Benchmark DAC1 now available with USB - Page 56

Originally Posted by euclid

holy crap! could 12.3v XLR out be dangerous high input into a preamp? i only have 15ft cable run.

is there any way to get the voltage under 6v for the XLR in calibrated mode, < 3.0v for each phase 0 and 180?

ps: i think i know why people have been happy with the balanced HD650 directly from the XLR output

Originally Posted by EliasGwinn

12.3Vrms will not be 'dangerous' for your pre-amp - that is, it will not damage your pre-amp. However, it may cause distortion if the pre-amp is not designed to accept +24 dBu input (which is the case for most 'audiophile' pre-amps and amps). Ideally, it would accept +24 or even +28 dBu to maintain the highest signal to noise ratio. That is, the S-to-N ration suffers when the signal has to be attenuated just to get into the (pre)amp, then the signal is boosted again within the (pre)amp. But....such is the case with most 'audiophile' (pre)amps. The attenuators in the DAC1 make it compatible with this type of gear, but also compatible with professional gear that will accept 'full-swing' signals (+24 dBu or greater).

If you set the output attenuators of the DAC1 to -10 dB, the max Vrms (in factory-set calibrated mode) will be 3.88V. The DAC1 is factory-set with -20 dB attenuation, which will yield a max Vrms of 1.23V.

Thanks,
Elias

Originally Posted by euclid

... a more civil voltage ...

Originally Posted by puntloos

Hi guys,

OK my test between the Benchmark DAC1, The Bel Canto DAC3 and the (built-in) DAC inside a Bow Technologies ZZ-Eight CD player is done.

Well, there's good news and bad news for Elias. (& co)

The good news is that the DAC1's audio quality beats the $7500 CD player's easily. The bad news is that the Bel Canto DAC3 sounds just as good as the Benchmark to me and one of my friends. The second friend had a mild preference for the DAC3 - so I returned the DAC1 (not just because of the minute possible audio quality difference, I was also allowed to still return the DAC1, and the DAC3 would have to be sold secondhand if the DAC1 had the way stronger vote.)

Did you compare the DAC1 via USB over the DAC 3 over USB using a 24/96 source? This may be important for those who see USB as their only acceptable alternative to computer-based audio and the DAC3 does not support 24/96 over USB. They claim, however, that it sounds as good if not better...just wondering if you tried this particular set up in your A/B testing.

Some more specifics:

Setup Used:
- Bel Canto Evo 4 gen2
- Quad 989 speakers.
- PC playing various audio sources (winamp -> kernel streaming -> M-Audio Revolution 5.1 -> 75ohm coax cable)

The test:
Essentially two people sat behind eachother (in the center of the room), while a third person would secretly switch between the 3 devices as source. Devices were all matched to the Bow's audio output. I know, this isn't exactly fair since at least the DAC3 uses digital attenuation. Oh well.

The ABX tests were then done with multiple sources :

- Always a use - Madeleine Peyroux (HDCD and normal CD)
- November '99 - Manu Katzche
- One without the Other - Dorian Michael - 192/24 DVDA
- Bad Condition - Steve Pierson - 96/24 DVDA

Sony Sound Forge 9 was used to downsample sources when needed. (best quality)

Of course for the CD player, some sources had to be downsampled. I have no idea how to make HDCD sources so the CD player had the advantage with Madeleine, but the disadvantage with the DVDA sources.
The DAC3 was not able to handle 192Khz sources, so we downsampled.
The results basically were as follows:

The statements below were verified by doing the actual ABXing, i.e. if the listener was able to pick out the source they claimed had their preference 3 out of 4 times when been given samples without telling which was which. Also a statement is only mentioned below when 2 out of 3 of our listeners agrees.

- We were able to distinguish between 96/24 sources and a 48/16 downsample, also played with the same DACs. (downsampling 96 to 44 did seem less fair). The differences were subtle, usually described as more defined highs, but also the stereo positioning seemed more defined.

- The CD player lost in every situation except when playing the HDCD version while the DAC's had to upsample the normal CD data. The conclusion seems to be that if you have a choice, get the HDCD.

- Lagavulin Whisky tastes very nice.

- The sound the CD player made was, in general, much thinner and sounded anemic. Also the depth of the soundstage just seemed less deep, all instruments sounded like they were on one line right between the speakers, no 3rd dimension.

- Nobody could distinguish between XLR and RCA('tulip') connectors anywhere in the signal line.

