6EM7 PP question

[TubeManiac]

in the diagram.. what king of LM33* ? do they use ? can't figure it out the last digit.

[Miles Prower]

Originally Posted by TubeManiac

in the diagram.. what king of LM33* ? do they use ? can't figure it out the last digit.

Looks like LM334. Since this already has a negative rail, it should be connected to that rail, not ground.

[tubelab.com]

Since this already has a negative rail, it should be connected to that rail, not ground.

The LM334 is the CCS used in this circuit. The schematic as shown is correct, the LM334 is grounded. It does work on 2 volts and this appears in Morgan Jones's book with a 6J6, but I don't have access to the book now.

An LM334 will fry and die on 52 volts. It is rated at 40 volts max, and 30 volts for some versions. Trust me, the little TO92 versions don't like 45 volts.

Since the circuit does have -52 volts available, use an IXYS 10M45 and do connect it to -52 volts. It will work better.

[mach1]

350Vp-k across the power triodes is way too high. You're working well into the area where severe bunching of plate curves occurs.

Check out Paul Barker's take on this circuit.