Connecting a DAC directly to an amp?

This is like groundhog day for me.  After going a week running my DAC directly into my amplifiers using relatively short 1M interconnect cables, I continued rearranging my system layout and reintroduced my buffer/preamp between the DAC and my amps and.....Shazam! Technicolor!  Better soundstage depth, better body, deeper tone, more impactful and deeper bass, and a more realistic and less electronic presentation.

It seems this happens every time I try to go without my preamp/buffer.  Maybe it is my SMc monos, which have input impedance of only 10K ohms, but it was also like this with my former Clayton amplifiers (but maybe not as profound an improvement), which had input impedance of 100K ohms.

The other thing I did was replace my well-regarded Oyaide power cords with 7 awg NOS Western Electric cords and wow, an immediately noticeable kick in the pants.  The amps are 650 wpc and are each run from their own 20A dedicated circuit.  Going from 10 awg to 7 awg made a substantial sonic improvement.  I don't typically notice huge improvements from cables and tweaks but this one was substantial.

It seems this happens every time I try to go without my preamp/buffer. Maybe it is my SMc monos, which have input impedance of only 10K ohms

Can't tar everything with the same brush, with this 10k input.

10k is a very low input impedance, there's no need for it these days, as things have problems diving it.
47k or higher is the industry standard, some tube amps like Rogue M120 mono were up to 1000k!!! (1mohm)

But if your source output stage is weak and maybe cap coupled (which could be too small with 10k) it's the problem, not because your going direct.

Cheers George 

With many of the newer high bit DACs (e.g. 32 bit) and depending on the input sensitivity of the amp (typically about 26 dB), and with about 12 dB attenuation per bit, even with the typical maximum 24 bits for most hi rez formats, one would most likely still have an abundance of bits available to negate the concern of bit stripping.

It’s not a 32bit ESS dac it’s a NOS R2R dac so yes even "bit stripping" could have been the biggest factor as well now you’ve bought it up, with 4v!!! output because of volume being set too low. His amps only need 1.2v for full output!!

From the manual total gain setting switches of the output V at full volume which he probably didn’t open it up to do .

Attenuation switches: Depending the input sensitivity of the used power amplifier the output of the Adagio can be reduced with -10dB.

Cheers George

My bad!. I was thinking in terms of the typical, not the OPs specifics.
Never mind🥺