It looks like you're new here. If you want to get involved, click one of these buttons!
Subscribe to our Patreon, and get image uploads with no ads on the site!
Base theme by DesignModo & ported to Powered by Vanilla by Chris Ireland, modified by the "theFB" team.
Comments
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Got the back off now and one of the EL34's has a distinct blue tinge to it whereas the other seems to be the usual Orange glow.
The amp is also well down on power - I can run it at almost full whack on the clean channel which normally gives you eye watering levels of spank but it's nowhere near that..
New EL34's tomorrow then, hopefully Karltone can give me similar specs to these so I can possibly get away without a rebias , however, failing that I'm going to get a bias probe as well as this thing eats valves by the looks of it...
It could be the one that *isn't* glowing blue…
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
The plate voltage on the Shiva is 550 and it's getting approx 80 watts out of a pair of EL34's which mathematically doesn't work!! - 25 + 25 = 50!!!
The Bogner recommended idle bias is 29-31 so I'm going to go for a new set of valves and bias it to 30ish which if MY maths are correct is about 70% diss at idle
And just to confirm, bias with no load (guitar/signal)?
I'd probably go a bit lower. Old Marshall 100-watters with that sort of plate voltage usually sound best at around 55-60%.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein