isolating SRPP stages

[bluebird]

In the eq I'm building there will be six 12au7 SRPP stages like in the Gyraf eq and G9.

Since there is no plate resistor what would be the proper amout of resistance to seperate each stage? In parallel from the main B+ of course. Would 100 ohms do it? each stage will have its own filter cap after the resistor.

My power transformer is showing 350V DC after rectification with no load. and I need 245V at each plate.

[gyraf]

The 12AU7 SRPP I use consumes around 2.5mA each stage.

I will recommend that you use a stabilized powersupply for this, as SRPP has rather poor PSRR (power supply rejection ratio). Use the TL783 setup from the G9 - that will easily supply current for eight stages.

To separate, I use 1K/2W and 10uF on each stage.

Jakob E.

[bluebird]

Thanks Jakob,

Do you think I could get away with using alot of filtering instead if the regulator. I'm just impatient and would have to order the regulator.

what about 200uF on the main B+ and 200uF for each stage?

The non regulated supply seems to work very well for the G9...so far.

[gyraf]

If it works - don't fix it..

[bluebird]

HA, very funny, ok then... :D