AC30CC2 crackling noise

[dudiluty]

Ok well it's been a few weeks and the amp is still at my techs workshop. He also is getting really tired of the amp.. there is a curse in this thing. Ghost amp he says.

He did a full recap, new tubes(again), replaced all the ceramic caps, resistors, jacks, some pots etc. The crackling is gone as far as he can tell for now after changing the preamp tube sockets. But.. there is still a loud popping sound when using the 'input link' switch and using effects pedals. He says there is like 3 millivolts on the switch and he haven't found out where the problem(voltage) is coming from.

Any one here had the same or identical issue ?

Thanks Again.

[Ewizard]

That's a bummer man. The big downside to PCB amps is that the phenolic material can become conductive if it gets hot enough. Soldering in new parts can heat up the material enough that it can get conductive between the traces. The only fix is to find where it has gone conductive, cut the traces out and run new wires around it.

It may just be one of those amps where you convert it to a point-to-point. You may have to get rid of switches for channel switching and what not, but it is either trash or rebuild it.

[dudiluty]

Well i got the amp back friday and it works again without any problems. He also did all the mods for me as well. The problem was that the pcb it self was leaking to ground so he isolated all the new preamp tube sockets from the board. Also replaced like every part on the pcb. Problem fixed and the sound is amazing. Now waiting for the bill..

[Ewizard]

Hey, congrats on your new used amp Sounds like you have a good tech!!!! It's always good when they go the extra mile. It's unfortunate that the cost is what it is, but at least you get to keep it.

This is one of my pet peeves about Two Rock and other higher-end amp makers using PCB boards. For the cost they are selling the things, you can forego the PCB and have a real amp. When the phenolic material gets hot enough it can cause the issues that you had. You just can't figure it out until you have replaced every part there is to realize it can only be one other thing. While many higher-end companies don't do board-mounted Tubes and pots, if it gets hot enough, there can still be an issue. And it's cheap, even if there is nothing wrong with it functionaly.

[dudiluty]

Hey, congrats on your new used amp Sounds like you have a good tech!!!! It's always good when they go the extra mile. It's unfortunate that the cost is what it is, but at least you get to keep it.

This is one of my pet peeves about Two Rock and other higher-end amp makers using PCB boards. For the cost they are selling the things, you can forego the PCB and have a real amp. When the phenolic material gets hot enough it can cause the issues that you had. You just can't figure it out until you have replaced every part there is to realize it can only be one other thing. While many higher-end companies don't do board-mounted Tubes and pots, if it gets hot enough, there can still be an issue. And it's cheap, even if there is nothing wrong with it functionaly.

He told me that when it does give me problems in the future i'll have to replace the board. But i looked everywhere but can't find it.. anyone has an adres ?