14-07-2023, 10:29 PM
And in any case, some of the earlier designs were really excellent. Once thermal runaway had been tamed ( more geranium than silicon ) and decent heatsinking had been available. some of the old amps were very good.
Even by todays standard. I made many guitar amps in the late 60's and 70's that were very reliable and very good quality ( more the design than me ). They used TO3 transistors and were mostly 2N2955 and 2N3055 complimentary pairs.
Later came MOSFETS that was another learning curve, but they truly were hi-fi and very powerful using only a few devices. Driving them was pretty tricky with large input capacitances, but that was soon overcome by using medium power
bipolar transistors, and the availability if true matched pair input transistors, with two devices in the one can. One base input was the audio input and the other base was the negative feedback, and both these transistors used a common emitter.
Performance, even by todays standards was exceptional.
So I think Rob's amp, with its overhaul, should be excellent as todays passives have improved immensely and are much longer lived and stable over their lifetime.
Cheers Rob and enjoy the music.
Joe
Even by todays standard. I made many guitar amps in the late 60's and 70's that were very reliable and very good quality ( more the design than me ). They used TO3 transistors and were mostly 2N2955 and 2N3055 complimentary pairs.
Later came MOSFETS that was another learning curve, but they truly were hi-fi and very powerful using only a few devices. Driving them was pretty tricky with large input capacitances, but that was soon overcome by using medium power
bipolar transistors, and the availability if true matched pair input transistors, with two devices in the one can. One base input was the audio input and the other base was the negative feedback, and both these transistors used a common emitter.
Performance, even by todays standards was exceptional.
So I think Rob's amp, with its overhaul, should be excellent as todays passives have improved immensely and are much longer lived and stable over their lifetime.
Cheers Rob and enjoy the music.
Joe
