Vyper 120 tube amp problem

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Vurrich
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Vyper 120 tube amp problem

Post by Vurrich » Wed Nov 18, 2015 7:11 pm

I have the Vyper 120 tube amp 2-12" speakers

It stopped making sound while playing the other night.
Took wireless off and plugged in a cable, tried another Axe. Same thing with no sound. tubes are lit well
I had changed out the pre-amp tube so I changed it back out.
Everything lights up but no sound whatsoever.


I can get the amp tubes checked where?
Certified Peavy repair center?


amp always sounded good.
I bought it like new from an individual with tags on it about two year ago.
Very little hours on it
It has blown fuses for unknown reasons on occasions

Classic30inCincy
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Re: Vyper 120 tube amp problem

Post by Classic30inCincy » Wed Nov 18, 2015 10:58 pm

Replace The Power Tubes...... :!: :idea: :!:

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robdean
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Re: Vyper 120 tube amp problem

Post by robdean » Thu Nov 19, 2015 3:18 am

Always wise to try putting a patch lead across the fx loop in case of a dirty connection in the send/return.

Also, try listening to the fx send - if there is signal there, the preamp is OK. Similarly, if plugging an external signal into the fx return makes loud, then you know the power stage is OK (fade in the signal else volume may blow your socks off).

Check there are no sneaky fuses you have overlooked - they are cheaper than tubes ;-)

And of course you have checked the speaker and cable? Tapping the poles of a 9v battery across the tip/sleeve of the jack should get a click/thump from the speaker. Don't forget to plug the jack back in right away after the test.

But after those brief checks, tubes are next suspect. Having a spare tube or two is very handy in such situations (and you never know when such a situation will arise ;-/ )

You don't need a Peavy specialist to check tubes. Unless you have a friendly local it may be cheaper to buy tubes and swap 'em yourself - even if not a fix, you'll get spare tubes out of it. Even just one spare tube is useful: simply swap out one at a time. But if none of the above solves things, then a tech will be required. Not sure they need be a Peavey service centre if an experienced freelance tech is much easier to get to - but that decision is much to do with your local circumstances and depth of pockets...

robdean
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Re: Vyper 120 tube amp problem

Post by robdean » Thu Nov 19, 2015 3:49 am

PS thinking about it again, I believe a Vypyr 120 should work at half-power with just two power tubes in place. Can someone here say which positions? That way you could test by swapping around your existing set of tubes to find if one is dead... (and BTW you may be surprised how loud 'half-power' is!)

rogue777
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Re: Vyper 120 tube amp problem

Post by rogue777 » Thu Nov 19, 2015 8:25 am

I'd go with the sneaky fuse idea.

I Googled Peavey Vypry 60 schematic and look at images. There is an image of Vypyr power supply. About every supply has a fuse, or two in it. That's F1-F5, five fuses at least to start with. Focus on power supply first. Replaces any open fuses with correct part from Peavey. If you find an open fuse also check power supply components for that supply. I figure the Vypyr 60 schematic is very close to the Vypyr 120 schematic.

Before you take it all apart, try a factory reset. Reboot the amp from a cold start, does it complete the Led sequence ok? And I would suggest you also call Peavey tech support for advice and help. If all the leds work, the pwr supply's may be ok. The other suggestions about the tubes may be it or part of the problem. Ck spkr cable.

Vurrich
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Re: Vyper 120 tube amp problem

Post by Vurrich » Fri Nov 20, 2015 11:40 am

Thanks for the replies guys
not sure what the sneaky fuse thing is but I did replace my main fuse just to see and put my original pre-amp tube in.
Got to find time to try the other test suggested and buy an extra tube.
You're talking are over my head on this stuff

My first Peavey amp lasted through the 70's and 80 without any problems til it got stolen.
This amp sounds great and so many diverse sounds yet seem problematic.

this amp blew about 6 fuses this year. no loose tubes.

robdean
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Re: Vyper 120 tube amp problem

Post by robdean » Sat Nov 21, 2015 3:01 am

'Sneaky fuse' was just a way of suggesting that there can sometimes be another fuse you have not noticed. The circuitboard of my Ultra has at least three fuses on it...

BTW blowing all those fuses is a concern. The underlying cause for that is probably worth looking into, if it continues or if you end up needing to take the amp to a tech anyway.

Enzo does not appear to have picked up on this discussion, he's the expert around here.

Vurrich
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Re: Vyper 120 tube amp problem

Post by Vurrich » Mon Nov 23, 2015 12:28 pm

Thanks
This seems a little more advanced than I am ready for.

airxxxwolf
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Re: Vyper 120 tube amp problem

Post by airxxxwolf » Sat Dec 26, 2015 1:46 pm

Did you ever find the problem? My Vyper 60 tube amp was doing
the same thing and I found that it had a bad input jack...

Vurrich
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Re: Vyper 120 tube amp problem

Post by Vurrich » Tue Jan 21, 2020 10:23 pm

I blew a single fuse more than once and found I needed all new tubes.

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