Peavey Delta Blues

fig

fig

Village Idiot
On the bench is my somewhat dusty Peavey Delta Blues. Not the most heralded amp in the world, lacks a master volume, and is certainly a pain in the rump to work on. Be that as it may, it is a solid amp with reverb, tremolo, and an effects loop. The TV cab is heavy duty and puts out a beautiful tone with the 15" Blue Marvel. Lower frequencies are not being handled correctly (buzzing). I suspect a cap (or 6) but I am hoping one of you amp gurus might expedite my search. My thought process leads me to think it may be in the tone stack, but maybe that's a fairly shallow assumption.

Armed with my trust audio probe and what may as the schematic, I'll start my tracing.

IMG_4690.jpeg
 
I had one of those amps, the tubes rattled and drove me crazy at times, but it did sound good I also had a 15" extension cabinet to go under it
 
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Barry said:
I had one of those amps, the tubes rattled and drove me crazy at times, but it did sound good I also had a 15" extension cabinet to go under it
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This one is the combo, and definitely not for gigging! I think it outweighs me!

I've had this one a good while, but it was in storage a few years, then sat at my son's house unused (because he took my Fender Blues Jr IV) :cry: It would be nice to have working, depending on what I find out.

Edit: btw...I don't gig.
 
fig said:
This one is the combo, and definitely not for gigging! I think it outweighs me!

I've had this one a good while, but it was in storage a few years, then sat at my son's house unused (because he took my Fender Blues Jr IV) :cry: It would be nice to have working, depending on what I find out.

Edit: btw...I don't gig.
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Mine was a combo also and I had a 15" extension cabinet, kind of a mini double stack! and I did gig with it until I got my Twin Reverb (I'm talking small gigs, very small gigs, private parties and the such
 
So it buzzes when you play a low note? That sounds possibly more of a mechanical problem than an electronic one. I haven't heard of a SS Delta Blues - shows how out of touch with Peavey I must be! I though the Delta blues was a 15" speaker version of the Classic 30 with added tremolo.
 
Barry said:
Mine was a combo also and I had a 15" extension cabinet, kind of a mini double stack! and I did gig with it until I got my Twin Reverb (I'm talking small gigs, very small gigs, private parties and the such
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Yep, it's got the extension cab jack. That's cool!
 
HamishR said:
So it buzzes when you play a low note? That sounds possibly more of a mechanical problem than an electronic one. I haven't heard of a SS Delta Blues - shows how out of touch with Peavey I must be! I though the Delta blues was a 15" speaker version of the Classic 30 with added tremolo.
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It is a 15" version of the classic 30 with tremolo, who said anything about SS?
 
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HamishR said:
So it buzzes when you play a low note? That sounds possibly more of a mechanical problem than an electronic one. I haven't heard of a SS Delta Blues - shows how out of touch with Peavey I must be! I though the Delta blues was a 15" speaker version of the Classic 30 with added tremolo.
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Hamish, that's correct. I'll try to get a clip of it but it's almost like a distortion effect. You're also correct about it (virtually) being the same circuit as the Classic.
 
Barry got it! The OP states that "it is a solid amp" and I read that as "solid state amp"! My bad.

99% of issues with tube amps are tubes. I take it you have tried replacing tubes? The EL84s would be the first place I would look. Also, I recently watched a video by Psionic Audio on Youtube about servicing a Classic 30
. It was quite interesting. The filter caps are inexpensive IC brand and I would be changing those to F+Ts. The fella from Psionic really seems to know his stuff.

The way the circuit boards are connected looks like a recipe for disaster! Who ever thought that was a good idea??
 
HamishR said:
Barry got it! The OP states that "it is a solid amp" and I read that as "solid state amp"! My bad.

99% of issues with tube amps are tubes. I take it you have tried replacing tubes? The EL84s would be the first place I would look. Also, I recently watched a video by Psionic Audio on Youtube about servicing a Classic 30
. It was quite interesting. The filter caps are inexpensive IC brand and I would be changing those to F+Ts. The fella from Psionic really seems to know his stuff.

The way the circuit boards are connected looks like a recipe for disaster! Who ever thought that was a good idea??
Click to expand...
Yep, new tubes, and thank you so much for that video! You are right about the layout. Certainly not conducive to painless troubleshooting. It seems almost intentionally that way 😅

I'll get some capacitors ordered. Thanks again Hamish.
 
fig said:
I just HAD to use THAT word huh? Are you loving the twin reverb? I came real close to building it instead of the 18watt brit.
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It was my go to the little bit of gigging I did, it's on a dolly in the basement now along side the Marshall Bluesbreaker I won in a Truefire giveaway
 
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Okayyyyyyy, I have released the Kraken.

Disturbing note: When I removed the FX loop I/O retaining nuts, they were stripped. Apparently, they had come loose at some point and someone (I bought this in a pawn shop years ago) decided to keep that from ever happening again! I'll have to replace those jacks.

No board scorching (even under the resistors) so heat is not a major factor here. I'll clean the pots and swap the filter caps (still haven't ordered them....doh!).

Still can't get over this origami pcb assembly! 🤪

IMG_4696.jpeg
 
HamishR said:
Haha! I just love working on amps.
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Hamish, I have also heard about some Amps having issues where the Send and/or Return jacks are closed when not in use & they get corrosion on the point of contact & it causes all sorts of trouble just like a Dry joint in a circuit?
I know it's an issue with the original Budda Superdrive 80!
 
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fig said:
Okayyyyyyy, I have released the Kraken.

Disturbing note: When I removed the FX loop I/O retaining nuts, they were stripped. Apparently, they had come loose at some point and someone (I bought this in a pawn shop years ago) decided to keep that from ever happening again! I'll have to replace those jacks.

No board scorching (even under the resistors) so heat is not a major factor here. I'll clean the pots and swap the filter caps (still haven't ordered them....doh!).

Still can't get over this origami pcb assembly! 🤪

View attachment 11995
Click to expand...
What's in that Purple Box!?
 
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