Solid State Amps for Quad ESL 57?

An extremely educational thread, even for non-Quad ESL owners like me. So based on the facts presented earlier, it appears that the ESL speakers do not follow the same amplifier requirements when compared to  "dynamic" or cone design speakers. In other words, even though almost ALL speakers can have significant fluctuations in impedance over the frequency response curve, the demands on the partnering amplifiers are significantly different based on the speaker design. As another example, I've posted a picture of the impedance curve for my (ESL) speakers - Martin Logan Aerious i, and according to the preceeding discussion, my "voltage source" amplifier is not handling the the peaks - midbass and midrange, properly. So by extension, this begs the question that every ESL speaker manufacturer should either develop and sell a matching amplifier or almost all ESL speaker owners out there will not be able to take full potential of their investments. The latter would be a sad compromise.

http://www.stereophile.com/images/archivesart/MLAFIG1.jpg

Thanks Atmasphere points noted and helpful

IOW, its impedance curve is not an efficiency curve like it is with many box speakers!! I can’t emphasize that enough- ESLs are fundamentally different in this regard.

The only amps I know of that can produce anything like a constant power characteristic are all tube amps. However, if you **do** use solid state, its quite evident that loop feedback should not be used in the amp’s design.

What they **do** confirm is that Quads can play bass quite nicely if you have the right amp on them!

For the bass they play its very good. If the music one listens to is satisfied by this ....great.

However most I know have left the 57’s due to the bottom octave missing and lack of HF’s.

The lack of HF’s being from what I mentioned earlier.

But this thread is 8 years old :^)

Jan 2017 - For speakers which are not full range, implying bottom octave missing or bottom couple octaves much lower in db on full range music; subs today take care of it very nicely and integrate well. But they do need to be setup well.

Kalali
So by extension, this begs the question that every ESL speaker manufacturer should either develop and sell a matching amplifier or almost all ESL speaker owners out there will not be able to take full potential of their investments.

Kalali
Well Quad do and Acoustat used to as well.
IMO, anyone looking to buy really "any" expensive speaker should be calling the company direct and asking them what amps are in their test labs. Likewise if buying amps - find out what speakers they are using. I have been making these calls in past.

This may not answer the OP's question, but I decided to have my long neglected Quad ESLs ('57s) restored along with my long unused Quad II amps. This is not intended to be my "main" system, but one I can enjoy in the house as a vintage set up, appreciating that the 57s do certain things extremely well within their obvious limits. Back in the day, I was never very successful at mating the '57s with subwoofers, and though I know things have improved on the subwoofer front, I'm not sure I'm going to try--at least on certain types of material, the old Quad can be spooky real.  I guess that means I'm not playing Black Sabbath at full tilt, but life is full of compromises. :) 

One of the experiences that "hooked" me into high end audio was the day I walked into a stereo store in Sherman Oaks, Calif. and heard John Coltrane's tenor sax flowing out of a side room. I asked the guy at the counter who was playing the sax?  He laughed and said: "Oh that's just the FM jazz station playing though a pair of Quad 57's."  He took me into the room and sure enough, no live sax there. Just a pair of Quad's, and all Quad solid state electronics.  It was the Quad 33 amp, the Quad 33 preamp, the Quad FM-3. All miniature in stature but glorious in sound.   

If I had an extra room where I could fit a vintage system, I'd most likely go with the above. 

Frank

^^^ Here's an interesting review:

http://hometheaterreview.com/quad-33-preamp-and-303-amp-reviewed/