XTC Bias Control

[guitarman967]

Does anyone know if there's a special tool to adjust the 101B's bias pot?
There doesn't seem to be the usual trimpot in there that you could adjust with a small screwdriver. It's more like a half circle
Am I missing something here? THX!

 

[zewango]

Small screwdriver works in mine.

 

[guitarman967]

Small screwdriver works in mine.

It's odd, the area is clearly marked BIAS and on most amps there would be a very obvious trim pot that would turn with a screwdriver but the XTC in question does not have that.
It's look like a half circle with the inside hollow right down to the chasis.
Anyone ever seen this before?

 

[J.B.]

Hmmm... I used a little screw driver too.

 

[guitarman967]

Hmmm... I used a little screw driver too.

I would post a pic but it's kind of a moot point now because I found a set of tubes that will bias up in the right range.
It's weird though, Looks like I might need a bigger screwdriver to turn this half circle thingy..Maybe that's the deal?

 

[zewango]

Post a pic, I needed a very small screwdriver