Fender 75 combo as hybrid donor???

[titanicslim]

Hey, gang, puzzle for you all.

I got this little 75 intending to rehab and turn him around for a quick profit- sort of fell into my lap- but there are a couple of issues:

Right now the output is a little lackluster. Not weak- the thing just about screams! Hard to imagine an amp putting out more volume with two 6L6s. It's just not very exciting. Maybe I just need more time with it.

Then I started thinking about ways to give it some sparkle. Has anybody ever Dumbilized one? Any reason I couldn't do the hybrid thing with it? What sorts of adjustments, if any, would have to be made. Heck, it's already got push/pull knobs waiting to be redeployed

It seems like it would be more desirable on the market than it is, with all carbon comps, all hand-wired and top-quality bits everywhere. They just aren't selling for their natural value.

Anybody got any experience with one of these things? I've heard that some of the hot pickers use them (they always mention
Chris Duarte) and swear by them.

Opinions, please.
Dave

[mlp-mx6]

I believe that dogears has a 75 conversion.

[Bob-I]

I believe that dogears has a 75 conversion.

Yes, I've heard it. Sounds damn good.

[tonelab2]

Had one back in the early '80s. !5" speaker. Big sound but as you say 'not very exciting'. I think it was Fenders take on the Mesa thing. Do it. A few on this forum have done it. It's a perfect donor.

[Darkbluemurder]

I have one, too. I still have not yet managed to get it out of its cab - I will take it to the shop tomorrow to let them try.

[titanicslim]

That's funny, Stephan, as I can't get mine into the cab. Of course, I'm not using an F-75 cab, but a smaller one from a Stage 112, I think- in hopes of saving weight. One end of the chassis is bent inward about a centimeter, so the mounting bracket doesn't align properly. I'm having trouble bending it back, as they have mounted the little board with the PS resistors right there and I can't get my bronze punch into position.

Hey, Dogears, You out there??? I'd really like to get your input before I start the clipping and the screwing and melting and the this and the that and the smoke and the stinking and the burning of the fingers and the yadayadayada. Really, Dogears and anybody else who's done this, Bluemurder needs you too.

[Runaway J]

So does RJ.
Got a 75 with a 15“ Celestion G100.
I’ve been thinking about using it as an ODS donor for a long time but was not sure if it may become collectable or not.
However, 75W switchable to 15W with 2x 6L6GC in ultralinear mode is very unique. Maybe a cool add-on to the hybrid concept.
Some things I like a lot with this amp (clean sound, reverb, tube buffered loop), others make me wonder what Fender was thinking when they designed it. Took me a long time to understand how this amp works because the schematic is a horror (had to draw it new) .
The most curious thing IMO is that the overdrive stage is fed by a mix of clean signal + reverb signal + (clean?) signal from the lead volume pot. Can’t imagine how this should ever sound well. Another thing is the totally chaotic wiring (see photo).
So …collectable or not … guess I‘d never be happy with the amp in its current state. Soundclips of converted 75's available ?

[titanicslim]

Well, I guess it's official. I've been watching eBay and these things just can't seem to bring over $300US, so I'm ripping it's guts out and ODSing it. I've been playing with it and getting some pretty good sounds out of it, but I think a 75watt Dumbleklang amp is definitely the way to use it. I won't be able to start the build for a while, but I'll keep you all up on it when I do.

Davy

[Darkbluemurder]

Hooray! The guys in the shop succeeded and got it out of the cab for me. The first look into the chassis made me just think what kind of a rat's nest is this? Why would anyone put the bias caps in the cap house? Why would anyone put an output tube matching or bias control in the middle of the rear panel? Does really anybody use a stereo jack to connect effects? No wonder they put in 500pf snubber on every gain stage because that is probably the only way to keep this thing stable.

Looking at this whole mess I came to the conclusion that there are two alternatives:

1. Gut it and build an ODS amp from the ground up and put the power supply caps into the chassis rather than under the cap can;

2. Leave it as it is and sell it.

I will have to think a while on that.

Cheers Stephan

[ampdoc1]

Those amps are dogs!!! But you've got some hefty transformers and a chassis. Take any of the Dumble schematics and build yourself a screamer.

[Jackie Treehorn]

Yes, I picked up a Fender 75 head for $175 abought a year ago. I did a Dumble type amp on it. It is ultralinear, no additional feedback, with post phase inverter master volume, skyline, HRM. I was going to just mod it, but I pretty much ended up removing everything, doing a blackface style reverb, while using the existing tag board. That may have been a mistake since it's still a pretty messy layout.

[img:640:480]http://theinside.net/misc/f753.JPG[/img]

I kept mostly carbon comp resistors and used sbe 716p in most spots. It came out sounding really well. Big midrange push!!

[Buschman]

You will spend $300 on a chassis & cabinet. That means you have a honking 15" speaker & free iron. Gut it & rebuild. If the amp becomes collectable in 30 years at least you had some fun with yours!