This is a review and detailed measurements of Benchmark DAC3 and headphone amplifier. The unit is on kind loan from member Dallasjustice and is highly anticipated evaluation by myself and I am sure many of you. As of this writing the DAC3 retails for USD $2195 from Benchmark site. Others discount it to $2,000 plus shipping. So not cheap by budget standards. But a huge bargain compared to high-end DAC which start at $10K and go up.
For way of comparison, I am also measuring the RME ADI-2 Pro using my Audio Precision APx555 analyzer. As you see below, the two units are pretty much the same width and height.
View attachment 13318
Depth-wise though, the Benchmark is almost twice as deep. Still, both comfortably fit on the desk.
From user interface point of view, the DAC3 has clear LEDs which i like but it still doesn't hold a candle to RME's nice displays with full spectrum view and such as you see in the picture. This is very helpful in measurement because it is a nice confirmation of what is being sent to it.
All the settings in RME ADI-2 Pro (and by association in RME ADI-2 DAC) are "soft" in that you can change them in menus. The Benchmark has far fewer settings and what it has requires opening the case and moving jumpers. While that is a more purist implementation, clearly not as user friendly. What is NOT user friendly is the interface in RME. In both ADC+DAC combo that I am testing here and its DAC-only version, they are maddening to navigate. If you tolerate it, you have many cool options including parametric (?) equalization.
I tested the RME ADI-2 Pro using its ASIO drivers. For benchmark I used ASIO4ALL after it plugged and played in Windows as a normal sound card.
The volume control on DAC3 changes the output balanced connections (in addition to headphones I assume). On the RME by default, it only changes the headphone output. I am sure there is a way to change that in the menus but I am not brave enough to figure it out.
The DAC3 volume acted interesting in that small changes would make no difference and then all of a sudden the value would change. Not sure what explains this. Analog pot driving a digital attenuation? It has a max and min so it is not a rotary encoder.
Testing these two devices is quite daunting given no less than three outputs: unbalanced, balanced and headphone. For this review, based on interest of its owner, I am only focusing on balanced output performance. I aim to at least cover the headphone performance before having to return the unit in the next day or two.
EDIT: A second loaned unit from Benchmark performed even better. Please see: https://www.audiosciencereview.com/...easurements-of-benchmark-dac3.3545/post-91447
Measurements
Please note that all measurements are made with USB input of the DACs. Two posts down there is a comparison of Toslink to USB.
I always like to match levels of DACs where possible to make a fair comparison. Alas, even though Benchmark documents that the unit by default outputs 24 dBu (12 volts RMS), it puts out copious more output than that. I had to use a "pad jumper" inside the unit to dial in -10 dB of attenuation to match that of RME ADI-2 which indeed maxes out at 24 dBu. In this dashboard view of DAC3, I have one channel with default output and the other with -10 dB:
View attachment 13319
As you see, the non-attenuated channel outputs nearly 20 volts RMS, corresponding to whopping +-28 volts or peak to peek!
With that kind of output swing if you are bored, you can hook up the DAC3 to drive your Christmas tree lights!
Dallasjustice uses the much higher output to good results in room equalization. The most effective way to deal with troughs in room response is to simply bring down the levels of all the other frequencies. This gives you a flat response but now you have much less gain to drive your speakers. Having so much headroom and output capacity in the DAC3 helps mitigate this.
For the rest of these tests, I ran with the attenuation at -10 dB to match the RME as mentioned. Note that performance without this attenuation is different (sometimes better, sometimes worse). Such is life when we try to make apples vs apples comparison.
Let's see how the two do in jitter and noise department:
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Starting with RME ADI-2 Pro, we see the same problem with random low frequency noise around our main tone at 12 kHz, resulting in that "skirt" around it. RME has since upgraded the clock both the Pro and DAC version so that problem is no longer there. I confirmed that in the DAC review but not in the Pro as I don't have that version as you see in that
review:
So that part is a "non-problem." The RME has slightly higher noise floor still. But the DAC3 has those two odd peaks. They are not symmetrical in level so likely not jitter. They are proportional to the position of the volume knob so the problem is prior to that stage. This is unexpected in this class product and from a company like Benchmark.
The news becomes quite positive for Benchmark DAC3 as we proceed with other tests such as intermodulation (SMPTE) relative to level:
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The DAC3 has a clear advantage of about 6 dB lower distortion+noise. It starts to clip sooner than RME but still at vanishingly small level of -110 dB.
THD+N measurements relative to frequency show similar advantage for DAC3:
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Looking at the spectrum of that at 1 kHz, we get this:
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Applying perceptual modeling to this is hard visually. They both have the same second harmonic distortion but from there on, one gets ahead and then the other. Over time I hope to create a mathematical model for this to generate better figure than THD+N which summs the power of all of those.
Slightly higher noise level is apparent here as with our jitter and noise analysis.
Switching to our favorite test, Linearity, we get this:
View attachment 13322
The DAC3 produces output essentially the same as the analyzer itself. I have put in the "19 bit" marker for historical reason (0.1 dB of variation) but really, this is as good as we can measure. The RME ADI-2 Pro lags a bit here but we know that the DAC version is superior, producing similar output to DAC3. Again from my previous review:
As a side-note, see how the measurements of the RME ADI-2 is very similar using my old analyzer (AP 2522) versus new (APx555). On APx555 I have increased the resolution some so that we can see finer variations but if I use the coarser ones used in the 2522 the results match very closely. So some progress in finalizing my APx555 settings to make them comparable to the older analyzer both as a sanity check and ease of comparison. Similar progress was made in IMD measurements I post above.
I think I will stop here as to not overwhelm you with too much data. As mentioned, there will be more to come.
For now, if you have any questions and concerns please raise them quickly as I will be returning DAC3 soon.
EDIT: headphone power and output impedance measures in this post and the one after it:
https://www.audiosciencereview.com/...easurements-of-benchmark-dac3.3545/post-86011
Conclusions
The Benchmark DAC3 as expected is a state-of-the-art digital to analog converter. Other than one set of noise spikes in jitter test, the rest of the measurements show exceptional performance. No glaring faults are seen at all. Its higher output level can be useful in room EQ applications to boot.
So of course the DAC3 goes on my
recommended list.
Considering the price though, the RME ADI-2 DAC retails at less than half the DAC3 price. While the DAC3 probably beats it a bit in objective measurements, I can't really justify the additional cost of it over that unit. So if money is no object and you have no use for the additional features of ADI-2 DAC, by all means get the DAC3. Otherwise, the RME ADI-2 DAC remains my pick for "expensive" DACs.
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As always, questions, comments, recommendations, etc. are welcome.
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https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (
https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
