Pass Labs “House Sound” vs. McIntosh “House Sound”

I’m going RCA/sub preout from the DEQX into the REL.

OK. So presumably you are using the volume control of the DEQX to change volume, rather than the one in the preamp.

Assuming that is the case I would reiterate my suggestion of trying an unbalanced connection of the DEQX directly to the power amps. Given the experience I mentioned earlier that was reported to me by another member (who also used a Premate), it seems very conceivable that you might obtain better results that way than with the balanced interconnection I assume you tried previously. And if so, perhaps you can eliminate both the DAC and the preamp altogether.

BTW, I use the unbalanced analog outputs of my HDP-5 directly into my power amp. I’ve never tried its balanced analog outputs, as neither of the power amps I presently have provide balanced inputs.

Best regards,
-- Al

@almarg I do use the DEQX volume control for the sub.  I put in a set of RCA's, but just get AC hum.  I unplugged the unit, let it sit for about 10 minutes, then plugged back in and turned on...same result.  Read through the manual, I didn't see anything that indicated one needed to select an output, other than the analog, analog/digital pulldown.  Switched between those, same result.  Possibly, the analog jumpers are set to high?

Not sure what might be causing that.

If the analog jumpers are set for too high an output the symptom would be distortion, not hum, and only when the combination of the volume of the music and the setting of the DEQX’s volume control is too high.

I assume that you don’t have the analog main outputs of the DEQX disabled in the configuration, and that you disconnected the XLR cables from the amps when you connected the RCA cables.

Beyond that, I see the following statement on page 160 of the latest version of the DEQX manual, regarding the 75 ohm specification of the output impedance of the unbalanced analog outputs:

[The unbalanced analog output impedance is 75 ohms] into an earth-referenced amplifier i.e. one where the RCA ground pin connects to mains ground. This is normally the case. The precise output impedance is 75 ohms, plus 75 ohms in parallel with whatever the amplifier puts in series between its RCA connector and mains ground. If the latter is open, then the impedance can be as high as 150 ohms (such as may happen with a two-pin power connector).

I’m not quite sure what to make of that, but perhaps there is some kind of incompatibility between the internal grounding schemes of the DEQX and the amps. Which in turn may only manifest itself when unbalanced interconnections are used between the two components, since balanced receiver circuits can be designed (and ideally should be designed) to ignore ground.

That’s about all I can think of at this point.

Best regards,
-- Al

I own a Pass Labs X 250 for LR Focal floorstanding speakers a X260.5 for my center channel and large Focal Rear speakers that I Run with my X5. I know that your are asking about A Pass Labs XP 20 however In my opinion McIntosh does not come close to the build quality and sound reproduction of almost anything Pass Labs makes. Pass Labs CS is the best they STAND behind what they sell 
My AV is a Krell 707

I've never heard a Pass Labs but I might comment on McIntosh.  McIntosh's 'house-sound' might best be described as exceptionally smooth with a wide soundstage yet not too forward.   McIntosh has excellent build quality, resale value and often understated fact that all of their component visually match in terms of color scheme.  Nothing like having a full rack of matching gear.  Personally I don't care about those features and I've found other gear that sounds better to my personal tastes.  McIntosh is like the Apple of audiophile gear, well built and respected but not doing anything extraordinary.   An excellent well-rounded setup could include a Pass Labs X25, Schiit Yaggi DAC, and your choice of tube preamp (my preference would be Prima Luna premium or Conrad Johnson classic depending on budget).