Some weird sounding Gain Channels (SOLVED)

zeen

Member
Hi together,

and first hello, my first posting in this forum.

I would gladly appreciate your thoughts / ideas on the following issue I have encountered with my VH4:

- Channel 1: sounds completely fine for me, full and nice very similar to the 4x10“ fender in the room
- Channel 2-4 give me some headache at the moment.

1. I realized some kind of metallic sound which starts already by setting gain to more than 9 (clock) and sounds like there would be some metal parts swinging somewhere (cabinet: 2x12“, V30). You can hear this especially by playing flageolet on a lower string…

2. The overall sound on the gain channels is a little bit „weird“, its not really punchy, somehow honky or as you would move your tone knob half the way down on your guitar. Difficult to me to describe sound, but as if you would use an old cheap amp…

Before I start now to change tubes etc, I would like to have some thoughts on this?

I am thinking of preamp tubes, but basically I have no clue…


Thanks a lot
 
Sounds like a preamp tube problem. The first channel would bypass many of the preamps tubes in the middle, perhaps thats why it sounds fine.

Get you a known good 12ax7, and swap each tube, one at a time with it until you find the problem tube. I would try this first to see if that fixes you up.
 
ok thanks,

now comes the noob question, just to ensure :)

can I change preamp tubes myself?

I mean, for my understanding preamp tubes does not need to bias afterwards, and can I just do this without bringing myself to danger?

thanks
 
Yep... check and/or replace your preamp tubes. I'd start with V1 & V2.

No biasing needed... just pull and replace. Be mindful of the pin orientation when replacing.
 
Thanks, tubes will arrive most likely tomorrow so will change over the weekend..

From an optical point of view I d not see any issue with the preamp tubes, but will try this.

btw, can someone tell what the Numbers on the Powertubes mean? (I am a little irritated that all but one have a handwritten "60" the other has a "58")?

regards

P.S.: @admin/mod:
by trying to upload a picture of it:

"Sorry, the board attachment quota has been reached."
 
Thanks peter

I will first try swapping the preamp tubes on the weekend. In case this wont help i will contact support :thumbsup:
 
zeen":39ptlhqi said:
Thanks, tubes will arrive most likely tomorrow so will change over the weekend..

btw, can someone tell what the Numbers on the Powertubes mean? (I am a little irritated that all but one have a handwritten "60" the other has a "58")?

regards

P.S.: @admin/mod:
by trying to upload a picture of it:

"Sorry, the board attachment quota has been reached."

Numbers on the power tubes are probably Bias point/Matching. 60 and 58 is close enough, no need to worry.
 
solved,

after replacing preamp tubes looks like back to normal... no clue which one it was basically replaced all of them...

Thanks!
 
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