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Topic: Fender Twin Buzzzz |
Joshua Tschetter
From: South Dakota
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Posted 14 Sep 2018 3:10 pm
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Hi Guys,
I recently acquired a very nice fender twin 65 reissue. I am hearing a buzzing noise coming from the speaker on the low end, especially when playing in a drop D tuning. I can only hear this on the low end, the first 20 minuets, as the tubes warm up it goes away. I replaced the original Groove power tubes with a matched quad of JJ’s, and had the 6 preamp tubes tested, they all tested good. This is driving me up a wall!! The best way I know to describe the noise, is somewhat close to what an old transistor radio sounds like between changing stations, a crackling hiss.
I’m not sure how to upload videos here, but I have sound samples recorded, and if anyone cares to get involved in my headache, I can surely email you the sound samples that I have recorded.
Any help would be greatly appreciated !!
Thanks, JT |
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Jack Stoner
From: Kansas City, MO
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Posted 14 Sep 2018 3:22 pm
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A Tube Tester cannot fully check everything in a tube. The only sure way is to replace with known good tube(s). |
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Joshua Tschetter
From: South Dakota
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Posted 15 Sep 2018 4:40 am
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I was not aware of that Jack, Thanks for the reply!
I guess my next move is to replace all preamp tubes... |
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Stephen Cowell
From: Round Rock, Texas, USA
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Posted 15 Sep 2018 4:53 am
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Try swapping speakers... an 8ohm cabinet won't hurt if you only do it for a while... many folks run Twins at 8ohms anyway.
It also might be an arcing socket... examine the final tube sockets (the big ones) for signs of arcing.
I don't think your problem is a tube... it might be time to seek a pro's help here. _________________ New FB Page: Lap Steel Licks And Stuff: https://www.facebook.com/groups/195394851800329 |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 15 Sep 2018 4:55 am
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If the sound takes 20 minutes to go away, you can be fairly sure it's not a tube. Tubes come up to temperature in only a few minutes, but all the circuit parts take considerably longer to warm up. (They usually get heated through the chassis or the tube pins.) You weren't real clear in the post, but if it's not really a buzz, but more "like bacon frying" sound, it's probably a bad connection or failing component somewhere that's causing it. Cold solder joints, plate resistors, or small caps are often the cause of such problems. |
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Joshua Tschetter
From: South Dakota
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Posted 18 Sep 2018 4:24 am
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Thanks for your input boys, I guess it’s time to take to a professional. |
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Jim Sliff
From: Lawndale California, USA
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Posted 22 Sep 2018 6:27 pm
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Yep - it needs to go to a tech.
It's unlikely to be a tube issue. it sounds more like a loose contact in a tube socket; bad solder joint; loose or failing ribbon cable; bad plate resistor or a problem on the circuit board related to heat, which is very common.
Depending on how old the amp is it may also be overdue for regular service - replacing filter and bias caps, voltage tests and cleaning/lubing pots, jacks and sockets. Filter and bias caps have a service life of about 15 years so if it's close they should be replaced whether they seem fine or not. Old ones can fail without warming, which can trigger a very expensive transformer replacement. _________________ No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Tim Whitlock
From: Colorado, USA
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Posted 25 Sep 2018 7:39 am
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Is the buzz is related to the reverb circuit? Does it go away if your turn the reverb control to zero?
Before you take it to a tech you could try a couple of easy things that might fix the problem, At least they are good maintenance tasks to do from time to time anyway. 1) Pull the tubes one by one and spray the pins with electrical cleaner. My Twin had some creeping crackling/hissy floor noise and doing this eliminated the noise. I do it at least once a year now. 2) Clean the in and out jacks on the reverb tank and the reverb jacks themselves with electrical cleaner. These connections are prone to getting dirty and are a common source for noise. 3) If you are comfortable with pulling the chassis, clean all of the pots with electrical cleaner. Spray the cleaner into the access slot in the pot while rotating the control back and forth. |
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