Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rafe on July 10, 2010, 11:55:34 pm
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First the noise ....from time to time on my 64 vibroverb custom I get this noise which I think is the ocean sound,even though I lived on the ocean and never quite heard it, although it's similar. It's more like the hiss you can make by putting your tongue to the roof of your mouth. It's not real loud and it waxes and wanes for lack of a better description. I've had the amp a while, 3 years, and it is intermittent and has always done it.. I was thinking plate resistors but have put off getting in there. I have also noticed from time to time that when I plug a cord into the amp it pops, almost as rudely as when you unplug a cord from a guitar .....Tonight I unplugged and replugged the cord while it was making the noise. It made the pop, and it stopped the hissing.....does anyone have experience on this or an idea on this?
Also if you haven't played one of these do so if the opportunity arises. I believe Fender got this one right. I've gigged it a dozen times and always get compliments on the amps tone. Thanks
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It' seems to me that a bad jack could generate this kind of noise. If an input jack pin is not grounded when nothing is plugged in, you can hear hiss, buzz and other noises. I don't know what kind of jacks are used in this particular model (standard, "ROHS"-plastic one, or other), but I would first try to clean their contacts. It happened to me with bad quality (were they fakes??) new Switchcraft-branded input jacks; exactly the same symptoms you described...
HTH,
Danskman
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Danskman, Thanks I was wondering if the jacks themselves could cause the symptoms. It's fairly true to original Vibro-verb with the switchcraft type inputs, I think they use Switchcraft but they might be switchclaft :laugh:I know NPC. So I'll see if cleaning helps. I've been playing since I posted and it's running quiet for 2 1/2 hours. sometimes it goes weeks......months....i'll post results