Jadis JA30 - Quad ESL63 .. 4,8 or 16ohms?

in 4 OHM mine sounded a bit thin in the mids but the bass seemed to jump out more. I was trying to cut back on bass but now, in 8 OHM, bass is softer not fuller, and the emphasis is on the midrange, which I like

I realize this is a Quad post (so I will stop hogging your space) but it is just funny to me Audio Note speakers and Audio Note amps work this way together, I presume 8 OHM is the intended hookup

Well Guys .. it seems we are in consert to agree the best ohms taps for tube amps paired with Quads ESL63 are the 8ohms.
Now we (me and Opera) are curious to know if you have experiences with OTL amps driving these speakers.
We never listened or tried OTL amps (like Atmasphere) but theoretically .. based on electrical impedance observational .. should be the best choice even over the Tube Amps (not OTL)

What do you think about?

Curio
You will have to borrow a pair of Atma-Sphere amplifiers to try with the Quads.

Natural sounding vocals are very high on my list.

With good recordings the illusion of a physical presence in the room is startling with the Atma Speres amps.
I used the Atma Sphere M60s with a refurbished pair of Quad 63s for a few years.

Tenor OTL amps I have also heard on the Quad 57s, just astounding.

Years ago the late Harvey Rosenburg bought the rights to the Futterman Otl amplfiers, re-worked the amp and used them exclusively on the Quads.

Thanks Stilskin!

You can't believe how much me and Giorgio are curious to try a OTL amp on the Quad ESL63s
Unfortunately we don't have any Atmasphere or Tenor Audio dealer around here to ask for a borrowing :-(

The Quad 63 has always been a great match with our M-60 and MA-1 amplifiers. The speaker has an impedance peak in the bass that is well over 40 ohms and many amplifiers, especially transistors, don't make a lot of power at that impedance. OTLs, OTOH, once you get above a certain impedance (depending on the size of the OTL) will exhibit a sort of 'constant power' characteristic, so their output power does not drop significantly in the bass.

Unlike a lot of box speakers, the Quad's impedance curve has nothing to do with either crossovers or resonant peaks. It has mostly to do with the inductance of the matching transformer and the capacitance of the panel. The result is that a constant power characteristic in the amplifier is desirable if you want to get the most out of the speaker.

see
http://www.atma-sphere.com/papers/paradigm_paper2.html
for more information.

With transformer-coupled tube amps, the trick is a moderate-powered amplifier that does not use a lot of negative feedback, usually set on the 8 ohm tap. With an OTL of course, you just hook it up. Since the 1950s, Quads and OTLs have always been the ideal match. The speaker is quite transparent and getting rid of the output transformer is very noticeable! Later Quads seem to be following the same path as Martin-Logan, by having very low impedances, in order to get them to work with transistors, but IMO/IME this tack never works- if you really use it with transistors it will be too bright and no bass. IOW tubes are still the ideal method with newer ESL designs but you have to use a set of ZEROs (http://www.zeroimpedance.com) to make them work.