Practice Amp Distortion / Does Anyone Even Try To Repair These ?

[Dennis D]

I'd put away my Peavey Envoy for a while and and brought it out again recently and it's developed what sounded like a ' loose screw ' buzz. So I actually glued and / or tightened all the screws I could reach, but even at low volume I'll get Low E distortion. Don't remember that happening before.
I bought this amp new 10 + years ago and it has never been on a gig. Do amp repair places even want to mess with $ 200. amp repair - or should I even bother ?

Any and all suggestions etc appreciated.

Thanks

[Litterick]

The buzz might be electrical. Have you tried plugging it into sockets in different parts of the house?

I am told that glueing a sheet of foil or aluminium to the underside of the top of the cabinet makes the Envoy a Faraday cage, blocking RF and EMF interference (presumably, the other sides are already shielded).

[burchyk]

You sure it is not a speaker cone rub?

[KirkP]

Try the amp with an external speaker and the internal speaker disconnected. Then try a different amp through the speaker in the buzzy amp. That will tell you if the problem is electronics or mechanical. Where you go from there depends in the result.

[Dennis D]

..not sure what ' speaker cone rub ' is......

...but for sure it's never been used at anywhere near 1/4 volume.....

Thx

[Dennis D]

Try the amp with an external speaker and the internal speaker disconnected. Then try a different amp through the speaker in the buzzy amp. That will tell you if the problem is electronics or mechanical. Where you go from there depends in the result.

Thanks - that makes sense......

Would headphones work as the external speaker ? I mean those would ( I think ) cut off the internal speaker, then I'd just listen for the distortion right ?

Interesting and thx again !.....

[KirkP]

Thanks - that makes sense......

Would headphones work as the external speaker ? I mean those would ( I think ) cut off the internal speaker, then I'd just listen for the distortion right ?

Interesting and thx again !.....

A schematic is online.
PEAVEY ENVOY 110 Service Manual download, schematics, eeprom, repair info for electronics experts

Looks like the headphone out is basically equivalent to a speaker out, so that’s worth a try.

If the buzz is present through the headphones, you could then plug the preamp out into a different power amp to determine if it’s originating from the preamp. That seems unlikely though.

On the other hand, if the buzz seems to be in the cabinet/speaker, you could try temporarily putting a different speaker in that cabinet and/or putting that speaker in another cabinet. It’s the process of elimination to isolate the problem.

[Dennis D]

A schematic is online.
PEAVEY ENVOY 110 Service Manual download, schematics, eeprom, repair info for electronics experts

Looks like the headphone out is basically equivalent to a speaker out, so that’s worth a try.

If the buzz is present through the headphones, you could then plug the preamp out into a different power amp to determine if it’s originating from the preamp. That seems unlikely though.

On the other hand, if the buzz seems to be in the cabinet/speaker, you could try temporarily putting a different speaker in that cabinet and/or putting that speaker in another cabinet. It’s the process of elimination to isolate the problem.

Thanks Kirk.
I at least found the name of the local Peavey warranty / repair guy. The ( cabinet or ? ) buzz appeared the first time I got it home and had to take it this same guy. Worst case I have to take it back to him fifteen years later.
I'll at least do the headphone test and go from there.

Appreciate it Kirk, and thanks again.

[Dennis D]

I'll at least do the headphone test and go from there.

Appreciate it Kirk, and thanks again.

Update......

I located the headphone mini-to-amp plug adapter and tried it. It didn't have any / seem to have any low-volume distortion at all, but half-way up I got the same Low E buzz.......

Hmmm......

[nevershouldhavesoldit]

I assume your headphones have an 1/8" plug and the phone-out jack is 1/4". Guitar cables have 1/4" plugs on them - if that fits into your headphone jack, it's 1/4". And if these dimensions are correct, you need a simple $5 1/8" female to 1/4" male adapter available at almost any electronics outlet, audio shop, music store etc that sells cables and adapters.

One of the commonest causes of rattles and buzzes that apppear only at a specific frequency or range is a loose part. Check all of the fasteners that hold the amp together, from those that secure the chassis in the cabinet to the speaker retaining nuts / fasteners. This includes the retaining nuts on the pots, jacks, switches etc. The cvibrations from playing through it can loosen almost any mechanically secured part over time. If it is a loose fastener, running into phones or an extension cab should eliminate the extraneous sound.

Also make sure it's not the guitar. Can you hear a rattle or buzz when you play the offending E unplugged? Do you hear rattling etc when you shake the guitar back and forth? I've had odd buzzes from weird things like a loose bridge height adjusting screw, a loose tuning machine locking screw, and a loose pickup. If you have another guitar, see if the problem is there with both.

