Fender 75

[blues man]

I just finished this rebuild and thought I'd share it with you guys. When I got this amp it was heavily modified and even had a solid state board on top of the original with a bunch of new holes drilled in it. I gutted it and reused the original fiber board and converted it into a super reverb without the tremolo and I added a master volume. I disconnected the extra ultra linear taps off the OT and capped them off and used a standard diode bridge rectifier. The reverb tank didn't work so I used a 3 spring rev tank out of an old carvin PA board I had. I also added a choke and used 2 10k res in the power rail. I hooked it up to a 4-10 bottom loaded with legend 105's and couldn't believe how good it sounded. I have never really like the 105's but they sounded real good with this amp. I used about $150 dollars worth a parts. I didn't try to do it neat, I just through it together and laid the heater wires on the chassis instead of up in the air and it's dead quiet.

[thermion]

Those 75's are a nice mod platform, b+ off the stock PT is pretty high though. Do you have the cabinet for it, if so does it have the 12 or 15" speaker? The square jensen ceramic 15 that came in some of those amps is probably one of the best speakers I have heard live. I made a brown vibroverb out of mine, I did keep the bright and mid pull pots though. I think I remade the lead knob a dwell control for the verb.
Can you make a guess as to what that extra solid state board was for?

[Willabe]

Looks like you did a nice job to me!


            Brad     

[blues man]

I acquired this amp as a bonus for rebuilding a customers  black face  bassman head and I am selling it back to him for $350 which is a really good deal for him. I just wanted to get my money back out it. The amp is a head so no speaker. When I first fired the amp up I had 525 volts on the preamp plate res and blew 2 preamp tubes. I missed the 100 ohm resistor to ground off of the input section to the phase inverter. I originally had built the power supply like the 100 watt Marshall on Doug's diagram on his library web site. Since the voltages seemed a little high after I fixed the missing resistor I Disconnected the center tap off the PT and hooked up the B+ to the power tubes and disconnected the UL taps off the OT and Put in 2 10k res in the power rail instead of the stock res on the super reverb sch. With no tubes I had 505v on the first preamp tube but when I put in all the tubes it dropped down to 233v. I did test the amp with the UL taps  connected and when I cracked up the vol all the way up with the master on about 2 to 3 the amp was still clean. Actually this amp is probably the best sounding amp I've rebuilt and the power tubes are 1 Sovtek 6l6 and a Peavy 6l6 and they are 3ma different. One is 35ma and the other is32ma. The matched set of Sovtek's I had read 35ma on one and 28ma on the other so much for buying matched tubes.  According to the owner the Riviera (don't know about spelling on that) shop in New york modified the amp for him and he said it basically sucked after that. I should of taken some photo's of it. The solid state board looked like some kind of preamp  tied in with the tube preamp.