Review and Measurements of Benchmark DAC1 USB DAC

[andreasmaaan]

Well to my ears. I've had a decent bit of listening to the 205. I thought it was not very good. (No DBT done, just listening).

What did you not like about it?

 

[Jimster480]

Well to my ears. I've had a decent bit of listening to the 205. I thought it was not very good. (No DBT done, just listening).

What were you listening to it with? With something that has output this clean I just don't see how its even close to possible for it to "sound awful". Unless you are using some bassy headphones or some high power requirement headphones and trying to drive it through the integrated amp?

 

[gvl]

remember folks, 99.9999987% gears that using ESS chips are enabling ASRC and the ASRC are not turn-0ff-able

Afaik you could jump through some hoops and avoid ASRC or something to that extent in earlier ESS chips, but mainstream products typically didn't do it as it was tricky and probably not blessed by ESS. ES9038PRO has proper support for external sync mode which effectively kills ASRC, several DACs expose this mode to the user, e.g. Matrix XSabre PRO.

 

[garbulky]

What did you not like about it?

People tend to act ornery when I describe what I heard so I'll refrain. Let's just say I'm not enamored with either the Oppo 105 or the 205.

 

[garbulky]

What were you listening to it with? With something that has output this clean I just don't see how its even close to possible for it to "sound awful". Unless you are using some bassy headphones or some high power requirement headphones and trying to drive it through the integrated amp?

Maybe awful is a strong word. But no I didn't like it. I listened to it using multiple amps and speakers.

 

[gvl]

Which begs a question, how can one not like perfection?

 

[DonH56]

One only has to look at the number of tube advocates to realize that accuracy often collides with preference in the listener's ears and mind. I loved my tube gear but never claimed it was more accurate (actually, the preamp was pretty darn good, but the power amp was not terribly accurate -- though it sounded nice).

 

[gvl]

I just couldn't find a "sarcasm" smiley

 

[amirm]

I just couldn't find a "sarcasm" smiley

I can add it if you point me to one.

 

[Blumlein 88]

I can add it if you point me to one.

https://emojipedia.org/upside-down-face/

 

[restorer-john]

I don't really see the sarcasm in that upside down smiley, but apparently it's the 'sarcasm emoticon'.

 

[Blumlein 88]

I don't really see the sarcasm in that upside down smiley, but apparently it's the 'sarcasm emoticon'.

My thoughts exactly. Don't know how this was the sort of official choice. I've seen blogs saying not to use it as it is no good. Rolleyes combined with a whistle seem more appropriate to me.

 

[Thomas savage]

We need a ‘ disappearing up your own arse ‘ emoji...

 

[Deleted member 2348]

Linearity test generated disappointing results however:

I still don't see why level linearity below -80dB should be important, but this might be interesting:

If you look at the measurements stereophile did on the DAC1 or at figure 19 in the AD1853 datasheet (the AD1853 is the DAC in the Benchmark DAC1) you will find exactly the same performance. This tells us two things:

(i) this linearity deviation is most likely not caused by tolerances in the DAC chip but by the delta sigma modulator.
(ii) your linearity test method seems to be working properly …

 

[Blumlein 88]

I still don't see why level linearity below -80dB should be important, but this might be interesting:

If you look at the measurements stereophile did on the DAC1 or at figure 19 in the AD1853 datasheet (the AD1853 is the DAC in the Benchmark DAC1) you will find exactly the same performance. This tells us two things:

(i) this linearity deviation is most likely not caused by tolerances in the DAC chip but by the delta sigma modulator.
(ii) your linearity test method seems to be working properly …

Hey, don't say this around Super Best Audio Friends. Just a friendly tip.

 

[έχω δίκιο]

Thanks for the review! There has been a Benchmark DAC 1 USB advertised on my local craigslist for $550. I thought seriously about it, but bought a used Emotiva Stealth DC-1 for $300. It connects directly to my power amp. My preamp's signal processing loop output feeds into the Stealth DC-1 analog input, giving me the analog source switching and phono preamp in the existing preamp with a remote volume control in the Emotiva Stealth DC-1 (that my preamp didn't have).

