input problem, help!

  • Thread starter Thread starter mikeanniston
  • Start date Start date
M

mikeanniston

New member
ok this is kind of a strange problem, i plan on bringing my amp in but just havnt gotten around to it yet. on my jcm 800, i plug into the high sensativity jack, and play away. sometimes when i turn down the volume on my guitar to clean up the sound a little bit, after a few seconds of playing, the sound gets scratchy and cuts out. its not my guitar, because i thought it might have been and put a new jack in. my cables are all brand new and work fine on other amps, and if it were a problem with the input on my jcm 800 wouldnt it cut out like that all the time, not just when theres a lower signal coming from the guitar due to cutting back on the volume? it has to be something with the weaker signal being pushed thro from rolling the volume back, but i really dont know... whats everyones insight? thanks!
 
ya got me on this one... and like you i would expect it to do it irrespective of how hard it's being driven at the input... all i can suggest is take it logicly the next time it happens and wiggle connections and pots etc till you can predict when it will happen... intermittent problems can be nerve wracking and expensive when on the bench... since ya cant fix it if it aint broke... sometimes it takes hours on end... sometimes it aint the $2 part... it's which $2 part...
 
mikeanniston said:
ok this is kind of a strange problem, i plan on bringing my amp in but just havnt gotten around to it yet. on my jcm 800, i plug into the high sensativity jack, and play away. sometimes when i turn down the volume on my guitar to clean up the sound a little bit, after a few seconds of playing, the sound gets scratchy and cuts out. its not my guitar, because i thought it might have been and put a new jack in. my cables are all brand new and work fine on other amps, and if it were a problem with the input on my jcm 800 wouldnt it cut out like that all the time, not just when theres a lower signal coming from the guitar due to cutting back on the volume? it has to be something with the weaker signal being pushed thro from rolling the volume back, but i really dont know... whats everyones insight? thanks!
Click to expand...

It sounds to me like it could be a dirty input jack or a cold solder joint somewhere in the signal path. I assume you've tried the same guitar and cable through another amp to discount that variable.
 
yess i have, ive playing with other guitars and cables and used the same guitar and same cables on other amps and no problem. its really weird, but obviously something with the 800...
 
mikeanniston said:
ok this is kind of a strange problem, i plan on bringing my amp in but just havnt gotten around to it yet. on my jcm 800, i plug into the high sensativity jack, and play away. sometimes when i turn down the volume on my guitar to clean up the sound a little bit, after a few seconds of playing, the sound gets scratchy and cuts out. its not my guitar, because i thought it might have been and put a new jack in. my cables are all brand new and work fine on other amps, and if it were a problem with the input on my jcm 800 wouldnt it cut out like that all the time, not just when theres a lower signal coming from the guitar due to cutting back on the volume? it has to be something with the weaker signal being pushed thro from rolling the volume back, but i really dont know... whats everyones insight? thanks!
Click to expand...

Does the amp have an effects loop, possibly using the cheap jacks that most amps use these days? I have had several amps that would lose volume after a while and it turned out to be that effects loop and the cheaps components.
It also might help to clean the jacks with a contact cleaner on a q-tip since there might be corrosion built up in there....:confused:
 
ever check the volume pot? thats what causes scratchyness in the sound and crackles. maybe when you hit the certain 'low point' it just craps out. i agree, check FX loop. on my valvestate, it has cheap inputs and i realized that it always used to randomly go out before i knew what an FX loop was, so id punch the amp and itd work...then i realized i needed a jumper plugged in, or my fx run through it, to complete a signal and get the sound to always work....must be bad solder points inside on the fx loop
 
You must log in or register to reply here.
Back
Top