Build Report! Rangemaster & Arbiter

[ZtaRDuZT]

After months of testing and biasing I finally completed my first two builds. The Rangemaster and the Arbiter.
Added filtering capacitor, protectiond diod and temp stabilizing diod for the germanium transistors.
The soldering went well but I had som trouble with the wiring. I had to rebiase the Arbiter and it was kinda
tricky to replace a couple of resistors with all the wiring attached to the board. They broke of all the time.
I used 24mm Alpha pots and that didn't leave enough space for the transistors in my 1590B size box, had to
bend them down and isolate them from the cover, but it's still too tight. I might be able to get it lower with
a slightly different setup on the board (board with copper islands, don't know what you call that).
But in the end I'm happy with the result. I've only tried them out on a small amp at home so far but I guess
it can't get worse with my tube amp and if that's true, I'm HAPPY.......

Lessons learned: Board setup, gotta come up with a better "wireplan" than this, there will be hell to pay if
something breaks down. I can't even get the board loose without desoldering AT LEAST half the wirework.
Making PCB's would make my life a whole lot easier but I don't have a place where I can handle the stuff,
We even painted outdoors, in the middle of winter (Sweden=Cold!).

Arbiter:
All measuring with fresh batteries
Q1
e 0
b 0.09
c 0.47

Q2
e 0.37
b 0.47
c 4.57

Rangemaster
Q
c 7.11

Pictures:
http://www.diystompboxes.com/smfforum/index.php?topic=36392.msg287349#msg287349

[Steben]

The bases of the Q's are very low...
It works probably, but am I wrong telling it's rather a low-medium gain device?

[ZtaRDuZT]

I aimed for the recommended values at GGG:
Q1
e 0
b 0.1
c 0.5

Q2
e 0.4
b 0.5
c 4.5

The hfe of the germaniums is supposed to be 86 and 134.
It's not a high gain setup I guess, but I'm not a high gain kinda guy either so....
I thought the variations from GGG values was to be considered small enough.

The labeling is rather nice (I think). Looks better on the full size pictures.
Sorry to say but I don't have anything else than MS Paint to work with so
I loose colors when resizing.

[petemoore]

tricky to replace a couple of resistors with all the wiring attached to the board. They broke of all the time.
  I drill a hole per wire, thread the wire through the edge of the board..'wire stays', having broken wire strands is something to be avoided.

[ZtaRDuZT]

Now that's smart, why didn't I think of that!




Thx for the tip