Can OTL's drive ribbons well?

OTLS are best with electrostatics. Theoretically they should work well with ribbons. My personal opinion- ribbons go with solid state. Tubes are too slow to get the speed out of ribbons. Happily there is a solid state OTL. The name escapes me now, but I'll find it.

Gregadd,

I 'm a bit confused with the "solid state OTL" statement. All SS amplifiers are Output TransformerLess (OTL) with the exeption of McIntosh amps that use autoformers at their output. As for tube amps being generally slower, I guess it could be true for some. However, tube OTL's are devoit of the one device responsible for slowing them down and that is the output transformer. The atmasphere amps in particular are regarded as some of the fastest sounding amps period, with specs such as rise time and frequency response that bear this out on the test bench as well. The only requirement is that they be used with loads that don't dip much below 8 ohms.

Gregadd, I'll beg to differ with you on one point you make: "Tubes are too slow to get the speed out of ribbons." One of the reasons OTL tube amplifiers are so good with electrostatics is precisely their speed. OTL tube amplifiers have incredible speed throughout their frequency range, coupled with high resolution and transparency; the impedance of the speaker is the only issue in how good a match there will be (and with an OTL like the Atma-Sphere MA-2 impedance is not much of an issue unless it's dropping sharply below 3.5 ohms or so). Whether a ribbon will be a good match for an OTL will be a function of impedance matching, not speed. Since many electrostatics have rising impedance curves, and since OTLs are happier with high impedance loads than are solid state amps, it makes for a good combination. I just don't know about ribbons.

As to solid state versus tube OTL speed, I'd match the speed of an Atma-Sphere MA-1 or MA-2 to that of the best solid state amps any day, the solid state amps certainly don't surpass the Atma-Sphere as to "slew rate" or "rise time" (rated at 600 volts/microsecond, matching the Spectral solid state amps which exceed almost all others).

As to traditional transformer-based tube amps, I'll agree with you based on my listening, but I personally prefer any number of them to ss for other important characteristics.
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AtmaSphere M60s have been a great match with my Raven R3.1 drivers.

In a tube amp, it's the output transformer that limits frequency response. Tubes themselves function nicely at RF frequency, and so do transistors for that matter. With an ultralinear circuit (with transformer secondary taps for feedback around the transformer) tube amps with transformers can be made flat to at least 20 KHz, and it is arguable whether higher response is necessary, since neither CDs nor LPs have signal content above this. SACD and DVDA may have higher frequency signals, but the audible effect is also arguable.