What is the best premp for Atma-Sphere MA-1 3.3 amp?

Thanks elrod. What amp/speaker are you using with MP-3?

thank you all for your comments. If MP-3 is 90% of MP-1, I doubt my ears can tell the difference. Then the question is, are you comparing version .3's? Or is there not that much difference between MK3 vs. MK3.3?

Bob

I agree with you about Ralph. He was so patient with me explaining his circuitry and philosophy. I have no doubt that their quality and service is as good as anyone.

@gdnrbob 
I am thinking about MP-3 3.3 VS M 1 3.3.

@vittles   

I am thinking about the same system: 745 driven by MA-1. 

1. What is your room size?  Is MA-1 powerful enough for you? Other than loudness, I don't know if MA-2 adds much in SQ?

2. Are you using MP-1 or MP-1 3.3?

sksos

Is it possible that your room was too big for SL 545?  What is your room size?

What did you use do drive SL 545? A-S MA-1?

So, do you think 545 was just too small for your room?  Not because of weak amp?

 @select-hifi    

A number of people indicated that A-S MA-1 goes well with 545s. Compared to Nords or other SS amps, you don't find MA-1s lacks the dynamic/punch sound of SS?

I know that Atma-sphere amps don't change power output according to speaker impedance. Are there any SS amps that have this type of response?  I couldn't find any.

@atmasphere 

Do you think MA-1 could have easily handled small SL speakers in the room size of @sksos ? MA-1 is 145W vs M-60 is only 60W.

m545

@sksos 

Are you using the Sanders amp with your 10e?  How does it compare with the other amps that you tried?

I don't listen at rock concert levels. Some people have recommended Pass X350.5 for SL because of its "tubey" sound despite being SS. But as Ralph at A-S stated, at bass frequency, impedance is 30 ohms and X350.5 is only putting out about 90 W. SS is fine with me, but it seems to me MA-1 will give more even SQ across the frequency range. Of course, X350.5 is giving out 350W at 8 ohms in the frequency range where most music lives and is therefore much more powerful than MA-1. Then the question is whether I need 350W in the flat portion of the impedance/frequency curve if I don't listen at rock concert levels and my room is medium size 400 sq ft. What do you all think?

@almarg 

Thank you for the thoughtful analysis. Reading your post, I felt like I was back in my Electrical Engineering class at MIT 40 years ago.

thanks gdnrbob

May be people with experiences in both tubes (especially Atma Sphere) and Pass Labs can chime in. In <40 HZ, A-S MA-1 is more powerful than Pass X350.5 (for Soundlab), but X350.5 is more powerful than MA-1 everywhere else. Did I get this calculation right?

Obviously MA-2 would be a great solution (220W), but it is mucho $$$$ especially if I don't listen at rock concert levels.

used. Looking for value.

@atmasphere 

Thank you for the explanation. If I understand you correctly, you are saying that even though Pass has more power at 1 kHZ than MA-1, it is the power requirement at bass that is more rate limiting because transients at bass frequencies makes up much of the amplifier's power demand. Did I get your concept right?