Start problem with Peavey vyper 75 w

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mokko
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Start problem with Peavey vyper 75 w

Post by mokko » Fri Jul 22, 2022 4:45 pm

have this amp since 2010 and don't star properly. Sometimes the lights don't start, but hear a sound, sometimes only the green lights start with no sound, and after a few tries it start normally. I press the amp modeling button a few seconds and the amp closes down. Is a software issue or board? Now I discovered everytime I touch the amp and efectts button the amp shut , but still irregular lights or shutdown.

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JamesPaul
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Re: Start problem with Peavey vyper 75 w

Post by JamesPaul » Thu Jul 28, 2022 6:27 pm

The original, first generation, Vypyrs would sometimes experience start issues. You can check that the firmware is current, which may help. Otherwise it was just to keep powering on/off. Some Deoxit on the Power Switch may also help.

The encoders, controls, will get dirty over time. You can try taking the knobs off, and spraying some Deoxit into them. Spin the encoder shaft after spraying. This may help with the erratic behavior when touching controls.
Enzo wrote:I find if the amp is working, that is a good point to stop fixing it.
James Paul's Peaveys
Decade, Classics, Ecoustic, Windsors, VYPYR, Triple XXX, XXL, VKs, Bandit, JSXs, VIP, Piranha and a Penta.

mokko
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Re: Start problem with Peavey vyper 75 w

Post by mokko » Fri Jul 29, 2022 7:04 am

I used to start on and off and now don't do nothing. The amp is dead

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JamesPaul
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Re: Start problem with Peavey vyper 75 w

Post by JamesPaul » Fri Jul 29, 2022 11:48 am

There are not a lot of serviceable parts, they were mostly designed with board swaps for repairs. A power supply board repair is probably a place components could be changed. There and I know people have changed encoders.

Any pops from the speaker when you power it on?
Enzo wrote:I find if the amp is working, that is a good point to stop fixing it.
James Paul's Peaveys
Decade, Classics, Ecoustic, Windsors, VYPYR, Triple XXX, XXL, VKs, Bandit, JSXs, VIP, Piranha and a Penta.

AlexxThreeSixx
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Re: Start problem with Peavey vyper 75 w

Post by AlexxThreeSixx » Tue Sep 06, 2022 9:18 pm

I too am having problems with my 75w but mines pops and then my distortion settings sound flat if that makes sense? Or like almost as if they had no gain at all any tips on what i should look into changing?

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JamesPaul
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Re: Start problem with Peavey vyper 75 w

Post by JamesPaul » Thu Sep 08, 2022 3:52 am

AlexxThreeSixx wrote:
Tue Sep 06, 2022 9:18 pm
I too am having problems with my 75w but mines pops and then my distortion settings sound flat if that makes sense? Or like almost as if they had no gain at all any tips on what i should look into changing?
Welcome to the forum.

So a pop from the speaker when you power it on? That is typical.

For the decreased gain, does the "pre gain" encoder appear to be operating normally? All the LEDs are still lighting up consistent with turning the encoder? One test which may help determine the issue is the encoder is, if previously saved presets still have the normal gain, and it is only when you are trying to dial in new presets the gain is low. I have seen reports of encoders behaving erratically. The erratic behavior was actually resolved by pulling off the encoder knob, spraying some Deoxit into the encoder, and then turning the encoder shaft both ways a few times. This may be worth a try as it does not take long, is inexpensive, and if you own a guitar amp and do not already have some Deoxit (or your favorite electronics cleaner) you will need it eventually.

Beyond the encoder, and if your previously saved presets have this decreased gain, this is my next thought. One of, if not, the biggest innovations with the Vypyr was Peavey's use of their analog TransTube (Chapter 3 - TransTube®) circuitry to produce the preamp tube distortion for the amplifiers being modeled. That frees up cycles on the Digital Signal Processor. It is possbile that one/some of those analog components, or their supply voltages, could be failing. Unfortunately although still analog components, they are implemented with SMDs to save space. Unless you have capabilities to change SMDs, there is likely not a lot that can be done. Possibly something could be done if it is the supply voltages.

Please try the preset and encoder testing, and let us know what you find.
Enzo wrote:I find if the amp is working, that is a good point to stop fixing it.
James Paul's Peaveys
Decade, Classics, Ecoustic, Windsors, VYPYR, Triple XXX, XXL, VKs, Bandit, JSXs, VIP, Piranha and a Penta.

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dak
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Re: Start problem with Peavey vyper 75 w

Post by dak » Thu Sep 08, 2022 6:14 am

JamesPaul wrote:
Thu Sep 08, 2022 3:52 am

Unfortunately although still analog components, they are implemented with SMDs to save space. Unless you have capabilities to change SMDs, there is likely not a lot that can be done. Possibly something could be done if it is the supply voltages.
In my experience, a fine solder tip, desoldering wick, lots of time, cursing and retrying, a multimeter and a looking glass, probably good tweezers are basically what counts as "capabilities to change SMDs" if you have a good plan of what you are doing. Unfortunately when tracking down errors, one tends not to have a good plan and occasionally has to remove and reconnect parts for checking out things. And this taking half an hour instead of a minute affects feasibility and motivation...

And these days, I'd also want better eyes to work with. I probably need to come up with some hands-free way of using a looking glass.

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