Be careful, SET w/o feedback will roll off the highs on QUAD's around 10-14kHz -3dB due to the low damping factor and capacitive nature of the speaker.
Also, some solid state amps develop a peak around +3 to +6dB 30-50kHz range.
Having said that I own 57's and enjoy them immensely.
Make sure to investigate the reliability of the 2805's. I owned a pair and loved them for two years, but in that time I had to return them several times for repairs not related to panel failure. I never over-drove them. The issues were around construction and quality control including loose internal wires and cold or broken solders.
After the third time back for repairs I gave up on them and moved on. In fact, the dealer dropped the line due to the quality problems they were experiencing from their customers. Also, there was only a 1 year warranty. Hopefully Quad has these issues worked out now with their plant in China.
Unless I was sure the QC was improved and they offered a more reasonable warranty, I would not buy new 2805's again but rather go with rebuilt 63's if I was to ever own Quads in the future.
Full disclosure: I sell and service Quad speakers so you can take my comments with the proverbial grain-of-salt.
The 2805 is a great speaker. It is a Quad! Basically it is the old ESL63 with an updated frame. The more rigid frame and additional mass versus the ESL63 does give the speaker a tad more resolution and a bit more bottom end authority. None of this is a dramatic. Many people would probably never know the difference.
2805/63 versus the 57. Depends on what you want. To my ears the ESL63 eclipses the original in every area of performance. The ESL57 is more forgiving, more euphonic if you like. For some this is exactly what they want.
The newer Quads are far more neutral than the original, more resolving even in the critical midrange and much better at the frequency extremes. SOTA performance in terms of soundstage/image presentation. It is also more dynamic and plays about 3dB louder than the original. The ESL63/2805 is a more honest/literal speaker.
IMO SET amps are not the ideal match with Quads. Frequency response and clipping problems will most likely be an issue.
I have seen nothing about the new Quads that would make me believe Quad has a significant QC problem. Stats are tempramental by nature. This may not be ideal for some users or dealers. In general the Quad designs are robust and reliable. I have seen many 20+ year old in my shop over the years that are in fine working condition.
If you want the latest and 'best' Quad and can afford the 2805 you can't go wrong. IMO a properly rebuilt ESL63 is about 90-95% of the 2805. Like any company that has been building basically the same thing for 30 years, a few changes/refinements will occur over the years. But the new Quad 2805 is essentially the same speaker as the original ESL63.
Hope this helps. Good luck!
I am a former Quad dealer and sold the 57 and 63. They are quite different and some prefer the earlier model. I myself would go with a used 63; they are available used at good prices, you can always move up if you want the relative small improvement the latest models give. I know Dave and I did not have the problems with the 63s that he had with the later ones. I didn't find them demanding as to amps, revealing yes, demanding no. I used them mainly with either Quad amps or Class A SS amps from Stax and Musical Fidelity. I also wonder how SET amps would work but then I am not a SET fan, I would check on Audio Asylum and other sites for experience of others with them.
I owned a pair of 63's for about 6 months with a pair of Celestion dipole subs. It was the GREATEST most ethereal sound ever for classical and jazz. It was a bit slow and shimmery for rock. My wife forced me to get rid of them because of their size. But I would repurchase a pair immediately if I could get rid of my wife!
I had Quad US63's for many years and ran them with Cary 805B SET 50W monos. Its a midrange system, no doubt, but then we all should know that...I would temper this recomm with the caveat that I think WE300Bs & GE211 tubes are required in this amp to get the harmonics, dynamics and the treble extension up to relative par (Chinese 211s are confused and screechy).
Still miss that system...
Great responses. Thank you.
Msomers88: For me, I would not want to go back to an amp that uses feedback. It sounds like the high end roll off is perhaps an impedance matching issue that I need to consider.
Asa: Yes, I've got the GE211 tubes in the Air Tights. It seems that perhaps you and Msomers88 have differing reactions to Quads and SET. In various threads some people seem to prefer more power and others SET.
Kantaja: Thanks for the thoughtful response. It appears you are with Msomers88 on the SET matching issue. I was unaware that the Quad2805 was so similar to the Quad 63. A rebuilt Quad 63 certainly costs less than a new Quad 2805.
Setting sonics aside, I am a bit confused by whether it is best to use higher power amps with the Quads and risk damage due to over-driving the speaker; or use less power and risk sonic under performance.
Cosmetically, I certainly prefer the 57.
Does anybody demo the Quad 63 or 57 in the Bay Area?
Don't worry about Quads and the size of the power amp. The speakers are equipped with protection circuitry to handle any issues. I personally use 280 watt/channel tube amps. Not because the Quad needs that much power, they don't by a long shot. I use that much power because I like what that kind of power does for the Quad, more specifically what the power supply will do in an amp that size.
All electrostats like power amps that have large, stable supplies. This describes the type of supply one will genrally find in large output amplifiers. Some smaller amps will have this type of supply but they are generally the exception rather than the rule.
I had one customer who damaged his 63s [several times in fact]. But he was a rock enthusiast who felt that buying the Quads would demonstrate how refined his taste was; they were entirely unsuited for his listening habits and I told him so. I once measured his listening level at 108db on the Nelson Reed 804s he was auditioning , they were perfectly happy with that level, the Quads will not do this kind of level. As long as you use a little common sense you can use a large amp, the Quads will play around 97db at 1 meter if I remember and that is fairly loud.
Stanwal said, "97db at 1 meter"
How do you get 2 Quads three feet from your ear?
I dont know either, but i guess if you ask them nicely and they are close talkers they just might.
Sound levels are taken at one meter, I thought that this was common knowledge but again I have overestimated Audiogon readers. It is easy to see that SOME distance must be specified in giving maximum speaker output, one meter is the distance that has been chosen. You are not REQUIRED to listen at that distance, but of course may do so if you choose.
108db, wow. I listen at about 75 to 85db at about 8' from the speaker.
That was not at one meter, but back 8' to 10' feet on my Radio Shack meter. I had left him to listen alone as this volume is way too loud for me but got the meter and came back in out of curiosity. The Nelson Reeds were designed for use in movie studios and would easily take this volume, my ears wouldn't.
Jj -- if you haven't seen it already, this might be of interest:
Robert, thanks as I had not found that Quad group. Jeff