Benchmark DAC1 now available with USB

[Crowbar]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif I too have found that steel conductors, such as those used in the PC mount connectors are detrimental to the sound.

Could be because it's magnetic--that could introduce some hysteresis. The question is is it no less than -100 dB from signal to be audible, or is this more placebo.

 

[cansman]

Hi Elias,

I just bought the DAC1 USB. It has astonishing resolution and is dead quiet!

I have a few questions, please:

1. What is the recommended operating temperature range? My unit is running really warm ( I should say hot) in tropical weather 31 degrees C.

2. Related to the above, are any of the circuitry running in class A bias?

Thanks!
cansman

 

[twsmith]

Quote:

Originally Posted by cansman /img/forum/go_quote.gif What is the recommended operating temperature range? My unit is running really warm ( I should say hot) in tropical weather 31 degrees C.

I've also noticed my DAC1 runs somewhat warm almost all the time even in standby mode (no signal), although it seems to get much warmer when in active mode. I've always assumed this is normal but is this something I need to be concerned about?

 

[EliasGwinn]

Quote:

Originally Posted by cansman /img/forum/go_quote.gif Hi Elias, 1. What is the recommended operating temperature range? My unit is running really warm ( I should say hot) in tropical weather 31 degrees C. 2. Related to the above, are any of the circuitry running in class A bias? Thanks! cansman

The DAC1 operates near body temperature (~100 degree F).

The DAC1 uses a high-current, low-impedance design which optimizes audio performance and uses significant power. This is a design trade-off. When designing audio equipment, there exists a trade-off between audio performance and power consumption. The same things that make an audio circuit superior also induces power consumption - specifically, high voltage rails, high currents and low impedance. These are important for two main reasons: increased signal-to-noise performance and higher bandwidth.

The opamps in the DAC1 (NE5532 and, in the DAC1 USB, LM4562) are both internally class AB. The have near non-existent cross-over distortion (internally biased) and very linear slew-rates.

If your DAC1 seems to be warmer then 100 degrees F, make sure nothing is placed on top of the DAC1.

Thanks,
Elias

 

[twsmith]

Quote:

Originally Posted by EliasGwinn /img/forum/go_quote.gif If your DAC1 seems to be warmer then 100 degrees F, make sure nothing is placed on top of the DAC1.

Elias,

What about placing the DAC1-USB on top of another component? Space is at a premium in my set-up, so I've had to stack mine on an amp that also can get fairly warm. There is nothing on top of the DAC.

Thanks

 

[Herandu]

Quote:

Originally Posted by EliasGwinn /img/forum/go_quote.gif The DAC1 operates near body temperature (~100 degree F). The DAC1 uses a high-current, low-impedance design which optimizes audio performance and uses significant power. This is a design trade-off. When designing audio equipment, there exists a trade-off between audio performance and power consumption. The same things that make an audio circuit superior also induces power consumption - specifically, high voltage rails, high currents and low impedance. These are important for two main reasons: increased signal-to-noise performance and higher bandwidth. The opamps in the DAC1 (NE5532 and, in the DAC1 USB, LM4562) are both internally class AB. The have near non-existent cross-over distortion (internally biased) and very linear slew-rates. Thanks, Elias

Do these NE5532 need high current with a low impedance, or is that for the DAC chips?
Also, are you sure that when designing audio equipment there is a trade off between audio performance and power consumption? Care to point us to the source of this information?

I have nothing against the NE5532. Very good set of chips for about U$1.00 a piece down my end. But I use those in cheap to build circuits. Would the AN627 etc not be more the kind of stuff we should be expecting in a high-end DAC? Or is the quality of the sound not down to the cost of the components, but to the high current, low impedance power supply

 

[Herandu]

Quote:

Originally Posted by audioengr /img/forum/go_quote.gif I guess you dont understand volume manufacturing process. These connectors would have to be hand-wired and hand-soldered. I believe except for the transformer/AC inlet and the S/PDIF jack, everything in the DAC-1 is machine assembled. If it were possible to machine-assemble these and maintain quality, they would probably be machine assembled too. Once you start adding manual interventions like this, the price goes up dramatically. Steve N.

