In the meantime, if you're really missing Audio Asylum, then maybe this will help entertain you. You should feel right at home.

Fitzmaurice was having some trouble with people in his forum, I spoke to him a couple of days ago. I guess he's deleted a lot of stuff, 'cause when I go back through some of the threads, I see a lot of "end of the internet" messages.

Hi, you can set the current by changing the resistance of R3 - "trimmer" pot. The best way, (as Doug explained earlier) is to use 9V battery, and connect it like on the diagram:

- our CCS is Q1, Q2, R2, R4 and R3 pot
- connect +pole of 9V battery to the upper mosfet drain (where you`d connect B+=200V in "Guinevere")
- connect minus pole to the "anode out" of our CCS in series with 100 Ohms resistor - see the schematic
- connect the voltmeter (set on about 4V range or so) between the points B & C (across 100 Ohms resistor)
- you can set the P3 in the middle position, and slowly turn it on one side - the "goal" is 1,5V DC reading on our voltmeter. Ohms Law - 15mA "through" the 100 Ohms resistor is 1,5V DC voltage "drop". When you decrease the resistance - current increases, and opposite.
- in my case, I get R3=100,5 Ohms for the first CCS I built, and 112,6 Ohms for the second
- you can leave R5=100 Ohms in place when you install CCSs in "Guinevere" and check the current again
- for more, see "Grup Build" forum, I posted new PCB

****check the safety fuse in the meter first. If it's blown, you won't get a reading.

***the bias LED's will go out. All the regulated current will bypass the amplifier triode through the meter.
regards,
Douglas