I think any mid to high-efficiency speakers (i.e. 89db and up) with 8-ohms (nominal) impedance will work just fine with most OTLs. Unfortunately too many of the popular high-end speakers tend to work at much lower (4 or 5) ohms. I bet one reason for this is, most people end up buying high-powered SS amps over OTLs or even SETs. I own a low powered (20 wpc) Graaf GM-20 OTL -- my speaker choice was a pair of Kharma Ceramique 2.2 over more the popular Wilson Watt-Puppy.
Why no threads on OTL amps?
I looked through the old thread list and didn't find anything on OTL amps. How come? Does nobody like them? Is there something wrong with them? Would you buy/notbuy one, and why? If you would buy one, which one do you like best? I always thought OTL was the best, but there doesn't seem to be much interest here on this forum for them.