M800 bias question

[paulbarrette]

I have the board all together and am biasing the j201s. I noticed that the bottom right trimmer is cranked down all the way and i am still seeing 8.6v. The others are all 4.6ish. Is this guy not meant to go to 4.6?



Thanks
Pb

 

[paulbarrette]

I tested the m800 without the case. Pass thru works. I have the trimmers at 4.6 except #6. I noticed it sounds more like fuzz. It is late. i will check the bias again tomorrow.

Pb

 

[BuddytheReow]

That last trimmer is just a tone control, not a bias. I just dimed it on mine since you can control the treble externally as well. Up to you

 

[paulbarrette]

That last trimmer is just a tone control, not a bias. I just dimed it on mine since you can control the treble externally as well. Up to you

Ok thanks. I will dime it and try it.

Pb

 

[paulbarrette]

They definitely sounds better. I had to rebias all the trims again. I am hoping they stabilize.
Thanks
Pb

 

[BuddytheReow]

They will. Since they all share the same power source you’ll need to dial in the bias twice.

 

[paulbarrette]

They will. Since they all share the same power source you’ll need to dial in the bias twice.

Ok great. I have it dialed in now. I backed off the tone a bit. I had it dimed but that was a bit boomy. It sounds great now. I am surprised how much it sounds like a Marshall

Thanks
Pb

 

[paulbarrette]

does anyone have trouble with the m800 keeping its bias? I dial it in and a few days later it is dull or bad fuzzy sound. Is this a j201 issue? Is there a way to test them? I have extra if i have to replace them

Thanks
Pb