Herbert problem - solved

  • Thread starter Thread starter nakedzen
  • Start date Start date
nakedzen

nakedzen

Member
My Herbert is making a very loud rumbling noise on all of the channels. It sort of sounds similar to when you have a faulty cable that crackles.

It doesn't make it if I play with at low volume, but when I turn up to rehearsal volumes it starts. The noise is most apparent with low palm mutes, after a palm mutes the noise stays on for a while.

The noise started a week ago, and only on the gain channels, and I tried troubleshooting the preamp tubes and swapped a tube from V3 which seemed to make the problem go away. Today at rehearsal it started to make the noise again, this time on the clean channel as well.

Any ideas what it could be? It's not the guitar, cables or cab since I used a different head with them without problems.

One other thing I noticed when I opened the amp up was that the transformers had gotten very hot, hot enough to melt some of the glue from inside the amp. :scared:
 
You need a tech. Maybe You swapped the wrong tube
or the issue is not easy to solve.

Have You contact Your dealer ? He would be the first
address. Where did You buy the amp ?

Thanks,
Peter
 
Thanks for the quick reply. I'll try swapping all of the tubes.

Unfortunately the only tech that I know of now works for Mad Professor so he doesn't do repairs anymore. I'll have to find out if there even are any good techs in Finland. I bought the amp used from ebay a year ago.

I contacted the finnish Diezel dealer if he knows of any techs.

E: The finnish importer (tubesound) promised to take a look at it.
 
I tried playing the amp through an attenuator set as a dummy load straight to my computer. It doesn't make the noise anymore, which leads me to suspect there's something inside the amp that vibrates creating the noise when it's on top of a cab. :(

E: Let me revise my assumption, it could be a microphonic tube since there comes a terrible amount of noise if I tap on the top of the headshell.

E2: Curious, I tapped the preamp tube in V1 lightly with a pencil and it stopped making the noise when I tap on the headshell. :confused:

Would be a very cheap fix if that did the trick though. :)
 
You need to change your tubes. That is most likely your problem, and even if it isn't, a fresh set of tubes is not wasted money anyway.
 
Yup a fresh set of tubes is in the mail, I'll get back to this thread if they won't resolve the problem.
 
Make sure you get the Diezel tube set. If Diezel is out of the EL34s get at least the Ruby preamp set to insure the tonality of your amp is on par with the factory amps.
 
Well, Ruby tubes are relabeled chinese, SED and JJ's. Chinese tubes with double the price the last time I bought them. I know they *claim* to test every tube but still. And I like to go with what I like. :)
 
nakedzen":37imanr3 said:
And I like to go with what I like. :)
Click to expand...
Exactly, run what tube sets have worked the best for you. Personally, JJ's have been awesome for me in all my amps.
 
You must log in or register to reply here.
Back
Top