Krank Krankenstein biasing help

[Calippo Tecks]

I'd like to check the bias of my Krankenstein and adjust it.
I have a feeling tubes are set way too hot, although this amp has all kind of weird problems. Color drastically changes when I open the volume (and this is not the zero to 1 sounds different problem, on high volumes the tone still changes drastically)

It has loads of other problems too, eq doesn't work like it should, I can barely turn it open, same for presence control, if I set it on 2 it sounds like it's on 10.

Only problem is it's a prototype and I've never done biasing, does anyone have an idea where there's a pot to change plate voltage? I'm pretty sure it's not a fixed bias in this amp.

By the way, it's the first 100 watt version.

Here are some pictures:

 

[Sloan]

Get a bias probe, like the weber biasrite or something and the bias is adjusted with that small potentiometer near the four large capacitors.

 

[ChrisTanakaCanwell]

I have a Rev from that era that has all kinds of weird problems too. FX loop sounds like shit, "Master 1" is unusable because it bleeds into the other two channels, and I had to lower the bias as well although I did buy it secondhand so it might not have been like that from the factory.

 

[Calippo Tecks]

I lowered the bias setting with the pot, without any idea how it is set now.
Right now I've set it just above where you start to loss tightness of your sound. The amp sounds a lot better already. The clean channel is not usable, sometimes it starts sounding distorted and all kind of weird things happen while playing (volume drops, weird coloring changes).

Anyway, right now it sounds more like a rectifier and a marshall.
By rectifier I mean the untight sound that needs a tubescreamer boost and by marshall I mean the 'hotter' tube sound you typically hear with most marshalls. Something in between, it's not bad, haven't tried recording it yet, but I have good hopes right now.

 

[fumunda]

Where do I bias the tubes on a Krankenstein Plus Combo?

 

[fumunda]

Anybody?

 

[fumunda]

Does anyone have diagram of Circuit b