Tenor 75 Wi OTL

Glory, I am glad this seems to be working out for you. On a further note it seems like these amplifiers throw off new levels of heat considering the power rating, 720 watts per amp!!! I'm not sure this is at full power or just when you turn them on, it wasn't clear but the venting through the fireplace chimney seems like a great solution. The outputs on these babies must be biased REALLY high which might be a big contributor to what you are hearing. I can't imagine what your energy cost might be adding a/c costs to compensate for the heat generated. I know the VZN80 was in the 700 watt range but it is stereo. I was listening in February when the weather is cooler and it REALLY warmed up the room in short time. Ventilation seems the only real practical option, enjoy!

The Trancendent is Class AB vs. Class A operation of the Tenor

Just FWIW, the math does not support the idea that the Tenor was class A, not if it is also 75 watts output. IME, the tube is difficult to operate in the A2 region due to the prodigious grid currents involved. The amp is class AB1, similar to the Transcendent in this regard.

The big difference is the fact that one is pentode and the other is triode. In OTLs that makes more difference than the class of operation, since you are not dealing with zero crossing issues or commutation (switching) of output devices (OTLs tend to be immune to these difficulties).

Glory,
You`re quite happy with the wonderful performance of your system, can you leave well enough alone and resist the urge to monkey around with it anymore? LOL.

Ralph out of curiosity, why is this amp putting out so much heat, 720 watts per monoblock? This seems quite high based on the number of output tubes at least compared to the Joule which uses this tube as well.

I suspect that it is biased a littler harder than the Joule if that's the case. We've yet to work on a Joule although we have serviced Tenors in the past.