by the USB bus on your computer, then there is a good chance that you're getting power-supply coupled noise into the amplifier stages and this could be mixing down and creating some harshness. I'd be curious about your impresions if you managed to go S/PDIF or Optical out of your laptop and into a seperately powered DAC device. Behringer makes a real cheap UCA202 or something that has a digital output, which should be sufficient provided the USB clocking isn't too crappy (since it uses a part that autosync's to the USB bus clock).

Jitter is another one of those artifacts where the actual frequencies of the music can get shifted around due to timing errors on the word clocks. Most everything has built-in phase-lock-loop filters which work to get rid of this almost completely so I had forgotten to mention that too.

[muel]

Btw, nice avatar, muel

Poor anti-aliasing filters, and I should probably include dither in this as well, will cause random frequencies (spurs) to pop up out of the noise floor that are not at all tonally related to the music being played. The worse the filters, the louder these spurs become. Even in bad systems, these spurs are usually relatively quiet, but with poor gain structure and/or very quiet passages they can become audible. I think most people would describe this as sounding "grainy" or "digital harshness"...

Your mention of “poor gain structure” certainly might be relevant to my situation... see what you think- With the Dacmagic (or the V-Dac) connected to the Scott 299b I often found myself turning the volume down via the control in Foobar. I now have the volume all the way up in Foobar and I have to have the volume on the integrated amp turned very low or it is just too loud. Even with a 6db Harrison Labs attenuator installed between the DAC and the Scott input the volume is around 70 db (estimation) with the volume control set at 8:00. Do you think this might have something to do with what I am hearing? I would describe the V-Dac as having a slight grainy sound while the Dacmagic can have a slight harshness. I can’t say that the harshness is any worse or better at any given volume, low or high.

These DACs aren’t USB powered as they have separate power supplies. Unfortunately, I don’t have any S/PDIF or Optical connections available on my desktop or my laptop. I’m limited to comparing an optical connection from the Oppo DV-980 VS. a USB connection from the computer playing a FLAC version of the same CD playing in the Oppo. That certainly introduces extra variables. Maybe I could find a interface card that would have an optical connection for test purposes on the desktop.

[sunnysal]

IMHO the Benchmark is hard to beat! Let me begin by saying I am not from the school of "pick a DAC for a sound", for me the DAC should be the invisible, perfect black box, niether adding or substracting anything from the recorded sound. becnhmark products have been tested and listened to and provide just such a service...warm regards, Tony

[doctorcilantro]

Try WASAPI or the new WASAPI [event mode] with J. River. They addressed some issues that cropped up with users of high end DACs like Weiss, Zodiac, and Lynx cards.

Foobar also has a WASAPI but via plugin. Many have found it sounds noticeably better than ASIO/ASIO4ALL.

Why not look into a HiFace and then find a DAC with a BNC coax input? The Eastern Electric DAC combo'd with the HiFace would make you happy for sure.

Some of the EMU USB units are well regarded, the 0202 or 0404 USB. The 0404 has digital i/o.