Neither the manual or website say anything about which tubes can be substituted in the D-Moll. Does it only take KT77/EL34 types, or can other types like 6V6 OR KT66 be used? If so, do you recommend certain bias settings or something?
Peter Diezel":1tz1ehnc said:Our amps accept other tubes too but we are a company
that needs reliable tubes. At the moment we are happy
with our stock tubes because of minimum warranty repairs.
To calculate your bias current:
Our amps have a plate voltage of 460 to 480 volts.
Let´s say it´s 470 volts average.
Maximum power (plate dissipation) of the tube X 0,7 / 470 volts
For example: 25 watts X 0,7 / 470 volt = 37,2 mA each tube.
To bias for 60% would result in more tight response but decreasing the clean sound.
25 watts X 0,6 / 470 volt = 31,9 mA each tube.
So we are happy to recommend 35 mA
Best,
Peter
ubermetaldood":v1ra9ync said:So if KT77's are 25w and EL34's are also 25w plate dissipation then there's no need to rebias for EL34's?
ubermetaldood":25856lpc said:So if KT77's are 25w and EL34's are also 25w plate dissipation then there's no need to rebias for EL34's?
esizer":20cep1l3 said:And Peter, my D-Moll's plate voltage was right around 500 volts. Is that something to be concerned about?
Peter Diezel":2lscxpsn said:esizer":2lscxpsn said:And Peter, my D-Moll's plate voltage was right around 500 volts. Is that something to be concerned about?
No concerns, you have a good wall supply.