Fender 75 Tube order?

[dhoward]

Hi I'm new here...
I have a question about a fender 75 head I have had @ a year.
Which tube is used for what function ...OD, Reverb, etc.??
And a good tube type for the location?
Thanks,
DH

[52 Bill]

Hi I'm new here...
I have a question about a fender 75 head I have had @ a year.
Which tube is used for what function ...OD, Reverb, etc.??
And a good tube type for the location?
Thanks,
DH

Welcome to the board.

Your amp has 7 tubes: 2-6L6GC, 2-12AT7 and 3-12AX7.

The 6L6's are the power output tubes.

One 12AT7 is used as the phase inverter, the second is used for the reverb tank driver and the distortion boost.

The three 12AX7s are used in the pre-amp, mixer, reverb recovery and FX loop driver stages.

[dhoward]

Thanks 52 Bill

Thanks,
I am trying to get this sounding better.
Dhoward

[pdf64]

Those can be fantastic sounding amps. the main problem they face is worn out tubes, and/or poor replacement tubes, and overheated resistors. Replace the screen grid resistors with flameproof, check the resistors in the negative voltage supply, fit a decent pair of wingedC or JJ 6L6s, and adjust the first 220ohm resistor in the bias supply to get them into a reasonable bias range.
Don't use the effect loop, it puts out a massive signal.
Fit a 3k3 bias resistor on the reverb driver, the 1k stock runs it at about 2 watts.
I think these were the last amps that fender made using the classic eyelet board method.
I'm working on a set of mods to get the best out of these and even out a few quirks. Peter.

[tim]

pdf64,

I'd be interested in the stuff you come up with...I have a Fender 75 head that's been languishing in my music room for about 5 years that I'm not entirely satisfied with the sound coming from it. I'm not a guitarist (I'm a bassist) but when I have friends come over to play and they see it and want to play through it, it just doesn't do anything for me. Not like the '64 Bandmaster Head I have sitting on top of the 75.

The 75 is biased on the warm side, I've played with preamp and power tubes but I just can't seem to get what I think I should be hearing out of the stupid thing...maybe it's just the nature of the beast but I'm thinking that this thing could be a tone monster, given the right TLC.

[dhoward]

I know there are some great mods that can be done on the 75 ..but I can not do them.
I will let you know.
I feel it could sound great.
I own some GREAT amps that are killer...
DST engineering UV6 custom amp.
Brown Note 44 Blue Monkey.
66 BF Twin.
66 Bassman head.