Electrostatics and tubes

 The Link shows a variety of info relevant to the Quad ESL Development.

At the end in the Red Highlight, there is a reference to EAR having a Amp Design to be coupled as a Direct Drive. I have heard the Public Demo' of these in the 90's and from that day on, ended a search for a Speaker. The experience is one of the most indelible for being extremely impressive, I have had during my long term interest in using Audio Equipment 

I am a original 57 user and this evolved into using a Stacked Pair of rebuilt 57 models using One Thing Audio replacement Treble Panels.

I also as a result of the impression made by EAR, had Monoblocks Power Amps, Designed / Commission Built using 845 Tubes and Hand Wound Transformers to drive the 57's. 

I am also very Familiar with Quad ESL's owned by other, being 57's and stacked 57's,  the 63 model from different era periods of production, through to the 2912.

The 57's in a Good Condition !!, hold their own in all Quad ESL Company.

Early production 63, built as the first 200 Models has been used in demo's against 57's ,a later model  63 and 2912's, where the early production 63, has stood out as attractive in use as the 57 and 2912, this is a very difficult find, leaving the early and later Quad Models as the easier options to acquire.

Later model 63's in my experience of the ones demo'd, are enjoyable when encountered in use, but when used as part of a demo' comparison to earlier / later Quad ESL Models, the later model 63's I am familiar with are shown to be wanting more of an improved end sound to compete.

The 57's and 2912's are used in different systems regularly listened to. As systems, these have also been used to add other types of audio devices to for demo' purposes.

Whether the 57's and 2912's are being used with a different Source, Analogue Digital, Pre Amp Design as SS or Valve, Power Amp's as a SS or Valve. The 57's 2912's are always able to offer an impressive end sound, as well as easily be able to produce a sonic difference to help evaluate a change being made with a Systems devices.

https://www.quad-hifi.info/public/esl57%5B3015%5D.pdf

I have owned Quad ESL-63s electrostatic speakers since I imported them from England in March of 1985.  I imported Quad amp and preamp at the same time but eventually replaced the electronics with a tube amplifier, an Audiomat Arpege integrated amplifier from a French company that is 30 wpc.

I should mention the reason I went to Quads in the first place was due to a chance reading of an article in Opera News that Quad Electrostatic speakers were the ideal speakers for opera lovers.  I love opera music and I love classical music and my experience suggests that the author of that article was absolutely right.  Quads are ideal for listeners who especially love the mid-range.  Voices, violins, piano, cello, guitar, etc etc sound so utterly natural and beautiful as though live in the room with you.   I eventually upgraded to an Audiomat Prelude Reference  MKII, another 30 wpc tube integrated amp that was an Arpege improved.  Just a wonderful integrated tube amplifier.  I also played with putting my stored in a closet Pioneer SX-1050 with 120 wpc to my Quads before I decided to buy the Prelude and it sounded great but I was worried about putting too much power to my beloved Quads, so I decided to go with the Prelude.  Besides, the Quads seem to be made for tubes.  That is their natural partner.

In 2017 I had my Quads completely refurbished.  What a treat to listen to them!

Many wonderful years later, I happened to audition a Luxman Tube amp and preamp that sounded beyond wonderful with my Quads.  Well over my price range of course, but I decided to buy them anyway.  

Then along came an opportunity to buy the US Monitor version of the Quad ESL-63s.  This from a friend who was downsizing.  He had just bought them from a refurbisher of Quads, so they were almost liked brand new!  
 

I have been invited to listen to the systems of fellow audiophiles and so far my system sounds better than some costing thousands more.  I attribute this to my Quads and their ideal pairing to high quality tube amplification.

The only way to criticize them is to knock their base. they don’t have a great bass but, honestly, I’ve never minded. I could add a sub, but I haven’t found it necessary.  I’m now 85 and I like to joke that I want my Quads buried with me.

The subject of Sub’s used with Quad ESL’s or a Tweeter to extend the upper frequency on 57’s is a widely discussed subject.

I have experienced Sub’s in use with a variety of Quad Models and a Super Tweeter in use with 57’s.

From a personal preference I find the additional Tweeter adds something that really appeals to me, ands would like to hear a Tweeter added as a Dipole Array to lift the higher frequencies.

I have detected on occasions that a added Bass is in use, from the experiences had, there does not seem to be the seamless integration into the produced end sound when the Bass is an added as a design being a typical Bass Driver set up. I am yet to experience a Dipole Array for Bass Drive Units being used.

Additionally, I have heard 57’s used with purpose produced Power Amplification that has been able to create the impression there is substantial Bass presentation , and the idea more lower frequency is required seems fleeting as an idea to be realised. I have even experienced others who have been demo'd such a set up, where some listeners have inquired which Sub Woofer is in use?

The Quad ESL (57) has been getting a bad rap for it's bass production for years. The speaker has quite good bass response down to 40 Hz. In most music, that would suffice. If you listen to rap/hip hop, electronic/dance, some of the newer movie soundtracks, and organ music, then the speaker will certainly not reach to those depths. The Quad ESL will even go below 40 Hz but at that point while the bass is still pleasing, it's more of the one not bass variety. I use a distributed bass array with two open baffle bass units next to the speakers and and additional two sealed boxes spread asymmetrically about the room. All bass drivers are 10", active crossover set to 100 Hz low and high pass with 24 dB slope. I use a Music Reference OTL-1 on the Quads and Bel Canto Ref 1000M monoblocks for the bass drivers. Works quite well.

I used several amps on Martin Logan Monolith IIIs in a 25X23X10.5 avg listening room with no power issues.  Audio Research Classic 60, Counterpoint 400, Bryston 4B.  However, my new wife had great issues with the terrible sound for rock, no bass, head in a vise dispersion for highs, lack of dynamic contrasts among others I forgot.  Dumped them for a pair of Legacy Focus and Signature IIIs (kept the latter).  We were happy for decades.