Dave’s OP6 Multi channel, power support question

[AardvarkBry]

I have built 4 preamp sections of Dave’s OP6, in one case like, which I suppose would be more like an OP7 with multiple outputs. I was hoping to be able to power all 4 units, with a shared remote power supply. I have 2 Triad toroidal, with 230v, and 12v, secondaries, both rated at 250va. How many pres will those support? Will I have to do major reconfiguring of his psu to power multiple channels?

 

[Whoops]

What is Dave’s OP6?

 

[AardvarkBry]

Dave P, builds a ton of stuff here, and has a lot of build threads. He built an RCA OP6 preamp and posted it on this forum years ago.

 

[Whoops]

Thanks, I was not aware of that project

 

[C12VR]

dc heaters? probably need a separate high voltage transformer; you will see a lot of voltage loss once you get into multiple preamps. Turns out it's very hard to get a suitable voltage without a big fat transformer; linear supplies tend to waste a lot of power at the current needed for an H+ supply (Hence why the schematic suggests 12v output for 6.3v supply). Ian, the tube mixer guy, recommends using SMPS supplies for the H+. You will definitely need to adjust component values such as the dropping resistor in the B+ line (more current, more voltage drop), maybe increase filtering too.
V=IR
use ohms law for current draw. This will tell you current requirements--rate the tx at twice the total current draw b+

 

[mattrad]

Maybe i'm way off here but I would guess you could power like 20 OP-6s with a 250VA PT.