sakis
Repair is easy... but to know why (besides being a chinese copy w/o the quality control) is another question that many don't want/care to know. carry on my friend.
Repair is easy... but to know why (besides being a chinese copy w/o the quality control) is another question that many don't want/care to know. carry on my friend.
well ....
in this case what you expect me to do ?????
say something like ok its a ber so its crappy so i dont bother ???? or you expect me to play god in the ber solders ???? i will not ....
i will provide anything possible to properly repair this / then try to see what caused it so it doesnt happen again / and after that if working its still goint to be the same crappy ber ...after all ...
what ever ....
polite and happy regards sakis
( i hope no hard feelings ...some things are not a question of opinion ....or even knowledge .... simply are given facts i see no point on trying to change them or improve them )
infinia said:
in this case what you expect me to do ?????
say something like ok its a ber so its crappy so i dont bother ???? or you expect me to play god in the ber solders ???? i will not ....
i will provide anything possible to properly repair this / then try to see what caused it so it doesnt happen again / and after that if working its still goint to be the same crappy ber ...after all ...
what ever ....
polite and happy regards sakis
( i hope no hard feelings ...some things are not a question of opinion ....or even knowledge .... simply are given facts i see no point on trying to change them or improve them )
Re: well ....
None here! I believe in repair as much as possible (I think we both like it) ber is good value ...only with fingers crossed. You are a good man sakis! I think if over a few glasses of Greek wine we both would see eye to eye afterall.
sakis said:
None here! I believe in repair as much as possible (I think we both like it) ber is good value ...only with fingers crossed. You are a good man sakis! I think if over a few glasses of Greek wine we both would see eye to eye afterall.
AndrewT said:
I never adjust to a specific voltage.
I apply 1 volt ac to input and monitor output into a speaker.
I then increase bias volts until cross over distortion goes.
I let it run for a while then readjust it.
No point putting more current through than really needed, it just wastes power and generates heat.
I can run my MOSFET amps at low levels without heatsinks using my method of bias adjust.
design - conservative or not?
I may have confirmed 10transistors as adequate, but again I cannot recall and would like to see the context in which I allegedly said that.
I can conservatively show a 3pair (6 output BJTs) that does 250W into 4ohms or 3pair that does 250W into 8ohms that easily meet my criteria for reliability.
I have posted results of the Leach clone using 3pair of plastic packaged BJTs that easily drives 8ohms to 170W and can be used to drive moderate 4ohms to over 310W, but that 4ohm capability does not meet my reliability criteria.
It would make a good (reliable) 6ohm capable amplifier if I needed such a beast. If I changed the transformer to 42+42Vac and fitted bigger heatsinks it would be a 250W into 6ohm amplifier that does meet my criteria.
sakis said:
I do not recall ever advising or recommending "at least 10 transistors... for 250W".infinia said:
I may have confirmed 10transistors as adequate, but again I cannot recall and would like to see the context in which I allegedly said that.
I can conservatively show a 3pair (6 output BJTs) that does 250W into 4ohms or 3pair that does 250W into 8ohms that easily meet my criteria for reliability.
I have posted results of the Leach clone using 3pair of plastic packaged BJTs that easily drives 8ohms to 170W and can be used to drive moderate 4ohms to over 310W, but that 4ohm capability does not meet my reliability criteria.
It would make a good (reliable) 6ohm capable amplifier if I needed such a beast. If I changed the transformer to 42+42Vac and fitted bigger heatsinks it would be a 250W into 6ohm amplifier that does meet my criteria.
news:
it seems as when i removed the transistors for testing i cutted a trace. i handwired all base-connections with wire and now the amp seems to work... i also received the spare parts today so everything should be fine. i hope this was the last time the amp failed.
it seems as when i removed the transistors for testing i cutted a trace. i handwired all base-connections with wire and now the amp seems to work... i also received the spare parts today so everything should be fine. i hope this was the last time the amp failed.
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