Benchmark DAC1 now available with USB

[lowmagnet]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif My big fat dilemma question for all you geniuses on this thread now is: can I run balanced HD 650s directly out of the DAC1 USB now in balanced mode, without purchasing a separate balanced amp?

I won't be able to answer that question for you, since I'll be using the standard front outputs. If someone local has a pair of senn balanced cables, I could try a direct output out the back of the DAC1 to test that at least. I'm not really convinced of running balanced for short runs, especially since balanced headphones don't ground.

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif Ooh, one more question... did we ever get an answer on whether the DAC1 USB will definitely be able to work with Vista as it does with XP?

Elias stated that they tested on this platform, yes.

 

[Davesrose]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif My big fat dilemma question for all you geniuses on this thread now is: can I run balanced HD 650s directly out of the DAC1 USB now in balanced mode, without purchasing a separate balanced amp? I can't afford both right now, but I really like the preserved upgrade path for the future if I can stick with just the DAC for now. What do you all think? And alternatively, if I can't drive a pair of balanced cans directly out of the DAC1 USB, will driving them unbalanced for the time being be as pleasing overall as the order I'm now thinking of canceling with HeadRoom? Many thanks for the advice!

Yes, you could run the HD650 balanced off of the DAC1's XLR output. The DAC1 has a switch in back for variable output: so the volume knob will raise and lower the outputs. I'm not sure how the HD650 sounds balanced out of a DAC1 though. I just used it single ended with its amp for a few weeks before my SP SLAM came. But HeadRoom now is selling some cheaper balanced cables, so it's easier to decide if you want to try and see.

 

[The Monkey]

I had planned to balance my HD 650 cable this weekend, but didn't get to it. Will do so soon, however, and will post impressions re the balanced out from the DAC1.

 

[schaqfu]

Quote:

Originally Posted by Davesrose /img/forum/go_quote.gif Yes, you could run the HD650 balanced off of the DAC1's XLR output. The DAC1 has a switch in back for variable output: so the volume knob will raise and lower the outputs. I'm not sure how the HD650 sounds balanced out of a DAC1 though. I just used it single ended with its amp for a few weeks before my SP SLAM came. But HeadRoom now is selling some cheaper balanced cables, so it's easier to decide if you want to try and see.

Wow, I thought people were saying you could run them right out of the rear XLRs but I couldn't believe my eyes! So that switch that toggles between "variable" and "calibrated" is simply a toggle of the volume knob to control the XLR balanced output? Is that designed with the idea of hooking headphones directly up to it, or is that more because some professional grade equipment have different standards for current connecting to balanced outputs and it's important to be able to shift between different boxes? Translation: is this a hack to be plugging balanced HD650s directly into the rear XLR outputs or is this actually something contemplated by design? If this delivers a true "balanced can" experience this is an unbelievable value compared to HeadRoom's already *very* reasonably priced Balanced Desktop with integrated DAC.

I'm dying to know if anyone has done this and can compare the experience. XLR balanced output direct to headphones from the DAC1 USB better or worse than traditional unbalanced front output from the DAC1 USB? Better or worse than first passing the balanced signal through a dedicated balanced amp like a HeadRoom Balanced Desktop?

Alert, Alert, Alert: VALUE OF THE CENTURY HERE if this works!!

 

[jpelg]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif I'm dying to know if anyone has done this and can compare the experience. XLR balanced output direct to headphones from the DAC1 USB better or worse than traditional unbalanced front output from the DAC1 USB? Better or worse than first passing the balanced signal through a dedicated balanced amp like a HeadRoom Balanced Desktop? Alert, Alert, Alert: VALUE OF THE CENTURY HERE if this works!!

Check out Ferbose's famous thread here for a lot more info.

Now as to whether you hear a significant difference, or if one exists you prefer it, is your call, and probably dependent on your headphone of choice. According to many here, Sennheisers seem to respond the greatest to balanced operation, but I'm not a proponent of either one (Senns or balanced setups).

I owned a Benchmark DAC1 from the first production run ("ages" ago in audio years), an Apogee Mini-DAC, and now a 2006 Benchmark. The older Benchmark's headphone-out worked very well with a pair of Audio-Technica W2002's, and perked up Sennheisers a bit. If Grado's were still my headphone of choice, I'd go with the Apogee and use the headphone-out, which is much warmer than its XLR-outs.

That said, I love my current setup (DVD-A -> '06 Benchmark DAC1 -> Ultrasone Proline 750's)

 

[EliasGwinn]

The balanced XLR outputs on the DAC1 will not drive any headphones well, as is true for most all line level drivers. Headphones need to be driven with a very low impedance source for decent THD+N performance. The output impedance of the DAC1 headphone amp is nearly zero (<0.01 ohms), vs. 60 ohms for the XLR balanced line outputs.

The DAC1's headphone amp will drive the Senn 650's with no problem at all. The 650's are 600 ohm headphones which are a breeze to drive compared to 60 or 30 ohm headphones. In fact, with the 650's, you can't turn the DAC1 volume pot up very much without the volume being too loud!!

