A Copernican View of the Turntable System

Hi Lewm,

Yes, I'm referring to the same tt on the Symposium and other products. For me it was a clear improvement: despite my initial (and over enthusiastically voiced!) suspicions concerning air-borne interference with a pneumatic approach.

Nandric, If one wishes to drive any of the full-range Sound Lab spkrs with a tube amplifier, particularly with an OTL tube amplifier, there is work to be done with the network that feeds the panel. I and others have made some modifications that help a lot. The stock OEM speaker is probably fabulous right out of the box with a first rank solid-state amplifier, but its impedance curve is treacherous for an OTL.

Dear Lewm: Congratulations on your birthday and by those Majestic's.

I know very well the Majestic's ( my friend and tonearm co-designer Guillermo own it. ) and are first rate speakers and as I posted two-three times the Sondlabs are almost the only elostrostatics I can live with.

I agree with Nandric about tube amps and especially OTL's. I heard the Majestic's with several amp options and the manufacturer recommended JC-1's are perhaps the better IMHO and obviously you don't have to " touch " the speakers to match tube units.
You know very well my take on that critical match between output impedance amplifier with the electrical impedance curve in the speakers where low very low output impedance is IMHO a must to have if you want neutral/accurate response.

Anyway, very good move/play.

Regards and enjoy the music,
Raul.

Raul, It's a bit of a secret, but I am on to a way of modifying the input of the Sound Lab so as to render it quite nice for my OTLs and anyone else's tube amps, as well. This is a collaboration among several Sound Lab users who prefer OTLs and/or tubes. To take a page from your book, I can't say any more than that right now, but I am listening to a primitive form of the final solution, and it is already a big improvement. I agree, the OEM Sound Lab is built for high power solid state amps, but it does not have to be that way.

OTLs are fine when driving a high impedance load. "Damping Factor", a term that SS amplifier makers love to bandy about, is a non-issue with ESLs. An ESL speaker does not develop a back EMF that needs to be opposed by a very low output impedance amplifier. In any case, Z at very low frequencies is very very high with an ESL. High enough to constipate many solid stage amps and to be ideal for OTLs.

I know some guys here in Holland who are wrestling with OTL
amps for 40 years. One can call such behaviour 'persistance', 'induration' or 'obsession' but during those 40 years they made many 'solutions' for the
impendance problem . The strange thing however is that they
try to solve this problem in the speaker. Some even produced speakers with 500-600 ohm impendance. Thanks to some guy called Bruce Rozenblat the problem is reduced to,say, 4 ohm. So it seems to be very easy to predict what Lew
'secret work' is about. He is tweaking some filter to put in front of his Majestic in order to protect the life of the (innocent) thing as well as his wallet.

Regards,