prob with amp...any ideas?


New member
hey dudes,

my amp's master volume fades in and out every now and then. any ideas what could be wrong? and turning the volume knob doesn't change the vol at all. it kinda maintains the level, so, the vol knob is ineffective.
hope someone can help...thks!
its a trademark 10 btw...

my friends tech 21 trade mark 60 all had the same problem.

i think its the contacts of the knobs.
go get yourself a can on contact cleaner spray... remove knobs and spray inside and twist and turn the knobs. it should work.
hey chanmin! thanks for the suggestion. will give it a shot. er...what is a contact cleaner ah? WD40 ah? and how does one remove the knobs?
ok basically the tech 21 is the chicken knobs you just yank them off... spray contact cleaner liberally...put back the knobs... and rotate the knobs vigorously...

haha it worked for my friend's amp though... seems to be a common prob with trademark series.. esp in singapore's humid weather.
ok don't just yank off the chicken head knobs! there might be a screw that you need to loosen before removing the knobs... look around the knob for a tightening screw - loosen and then remove.

contact cleaner isn't WD40... just go down to your neighourhood hardware store and ask for contact cleaner. happy spraying!
heya, don't know if i got the right fluid but i guess better safe than sorry. have taken out the thing to look at it, ain't much to look at really. haha. i got a can of selley's anti-rust thinggie will that do the trick?
am still waiting for tech21 to email me back. hope they got some ideas too. maybe the pot itself is whacked..? hope not..
anyways, i took the thing apart and tried cleaning it. it worked for a bit. but now the sound is fading in and out again. sigh...
hmm sounds like you'll need to bring it back to the dealer to have it serviced... sinamex is the dealer right? their after-sales is not too bad...

btw selley's anti-rust is not contact cleaner...
okie for the benefit of those who might face the same prob in future...

got a reply from TECH21 ...these guys are super fast...

basically, use contact cleaner as suggested above to clean out the knobs first. if still don't work, then spray the inputs/outputs (fx loop, spkr extension, headphones out...) and then use a jack to insert/pull out about 25-30 times to clean it out. cos that could be causing the signal to break up. problem is with oxidization due to humid climate. nothing wrong with spkrs / amp. just needs cleaning properly every now and then.


p.s. my amp working beautifully again... :)