Stealth Bias adjust

[sloober]

Have been working on a friends 800c for the past few weeks. Waiting on 2 caps...
One thing I did was to ad an adjustable bias pot. I got to thinking there is no way he is going to open this up and mess around with probes, way to dangerous for him!
So I decided I would add test points like I used on my Altec with such good results. There were several vent holes around an unused can cap that would work perfectly. But mounting the bias pot top side would have called for a hole drilled in the chassis. Not wanting to drill it, and not wanting to alter the look too much, I came up with a pretty good solution. I had a slightly shorter can cap from another 800c. I had already gutted it and sawed it off. I made a small bracket for the pot and jb welded it inside the can base. I mounted this in place of the old can on the chassis. Then using the top of the can and a cardboard sleeve from another can cap, made a cover. Hidden and mostly stock looking when on, pops right off to adjust bias! Pretty darned cool! John

 

[dsndblm]

Sweet! I like leaving things as stock looking as possible. The mod looks great/

I have a nice 500C that is sitting here waiting for someone with some time to restore it..... Any takers??

 

[sloober]

I'm in...come on over...

 

[WopOnTour]

That looks pretty good sloober!
I've got an 800 that I've been sitting on a while now and plan to do something similar. Was thinking of just removing the entire Reverb plate (splice instead of jumpers) and mounting my individual adjustment pots there.
Still, nice job with the stealth!!
WOT

 

[bharper]

now lets hope he jerks on the right cap! excellent stealth!

 

[sloober]

Finished up the project. I decided to use different color jacks so all I need to do to mark the tube it goes with is a small colored dot. I painted the cardboard sleeve with several coats of silver paint and made a small decal on the back with basic instructions. I can roll up a full adjustment sheet and stick it in the cardboard tube.

I like it so much I now have to do the same on my own 800c. It is so much easier to set and monitor the bias. Not that it changes too much, but there is a big difference between new and old tubes. John