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Title: Diagnosis - strange noise Post by: fm4 on January 31, 2009, 06:13:54 PM Hi,
My Overtone Special 100W is up and running for a couple of month now. Voltages are OK, 1/2 power mod is installed and working. I build the Kleinulator and it is working smoothly. Overall, great amp and great tone....but... only thing that I find quite annoying with my amp is a strange noise, which shifts between cracking and something that you would get when you rub two balloons. I checked again voltages and cold soldering joints, but strange enough everything is working well. The noise is not influenced by any poti or switch, nor the master/preamp volume. It's just there. The funny thing is that this strage noise seems to come and go. One week nothing at all, then again for 10min. I switched power and preamp tubes, no change. If anybody has ever experienced something like that let me know. It would help me to track down the culprit faster. Or maybe it is just Voodoo.... ??? Thx, fm4 Title: Re: Diagnosis - strange noise Post by: hywelg on January 31, 2009, 11:06:41 PM I spent over an hour last saturday prior to a Sunday gig chasing a funny rattly/buzzy noise that I was getting from my strat. Changed all three pre-amp tubes one at a time, took the back off the cab, tried another speaker cab. Swapped guitars and it stopped. OK I thought that narrows it down s/c's vs H/B's. Anyway to cut a long story short. I have two Push/Push switches on my strat and when either of them is UP i get this very subtle buzz on held notes. Sounds like something in the cab rattling, but its definitely to do with those switches. Haven't had chance to rip it apart to find out why yet, I do hope its not because they are worn, they've only been in 2 years.
Anyway the moral of this tale, just cos your amp is buzzing, don't mean its the amp! Title: Re: Diagnosis - strange noise Post by: fm4 on February 02, 2009, 06:12:56 AM Anyway the moral of this tale, just cos your amp is buzzing, don't mean its the amp! Hywelg, Good point and well taken. Following your suggestion, I tried to change the guitar while hearing the "voodoo" noise and saw that the noise stays even when I entirely unplugged the guitar cable from the amp. I'll have to go on hunting for the culprit within the amp. The first time my band colleagues heard it, one was asking who had the guts to far** in the practice room...I guess they have to stick with it a bit longer ;D Thx, fm4 Title: Re: Diagnosis - strange noise Post by: hywelg on February 02, 2009, 09:27:47 AM Have you tried moving the tubes in their sockets whilst the amp is producing that noise? Other than that I guess you'll have to try chopsticking various components/connections whilst its on (don't do this unless you're sure about what you're doing). However if you say its unaffected my the master volume, and the other controls have no effect either, then, start from the speaker and work backwards.
Title: Re: Diagnosis - strange noise Post by: nickm57 on February 03, 2009, 06:20:00 AM lead dress.
these amps are very sensitive. Check the shielded cable Input - V1 tube and the OD tube to relays and pots. Nick Title: Re: Diagnosis - strange noise Post by: fm4 on February 05, 2009, 06:13:51 AM lead dress. these amps are very sensitive. Check the shielded cable Input - V1 tube and the OD tube to relays and pots. Nick Dear hywelg and Nick, I was chopsticking around the indicated shielded cable and although I could not reproduce the noise (the amp had its quiet moments), it was obvious that the solder joints are not optimal. I have redone them and now chopsticking around this area has not effect whatsoever. :chairdance: Let's see if my amp behaves now :D Thanks for the help!! fm4 Title: Re: Diagnosis - strange noise Post by: nickm57 on February 05, 2009, 09:07:46 AM The run of the shielded cable from input to v1 was very sensitive on mine. Fine the place for the run where it is quietest and try to get it to sit there. sometimes just re soldering it into the position will do the trick
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