[emmodad]

Quote:

Originally Posted by Dougr33 /img/forum/go_quote.gif Seriously, are you okay? You could have taken all this energy (and typing) and helped the next 20 people trying to find answers but lacking your search savvy. Wow.

just fine, thanks for asking.

somewhat dismayed with increasing number of folk who default to loading Elias' inbox without doing very simple homework. the product documentation is (one would think) an obvious starting point; and although i appreciate the compliment

, a google search on "benchmark DAC1 components" doesn't seem like rocket science.

Elias's involvement in this thread and his contribution to head-fi are not only unique and to be appreciated, but he's involved in several other boards too. Respectfully, just hoping that folk could keep same in mind, do basic research and not load him with stuff which has been asked & answered.

 

[EliasGwinn]

Quote:

Originally Posted by pbarach /img/forum/go_quote.gif So if I have a 24-bit audio file on my Windows XP PC, then this will be transmitted at 24 bits (and bit-perfectly) to the DAC1 via the USB input?

Exactly. That is the major difference between our USB interface and most other computer audio interfaces.

But this is not only important for 24-bit audio files, but for 16-bit audio files also. The reason is that audio software and other internal processes may result in 24-bit audio streams, even when playing 16-bit audio files. A simple example is when a digital volume control is used. When a process like this occurs, the operation usually results in 24-bit data because of the math (e.g., remainders). If the audio interface is not 24-bits and/or bit-transparent, the result can be a severely distorted version of the audio.

Quote:

Originally Posted by pbarach /img/forum/go_quote.gif An additional question: If I decide I don't need the USB input, and I decide instead to purchase the DAC1 model that comes without the USB input, are there any other differences in the circuit design or components of these two DAC1 models, other than not having that USB input in the less expensive model?

Yes, there are several feature differences and a very important difference in the circuit.

The new features include:
1) Auto-standby
2) An auto-mute function w/ headphone usage
3) multiple gain rages for the headphone amp
4) and, of coarse, the USB input

The new circuit change is the output drivers are built around the new National Semiconductor LM4562 opamps. These came out a few months before the DAC1 USB was developed, and we jumped at the opportunity to use them.

The LM4562's are exceptional drivers, capable of delivering high-currents and driving low-impedance or high-capacitance loads without distortion. They have since been implemented in high-end audiophile gear across the board, and are quickly becoming recognized as the best part for the job.

The DAC1 PRE uses the LM4562's all throughout the analog circuitry, whereas the DAC1 USB uses them in the output section only.

Thanks,
Elias

 

[MarkyMark]

Hi Elias,

I have the DAC1 classic (March '07 build) and have read that the HPA2 was designed to drive headphone of 60 ohm or higher (I understand this has been changed to 30 or higher for the USB model). What problems would arise from attempting to drive my Denon headphones, which are rated 25 ohms?

Also, a suggestion for improving the product would be the addition to the DAC1 to be able to indicate the bit depth and sample rate of the incoming digital feed.

Cheers

 

[EliasGwinn]

Quote:

Originally Posted by stvn758 /img/forum/go_quote.gif Kikatek.com | (F8V3152AEA) Belkin Toslink Splitter ODT F/ 2 x ODT F (Blister) How about this, looks perfect. No messing about, no power source - obviously don't play both CD players at once.

I'm not sure. There isn't much information about it. I don't know how it works, so I'm a little suspicious.

Thanks,
Elias

 

[EliasGwinn]

Quote:

Originally Posted by MarkyMark /img/forum/go_quote.gif I have the DAC1 classic (March '07 build) and have read that the HPA2 was designed to drive headphone of 60 ohm or higher (I understand this has been changed to 30 or higher for the USB model). What problems would arise from attempting to drive my Denon headphones, which are rated 25 ohms?

The HPA2 that is built into your DAC1 is the same as that built into the DAC1 USB (with the exception of the mutliple gain ranges, which is only available on the DAC1 USB, and more-so on the DAC1 PRE).

The only problems that arise from a low impedance headphone is usually ultra-high sensitivity and a reduction in damping factor.

The high sensitivity may simply make the headphones difficult to use because of the high output levels.