 

[The Mule]

I still don't see why level linearity below -80dB should be important, but this might be interesting:

If you look at the measurements stereophile did on the DAC1 or at figure 19 in the AD1853 datasheet (the AD1853 is the DAC in the Benchmark DAC1) you will find exactly the same performance. This tells us two things:

(i) this linearity deviation is most likely not caused by tolerances in the DAC chip but by the delta sigma modulator.
(ii) your linearity test method seems to be working properly …

Quick question, but I admittedly don't know a lot.

The problem with linearity is at really low input (output?) level? If you read through the Stereophile review, the original firmware had a problem with muting the output if the input level was too low. Could that be the cause?

 

[John_Siau]

What you say is true. Yet the DAC 3 was meant for pro use. A sensitivity of +4 dbu is 1.23 volts and assumes 20 db headroom or +24dbu max input into monitors you might be feeding. 24 dbu is about 12.3 volts. The DAC 1 was set to 2 volts, but could be calibrated to anything up to about 3.7 volts. While it too was meant for pro use it didn't put out as high a voltage. The DAC3 also can have internal jumpers set to 10 or 20 db pads which according to Benchmark preserves the full dynamic range. So it could be configured so that it still has an actual advantage with a lower realized noise floor vs the DAC1.

The DAC1, DAC2 and DAC3 all have internal pads on the XLR outputs that should be used to set the output levels to the range that is required by the downstream device. This will allow direct interfacing to virtually any pro or consumer product.

The maximum output from all three devices is approximately the same. It is about 27.5 dBu. The calibrated level is +24 dBu at 0 dBFS prior to the pads. Consumer-grade XLR inputs will require the use of the 10 dB pads. Some power amplifiers will require the use of the 20 dB pads. The Benchmark AHB2 power amplifier is designed to accept full studio-level balanced signals (in low gain mode) and the pads should be set to 0 dB.

Turning down the volume control is not a substitute for selecting the proper pad setting!

Excessive use of the volume control skews the measurements by adding excessive noise. This in turn impacts the linearity measurements, which at their low end are really SNR measurements. The tests should be run at or near maximum volume (or the calibrated switch on the back of the DAC1 should be enabled).

At the calibrated volume setting (and any pad position) the DAC1 will deliver a SNR of 114 dB unweighted and 116 dB A-weighted. (19.4 bits unweighted)

In contrast:

At the calibrated volume setting, the DAC2 will deliver a SNR of 123 dB unweighted and 126 dB A-weighted. (20.9 bits unweighted)

At the calibrated volume setting, the DAC3 will deliver a SNR of 126 dB unweighted and 128 dB A-weighted. (21.4 bits unweighted)

The DAC2 and DAC3 are 9 to 12 dB quieter than the DAC1. This increases the effective bit depth by up to 3 bits.

The DAC1 was introduced in 2002, but was definitely ahead of its time. In 17 years we have gained about 3 bits in effective performance. THD has also been reduced. But, the biggest sonic improvement may be the elimination of the clipping intersample peaks that exceed 0 dB FS. The DAC2 and DAC3 have 3 dB of headroom above 0 dB FS. See:

https://benchmarkmedia.com/blogs/application_notes/tagged/inter-sample-overs

for a series of papers on this topic.

There are still thousands of DAC1 converters in daily use in recording studios around the world. Many others have upgraded to the DAC2 or DAC3.

 

[John_Siau]

Quick question, but I admittedly don't know a lot.

The problem with linearity is at really low input (output?) level? If you read through the Stereophile review, the original firmware had a problem with muting the output if the input level was too low. Could that be the cause?

USB input only. This was intended to mute a USB initialization transient, which we later solved by other means. There was never a mute on the other inputs.

 

[John_Siau]

Yes, that’s (only) four years apart.

So it strikes me: If @amirm makes more «historical» analyses, we may conclude when the development in (digital) audio started to flat out (a bit). Dare we hypothesize that a lot happened between 2008 and 2012, but less thereafter?

The DAC1 was introduced in 2002.