66 BF AB165 Bassman BIN eBay DOA Score

[ToneMerc]

Got this rough but internally unmolested relic off of eBay, the seller never attempted to fix it and sold it as not working, for parts only.... to cheap to pass up. The power cord was missing the AC plug and the fuse holder had a piece of electrical tape in place of the fuse cap.

I attached a plug on the end, added a fuse cap and popped in a 3A slo-blow....Pow! Disconnected the B+ lead from the rectifier board and checked the diodes for shorts. Low and behold, all 3 facing the front were shorted!, I soldered in 6 new UF4007 diodes and she's running again.

All the lytics are either late 65 or very early 66', so obviously it needs a cap job. Suprisingly, all of them are in the 5-25% range.

TM

[ChrisM]

What's with the 220K resistors going from the PI plates?

edit: thought those weren't stock, I see them on the schem now.

[jelle]

That is a fun amp! Congrats!

[Dr-Joned]

I never have that kind of luck!! Congrats

[ToneMerc]

I never have that kind of luck!! Congrats

Thanks nor do I, it was all about timing and just spotting it not long after it was listed. I knew it was not going to make it to 8 hrs and certainly not a week. I'm going to re cap it, clean the pots, wash the tolex and call it a day.

TM

[LeftyStrat]

What a score! Man I need to set up some saved searches for "amp for parts".

Years ago, before eBay implemented fuzzy search and autocorrect for listings, apparently some people made a killing with searches for misspellings.

"59 Startocaster, BIN $500"

I can only imagine.

[M Fowler]

Nice find Mike way to go lucky dog

[sepulchre]

Great find!

I'm with Dr-Joned. The only time I find anything like that is when the wallet's gone dry.

[Reeltarded]

Thanks nor do I, it was all about timing and just spotting it not long after it was listed. I knew it was not going to make it to 8 hrs and certainly not a week. I'm going to re cap it, clean the pots, wash the tolex and call it a day.

TM

A great day! This is how happiness is made.

Good amp! Good job on the catch!

[Smitty]

What's with the 220K resistors going from the PI plates?

edit: thought those weren't stock, I see them on the schem now.

Those provide negative feedback.

I find this amp is a great platform for a guitar amp and lose those resistors pretty quickly. I keep the Normal channel stock, rewire the phase inverter like an AB763 and then go crazy with four triode stages on the bass channel to create some nice overdrive tones.

Lots of possibilities.

[sepulchre]

Aren't those grid leak/bias feed resistors?

[ToneMerc]

Aren't those grid leak/bias feed resistors?

Nope, as Smitty stated they provide feedback(positive), the OT phase is reversed and the bias circuit is different as well.

TM

[sepulchre]

Ah, okay. Live & learn.

[ToneMerc]

Replaced the bias supply cap, the caps under the dog house, removed the "death cap" and converted it a 3 prong AC cord.

TM