Diezel VH4 power tube toggle switch - which way for EL34?

azzzy

New member
This might be a strange question but here goes. That little toggle switch in the back right in front of the tube 2 - which way is for the EL34: towards the ON switch or towards the Input jack?

I bought a used VH4 a while back, which came with 6550's. The tubes were destroyed in shipping. Initially I was going to replace them with KT88's (and spent almost a grand on a quad of old stock Genalex K88's) but then read that KT88's may damage the amp and I should use either EL34 or KT77. I only found a pair of NOS Genalex KT77's and can't find another pair to make it a quad, so I decided to go with the EL34's in the meantime (I have a pile of old stock Mullard and Amperex EL34's). I took the amp to a shop to have it rebiased. Unfortunately the shop that so far had always been great this time turned out to be horrible. The guy in the shop didn't get around to the amp in 6 months! :thumbsdown: I mean I have other amps I could play through but... 6 fucking months! Anyway... I was so pissed that when I finally picked up the amp I didn't even bother checking the sound. When I finally plugged in the amp sounded horrible. There was essentially no clean sound on channel 1 and the rest of the channels sounded super compressed. The guy didn't even bother biasing the amp! Didn't even take the chassis out! I know - he "worked" on it while I was there. I just wanted to get out of there and didn't confront him on the spot, and now that I have the amp back I don't even want to deal with that bullshit. So...

I noticed there is a toggle switch in the back. I see in pics on other VH4's it's labeled 6L6 and EL34. Mine is labeled L and H. I don't know which one is for EL34. Right now it sits on L. I can't remember where the switch was when I had KT88's in it - the amp sounded good then. I don't want to fuck around with it without knowing what I'm switching to and I don't have the time right now to take it to another shop (and won't have time for a while). Please tell me, which way the switch should be for the EL34's. Thanks much.
 
wezzleyz":3aqpbotg said:
pic from the rear, tube 1 is left, tube 3 is right :)

Thanks a lot. Yeah, the switch on mine is in what appears to be the 6L6 position. I just hope this convention was kept for all VH4's. :)
 
Thanks, guys. Flipped the switch - much better. Still not great - now the bass is too loose and the clean sounds weird - but at least the clean channel now has clean sound. The EL34's are glowing too bright. The amp clearly needs biasing. Will take it to a reputable shop when I finally have time for it.
 
Can I resurrect this thread? I had the same issue (tubes destroyed in transit) and I’m wondering if the switch might have been knocked also. There’s no label at all on my switch so wondering which setting is for 6L6? Left or right?
 
From where ya amp is facing towards the back panel of the amp toggle switch towards left is for 6L6 and right is for EL34... mine is a 2008 VH4... wonderful wonderful amp !!
 
sampryor@me.com":1fugda63 said:
Can I resurrect this thread? I had the same issue (tubes destroyed in transit) and I’m wondering if the switch might have been knocked also. There’s no label at all on my switch so wondering which setting is for 6L6? Left or right?

FYI, mine had issues beyond tube bias. So if you're having similar problems you might wanna take it to a tech.
 
hopkinWFG":3jpene2e said:
From where ya amp is facing towards the back panel of the amp toggle switch towards left is for 6L6 and right is for EL34... mine is a 2008 VH4... wonderful wonderful amp !!

Awesome thanks for that!
 
sampryor@me.com":1hez8c22 said:
hopkinWFG":1hez8c22 said:
From where ya amp is facing towards the back panel of the amp toggle switch towards left is for 6L6 and right is for EL34... mine is a 2008 VH4... wonderful wonderful amp !!

Awesome thanks for that!

Arhh... no problem i tried to attach a pic but cant if your keen on a picture to confirm.. kindly PM me ya email and i will send to you... :)
 
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