#1
Hi, I just got a Peavey Valveking 212 combo and I wanted to know about the tubes bias on these things. I've been reading that there are ways to adjust the bias. First off, I've heard some descriptions of what tube bias is, although, I'm still a little unclear, what effect will it have on the tone and playability, overall?

Also, I have no knowledge about opening up amps or schematics. How hard it is to actually do the mod where the bias becomes adjustable? What are the advantages of an adjustable bias on the tubes?
#2
These amps are a none adjustable fixed bias. Which means it can't be adjusted. For example if you order new tubes from the tubedepot or something tell them your amp and model and they send tubes already matched and set to that bias.
I just did this with my 112 valveking
#3
And If you have no knowledge of working on tube amps I wouldn't open it up if I were you. Those capacitors hold enough charge to kill you. Be careful man.
#4
Quote by Nikolai-Paul
And If you have no knowledge of working on tube amps I wouldn't open it up if I were you. Those capacitors hold enough charge to kill you. Be careful man.


x2. All the bias mod does it take it out of crossover distortion. It's noticeable but not really worth it. Like 5%, adds a little warmth.

If you don't know what you are doing with the amp I wouldn't recommend it.

How comfortable are you with electronics and high voltages?
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#5
I have the 112 version of that amp. As Nikolai-Paul mentioned, the bias in not adjustable on them. Most tube vendors will allow you to tell them which amp you have, so they can select the correct power tube(s) for it.
#6
Hey dude!

Everything these guys have said is true. I personally wouldn't worry about the bias mod or the power tubes for that matter unless you really need to. If you need new power tubes just buy a matched Quad of 6L6s. JJs (brand) would work well.

Tonally, you will get a lot more noticeable change with preamp tube changes and speaker changes. Those are both things you can experiment on your own and learn a lot at the same time. Hit up the 'Only Valveking Thread' and the associated wiki pages.

I used to have a VK112. My first tube amp. Great starter amp and lots of good to tones to be found if you are patient and like messing around with things (just don't go inside the metal chassis as mentioned).
#7
Yeah and with my 112 valveking I replaced the speaker and tubes with an eminence Texas heat and a full set of JJ tubes. Some of the cheaper mods you can do but It was night and day in terms of my tone I wanted.