Eversolo DMP A6 with or without preamp

Direct feed into the amp sounds more clear and transparent.

Shocker.  That’s exactly why I recommended trying some more neutral/transparent tubes.  You can play with wires and tubes if you want, but it sure sounds like too much thick Mac syrup in your system and the A6 is giving you a needed dose of transparency and fresh air when combined with your amp.  If you can, try something like an ARC, Linear Tube Audio, or Backert tube preamp in your system and you may be very positively surprised as they’ll all offer much more than the A6 could ever hope to as a preamp — as they well should.  I think the A6 gave you a small glimpse into the improvements you could have in store, and I’d recommend pursuing that further as there’s clearly (pun intended) something there. 

Thanks for all the great advice. 

I'm going to order some Telefunken tubes for the C2300 (highly recommended on the forums and why not) but also give the preamp more time for my ears to adjust. Never know how it's going to end up but should be a lot of fun with lots of different variations.

Trade in the C2300 for a digital preamp.  I have the MDA200,  it has the preamp section from the C53, and it sounds wonderful straight into my 7270.

I prefer a dac/preamp combo with separate streamer, as compared to streamer/dac with separate preamp. 

You can get the MDA200 for about the same price you can sell the C2300 for, and it has the latest D2 dac.

eyelai777, your experience makes sense.  If a source such as your Eversolo streamer has a variable output with sufficient voltage and current, then you can drive an amplifier directly.  This eliminates interconnects, contacts, potentiometers, capacitors, gain stages (tube or SS), and power supplies that can only get in the way.

Of course, we audiophiles often have multiple sources (e.g. discs, phono, tape, radio) so a pre-amp is a convenient way to select, buffer impedances, and control gain/attenuation. 

Your Mac pre-amp should be close to transparent. I recommend setting the Eversolo output for bypass and re-evaluating.  It's possible that "analog volume setting to max" in variable mode may not be the most linear or noise free condition.

If the sound is still "veiled" then you could experiment with premium tubes as suggested by another post or explore other solutions if you choose.

I have not used the eversolo before. I would say that it depends on the output section of the Dac. I used to use a dCS Bartok straight into an amp and it was good. I have since moved to MSB w currently with the premier Dac and s202 amp. There is synergy there as they are designed to work together. MSB dacs are also designed so there is enough output coming from their ladders. This eliminates the need to boost the signal at the output stage. The implementation of the volume control is really important too.