The Chetboard

Happy New Year, fellow Chet-boarders!
O.K., here's a question for those of you knowledgeable about electronics. I have a 2006 Nashville Classic and the gentleman I purchased it from had worked as a repairman in various music stores over the years and he told me he had installed a treble-bleed capacitor on the master volume control. It did it's job as the guitar sounds crystal clear even at very low volumes. The problem I'm having is that after playing for an hour or so, all of a sudden there will be a big drop off in volume and the sound becomes very distorted, like it would if you had a bad cable or something. I've ruled out bad cables and all the obvious things.The funny thing is that everything goes right back to normal within 30 seconds or so and then it never happens again during "that" playing session even if I go on to play for a couple more hours. It's not the amp, as it did this with one that I recently sold as well as the new Traynor I recently purchased. So, what I'm wondering is would it act this way if it was the treble-bleed capacitor going bad? I know very little about electronics and was wondering, do these things "heat-up" and break down temporarily? I do fiddle with the volume and tone knobs alot trying to tweak in that "perfect" sound on each tune I play and was wondering if that would somehow tax the capacitor and cause this. Please forgive my ignorance but, I'm grasping at straws here and any help or suggestions from those of you that know about such things would be greatly appreciated. Thanks, Tom W.

Chances are its more a bad solder connection or a lead intermittently touching something, capacitors working at low voltage don't often break down and suddenly go right again(but just to clear myself i guess theres a very very slim chance it could)
Rob(uk)

could it be your amp?

I kinda agree with Rob. I think a capacitor either works or it doesn't. Bad solder joints are a nightmare to track especially if it's an intermittent problem.

I'd check and see if the guitar does it on another amp.

You might look up how to clean contacts on a pot. there may be dust in the potentiometer. They used to make spray on pot cleaner that used a pipette like WD-40 so you could direct the spray better. Get some, read the directions and try that.

If you ever find a solution let us know what it was

Tom Workman wrote:he told me he had installed a treble-bleed capacitor on the master volume control.
It's not the amp, as it did this with one that I recently sold as well as the new Traynor

Couple of ideas. What else is on the household circuit where you plug in the amp? Do you play other guitars thru that amp on that circuit witout issue? Best, Mark

LMark wrote: What else is on the household circuit where you plug in the amp? Do you play other guitars thru that amp on that circuit witout issue? Best, Mark

Hmmm... Mark Knophler once mentioned you could hear Leona's refrigerator kick in on Chet's recording circiut so LMark may be onto something there...

(Victory! Finally figured out how to get the quote thing to work!!!!)

Take the guitar and amp to a different room that's on a different circuit to see if the problem still exists.

If it does, then take them to another building that's fed from another utility company transformer to see what happens . . .

I had a similar problem at a condo that I'd rented that was about 1000 feet from a sub station.

There was a guy from the cable TV company working on a signal noise problem at another unit. I'd struck up a conversation with him, where he'd asked me if I'd been experiencing any picture noise problems.

I'd told him that I hadn't noticed any picture noise, but I had a 60 CYCLE HUM FROM HELL in my audio system ! ! !

The old-timer, a guy in his 60's, immediately walked over to a copper grounding rod, grabbed and pulled about a 10" section of the 8ft. rod that had broken off, as the soil here (high in manganese & zinc) had literally eaten the copper in two.

He went to his truck, came back and drove a new rod in the ground, re-connected the ground wire, solving a problem that other cable company legends in their own minds were unable to resolve for several years from what I'd been told by my neighbor . . .

Tom,
Check the nut that holds the input jack on the guitar. Ocassionally, the nut on my guitar gets a little loose affecting the connection and then the sound is intermittent. I think it's from putting the guitar cable in and out every day. I've had to tighten it a couple of times and now I keep a look out for that.
Thanks,
GaryL

Gary... can't you put a lock washer on that thing to eliminate that?

GaryL wrote:Tom,
Check the nut that holds the input jack on the guitar. Ocassionally, the nut on my guitar gets a little loose affecting the connection and then the sound is intermittent. I think it's from putting the guitar cable in and out every day. I've had to tighten it a couple of times and now I keep a look out for that.
Thanks,
GaryL

I assume you're speaking of the 1/4" OUTPUT jack on the lower bout of the body. There's really no way that the nut holding the jack into the body being loose will cause any noise unless it was a steel-body Dobro.

BTW . . . Slightly squeezing the nut out of round in a vise will permanently solve the problem of it loosening.

If it were anything even remotely related, it would be the ground wire at the tail pin that grounds the strings to the instrument's electronics, in this case through the Bigsby.

I usually loosen the strings, remove the strap knob and screws, flip the tail hinge of the Bigsby up, re-position the ground wire to obtain a better connection and then re-tighten the aforementioned . . .

BTW Gary, If the loose output jack nut is causing an intermittent connection noise, you should remove the nut, remove the bridge pick-up, snag the jack with a hooked piece of wire back through the bridge pick-up cavity and examine it for loose contact tension or physical damage.

If the aforementioned are ALL OK, look for cold or faulty solder connections . . .

OK . . . I'd read, and re-read Tom's original post several times, and this is what I come up with . . .

If this so-called treble-bleed cap (???) that this guy installed is a bi-polar cap with too low of a voltage rating, it could be charging to it's peak and then rolling the higher frequencies off until it's discharged . . .

http://wpc.077d.edgecastcdn.net/00077D/gretsch/support/schematics/wiring/G6122-1959-Chet-Atkins-Country-Gentleman-Circuit.pdf

NOTE: the 22.3K CAPACITOR illustrated for the MASTER TONE POT is supposed to be a .022uf 100V RADIAL or AXIAL CAPACITOR.

BTW . . . Adding a cap to the master volume pot would render the master tone pot ineffective.

I have absolutely NO IDEA what he was trying to do here ? ? ?

Also . . . If you're frequently adjusting the controls, you might consider upgrading to CTS, Centralab or Allen-Bradley pots, with maybe a QUALITY CAP and a Switchcraft 1/4" output jack as I've heard that Fred Gretsch chose to cheap out on their quality during the pre-production bid specification.

I wonder HOW MANY dead Gretschs have left a player on stage with his panties down round his ankles ? ? ?