Preamp dillema for McCormack Ultra Platinum

Well, there's a Hegel P20 and a Pass X2.5 available here now in your price range that I'd think would both be a nice improvement in refinement over your Ref50 (and at least get rid of the unnecessary ADA processing -- EEK!).  For a little more and moving to tubes there's an Audio Research LS17, or for again a little more there's a VAC Standard LE that could be a really nice sonic match for what you're looking for.  Obviously check that these work with your DNA1 -- I'd look for a bit under 10kOhms output impedance just to be safe.

Just FYI and FWIW, I'm looking at a Sachs SP14 (about $2k stock) or a Backert Rhumba 1.2 (one here now for $2400 I wish I could buy -- dammit).  Looking forward to what a little tube magic can do in front of my SMc amp.  Anyway, hope this helps and best of luck. 

Thanks for that, I will look into them. I would like to think my VTL 2.5 would work the way I want but this one has 20db of fixed gain.

The Hegel P20 does look nice, I do like the remote... :) 

I have several of Steve's upgraded amps.  In fact, I just got back a modded DNA125 with some new stuff he hasn't done before.  It's phenomenal.  I also have legacy DNA.5 Platinum stereo amps and a single monoblock that I use for center channel.  I also had the TLC1 and RLD1 in the past in my system.

First of all, you have a great amp that will mate well with virtually any preamp.  The only exception is if you got yours modded to have balanced XLR inputs with Lundahls xformers.  This might make it slightly less friendly to certain preamps with high impedances.  There aren't many like that, but it's something to note.

The gain on Steve's amps is fairly high, so you can get away with a passive preamp...especially if you are using low capacitance interconnects and short runs.  The TLC1 is a good passive because it also has a buffered output in case you need to run long cables.

The RLD1 is also a nice piece for your budget, but my first question is why do you need a preamp?  Do you need multiple input selectors and/or a phono stage?  Many DACs now include a preamp/volume control, so I ask that question because doubling up on a preamp from the DAC and then a separate preamp can cause issues.  You have a tight budget, so I'm trying to potentially save you some money by just buying a high quality DAC with volume control.

Alternatively, if you need multiple input selectors and absolutely require a preamp, then I would look at a used CJ 17LS.  They are tough to find and probably a bit more than your budget, but it is a great preamp that I used to own. 

ARC makes great preamps too.  In fact, I'm even selling a used ARC preamp right now (LS12) that is actually SS.  I used it with McCormacks prior to getting a DAC with volume control.  It's got less gain than your VTL and sounds great.  Balanced is a noticeable benefit, but if you didn't have your amp modded to included balanced inputs, then it might be overkill.

I'd be happy to cut a fellow McCormack guy a deal, but frankly, I think the used RLD1 deal on Audiogon right now for under $600 might be your best bang for the buck.  The good thing about the RLD1 is that Steve can mod that too, so it's future proof like your amp.  It's probably your safest move if you really need a preamp.