Crackling sound from Ampeg SVT CL

[Lovep]

I had a very similar issue with my V4BH and my local tube tech diagnosed it as several broken solder joints on the circuit board. The tubes were fine. Once he repaired the solder joints, the amp sounds incredible. Take it to a certified amp technician.

 

[B-string]

Yea, it is.

I should add that I can't fault the guy too much. He spent a good amount of time and I think got as far as he could with it. His fee was very reasonable and he thought it was fixed when he gave it back to me. It wasn't happening when I went to his shop to pick it up. I tried it right there with him in his shop and it wasn't happening. Then I get it home and the very next day it's happening again. Note that the tech was able to repro the issue many times in his shop, including with me there. It's not like the issue only happens in my basement.

Be sure to pass along the temperature condition to the next tech, it is very important for the process. In fact all that has been attempted to each tech it lands with. As beans mentioned solder joints can do this and my rule was any excessive solder mound is hiding a cold joint. I hope they still make a circuit cooler spray to treat caps/resistors in operation. It used to be in the horse and buggy days a CFC refrigerant and I did see CO2 from later manufacturers. This stuff should ONLY be used by well trained personnel and I stress ONLY, it is not for DIY even if you believe you know what you are doing. The old school tapping with a wooden "orange stick" is still viable for through hole components (not SMDs).

There are enough circuit heads here that a "Oddest thing you ever encountered in repair" might be a fun thread, but armchair "internet iron wielders" might set out on mass destruction testing out those odd finds as their problem solvers. Fun thought for a thread though.

 

[pcake]

how much time a person who purports to be a professional doesn't matter to me - it's results i'm after. the problem isn't fixed, and he said that an obvious problem is SOP. i avoid service people who tell me this. no amp is designed to crackle.

 

[IronLung1986]

Thanks everybody. All very true. The amp will go next to an authorized Ampeg repair shop from the Yamaha site. In fact it's my usual local music store, which I had avoided in the first place because they have a very long waiting list and I thought that maybe the quality of service would be better at this other place. I'll let them take a crack at it and we'll see. Probably won't be till next summer lol. I'm on the waiting list.