2. amps-preamps
  3. 1166283308

Preamp Quandary - sonics vs. ergonomics??

I have been auditioning (buying and selling) preamps for over a year now. My only absolute criteria is that the preamp must be a fully balanced design that has low enough output impedance to effectively drive my McCormack DNA 500 amp (10K input impedance). However, since my system is in the living room, there are some ergonomic considerations including the potential for other users. After trying several, I currently have two pretty good but different preamps, an Atma-Sphere MP3 that is maxed out with teflon caps, regulated power upgrade, caddock resistor package, and user-applied 3M constrained layer damping sheets. It also has Jensen transformers for phono that I do not use. My other preamp is an Ayre K-5xe which is an outstanding ergonomic match with my CX-7e source. The comparisons are;

Ayre K-5xe - very user friendly, stays on all the time, uses the same remote as my CX-7e source, no heat issues, dead quiet, smooth sounding with tight punchy bass and adequate decay for a SS unit, no turn-on/off issues, heat, DC worries or other tube related concerns. In other words a competant performer which is the perfect operational match for my situation.

Atma-Sphere MP3; deep bass, dynamics that you can feel in your chest, well-extended for a tube unit and has that "rightness" only tubes seem to be able to provide, outstanding 3-dimensionality, and an outstanding midrange that puts the performers in the room with you. In short, this is the best sounding preamp I have heard in my system, but not the easiest to use.

Have any of you made a similar choice, and did you have any regrets?
mitch2
mitch2 OP
4,252 posts
 
More good responses, and a good discussion, thanks guys. Jmcgrogan2 - I must have been thinking of the Ref 2, you are right the Ref 3 is more expensive. Bob_Reynolds makes a good point, and that is exactly where I am at now, trying to decide if I am able to simply forget about it and enjoy the music. With either of the two preamps I have now, my system is perfectly matched impedance-wise, and sonically, but they just don't sound the same. I can't really lose, both sound great, I just like the sound of the A-S better. Actually Kurt's suggestion is my "plan B." If a K-1xe or K-1x had been available at a lower price, I would have tried one of those first instead of the K-5xe, but after reading all the rave reviews I thought that maybe the 5xe would have been close enough, and it may still be, but I will probably eventually try and hear the K-1xe or maybe the 1x to start then go for the upgrade. So, whichever of the two I now have that I decide to sell, I will probably stay on the lookout for a decent priced K-1x to try. These may start to become more available if Ayre releases a Ref series preamp as they say they plan to. In the meantime, I will have a hard time giving up the Atma-Sphere. The other thing I always consider is the company itself, and in my opinion SMc-McCormack, Ayre, and Ralph and crew at Atma-Sphere are all at the very top of service-oriented audio, you just cannot go wrong with any of those. Finally, Jaybo which McCormack pre do you suggest? The only one I would consider trying is the RLD-1 with full SMc upgrades, but it is not balanced. Steve has been promising a new preamp for about a year now, and I will be real curious to see what he comes up with.
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unsound
7,344 posts
 
Perhaps a Sonic Frontiers Line 3 will satisfy all your needs?
herman
2,282 posts
 
The input impedance of each channel is usually detetermined by a single resistor on the amp's input. If this is the case with your amp then any competent tech could change that resistor and raise the input impedance.

Why not check with the manufacturer? They choose such a low value to minimize noise that the amp can pick up through the inputs, but unless you live in an extremely electrically noisy enviroment (unlikely) then increasing it doesn't affect the performance.
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