I don't believe that for one moment. It might be true in a Western factory and Japan, but not so in China, and less so in Taiwan and South Korea. I have seen the rows of people on the assembly lines assembling and soldering up together quite complex items that were not subject to additional labour cost. Factories I have toured are the likes of Jesmay, Tonic, Archief etc. All low cost solution providers that use a lot of hand labours in stead of just machinery.

 

[cansman]

Thanks Elias for all your feedback. I actually decided to buy the DAC1 USB after reading through this thread.

Cheers,
cansman

 

[EliasGwinn]

Quote:

Originally Posted by twsmith /img/forum/go_quote.gif Elias, What about placing the DAC1-USB on top of another component? Space is at a premium in my set-up, so I've had to stack mine on an amp that also can get fairly warm. There is nothing on top of the DAC. Thanks

This shouldn't be a problem. It will increase the temp of the DAC1, but it should not affect its performance at all.

Thanks,
Elias

 

[EliasGwinn]

Quote:

Originally Posted by Herandu /img/forum/go_quote.gif Do these NE5532 need high current with a low impedance, or is that for the DAC chips? Also, are you sure that when designing audio equipment there is a trade off between audio performance and power consumption? Care to point us to the source of this information? I have nothing against the NE5532. Very good set of chips for about U$1.00 a piece down my end. But I use those in cheap to build circuits. Would the AN627 etc not be more the kind of stuff we should be expecting in a high-end DAC? Or is the quality of the sound not down to the cost of the components, but to the high current, low impedance power supply

The 5532 doesn't need high-current...it provides high-current. The 4562 provides even more current....hence the 'High-Current Output Drivers' in the DAC1 USB.

The reason one would want a high-current chip is because a low output impedance requires a lot of current. The chip must provide high current-output before distortion. A low-impedance design is desirable because it offers significant improvements in bandwidth because the effect of the RC network will be minimized.

Also, we run these chips on 18V rails which provides an excellent signal-to-noise ratio. This consumes a lot of power as well. For these reasons, it is at the expense of power consumption that we achieve superior sonic performance.

Thanks,
Elias

 

[cansman]

Elias,

I have set iTunes volume to maximum. The Audio MIDI Default Output is set to Benchmark 1.0 @ 44.1kHz and 24-bits

I am probably just hearing things but I find that toggling the System Output between Benchmark 1.0 and Built-in Audio (Properties for Built-in Audio at various volume settings and mute) is varying very slightly the sound!

Shouldn't the choice of System Output (Benchmark 1.0 or Built-in Audio) not matter? I believe that the System Output is concerned with alert and interface sounds rather than the streaming audio output.

Would you be able to clarify? As I said again, I am probably hearing things in my head!

Thanks so much!

cansman

 

[EliasGwinn]

That's interesting... I'll have to look into that. I tried it for a moment and couldn't hear a difference, but I only listened very briefly. It could be that there is some mixing happening...similar to kmixer. And when the mixing happens, there may be some DSP (sample-rate conversion or something) that affects the quality. I'll try to find some time to put it on the bench and determine what is happening, if anything. For right now, I would suggest to leave 'System Output' to 'Built-in'.

Thanks,
Elias

 

[cansman]

Thanks Elias. For your info, it appears to my ears that the best setting for System Output is Benchmark 1.0. But at the same time, Properties for Built-in Audio be set to maximum volume, unmuted.

Cheers!
cansman

 

[cansman]

BTW, I'm using the USB input, if that matters.

Thanks!

 

[Wiza_Gab]

Can it be a good DAC for electronic music or rap ? (I listen to alot of different kind of music too)

And cansman, why do you have a DAC1 and some headamps, I tought it was a stand-alone DAC, it doesn't sound good without headamp ?