Bare Knuckle Pickups Forum

Forum Ringside => Tech => Topic started by: Woogie on December 16, 2007, 02:17:42 PM

Title: How ironic
Post by: Woogie on December 16, 2007, 02:17:42 PM
I sit down to make you guys some Holydiver/slowhand/JCM800 clips and my JCM has blown a valve or two.

How do I diagnose if it's blown a valve? I`ve tapped them all with pencils and they sound the same. They look the same as usual. It just crackles and makes a loud squeeling when I turn it on.

What's caused this? I did what I always do. The valves aren't even that old. I don't want to replace them all cos it costs a fortune.

Cheers
Title: How ironic
Post by: HTH AMPS on December 16, 2007, 02:25:08 PM
pull the EL34s one at a time and see if the noise stops.  of course you'll still need one of them in the amp to get any sound.  

 :twisted:
Title: How ironic
Post by: 38thBeatle on December 16, 2007, 02:38:06 PM
Why not use the VC30 for now.When you get the JCM running do another clip for comparison (he says as if making a clip is something he does every day).
Title: How ironic
Post by: Woogie on December 16, 2007, 02:48:40 PM
Quote from: HEAVIER THAN HELL
pull the EL34s one at a time and see if the noise stops.  of course you'll still need one of them in the amp to get any sound.  

 :twisted:


Are you sure?!?!

Quote from: 38thBeatle
Why not use the VC30 for now.When you get the JCM running do another clip for comparison (he says as if making a clip is something he does every day).


Yeah I made a Laney clip with a Zakk OD running through it but its .amr and I dunno how to convert/chop it.
Title: How ironic
Post by: HTH AMPS on December 16, 2007, 03:11:03 PM
I wouldn't have said it if I wasn't sure.  Remove the EL34s one at a time, if one is dodgy the noise will stop when it's removed.

If the noise doesn't stop when you've ruled out all the EL34s, move on to the ECC83s starting with V1 (the one closest to the input).

Have you got any spare ECC83s? - if so try swapping the ones in your Marshall one at a time to identify the dodgy one.

 :twisted: