Monoprice desktop and Drop 789 have nearly identical low noise floor. In gain 3 position, both units have higher noise floor due to gain * (amp preamp noise) + gain * (upstream DAC noise). To lower the noise floor, use the lowest gain knob setting that still achieves the SPL you need at...

789 has same # opamps in the signal path for XLR-in vs RCA-in.

Hi! DAC3 B is a great pairing with AAA and we use the two together to demonstrate AAA on the road. 789 XLR inputs can tolerate: up to +19dBu input (XLR or RCA) in Gain 1/2 up to +8 dBu input (XLR or RCA) in Gain 1/2/3. When paired with DAC3 I recommend: a) set DAC3 XLR Output Pad Jumpers to...

All good! Balanced signalling is great for audio but the reason why is misunderstood. Balanced signaling is just a subset of the important thing: differential signalling. Differential signalling reduces noise and hum pickup by keeping signal lines clean and separate from dirty shields and ground...

Opamps contain dozens to hundreds of devices, all precisely matched and temperature compensated. You usually can't replicate that in discrete without a ton of work.

No, we don't just use half the input signal. We use it all, through an instrumentation opamp differential input stage. Both 789 input types are extremely high quality with impeccable measurements. For most setups, indistinguishable. Choose the DAC you like best, and if you must use RCA use...

You can achieve max output on all HP outputs with 2V unbal or 2V bal. Gain is same.

Hi, Unfortunately you can't take XLR bal out from DAC and reduce to RCA because it will short one of your DAC bal outputs. Just use XLR DAC out to AMP XLR in. For a given headphone jack e.g. 1/4", the 789 gain is same whether using RCA or XLR input. It has a diff input stage.

Cable shields have non-zero impedance that conducts CM noise currents. So you want cables with separate copper for shield and for signal ground, ideally along the entire length.

Yes that cable will work well. Very nice.

Yes these graphs were taken with 32 Ohm linear resistor. You're correct - headphone impedances often vary with frequency. This is why amp output impedance (Zout) matters. It's important to have low amplifier Zout < 0.1 Ohms like the 789. Other amplifiers with higher Zout will cause gain...

789 frequency response is completely neutral (transparent) and output impedance is extremely low. Attached are 789 freq response plots for 32 Ohms, single-ended output. Note how dead-flat the curves are across the entire audio band including the mids region. It's more likely that HP Freq...

Yes this is proper wiring. CM currents are often current sources and will flow on the lowest impedance path. In this case we want them to flow from RCA sleeve to pin 1, leaving wires 2,3 unadulterated. If you float wire 1, then the CM currents will try to push through wire 2/3 in parallel and...

I'd be concerned. 3m RCA is pretty long and can pickup RF fields. Instead consider two of these from amazon.com. Any CM current from RF pick up will be restricted to the shield, and the inner signal pair will remain clean: Monoprice 10ft Premier Series XLR Male to RCA Male Cable, 16AWG (Gold...

Hi. - Yes AC mains-connection transformers, whether 50/60 Hz linear toroid or SMPS, are often the source of this common mode noise injection. Battery-powering everything upstream (e.g. source + DAC) is a great way to prevent that CM injection. - Keep Source-DAC and DAC-amp cabling short to...