EL84 amp counterexamples, please

[eschertron]

Yup. I don't know if the 5e8a is an example of a preferred overdrive Twin. Not the design usually copied by cloners and boo-teekers.

Right, that's exactly my point. Is this design a prime example of why designers DON'T use the cathodyne to drive (or rather, overdrive) the power stage? I did notice that the 5f8 and other designs switched to the LTP.

And so, are there fans of this design as well as detractors? Or has this design been pretty well retired?

[Zozobra]

Not quite what you're after but the VHT/Fryette D60 uses an AC coupled cathodyne PI which may be worth having a think about, granted that is a pretty clean power amp. Other notable examples would be things like the various old orange/matamp designs and the Electric MV120 which use DC coupled cathodyne PI designs which are very much about the aforementioned warts!

[Enzo]

Remember, when they designed these amps 50-60 years ago, overdrive was the last thing on their mind.

[eschertron]

Remember, when they designed these amps 50-60 years ago, overdrive was the last thing on their mind.

Point well-taken. I think this is the issue that has me the most confused from this thread: is an amp like the '57 twin (5E8A schematic) an example of an amp that gets "warty" when overdriven? I want to hear that sound so I can identify and come to grips with it. And how much compression and lower-order harmonic distortion can one get from an amp like this - actually *this* amp, since I'm using it as an example - before the warts become prominent?