Bassman 70 into a ODS

[guitardude57]

I recently picked up a Fender Bassman 70, and wish to convert to a Dumble ODS. I once had found some docs from Normster on a conversion he had done.......but can't find them now. Anyone know where to look, or if Normster could chime in would be wonderful. Thanx, Mike

[Sweetfinger]

I bought a Chevy Blazer, but I think I'm going to convert it to a Lotus Seven.

[guitardude57]

Just the kind of response I was looking for.........

[Two Tone]

The Amp Garage :: Index

[guitardude57]

Thanks,

I've hung there for a while, but new to the Dumble forum though.

I had a major crash in the computer and lost some links I saved. Just glad I did a back up a few days before the crash. New hard drive installed in the wee hours this morning. So far so good.

I am trying to compile more info on the ODS from as many sources as possible for ideas on the conversion. For now I want to mainly mod the preamp re-using as many parts as possible, and install footswitching/relays later. Thanks, Mike

[Sweetfinger]

For now I want to mainly mod the preamp re-using as many parts as possible, and install footswitching/relays later. Thanks, Mike

The longer version of my less than helpful previous post would be that this is such a drastic rebuild, that you would be better off not hacking a vintage amp and instead building from scratch, or perhaps using a less valuable amp as a platform, like an old Peavey Deuce or Classic. The pieces of a SF Bassman that you'll be able to use are: the cabinet, chassis, transformers, and possibly some of the pots. Everything else is going to go in the trash, and you're going to have to drill plenty of new holes. Nothing wrong with Peavy iron, and many old Peaveys will likely have a lower voltage tap for relays and there's plenty of holes for all those nifty little switches that Dumble peeps love! You could recover a Peavey and it'd actually look more like a Dumble than a Fender, too.

[guitardude57]

I can appreciate that last statement.

I picked up the B-70 specifically to rebuild into an ODS, so not concerned with any mods to the original. To me it is just a donor
This is far from the first rebuild I have done. After having owned just about every kind of amp over the last 40 years, find fun, and great joy in building things that have nicer tones then store bought. Look what folks like Fuchs have done. Works for me.

[ThermionicScott]

I'm pretty sure the Bassman 70 has an ultralinear OT, too. If you're avoiding output-stage distortion in favor of preamp gain, then that might not be a concern.

- Scott

[guitardude57]

Yes, the UL will be tied off and not used.

I have Thursday and Friday off from work, so I will start tearing into it.

I've been trying to find a Rev. E ODS 50 set of docs, haven't been able to find them anywhere yet. Supposed to be the most current. Checked on Ampgarage, they are somewhere..............