Looking for a good balanced preamp: Atma MP-3?

I'm seeking a balanced preamp to be used with hybrid monoblocks and a variety of different 2-way speakers. My preference would be tube -though I would consider a good ss -and my budget is below $5000 retail.

The amps that I have sound more forward than I expected so I would be looking for a preamp that is certainly not aggressive. However, I definitely don't want a euphonic tube preamp that is used as a tone control. I believe that I can ease down the treble of the amps by changing the driver tubes.

I've considered the Atma-sphere MP-3 and I would be interested to know if anyone has experience with it? I've heard mixed reviews but have not heard one. Another that I've considered is the Simaudio Moon P-5.

Thanks for
The BAT pre-amps are pretty dang good if you ask me.
Pass Labs X1 or Bryston BP26.
Forgot the Parasound JC-2.
Forgot to say that I use my BAT with hybrid monoblocks too. Which monos are you looking at?
Your impression of Atma-Sphere preamps is accurate: neutral, transparent, open & extended at the extremes, and great value if you need an integrated phono section. The tonality can be shifted with NOS 6SN7s. If you go for it, stretch for the V-Cap option.
You want a differentially balanced preamp to match the monoblocks. PS Audio GCP 200 and GCPS are giant killers with ultimate flexibility and full-function remote
Another option would be the Ayre K-1XE. This preamp is very well reviewed by the Audio magazines (both on-line as well as print). Used they go for under $5K, (and closer to $4K if you only want the line stage, although, the optional phono boards are well worth the price of admission). If you must buy new, (your post said the preamp should "retail" under $5K), the K-5xe is also very good, and would meet your budget constraints.

I use the K-1XE with my hybrid amps, the Lamm M2.1s. They work very well together, IMHO. (I believe I am done looking for amplification equipment for a very long time.)

Good Luck in your search!
I've had a few emails regarding this thread so I guess I need to chime in: the MP-3 is fully balanced-differential from phono input to main output. The output is patented, is direct-coupled and the preamp is zero feedback throughout. It employs a true bi-polar power supply, not unlike solid-state designs in that regard. Even the volume control is balanced, made out of a custom-built switch and made up with fixed resistors.

It was first introduced in 1997 and evolved out of the MP-1 which was the first fully-differential preamp made, so far as we know (fist introduced in 1989).
Don't know if this is late, but thought I would add: I have the sims p5 and am very happy, and the w5 too. Never any strain, neutral and just simply got everything going right, imaging air transparency.
Though now I am moving into tubes and going with the atma's- without ever hearing them but based on a-goner's comments and because as most everyone says tubes are the way to go, I just got the atma's m60 and will get their pre soon.
Will post some comments when things have settled.
You are going to love the Atmas with your Merlins - my favourite combination after trying many, many pre/amp combos with the Merlins - thought the CAT JL2 was excellent, thought considerablly more expensive.
Audio Horizons TP 2.1,peruse the AH thread on this forum for comments,reviews and dialogue.