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Topic: Bad pot or jack? |
Nathan Guilford
From:
Oklahoma City
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Posted 23 Jul 2013 9:28 pm |
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I had a intermittent scratchy sound tonight that I couldn't track down. Tried different cables and amps. Is this what a bad volume pot sounds like? Could it be the jack on the volume pedal? Help?
_________________
'02 Carter S-12 uni
‘76 MSA D-12
www.toothbrushers.com |
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Lane Gray
From:
Topeka, KS
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Posted 23 Jul 2013 10:06 pm
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In the absence of more detailed symptoms like under what conditions it happens, I would first suspect the volume pedal. It is the weakest link in the chain and most likely to fail.
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
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Posted 23 Jul 2013 11:01 pm
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Nathan,
As Lane said, probably a bad pot in the pedal. Couple things to keep in mind. If you're not actually playing, there won't be any scratchy noise. It only happens when signal is applied. Also, it only happens while changing volume with the pedal. No pedal motion, no scratch. (usually. . . that is)
Best regards,
Craig Baker 706-485-8792
cmbakerelectronics@gmail.com
C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024 |
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Nathan Guilford
From:
Oklahoma City
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Posted 24 Jul 2013 4:30 am scratchy
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That's what I thought too, Lane. And good point Craig. Actually it happens even if the pedal is not being actuated. I use a Goodrich 120 and a couple of pedals into a Peavey. It would best be described as a crackle, crackle, then nothing. Confusing! As I said, I substituted cables, but no change. It will be fine for a song or two and then act up and then quit. I think before I go replacing pots, I try to borrow a vol pedal to diagnose. Thanks for the help.
_________________
'02 Carter S-12 uni
‘76 MSA D-12
www.toothbrushers.com |
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Lane Gray
From:
Topeka, KS
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Posted 24 Jul 2013 4:41 am
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Peavey what? If you have loops, the switching jacks are notorious for that.try running short cables from out to in.
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
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Posted 24 Jul 2013 5:19 am
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Nathan,
It sounds like you've eliminated the volume pedal. The cause is usually microscopic arcing somewhere in the chain. Could be a part breaking-down, or a solder connection that barely passed quality control. Remove items from the chain one-by-one and you should find it before long. Nothing harder to chase than an intermittant problem. Please let us know your findings.
Play well and best regards,
Craig Baker 706-485-8792
cmbakerelectronics@gmail.com
C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024 |
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Jack Stoner
From:
Kansas City, MO
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Posted 24 Jul 2013 5:46 am
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| A bad coupling cap somewhere can cause this, although not the only cause. |
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Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
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Posted 24 Jul 2013 6:45 am
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Jack is 100% correct. Especially electrolytic caps. They're just like people. If they sit around too long, they'll dry out and go bad.
Best regards,
Craig Baker 706-485-8792
cmbakerelectronics@gmail.com
C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024 |
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Steve Lipsey
From:
Portland, Oregon, USA
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Posted 24 Jul 2013 6:48 am
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and check your power connections to your pedals, and the power cables...a flaky one there also would do exactly what you describe.
_________________
https://www.lostsailorspdx.com
Williams S10s, Milkman Pedal Steel Mini & "The Amp"
Ben Bonham Resos, 1954 Oahu Diana, 1936 Oahu Parlor |
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Bob Hoffnar
From:
Austin, Tx
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Posted 24 Jul 2013 7:58 am
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Try running a short cable from the pre eq output into the pre eq input.
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Bob |
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Bob Hoffnar
From:
Austin, Tx
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Posted 24 Jul 2013 8:04 am
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From an old thread
| Jack Stoner wrote: |
There can be problems with some of the jacks in the amp. Connect a guitar cord between the preamp out and the power amp in and see if that does anything. If not, connect the guitar amp cord between the effects loop out and the effects loop in. If either one of these makes it work again there is a problem in the contacts on the jacks. Sometimes just plugging in and out a couple of times will operate the jack contacts and fix them, but if it don't it will have to be taken apart and contact cleaner sprayed on the jacks to try and get them going.
If it's not a jack problem, it COULD be one of the Molex connectors inside. If yo have to get into it, Disconnect each Molex connector, spray both the male and feamle pins with contact cleaner and then reconnect. Same way with the "flakey" Molex connector for the reverb.
If this doesn't fix it, it's time for a trip to the repair shop. Although you will have to ship it, the Peavey factory repair center is the best option (and their prices are very reasonable). |
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Bob |
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chris ivey
From:
california (deceased)
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Posted 24 Jul 2013 8:44 am
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| sounds like a chord or amp. eliminate/check every chord and effect . it's in there somewhere. |
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Nathan Guilford
From:
Oklahoma City
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Posted 24 Jul 2013 9:03 am
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| Lane Gray wrote: |
| Peavey what? If you have loops, the switching jacks are notorious for that.try running short cables from out to in. |
I'm a bit embarrased to say it (and that's why I omitted it first) but my amp is a Bandit 112. Yeah, yeah...please don't throw any rotten tomatoes. It's what I started with and I've done some mods along the way. Really some surprisingly sweet tones out of it. It has an effects loop, but I believe it is post eq.
I'll try the easy stuff first. power cables, in/out jacks and I'll open it up and look at solder joints, but the caps in the amp scare me! Isn't this the part that everyone warns you against monkeying around with? LOL!
Thanks for the help everybody, I'll work on it and post when I figure it out. Let me know if y'all think of anything else.
_________________
'02 Carter S-12 uni
‘76 MSA D-12
www.toothbrushers.com |
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Craig Baker
From:
Eatonton, Georgia, USA - R.I.P.
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Posted 24 Jul 2013 12:36 pm
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Nathan,
With no cord plugged into the amp, The amp should be dead quiet. If that's where your static is, it may be time for an good amp repair tech. I don't remember the Bandit. Tube or transistor? Either way, if you're going to do the work yourself, be careful. You can damage a transistor amp, and a tube amp can damage you.
Best regards,
Craig Baker 706-485-8792
cmbakerelectronics@gmail.com
C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024 |
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Lane Gray
From:
Topeka, KS
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Posted 25 Jul 2013 1:14 am
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It's an 80 watt "TransTube" amp. I think that means tube preamp and SS power.
If you can get a good tone you like out of it, sounds better than the Nashville 112
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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Jack Stoner
From:
Kansas City, MO
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Posted 25 Jul 2013 2:27 am
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"TransTube" is Peavey's designation for transistors that are run to mimic tubes. It does not indicate part solid state and part tube.
E.g. the Peavey TransTube Fex unit, which is all solid state but the preamp is operated in a way that mimics tube operation. The TransTube Fex is the solid state version of the TubeFex which does have 12AX7 tubes in the preamp section. |
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Lane Gray
From:
Topeka, KS
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Posted 25 Jul 2013 3:06 am
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Thanks, Jack. A brief googling didn't turn up much detail.
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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Jack Stoner
From:
Kansas City, MO
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Nathan Guilford
From:
Oklahoma City
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Posted 25 Jul 2013 2:05 pm
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The main reason I have this amp is because it is cheap. I got it from a friend for $70. Loud clean, the reverb hums, the distortion side sounds bad in my opinion. But I put some new chips in it for more headroom, replaced the frayed power cord, and it has a good sound at a medium volume. For the past couple of weeks I've been putting a art vocal tube preamp in front of it and that sweetens the tone too. Just kinda using what I got. So far I've cleaned all relevant jacks and no crackle anymore. <shoulder> <fingers>. Could it just have been "dirty power" problem at the site?
_________________
'02 Carter S-12 uni
‘76 MSA D-12
www.toothbrushers.com |
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