Odd sound from preamp tubes

white room · Post by **white room** » Sat Jan 22, 2005 11:09 am

I have had this problem for a long time of where when I play high notes I can hear what sounds like bits of metal vibrating in the preamp tubes but I don't think it's a spring because I can turn the Hot Plate all the way down and still hear it and it only does it from 2 on up on the volume.

I have swapped out tubes and it still happens, It's not real noticable but I can hear it. Is this normal when your cranking the amp? I'm not sure if it is coming from V1 or from V1 and V2.

Billy Batz · Post by **Billy Batz** » Sat Jan 22, 2005 11:16 am

Its pretty normal to hear those metallic sounds when your running your amp hard and you have it attenuated to the point you can hear quiet things over the amp. My SLO does it, all mys Marshalls did/do it. Im not sure if thats the same thing your talking about but I think it is. Transformers make noise too. I usually just use a rubber mallet and tap them a bit and they stop.

white room · Post by **white room** » Sat Jan 22, 2005 11:35 am

I thought it may be normal since I have noticed it for a long time.

I usually don't hear it since I keep the HP up pretty high but playing at 7:00 a.m. is when I hear it since the volume has to be attenuated pretty low

Update: I put my ear up to the OT and that it is where the sound is coming from and not the preamp tubes. I didn't know OTs would do that. I learn something new each day