I have good experience with Wayne Picquet on multiple restorations of panels. Others , however claim not to have good experience with delivery or lack there of. I have never not received exactly what I have paid for. YMMV and all that. I'm using the Picquet panels now and have done 3 different panel sets with him.
I must say that I have had the EU panels, The UK panels New Old stock ESL panels, locally manufactured panels and the Picquet panels out perform all of them in many ways.
Gary Jacobson's site reviews several panels as well and comments on each re-builder.
As far as Sheldon Stokes, he wrote the guide on how to restore for the DIY community and he has always had the time to answer any questions I had via email even if I was not spending money with him. You have to respect that. I consider him an expert.
Electrostatic Solutions appears to have a great reputation as well , however, I have never done business with them.
I can only comment on mine, but I believe the componentary is pretty similar
1. Leg height upgrade, I much prefer better bass and tonal adjustability
2. Protection circuit this is a must
3. New drivers you may or may not need these,
4. New transformer and resistors and Hv caps probably need replacing
5. Fine grade Mylar which increases output
These are all doable, and only improve reliability
Others to consider
Removing repadding, I have tried both and like it with the padding behind in my smaller bed room , but in a very large room, there are advantages of removing it
Change or removal of front grill, I assume this will give benefits sonically, but the speakers looks pretty weird
I don’t because I have a toddler currently
I cannot comment on the gentlemen who do this is North America ,
I have only heard Electrostatic solutions Quads
They offer all these upgrades
I have heard 4 different versions of their Quads
I do recommend the lighter Mylar if you want to play loud
I am seeing over 90 dB continuous at the listen8ng position of 10 feet from speakers in a 18 by 21 foot room with 15 foot ceilings !
I have started to play with mine and dial them in and for personal listening they really are wonderful, and for the price amazing
Please do consider what amplifiers you will use with them, as they do need a sympathetic amplifier matching, doesn’t need to be powerful, but must be able to handle them
If you don’t already have a suitable amp, then consider this as part of your purchase
Hope that helps
I have no association with electrostatic solutions
One of the best PP amps on the ESL was the Audio Research M100. The small Heathkit EL84 amps do not have the slam but sound very good and as mentioned the MC225 is very nice as well.
My favourites are the Wyetech SET 211 and Futterman followed by the Mac. I am not particularly fond of the 6550 for the ESLs as they are so revealing in the critical midrange and that tube, for me, midrange is not the strong suit. I have literally tried dozens of amps on the ESLs including my refurbished pair of Quad IIs
I found these speakers don't like SS amps at all...or hybrids...basically anything that is a voltage source because for most of the range they are high impedance speakers. They like current sources that can swing voltage. A Lamm ML1.1 would probably work better (90 watts of tube power). A KR VA350i also worked well on them but nothing did what this otherwise unimpressive Golden Tube Audio amp could do on them. It was like that amp was just waiting for a speaker like that.
Mr.Morricab, with all due respect your statement that ESL's57 " don't like hybrids"... "because they are high impedance speakers"... does not correspond to all the truth, at least if one considers the excellent stereo amplifier CROFT model 7 R (regulated). It is a hybrid design with valves taking care of the 1st stage amplification and very high quality SS BUZ 900/905DP MAGNATEC Mosfets delivering the output, regulated HT with a 300VA torroidal PSU, with 50/55 watts per channel (input 12AX7 or - in my case - 12AU7), that easily drive my two pairs of stacked quads esl 57s. TUBE CAD Journal on "Hybrid Amplifiers" April/May 2001 :"The common approach is use tubes for voltage gain and MOSFETs or transistors for current gain. This arrangement appeals to our sense of fairness: tubes are happiest with voltage and woefully current limited; solid-state devices are current ebullient but fearful of over voltages. An exaggeration this, but not without a kernel of truth. Which solid-state device should be used in the output stage? The transistor wins in theory, but the MOSFET wins in practice is the quick answer. The transistor has a much greater transconductance which makes for a greater gain, which in turn allows for more feedback, which ultimately lowers more distortion. Yet, the MOSFET is used in most professional, high-power amplifiers because the MOSFET does not blowout as readily as the transistor does. Furthermore, the MOSFET is almost always used in hybrid designs due to its reputation for being more tube like in sonic character and because its gate represents a high impedance that is theoretically easier to drive than the transistor's base." ( http://www.tubecad.com/april_may2001/index.html )
Chris Beeching ( http://www.quadesl.com.articles/quad _stacking.html) says that "Also, by connecting them in parallel the overall impedance curve is considerably flatter, and hovers around 8 to 12 ohms rather than the 15-going-on-30ohm curve for a single panel", so your statement, I understand, regarding "hybrid" amps do not apply to a pair of quads ESL 57 when stacked in parallel, specially when driven by good "hybrid" MOSFETS amplifiers...anyway, MOSFETs being "CURRENT EBULLIENT" are happy with this "high impedance..." speakers...
In the TUBE's simplest configuration, triode amplifier, the plate current is function of grid voltage, as drain current is function of gate voltage in a MOSFET
The MOSFET, on the other hand, is less sensitive to shifts in the bias voltages, as it has a much lower transconductance. Furthermore, MOSFET output stages always require a much higher quiescent idle current, which increases the percentage of Class-A operation in Class-AB mix, which is all for the good, as the first watt of power is sonically the most important watt. Add to these benefits the advantage of virtually no thermal runaway, and the MOSFET appears to be the clear winner/.
MOSFET advantage TUBES in all aspects: -Very higher transconductance (two magnitude order, typically 3,5 mhos)
-Direct load coupling (transformless) this mean higher bandwidth, less distortion, more damping factor.
-Better gain bandwidth product.
-Power bandwith one magnitude order higher than TUBES.
Mike, thanks for your comment. My steel pedestals were carefully made by Dr. Marcius. Below are two links to his videos on YouTube. He too uses Wayne Picquet's best panels in triple stacked configuration plus two "bass only"(...) panels and builds its own amplifiers (OTL's) and Turntables. Solid professional electronic teacher and a great guy to talk with...
View attachment 45787
Well after many weeks of satisfying listening I took the advice of others and hauled my Lamm m1.2 up the stairs and onto the Quad ESLs
After some fiddling with the bias settings and very slight speaker adjustment
I sat down to a pretty stunning presentation clarity and timbre were excellent with tremendous raw power wow