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previous: shane Gareth420v is considered kinda ... -- 2/2/2004 12:00 PM

Re: HELP convert el34 amp to 6v6s ?

2/2/2004 12:21 PM
gazza	Re: HELP convert el34 amp to 6v6s ? Hi, good idea about the screens - i'm not too sure what there is in the amp at the moment - it might just be a single shared resistor. its a pair of EL34's and the tranny is (acording to the schematic with the amp) for an 8 ohm load. there is no impedance selector ! ( the amp has been used with a 4 ohm cab for years ) so If I run a pair of 6v6s into that tranny with a 16 ohm load, I'll have doubled the impedance to the tubes anyway ? so maybe 6-8k which is closer to what the 6v6's want at least. I have no idea what the various 6v6gt's will take on their plates - I have some cheap new ones (rebranded from maplin as edicron) and I have some nice mazda NOS JAN ones. Its really tricky to know what to run the tubes at since the data sheets all say 285-300 volts for 6V6GTs BUT loads of amps (esp. old fenders) run them at 400 to 450V ! I just don't know what my tubes will take ! Am i correct in thinking that I can't really judge how the tubes cope with a high plate voltage untill they break ? Gareth.

2/2/2004 12:21 PM

gazza

Re: HELP convert el34 amp to 6v6s ?

Hi,

good idea about the screens - i'm not too sure what there is in the amp at the moment - it might just be a single shared resistor.

its a pair of EL34's and the tranny is (acording to the schematic with the amp) for an 8 ohm load. there is no impedance selector ! ( the amp has been used with a 4 ohm cab for years )

so If I run a pair of 6v6s into that tranny with a 16 ohm load, I'll have doubled the impedance to the tubes anyway ? so maybe 6-8k which is closer to what the 6v6's want at least.

I have no idea what the various 6v6gt's will take on their plates - I have some cheap new ones (rebranded from maplin as edicron) and I have some nice mazda NOS JAN ones. Its really tricky to know what to run the tubes at since the data sheets all say 285-300 volts for 6V6GTs BUT loads of amps (esp. old fenders) run them at 400 to 450V ! I just don't know what my tubes will take !

Am i correct in thinking that I can't really judge how the tubes cope with a high plate voltage untill they break ?

Gareth.

Replies:

Wild Bill Gareth, some tubes will handle a hi... -- 2/2/2004 2:28 PM
Dan McCue Gazza, another thing to remember is... -- 2/2/2004 4:24 PM