webster Posted May 20, 2004 Report Share Posted May 20, 2004 hey my amp has a problem with what i think is the switch. When i turn the amp off it makes a bang noise. It only does it when the amp is on clean channel and not on dist and it happens no matter if the vol is up or down. I can't work out what the problem is and can't even think of any posable causes, i think its the switch but since it only happens on clean i am confused. please help. Quote Link to comment Share on other sites More sharing options...
lovekraft Posted May 20, 2004 Report Share Posted May 20, 2004 What amp? Quote Link to comment Share on other sites More sharing options...
webster Posted May 20, 2004 Author Report Share Posted May 20, 2004 its a park G25R 25Watt Its crap but i still want it to work Quote Link to comment Share on other sites More sharing options...
nonamemx Posted May 20, 2004 Report Share Posted May 20, 2004 My amp pops. Its pretty common. Quote Link to comment Share on other sites More sharing options...
Curtis P Posted May 20, 2004 Report Share Posted May 20, 2004 mine makes a rattle sometimes, i think its pretty common, how old is it also? Curtis Quote Link to comment Share on other sites More sharing options...
lovekraft Posted May 20, 2004 Report Share Posted May 20, 2004 Sounds like the solution is to change to the distortion channel before you turn it off. I can't find any schems for any of the Park SS amps, so I can't really be much help, I'm afraid. Quote Link to comment Share on other sites More sharing options...
webster Posted May 20, 2004 Author Report Share Posted May 20, 2004 the amp is pretty old, i'd say maybe 6-8 year cos i bought it 2nd hand with a guitar a few years ago. Do you recon if i replace the switch it would fix the problem or is the switch not related to this problem. Quote Link to comment Share on other sites More sharing options...
ansil Posted May 20, 2004 Report Share Posted May 20, 2004 sounds like a voltage spike coming through the audio circuit. hmm anyone think it could be a faulty cap that his held open with a trickle charge and it completely discharges when the power is disengaged.. just throwing out ideas.. sometimes if you ahve a bad cap or one that is going bad it will do similar things.. Quote Link to comment Share on other sites More sharing options...
PaulNeeds Posted May 20, 2004 Report Share Posted May 20, 2004 try turning it down to 0 first. Quote Link to comment Share on other sites More sharing options...
Jon Bell Posted May 21, 2004 Report Share Posted May 21, 2004 sounds like a voltage spike coming through the audio circuit. hmm anyone think it could be a faulty cap that his held open with a trickle charge and it completely discharges when the power is disengaged.. just throwing out ideas.. sometimes if you ahve a bad cap or one that is going bad it will do similar things.. I know a guy who repairs TVs and stereos, etc. for a living. He's mentioned this problem before with guitar amps and he said its usually a cap thats going bad and is likely to fail (like what Ansil said). Quote Link to comment Share on other sites More sharing options...
webster Posted May 21, 2004 Author Report Share Posted May 21, 2004 it does it a bit on the distortion channel but its not as noticable. It happens no matter if the vol is all the way to 0 or 10. Quote Link to comment Share on other sites More sharing options...
webster Posted May 21, 2004 Author Report Share Posted May 21, 2004 so if it is a cap, can it be replaced? i dont really know what a cap is, if it can be replaced could it be done at home? Where could i got one? Quote Link to comment Share on other sites More sharing options...
nonamemx Posted May 21, 2004 Report Share Posted May 21, 2004 If you do have a faulty capacitor, how is this going to affect your tone? Somethings crazy with my amp right now. (Peavey Classic 30- all tube) The overdrive doesnt overdrive very much. I have brand new Groove tubes ( I replaced both power and preamp in my search for the tone solution) The clean isn't shimmering as much. Could all these problems be the fault of a screwy little capacitor? Quote Link to comment Share on other sites More sharing options...
lovekraft Posted May 21, 2004 Report Share Posted May 21, 2004 If you replaced all 4 El84s, I'd have somebody check the bias on the power tubes. Of course, in that amp, it could be anything from dirty relay contacts or a bad pot to power supply problems. You should let an amp tech take a look at it - it's going to be hard to diagnose the cause unless there's an obvious problem like a burnt resistor. Before you take it in, you might want to try pulling all the tubes (turn the amp off first, of course) and spray a little RatShaq tuner cleaner on the pins, wipe off any excess, and plug the tubes back in to see if you've got a dirty socket, and swap out each tube one at a time with a known good tube to see if you got a bad one (even new ones aren't always good). I'd also recommend either JJ or Sovtek tubes - GT spends a lot more on marketing, but their tubes have consistently disappointed me. Regardless, check everything you can, and if that doesn't fix it, call the doctor. Quote Link to comment Share on other sites More sharing options...
webster Posted May 21, 2004 Author Report Share Posted May 21, 2004 ok, i worked out my last question about the caps. My next question is if it is a cap how would i test them to find out if or which one? Quote Link to comment Share on other sites More sharing options...
nonamemx Posted May 21, 2004 Report Share Posted May 21, 2004 hmm. Its supposed to be Fixed Bias. Quote Link to comment Share on other sites More sharing options...
syxxstring Posted May 21, 2004 Report Share Posted May 21, 2004 ok, i worked out my last question about the caps. My next question is if it is a cap how would i test them to find out if or which one? The nice thing about caps is often they physically show signs of distress. The tops will bulge up. In my experience as a computer tech you can often see a physically bad cap. Example, a freind was having problems with his computer booting and then shutting down and not rebooting. Popped the side off, blew 5 years of dust out with the compressor. Wiped said dust off the front of my land rover.(you can skip this step if you dont have a rover, or dont point the dust at it) Booted it up and saw the caps on the mother board all had domed tops and the little croses at the top were split. They also became too hot to touch after about 30 seconds.(power anything off and know what your touching first, trust me I used to fix Pc monitors) He's getting a new mother board and to be safe powersupply.(often bad/weak ps will damage these type things) So what im saying is, if you are qualified. Unplug your amp let it sit for abit(overnite) so the circuits are all discharged. Remove the chasis and physically inspect everything. You may see burnt/cracked components, or caps with the tops bubbled or poped. When you can see phsyical signs of distress on a component you can put down the testing equipment and replace it. Quote Link to comment Share on other sites More sharing options...
webster Posted May 21, 2004 Author Report Share Posted May 21, 2004 ok, ill try that tonight and let you know how i go. thanks Quote Link to comment Share on other sites More sharing options...
webster Posted May 21, 2004 Author Report Share Posted May 21, 2004 i had a quick look at all the electronics and everything in there looks normal, i think. the only thing that looks a bit wrong is the green rectangular caps have little pointy things at the top. Is this normal or is this what you ment by bubbles? Quote Link to comment Share on other sites More sharing options...
syxxstring Posted May 21, 2004 Report Share Posted May 21, 2004 id have to see pics maybe Quote Link to comment Share on other sites More sharing options...
webster Posted May 22, 2004 Author Report Share Posted May 22, 2004 im sure if they are suppose to look like that, have a look. Quote Link to comment Share on other sites More sharing options...
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