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Title: it's really quiet and hums!!!! Post by: lstead on May 13, 2008, 03:23:42 AM hi guys,
i put it all together and the normal input just has a very faint guitar sound. the FET is much louder [still quiet, though] and buzzes. most of the background noise goes away when you touch the chassis! i had to swap out the brown and blue wires on the tubs, PIN 3 to stop a horrendous holwing noise. now i am stuck and rather depressed. any helpful suggestions??? thanks, laurie ps. not sure if any tone controls are working at this stage. Title: Re: it's really quiet and hums!!!! Post by: fred on May 13, 2008, 07:22:33 AM Oh dear, thats horrible when that happens. hmmm, well, you clearly have a grounding issue so it would be worth checking all of your earthing points. Also, a lack of volume would suggest a problem in the power amp. And also would be handy to check continuity at all relavent spots. I can't really help though, i'm just a beginner. Good luck.
Title: Re: it's really quiet and hums!!!! Post by: BGSoul on May 13, 2008, 02:49:29 PM Have you grounded the ground bus over the pots? Possibly you have but its too easy to forget. Must be an obvious grounding issue.... :-\
Title: Re: it's really quiet and hums!!!! Post by: lstead on May 13, 2008, 05:36:40 PM ok.... i found that the normal input wasn't properly grounded and now it works....except the OD channel isn't. deep and bright and jazz and PAB work but not overdrive? ia m looking into this. also the clean channel is very piercing at the top end.......what trimmer settings would help this or am i missing something obvious?/ as if........laurie
Title: Re: it's really quiet and hums!!!! Post by: gbergl on May 13, 2008, 06:56:20 PM I would suggest carefully reassessing each solder connection using a magnifying glass. Some have used a chop stick to tap on each connection with the amp connected to the speaker and turned on (use extra care not to touch anything except with the wood because of the high voltages). You may find a "loose" connection where you hear extra noise when tapping on the solder connection.
You might also check for any debris (solder, wire, etc) laying loose in the chassis or in each 1/4" input jack. Good luck. Greg Title: Re: it's really quiet and hums!!!! Post by: ChrisL on May 14, 2008, 01:39:05 AM Reflow every solder joint. Confirm every component's value to the layout. Take voltages on all pins and post them back here. Also, get a camera ready for some detailed photos should you not find your problem.
Troubleshooting is a bi%$h but it's inevitable in amp building. Title: Re: it's really quiet and hums!!!! Post by: lstead on May 14, 2008, 05:44:13 PM wooohooo!!!! 2 cold soldewred grounds and a tube tip holder [or whatever you call it and it is working! there's a lot of tone to cover here, too so i will be playing for hours. oh deep joy. laurie
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