Thats the reason the DAC1 USB has 10dB pads on the headphone outputs. This gives you the ability to really dig into the volume pot before it becomes too loud. The pads are also defeatable for lower impedance headphones.

Thanks,
Elias

 

[EliasGwinn]

EDIT: Please ignore...this was an accidentally repeated post (ie, same as previous post)

 

[laxx]

The HD650's are 300 ohm. =T

 

[EliasGwinn]

Quote:

Originally Posted by laxx /img/forum/go_quote.gif The HD650's are 300 ohm. =T

You are absolutely right. I stand corrected.

Nevertheless, the DAC1 USB can drive headphone loads as low as 30 ohms.

Thanks,
Elias

 

[milkpowder]

Just something I was wondering: Will the non-USB DAC1 get all the non-USB related tweaks that the DAC1 USB gets, if any? I'm seriously considering a DAC1, but probably won't be needing the USB function.

Thanks in advance.

 

[The Monkey]

Quote:

Originally Posted by milkpowder /img/forum/go_quote.gif Just something I was wondering: Will the non-USB DAC1 get all the non-USB related tweaks that the DAC1 USB gets, if any? I'm seriously considering a DAC1, but probably won't be needing the USB function. Thanks in advance.

x2, and in addition: if yes, will those of us with the DAC1 be able to send in for an upgrade?

 

[schaqfu]

Quote:

Originally Posted by EliasGwinn /img/forum/go_quote.gif The balanced XLR outputs on the DAC1 will not drive any headphones well, as is true with most all line level outputs. Headphones require a very low impedance source driving them for decent THD+N performance. The output impedance of the DAC1 headphone amp is nearly zero (<0.01 ohms), vs. 60 ohms for the XLR balanced outputs. The DAC1's headphone amp will drive the Senn 650's with no problem at all. The 650's are 600 ohm headphones which are a breeze to drive compared to 60 or 30 ohm headphones. In fact, with the 650's, you can't turn the DAC1 volume up very far without the volume being too loud!! Thats the reason the DAC1 USB has 10dB pads on the headphone outputs. This gives you the ability to really dig into the volume pot before it becomes too loud. The pads are also defeatable for lower impedance headphones. Thanks, Elias

Thank you, Elias. That hits right to the heart of my question. But my motivation in asking is different -- I wasn't interested in connecting the HD650s out of the XLR outputs because I was concerned about achieving sufficient output. I am totally sold that the DAC1 USB's very fine headphone amp is more than enough. I was interested in the XLR outputs because they are balanced, and some among the Head-Fi community, most notably HeadRoom Corp., have burned oodles of hours evangelizing the benefits of driving headphones in balanced fashion out of a balanced amp. (See HeadRoom's description of their new budget-ended balanced amp here: http://www.headphone.com/products/he...lanced-amp.php) I would be purchasing Sennheiser HD650s with a modified balanced output XLR cable, totally eliminating the 1/4 TRS connector.

The holy grail of bargain-finding I was hoping to pull off here was taking advantage of the DAC1 USB's powerful balanced analog output to completely skip the $1000+ separate balanced amplifier between the DAC1 USB and the balanced HD650s. This would be earth-shattering value as far as I'm concerned, since I had already decided to spend more on such an amp alone than on the DAC1 USB, as have many others.

Given that we can attenuate the output of the DAC1 USB's balanced XLR outputs to such a profoundly huge degree -- up to and including the -30Db jumper pads and the entire range of the volume potentiometer -- don't you think it's possible that the DAC1 USB could be used to deliver a quality balanced output signal directly to high impedance headphones like the 300ohm HD650s? Oh pretty please? If, like me, you believe the Sennheisers benefit from a balanced versus unbalanced signal, this would save me the extra cost of a dedicated balanced amp which, after all, would essentially be taking the DAC1 USB's balanced XLR output and, in all likelihood, adding even more power to it before sending it to the headphones.

Thanks so much for your thoughts on this. I honestly believe that if this is an even accidental benefit of your excellent engineering and marketing design, this would double your market among the headphone audiophile community in one fell swoop.

 

[schaqfu]

Yo ho, the innards start to bubble to the surface. It seems Benchmark's "Advanced USB" breakthrough was the work of a third party company called CEntrance.

http://appleproaudio.com/index.php?n...rticle&sid=732

Don't get me wrong: there is nothing wrong at all with hiring consultants and buying technology strategically and intelligently. I'd say Benchmark made a Class A business decision here. I'm glad they did.

 

[milkpowder]

Ah! Maybe that's why there's such a significant price premium

Then again, as long as the product lives up to its expectations, price is not really an obstacle.

 

[lowmagnet]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif Don't get me wrong: there is nothing wrong at all with hiring consultants and buying technology strategically and intelligently. I'd say Benchmark made a Class A business decision here. I'm glad they did.

CEntrance are also trying to wrap their collective brains around Firewire audio and make it a time-critical and viable platform for high-bandwidth audio. More power to 'em.