Recommendation for a highly resolving amp


I have Don Sachs 2 tube preamp driving Pass Labs X350.5 driving Sound Lab M545 ESL speakers. I like the sound very much, but when I went to hear my friend’s Spectral system (driving Quad2912 ESL) I realized my system can benefit from having a higher resolution amp. Spectral amps need all Spectral preamp/cabling, which would be quite expensive. What would you recommend?
128x128chungjh
The Don Sachs preamp is probably not your issue. I have this preamp...it's incredible.

If you took your friend's system and dropped it in your room, it would probably not sound the same anyway.

If the room is wrong, you will get time smear among other things.

The sounds seems to be really good until you reduce some smear and then you think, 'how did I think that was sounding good at all?' 

You really won't know until it's reduced. I say reduced because I don't think you can realistically remove all of it...nor would you want to...everything would sound dead. 

I now have dedicated AC lines, 15k more in upgraded components and the room in my old home kills this system. I was using an old Carver amp (although I too was using a Don Sach Model  2 preamp).

Is your room a dedicated listening room or a living room situation? If it's a living room, then you need to be clever about the acoustics.








Some highly resolving amps I am personally very familiar with:
Benchmark AHB2
Bryston 28B cubed
First Watt SIT-3 and M-2
This one is super easy to figure out!
If you want to be 100% sure it’s the amp, connect your Lumin directly to the X250.5 using XLR or RCA interconnects and use Lumin volume control.
My money’s on the preamp as a culprit. 
Pass Labs amps and preamps are very transparent and resolving. I used to own Pass X250.5 and I am pretty sure the amplifier isn’t your issue.

Btw what cables are you using?
I am not sure what your budget so I can’t make a recommendation but I do not think you issue is the amplifier. Your pre-amp has a tubed output stage with 6SN7 tubes. What tubes do you have in there ? They can impact your sound significantly. You might try a Pass Labs pre-amp or other solid state linestage as well.