DAC-Preamp having these specifications?

@celander

Yes they have addressed fully the common PLL issue of slave hunting master. In some cases the way that a slave adjusts to a master can actually produce worse jitter - they have fully addressed this. They reduced the clock cycle adjustment rate to below 1Hz which should be completely inaudible (this is the maximum frequency tone you could hear if the slave was in continual adjustment to try to match the master - of course 1 Hz isn’t audible). Mathematically their technique is both solid technically and elegantly simple and runs at 250 GHz with clock adjustments of 4 picosecond.

@celander

The DAC 3 is more advanced than the HDR-VC of the DAC 1. The DAC 3 has 32 bit DSP volume control also in addition to passive attenuators and active analog gain circuit. So for best results you should feed the DAC 3 the full bit perfect signal (no software volume control). The rule of thumb is keep volume as high (without clipping) as you can to maintain headroom and highest SNR. 

@celander



Make sure you use RCA outputs if you are concerned about noise, Benchmark has pro-grade RCA - it runs at about 18Volts. This is a lot stronger than regular consumer RCA (2 volts) and confers a huge advantage. The SNR advantage is about 13dB.

Benchmark wrote an article about volume control in their older DAC 1. It is dated but the concepts are valid.

https://benchmarkmedia.com/blogs/application_notes/13095789-volume-control-technologies


The Benchmark DAC 3 combines active analog gain control, passive low-impedance attenuators, a 32-bit digital gain control, and a servo-driven volume control. It basically uses a combination of Steve’s methods in order to minimize deliterious affects of excessive volume attenuation from one approach.

It is important to keep headroom so running signals as high as possible through an audio device and chain helps achieve the lowest noise. Running high signal levels is the way to do it and as Steve explained any attenuation through DSP, resistors or otherwise is going to reduce performance. A precision resistor pad on the output is an excellent way to allow a device to run at the highest signal levels possible and maintain good SNR while still attenuating the signal enough not to overload the next stage.

If you are really serious about noise then you should purchase their HPA-4 and run the Benchmark DAC with no attenuation at reference level (close to full volume) and feed the XLR analog output to the HPA-4 (for volume control prior to power amp). Personally I think this is overkill as the DAC 3 has one of the better volume control systems currently available on most DACs.


https://benchmarkmedia.com/blogs/application_notes/benchmarks-256-step-relay-controlled-attenuator

The ESS 9038 is multi-channel for HT. Higher performance when you average 4 channels per side to get stereo. I think there are some products that use it for stereo. The implementation is just as important as the chip.

@celander
https://www.stereophile.com/content/benchmark-dac3-hgc-da-preamplifier-headphone-amplifier-measurements

Check our the measurements of the Benchmark DAC 3.



If there is any internal jitter it has not shown up in any of the measurements - so likely very small.

The J-Test is perfect. Discrete components aren’t necessarily better - usually you can achieve a lower noise floor but at -160 dbfs the noise floor is pretty low on the DAC 3...