ureche wrote:Hi, i was wondering, if there is any sonic difference in using a solid state vs tube rectifiers?
I was thinking of going with ss rectifiers, this will also have an impact on PT cost, as i get rid of the 5v heater.
So, if i go solid state, i will add a switch for B+, or a 60 seconds delay circuit.
Should i increase the capacitance ? What would be the recommended values for 80/40/20/30 ?
A 60s delay _might_ create more problems then it solves . Think for a moment what
happens when 60s has occured, all cathodes are hot, all electron clouds are
saturated. Then a sudden surge of B+ will cause all coupling caps to charge, but as they
are uncharged they will for a moment drive the el34 grids to a positive voltage, a
surge will flow in the el34. Not good. Especially if someone has "improved" the circuit
with larger coupling caps. The above will cause surges and eventually flash-over.
The same goes for a coupling switch for B+.
The beauty with rectifier tubes is that they will gradually increase B+, and so
slightly ahead of the cathodes heating, coupling caps will charge slow.
The next best is to apply B+ at once and have the tubes gradually start conducting.
Look around. Lots of amps ( or devices) uses diodes and no delays, with no harm.