The low damping factor will cause more distortion (resonance) then would occur with higher impedance headphones. Fortunately, the HPA2 has an ouput impedance of 0.01 ohms, so it is probably the best suited for low impedance headphones.

When we quote a minimum impedance, we say that we only guarentee our performance specs to that minimum. It doesn't mean you the unit will actually be damaged by using low impedance cans (unless they're below 5-ohms!!).

Thanks,
Elias

 

[luciyuspax]

Which gain setting should be used for properly driving sennheiser hd600 to loud levels? I will be buying dac1 usb in a few months. Will I have to open dac1's case or will it sound perfect for hd600 right out of the box?

 

[feoteng2003]

Hello, EliasGwinn

I am currently using DAC-1 through XLR to my Dynaudio BM5A
Just wondering what would be the best set up for both?

Balanced Analog Outputs:10db or 20db?


-4db or 0db on BM5A?

 

[poo]

Quote:

Originally Posted by luciyuspax /img/forum/go_quote.gif Which gain setting should be used for properly driving sennheiser hd600 to loud levels? I will be buying dac1 usb in a few months. Will I have to open dac1's case or will it sound perfect for hd600 right out of the box?

That really depends on your ears... out of the box with my HD650s I rarely get past half way on the volume knob - which for me is really loud. Usually 'comfortable' listening for me is around 1/4 of the full volume I guess.

 

[EliasGwinn]

Quote:

Originally Posted by TreAdidas /img/forum/go_quote.gif You know it is funny you ask that because when I first saw it I thought wow that is good combo but I wished it were the inverse! A black faceplate with silver knobs would look soooo trick.

Interesting!!

 

[EliasGwinn]

Quote:

Originally Posted by luciyuspax /img/forum/go_quote.gif Which gain setting should be used for properly driving sennheiser hd600 to loud levels? I will be buying dac1 usb in a few months. Will I have to open dac1's case or will it sound perfect for hd600 right out of the box?

Hello Luciyuspax.

As Poo mentioned, it really depends on you listening preference. The DAC1 USB only has one alternate (10 dB lower) gain setting, and it is shipped in that setting. If I had to guess, I'd say that you'll be happy with that setting.

If you find you need more volume, you can change the jumpers to the higher gain setting.

If you find you want a lower gain range, you'll need the DAC1 PRE. It has a three gain ranges: original, 10 dB lower, and 20 dB lower.

Thanks,
Elias

 

[EliasGwinn]

Quote:

Originally Posted by feoteng2003 /img/forum/go_quote.gif Hello, EliasGwinn I am currently using DAC-1 through XLR to my Dynaudio BM5A Just wondering what would be the best set up for both? Balanced Analog Outputs:10db or 20db? -4db or 0db on BM5A?

Hello Feoteng.

The best gain setting for your BM 5A's is '-10'. This will maximize your signal to noise ratio.

After you've set that, follow this article's instructions to determine the best attenuation setting in the DAC1: Benchmark Media: Feedback Newsletter

Let me know if you have any questions about this...

Thanks,
Elias

 

[rmh1]

How about a Black on Black Pre, like all your other equiptment? I still think thats the best look.

 

[poo]

^ Nice avatar...

 

[EliasGwinn]

Quote:

Originally Posted by rmh1 /img/forum/go_quote.gif How about a Black on Black Pre, like all your other equiptment? I still think thats the best look.

We'll probably keep the black face/black knob option available indefinately. Aside from the asthetic quality, a low-profile face is essential in some setups.

Regarding other color schemes...

I enjoy hearing about everyone's opinions and suggestions for color schemes! They are all taken to heart, and we will keep them in mind for the future.

If we heard an OVERWHELMING number of responses for a specific variation, we would absolutely consider it. However, we are really excited about our new color scheme (silver faces with black knobs), and apparently a lot of end users are as well! So, we plan to ride it out for a while.

Thanks,
Elias

 

[rmh1]

@ Poo - See you in Brisbane Mate! For the Bledisloe Cup!

@ Elias - Didn't see the option of a Black FacePlate anywhere for the Pre. Is this an option?