Rickresource Rickenbacker Forum

HI,
I just bought an old M8 amp on an impulse.
After I got it home I took it apart and did a search on the net found that the transformer was replaced with a much lager one and it now has a ECC83 (12AX7) instead of a 6AV6.
My question; is the ECC83 a compatible replace for the 6AV6 or since the transformer and cap can was replaced it doesn't matter and now uses the ECC83?
Would you recommend using a lower gain tube like a 5751 or 12AT7?
thanks~

Most M8's had a 12AX7 preamp tube. The 6AV6 is 1/2 section identical to the 12AX7 but is a seven pin tube. Check to see if the socket is original. If it is a nine pin, your M8 uses a 12AX7. As for the transformer, several different varieties were used over time. Do the soldered connections look new? Are the voltages in line with common practice for the rectifier and output tube? Schematics are rarely true for the life of a model run regardless of manufacturer. Fender and Marshall amps vary greatly sometimes within a model year. The M8 is a great little monster and is pedal friendly. One of my recording faves!

Thanks for the info I was going by the drawing posted on the RIC homepage and just wondering to what extent this was changed. Looks like the 12AX7 was used on this one the socket looks original. Just replaced the tubes, put on a three prong power cord replaced the original speaker with a Weber 8A sig. (I wrapped up the old Oxford for safe keeping since it looked original I didn't want to blow it) and this M8 sounds great I use it most every day. I really feel lucky to have found this amp it's a keeper!!