Hi all,
I have had a Triumph PAG 60 for about 5 years now. Just recently It has been acting up/ noisy lots of background .
I have replaced the V1 tube with a good new one, no change.
I took the chassis out and reseated all of the ribbon connectors, no change
Probing the circuit board with a non conductive probe I have found c13 extremely sensitive to tap tap tap.
Also the third wire on the ribbon connector closest to V1 and wire 3 on V2 are also very micro phonic!
any suggestions on what to check would be extremely helpful.
I have enough electronics background to not kill myself and able to measure test points but need some help
This is my Gigging amp.
PS
I have found the spring in the reverb tank has come apart , I have ordered an new tank. the plug is now disconnected from the chassis.
So reverb is not the issue with the sensitive caps and ribbon cable
TIA
Robmo
Triumph PAG 60 very microphonic
Re: Triumph PAG 60 very microphonic
Did you try other position tubes? I mean other than V1?
While it is running, tap on each tube with a pencil or something. Anyone else sensitive? When you tap on the cap, you are also vibrating everything around it. But the simple test is to just replace it and see.
While it is running, tap on each tube with a pencil or something. Anyone else sensitive? When you tap on the cap, you are also vibrating everything around it. But the simple test is to just replace it and see.
Re: Triumph PAG 60 very microphonic
Enzo,
Yes I have replaced them all. I have tried many new tubes in the V1 position and all about the same.
The c13 cap is the most sensitive area to tap tap, even the slightest touch is audible.
Second sensitive area to tap/touch is the ribbon cable that come from v1 and v2 that are draped over some electrolytic caps c56 and c57. particularly the third wire.
Yes I have replaced them all. I have tried many new tubes in the V1 position and all about the same.
The c13 cap is the most sensitive area to tap tap, even the slightest touch is audible.
Second sensitive area to tap/touch is the ribbon cable that come from v1 and v2 that are draped over some electrolytic caps c56 and c57. particularly the third wire.
Re: Triumph PAG 60 very microphonic
I have also checked all the other tubes for micro phonics, they are good.
Re: Triumph PAG 60 very microphonic
SO did you replace the cap?
Re: Triumph PAG 60 very microphonic
Not yet. I dont even have one to jumper it with. I am thinking about a full recap anyways due to its age. To replace the cap I have to pull the board out so might as well give it a full freshen up. I really like this amp.
Re: Triumph PAG 60 very microphonic
Enzo,
My mistake it is C12 that is sensitive. What does that cap do?
My mistake it is C12 that is sensitive. What does that cap do?
Re: Triumph PAG 60 very microphonic
PAG 120 schematic
- Attachments
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- Peavey Triumph PAG 120 Schematics.pdf
- PAG 120 Schematic
- (808.7 KiB) Downloaded 126 times
Re: Triumph PAG 60 very microphonic
Just signal path from post controls up to grid of V1b.
Jumpering a microphonic cap with another - I assume you mean tack in parallel - won't make the one still there less microphonic. ie test won't work there.
In general, electrolytic caps age and merit replacement after a while. Film caps and ceramics generally don't. individual caps may fail, but mostly no reason they won't last 50, 75, who knows how many years. Replacing every cap in an amp is just adding all those opportunities to add problems. Just my opinion. Anything with a polarity, pretty much, is what ages.
Peavey back in the 70s, in the days of transistor preamp stages - before op amps - used a ton of little 2uf 35v e-caps, and I can count on every one of them being leaky at this point.
Jumpering a microphonic cap with another - I assume you mean tack in parallel - won't make the one still there less microphonic. ie test won't work there.
In general, electrolytic caps age and merit replacement after a while. Film caps and ceramics generally don't. individual caps may fail, but mostly no reason they won't last 50, 75, who knows how many years. Replacing every cap in an amp is just adding all those opportunities to add problems. Just my opinion. Anything with a polarity, pretty much, is what ages.
Peavey back in the 70s, in the days of transistor preamp stages - before op amps - used a ton of little 2uf 35v e-caps, and I can count on every one of them being leaky at this point.
Re: Triumph PAG 60 very microphonic
Enzo,
If you weren't so far from me I would consider shipping you the chassis!
That would be expensive.
If you weren't so far from me I would consider shipping you the chassis!
That would be expensive.
Re: Triumph PAG 60 very microphonic
It would be especially expensive as I retired a few years ago and no longer have a shop. I'd have to send it right back.
I have to believe in a place the size of Tucson, there are competent amp techs.
I have to believe in a place the size of Tucson, there are competent amp techs.