Anyone Have a Fender 75 Amp?

jkats · December 3rd, 2003, 11:16 AM

I just acquired a Fender 75 chassis with all wiring and transformers -- no faceplate, knobs, cab, tubes, reverb tank or speaker. I understand that this was Fender's attempt at a Mesa Boogie, but I bought it to build a portable clean amp. I'll build a solid pine cabinet and install a single (high-powered) 12" speaker. However, since I bought only the chassis, there is no tube chart. Can anyone tell me the preamp tube line up? Also, how did Fender hold the chassis in place on this model. since it doesn't appear that the standard chassis bolts/straps were used? Thanks!

Wally · December 3rd, 2003, 01:04 PM

That amp uses a 12AT7 for reverb drive and a 12AT7 phase inverter. The reverb recovery and all preamp stages are 7025, and the power tubes are 6L6.
The chassis is probably attached by 'nut clips' that slip onto the chassis at the four holes on the top sides of the chassis and machine screws. The 75 came in 40 versions...1X12 and 1X15 combos, 4X10 and 2X12 piggybacks. It would be of interest to know which OPT that one is. Maybe they used a 4 ohm OPT for all versions, or is it a multi-tap?

jkats · December 3rd, 2003, 04:43 PM

Wally, thanks for the response and for the tube listing -- would you happen to know the order of the 12AT7s and 7025/12AXYs? I don't know about the OT impedance, but I'll check the part code on the OT. The previous owner found the chassis in a makeshift cab with a 15" speaker, so I just assumed it would be an 8 ohm tap, but you make a good point, and I'll check. (The speaker impedance also may be marked on the back panel by the output jack, but the chassis's packed in a box in my office right now, and I'll check it when I get home tonight.) Where would I find the clips to secure the chassis to the top of the amp?

Wally · December 3rd, 2003, 05:07 PM

Look here http://www1.korksoft.com/~schem/fend.../fender_75.pdf
The tube order is noted in the schematic....V1,V2 etc. If the tubes are laid out in-line, that should make it easy. I am not so familiar with that amp as to know how the tubes are laid out.

jkats · December 4th, 2003, 11:27 AM

Wally, I checked the back panel and it specifies a minimum load of 8 ohms, so it must be one of the single speaker models. Thanks again, and I'll post this over on the Weber BBS to see if anyone there might own one of these!

jazzguitar · December 5th, 2003, 12:14 PM

It does have the standard chassis straps mounting, but the bolts were much shorter as they went into the top of the chassis. Besides, all the hardware was chrome plated in black.

December 3rd, 2003, 11:16 AM	#1 (permalink)
jkats Tele-Meister Join Date: Mar 2003 Location: Portland, Maine Posts: 221	Anyone Have a Fender 75 Amp? I just acquired a Fender 75 chassis with all wiring and transformers -- no faceplate, knobs, cab, tubes, reverb tank or speaker. I understand that this was Fender's attempt at a Mesa Boogie, but I bought it to build a portable clean amp. I'll build a solid pine cabinet and install a single (high-powered) 12" speaker. However, since I bought only the chassis, there is no tube chart. Can anyone tell me the preamp tube line up? Also, how did Fender hold the chassis in place on this model. since it doesn't appear that the standard chassis bolts/straps were used? Thanks!

December 3rd, 2003, 04:43 PM	#3 (permalink)
jkats Tele-Meister Join Date: Mar 2003 Location: Portland, Maine Posts: 221	Thanks! Wally, thanks for the response and for the tube listing -- would you happen to know the order of the 12AT7s and 7025/12AXYs? I don't know about the OT impedance, but I'll check the part code on the OT. The previous owner found the chassis in a makeshift cab with a 15" speaker, so I just assumed it would be an 8 ohm tap, but you make a good point, and I'll check. (The speaker impedance also may be marked on the back panel by the output jack, but the chassis's packed in a box in my office right now, and I'll check it when I get home tonight.) Where would I find the clips to secure the chassis to the top of the amp?

December 4th, 2003, 11:27 AM	#5 (permalink)
jkats Tele-Meister Join Date: Mar 2003 Location: Portland, Maine Posts: 221	Output Impedance Wally, I checked the back panel and it specifies a minimum load of 8 ohms, so it must be one of the single speaker models. Thanks again, and I'll post this over on the Weber BBS to see if anyone there might own one of these!

December 3rd, 2003, 01:04 PM	#2 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 4,031	That amp uses a 12AT7 for reverb drive and a 12AT7 phase inverter. The reverb recovery and all preamp stages are 7025, and the power tubes are 6L6. The chassis is probably attached by 'nut clips' that slip onto the chassis at the four holes on the top sides of the chassis and machine screws. The 75 came in 40 versions...1X12 and 1X15 combos, 4X10 and 2X12 piggybacks. It would be of interest to know which OPT that one is. Maybe they used a 4 ohm OPT for all versions, or is it a multi-tap?

December 3rd, 2003, 05:07 PM	#4 (permalink)
Wally Friend of Leo's Join Date: Mar 2003 Location: Lubbock, TX Posts: 4,031	Look here http://www1.korksoft.com/~schem/fend.../fender_75.pdf The tube order is noted in the schematic....V1,V2 etc. If the tubes are laid out in-line, that should make it easy. I am not so familiar with that amp as to know how the tubes are laid out.

December 5th, 2003, 12:14 PM	#6 (permalink)
jazzguitar Tele-Meister Join Date: Mar 2003 Location: Germany Posts: 280	It does have the standard chassis straps mounting, but the bolts were much shorter as they went into the top of the chassis. Besides, all the hardware was chrome plated in black.