[pauln]

I'd put away my Peavey Envoy for a while and and brought it out again recently and it's developed what sounded like a ' loose screw ' buzz. So I actually glued and / or tightened all the screws I could reach, but even at low volume I'll get Low E distortion. Don't remember that happening before.
I bought this amp new 10 + years ago and it has never been on a gig. Do amp repair places even want to mess with $ 200. amp repair - or should I even bother ?

Any and all suggestions etc appreciated.

Thanks

If you take it to be serviced, they are going to do things you can do yourself to diagnose the problem.

The screws holding the speaker to the motor board must NOT be tight; they should be only moderately firm.
The screws holding the motor board to the cabinet should have compressible washers that limit how tight they fit. If the amp has been stored a long time you might loosen the motor board and examine it for any warping due to moisture changes... buzzing on low guitar pitches often happens because the motor board is not fitting quite right.
Check that nothing like a wire or whatever is resting against the back of the speaker cone. Also, set the amp upright on the floor and then place it on its side, then upside down, them on its other side... listen for anything loose rolling or slipping around, especially anything that might have fallen into the back of the speaker.
Do as mentioned in post above - play amp through an external speaker, play speaker from another amp - see if you can isolate the buzz as an amplifier sound or a speaker/cabinet sound.

For all you know, a mouse made a little nest between the back of the speaker and the frame... or there is a dead roach stuck back there, etc...

You say you don't remember this happening before, but then say it happened when you first got it home (a similar situation to having been "left alone unplayed" for a while, in this case since manufactured). Did you find out what was the cause the first time?

[nevershouldhavesoldit]

The screws holding the speaker to the motor board must NOT be tight; they should be only moderately firm.

This is very important. Far more damage is done by overtightening fasteners than by undertightening them. Do not just crank down on every screw, bolt and nut in sight. If one is clearly loose, tighten it finger tight and only a little bit beyond that. If it comes loose again, either use a thread locker (like blue Loctite) or a locking washer or nut. If you're really twisting hard, you're twisting too hard. And if a threaded assembly (screw/bolt, washer(s) and nut) comes loose very quickly every time you tighten it, one or more pieces in it is probably compressed or worn enough to justify replacing all of the pieces (a cheap and simple matter).

[Dennis D]

If you take it to be serviced, they are going to do things you can do yourself to diagnose the problem.

You say you don't remember this happening before, but then say it happened when you first got it home (a similar situation to having been "left alone unplayed" for a while, in this case since manufactured). Did you find out what was the cause the first time?

Again, that first time fix was ten plus years ago, and not sure what got said, but it's been livable 'til recently........I did find some dry glue residue on the screws that hold the Peavey faceplate logo / trim pieces when I snugged those screws up last week..........

Thanks !!

[rpjazzguitar]

A lot of buzzing problems are mechanical, meaning something is vibrating that shouldn't be vibrating.

If you can open up the amp, reproduce the problem and then start pressing on things and wiggling wires (using something that doesn't conduct electricity like a wooden chopstick) you might get lucky and find the problem.

Parts that have mechanical stress, like input jacks, are particularly vulnerable. Although if it developed the problem while sitting in a closet that may argue for something else. Still the touch-and-wiggle method is free and easy.

Last time I did this it was for an Ampeg Reverberocket which had eluded diagnosis for years. The problem, discovered by wiggling wires, was that the RCA connector to the reverb tank had become loose over time. I had pressed it in many times without benefit. What it needed was for me to take it out, spread the little wings on the jack slightly wider and plug it back in. 10 second repair for free, once I figured out what was wrong.

Good luck!

[Dennis D]

A lot of buzzing problems are mechanical, meaning something is vibrating that shouldn't be vibrating.

If you can open up the amp, reproduce the problem and then start pressing on things and wiggling wires (using something that doesn't conduct electricity like a wooden chopstick) you might get lucky and find the problem.

Parts that have mechanical stress, like input jacks, are particularly vulnerable. Although if it developed the problem while sitting in a closet that may argue for something else. Still the touch-and-wiggle method is free and easy.

Last time I did this it was for an Ampeg Reverberocket which had eluded diagnosis for years. The problem, discovered by wiggling wires, was that the RCA connector to the reverb tank had become loose over time. I had pressed it in many times without benefit. What it needed was for me to take it out, spread the little wings on the jack slightly wider and plug it back in. 10 second repair for free, once I figured out what was wrong.

Good luck!

Funny you mention an Ampeg - -the practice amp this replaced was a Gemini w.15 in. Jensen........memories, memories.....: )

Thanks !!