blackface deluxe reverb 1967 farting bass

[hewo]

Help
Must resolve fart noise of bass string notes.
Power supply already recapped.
Solidstate plugin rectifier, maybe voltages exceeded?
6L6 duet installed, how can this be?
Client did testify amp worked like this nicely until "fart" bass notes trouble started up.
Amp is pretty corroded from rain exposure, client found it rubbish dumpster back in 1970's.
Is this amp "restoreable" back to stock?
I cant find model number on chassis to get schematic.

[Leo_Gnardo]

Client did testify amp worked like this nicely until "fart" bass notes trouble started up.
Amp is pretty corroded from rain exposure, client found it rubbish dumpster back in 1970's.
Is this amp "restoreable" back to stock?
I cant find model number on chassis to get schematic.

I'd suspect the speaker first. Nearly 50 years old? Paper might be ripping, glue coming unstuck. Maybe foreign object stuck between cone & frame, an old gum wrapper, potato chip, guitar pick, insect, coin, washer, whatever. I've seen 'em all.

Of course it makes sense to try the amp thru a known good working speaker too.

Nice find, a dumpster diver's delight Deluxe! "The price is right." Definitely a candidate for standard restoration. Deluxes are dam' fine amps, always worth the effort. Don't mind the rust. One of the best sounding Bassman heads I ever had spent its first 30 years playing shag on a North Carolina beach, rusty as hell but oh what a tone. Restored & sold to a satisfied buyer.

Deluxe schematics were pretty much the same from day one. I'm sure you can rattle one up in seconds on Google.

[Jazz P Bass]

This is not a high power amplifier.

Your best bet (after trying a different speaker, thankyou Leo) is to scope the output.

Fender tone stacks are notorious for clipping the bass frequencies looong before the mids & highs.

It may be (if the speaker proves good) that the owner is pushing it into distortion without realizing it.

A quick fix is to lower the value of the first preamp tubes cathode bypass capacitor.
Stock is 25uf.

Schematic:

Deluxe_Reverb_ab763.zip

[hewo]

client requested bring me rectifier tube, spkr, pan

This is not a high power amplifier.

Your best bet (after trying a different speaker, thankyou Leo) is to scope the output.

Fender tone stacks are notorious for clipping the bass frequencies looong before the mids & highs.

It may be (if the speaker proves good) that the owner is pushing it into distortion without realizing it.

A quick fix is to lower the value of the first preamp tubes cathode bypass capacitor.
Stock is 25uf.

Schematic:

[ATTACH]37051[/ATTACH]

Ok, I'll get those parts from client, only chassis brought alone.