Crackling noises... HELP

[OlinMusic]

I stuck some new JJ E34Ls in my Dragon along with new pre's
The tubes seem fine, the glow a normal color. This used to have EH's in it.

Well, no, I didn't rebias. I suddenly get some radio frequencies and crakling noises from an amp that used to be dead silent.

Either way it sounds killer!

 

[Gearjoneser]

Re: Crackling noises... HELP

Swap out all the pre tubes, and plug your guitar with a new cable into the amp, and see if it persists.

 

[OlinMusic]

Re: Crackling noises... HELP

Wait! Swap them out even though they are already all new? The 12ax7s I mean

and hmmm yes, my cable is ****ty
For the first time I am getting radio signals thru my amp as well - is that the cables?

 

[OlinMusic]

Re: Crackling noises... HELP

I tried a Mesa 12ax7 in V1 and it seems to have almost taken the problem out - but this amp was dead silent.

Could it be the new JJ tubes? Is it a bias issue. I thought the bias was roughly right, the tubes glow nice and even, the amp sounds good.

It has crackled with no cable in the amp. As I stated, it is now much more subtle.

 

[Robert S.]

Re: Crackling noises... HELP

Tubes can be bad straight from the box and shipping can loosen them up a bit but just like light bulbs you sometimes get a stinker.

Put the JJ back in V1 and let the amp warm up. Using the erasure end of a pencil gently tap on each pre and power tube and see if you can make the crackle happen. If not, then replace V2 with the Mesa tube and see if it clears up. If not put the JJ in V2 and replace V3 with the Mesa. Keep doing this until you (hopefully) find the problem.

It's my guess that you have a bad tube in there somewhere. If you find it, I'm sure you can have it, or the pair replaced if it is a power tube.

 

[OlinMusic]

Re: Crackling noises... HELP

ahhhh ah haaaaa!

I will try this!

 

[OlinMusic]

Re: Crackling noises... HELP

Had to report - not only was the advice successful

I put a Mesa 12ax7 Russian-2 in both V1 and V2 with the rest being Teslas (incl the balanced PI tube) and it's like a new amp, JJ E34Ls in the Power. I had never been so into the tone of my Framus Dragon until now. The crackling is gone and the Mesas sound much better than just the Teslas alone. The output seems louder too.

Sounds good with G12H30s and V30s. It's like the sonic ground between VHT and Soldano - with a lot of Marshall in CH 2, but all these amps are somewhat Marshall clones.

You guys saved me a lot of time, money, and hassle. As always, thanks!

 

[lastwinj]

Re: Crackling noises... HELP

very possible that the amp is sensitive to marginal tubes. JJ are the finest tubes out there, IMO. but, i have also had some go bad after a few weeks. happens to EVERY manufacturer or brand.

also, sherman was spot on. hands down the best way to figure some problems.

germ