Solid State Amps for Quad ESL 57?

Kalali         1/8/2017

+1

Nice thread !

 The loudspeaker/Amplifier partnership should be viewed as a matched pair.

When building a system one should first choose a loudspeaker, then find an amplifier (within budget) that is up the task. 

I made the mistake of purchasing a Quad 57, and was unable to find an amplifier that could do justice to it. I had to build a suitable amplifier. At that time ( A very long time ago ) the only serious amplifiers I was aware of were the Mark Levinson ML_2 and the Bedini. The ML_2 was the inspiration for my amp.

ML_2            Mono - Pair            25, 50,100 watts into 8, 4, and 2 ohms
My Amp        Mono - Pair           50,100, 200 watts in 8, 4, and 2 ohms
We never tested the amp at one ohm, but it was designed to be stable into one ohm. Eight 150 Watt Motorola bipolar output transistors per channel.

ct0517                            1-09-2017

I am not sure that ohms law is the correct tool to unravel the mystery of the Quad 57 which present a capacitive load. My own experience is that very little power is required to reach acceptable music levels in a small/medium sized room. A friend of mine drove his quads with a 12 watt per channel solid state amp at bass levels which surprised me. 

Roger Modjeski  had the same experience: "The RM-10 came into being in early 1990, when I noticed I rarely played music above a few watts on my Vandersteen 2C speakers. Later, I acquired a pair of the old QUAD electrostatics and achieved the same listening levels at even lower power."


 

ct0517                     01-09-2017

  " btw - do your amps have a brand name ?"

" No. The amp I refer to as "my amp" was a joint project with four other friends. Five amps were built, each one slightly different. Four stereo versions, each with separate power supplies, while mine was built as mono-blocks. " 
Four of the amps were used to drive Quads, and one was used to drive a pair of Apogees. Three were built to produce 40 watts per channel, which was thought to be safer for the Quads. My friend with the Apogees actually used 16 output transistors per channel. This lead to heated arguments between us.

I am no longer in possession of the amp.

.

Amendment to my post above. One PAIR of Decca Ribbon tweeters.

glennewdick                     1-09-2017

I have heard stacked Quads. AWESOME  It was at " Sound Components "  a high quality dealership in Miami. They had in the their showroom a system referred to as the " HQD" system. Stacked Quads, one Decca Ribbon tweeter and a 24" Harley sub-woofer housed in what looked like a coffin.
But this is the first time I have heard of stacking 3 pairs of Quads.

The funny thing is that when I had my Quads I was never aware, while listening to music, of any deficiency in the bass or treble. It was only when my brain kept telling me the bass did not go low enough and that the high frequencies were rolled off.

bdp24                                   01/10/2017
 
" One great way to add bass to the 57 is with a pair of Magneplanar
Tympani bass panels. "

Agreed. It might even be the best way, provided the quads are allowed to run full range.

ct0517                    1-11-17

" When discussing the Speakers with the Amp manufacturer, and he/she can’t answer directly with facts, and says.

"Oh, don’t worry your speakers won’t hurt our AMP"

Then it’s not the right amplification for these Quads "

Soon after I purchased my first pair of quads I asked a Technician who was building amps on his dining table whether his amp would damage my Quads and he replied. " No, my amps are kind to loudspeakers." I was so impressed with his reply that we became good friends but I never tried his amp on my Quads.