I've also been wondering about those RET v.s Perforated Emitter Technology phrases. Maybe both means the same, but Onsemi chose another term to avoid patent infringements?
Best regards!
I’ll bet the size and density of the holes is different, but the idea is the same. The On Semi version gives up some fT for ruggedness. Even their version of the 3281 has more capacitance than the original Toshiba - again, giving up some fT for ruggedness. They seem to do that a lot.
The transistors should be fine with audio at 3MHz.
The problems usually occur going the other way.
I bought a 1980's 2N3055/MJ2955 amplifier with outputs missing.
I bought in new parts and the amp oscillated badly.
I had to slow down the VAS with a bigger capacitor to stop it oscillating.
The problems usually occur going the other way.
I bought a 1980's 2N3055/MJ2955 amplifier with outputs missing.
I bought in new parts and the amp oscillated badly.
I had to slow down the VAS with a bigger capacitor to stop it oscillating.