Author Topic: Loud Pop!  (Read 783 times)

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Offline -dcb-

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Loud Pop!
« on: December 13, 2010, 10:43:56 pm »
Hello Everyone!  I have a Sunn Beta Lead 212 combo that makes a really loud pop when I turn it off. Ive done all the obvious things like turning down volume levels and even pulling out the guitar cable.  This makes no difference, Im worried about blowing my speakers!  If anyone has had similar problems or any helpful advice, it will be appreciated. thanks
-dcb-

Offline jdfarrell81

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Re: Loud Pop!
« Reply #1 on: December 16, 2010, 04:44:36 pm »
Howdy,

Although I'm not sure what causes it, I've seen this happen with countless amps. For the most part, I don't think it's a danger to your speakers.

Maybe what you're experiencing is above and beyond the normal "pop" a lot of us are familiar with. In any event, taking the amp to a tech couldn't hurt.

Hopefully someone with more knowlege will chime in, but I wouldn't worry too much.

Offline Rex B

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Re: Loud Pop!
« Reply #2 on: February 05, 2011, 02:51:05 am »
Yep, they did that, at least the early Betas did. Your amp might be from an early pilot run. I am pretty sure we ran an ECN to fix it, it was a pretty simple fix, but unfortunately I don't remember exactly what we did. Rod Goldhammer and Howard Goetz were the circuit guys on that one. I think it may have been  caused by the outputs latching on to one of the power rails when the AC power was cut. The Beta power board was basically the same amp as the SA10/11/20/21, so maybe those schematics show the mod. It sounds awful, but I am not aware of it damaging any speakers. Some of the early fixes made funnier noises; squeaks squawks, farts, burps, duck noises etc.
Engineer Sunn 1977-1983, Fender 1984-1990
Model T Red Knob
200S Cabinet JBL D140Fs
Sunn SB 300 (Proto Coliseum 300)