Finally, we tried introducing jitter by (instead of using 75ohm coax cable) we used two long (10m) single strands of standard lamp wire. No luck, both DACs played just fine.

In the end I guess the conclusion must be that sound-quality wise the DAC3 and the DAC1 are very close rivals, and your choice will be mainly based on things like:
- Aesthetics, few people will disagree that the DAC3 is built 'prettier', while the DAC1 is an industrial looking piece of equipment.
- Headphone outs. The DAC3 has none.
- New Price: DAC1-USB was about $1300, DAC3 is $2500 (also USB)
- Remote: DAC3 has one, DAC1 doesnt.

In my case, I bought a brand-new, in-warranty DAC3 for $1500, which perfectly matches my Bel Canto amplifier, so the choice wasn't hard. Sound quality wise, either will do just fine for most people, including me.

Originally Posted by dmk005

Did you get a chance to compare a 24/96 source with the DAC1 over USB with the DAC3 over USB? I obviously ask because the DAC3 does not support 24/96 over USB but they still claim their implementation sounds just as good or better than the DAC1 24/96 over USB. If you use a PC as a source, USB is a must and I wonder what your tests may have turned up.

Originally Posted by puntloos

One more quick question for Elias (but others are welcome too ):

- Given a pristine (or at least not badly damaged) CD, would you prefer a 'high end CD transport' with SPDIF out, or a 'standard' computer (PC + normal CDRom player with proper ripping software and SPDIF out), or no preference at all?

Small elaboration:
Many audiophiles seem to think that some hugely expensive CD transport can more accurately read CDs than a normal PC CDrom player can, even though the PC uses all ripping techniques like C1/C2 correction, accuraterip etc etc. Any truth in this?

Mind you when a CD is (badly?) damaged I'm at least a bit more open to believe that a top class CD player might be able to approximate the original data better than a CDRom player. Still, the CDRom player isn't in a hurry and could take as many tries as it wants to read the real data..

Thoughts?

Originally Posted by EliasGwinn

Puntloos,

This is a very good question...and, unfortunately, I don't have an answer for you. We've been asked this question many times, but there are so many factors which would make it incredibly difficult to test. Specifically, it would be difficult to say that one type is better because every drive uses different lasers/readers/decoders/drivers... In other words, its completely possible that CD player 'X' is better then CD-ROM 'Y', and CD-ROM 'Y' is better then CD player 'Z'....even if 'Z' is $10,000!! (Please don't ask me what CD player 'X' is... )

Originally Posted by puntloos

Hmm, nope, both DACs claim that the source is really irrelevant (be it USB/SPDIF/TOSLINK, all simply get 'dejittered' and the perfect input signal gets fed to the DA section) so comparing 24/96 and 24/48 (I think thats the current max of the DAC3 on USB) is a bit unfair.. I don't have a long USB cable anyway. But why do you say that using the PC as a source, USB is a must? My M-Audio card nicely supplies 192/24 from its SPDIF, which I've tested with some DVD-audio tracks at that rate.

btw Bel Canto is planning to release an update to their USB in Q3/Q4 2007 which should get them in line with the DAC1. But again, USB really Isn't my cup of tea.

Originally Posted by dmk005

Actually, I would argue it is not unfair. Bel Canto told me they think their 24/48 over USB sounds better or at least as good compared to what they have heard from any current DAC who claims to support 24/96 over USB. The only one I know of is the DAC1.

Originally Posted by puntloos

(and as most people here agree, which connection type, USB, SPDIF/etc, don't matter).

Originally Posted by EliasGwinn

This is true to an extent. But, to avoid confusion, it should be pointed out that there are major differences in the USB capabilities between the Benchmark DAC1 and the Bel Canto DAC3. Specifically, the Bel Canto is only capable of up to 48/16...it cannot stream 24-bit audio via USB. This means that any 24-bit source or any 16-bit source that was increased to 24-bit will be truncated.

The DAC1 can stream 96/24 'bit-transparently'. Even the M-Audio PCI cards are not capable of bit-transparency. The DAC1 is the only device (including PCI, USB, etc) we have found to be proven 'bit-transparent' when streaming digital audio from a computer at resolutions up to 96/24.

Thanks,
Elias

Originally Posted by integrale

So a simple question: is everything the same on the DAC1 as it is on the DAC1 USB? Have there been any changes to the DAC1 in the last few years, or would even a used unit provide the same performance?

Originally Posted by Rivendell61

integrale, see this post:
http://www.head-fi.org/forums/showpo...&postcount=216

Mark