diytube.com

When you set up a CCS like on Shannon's boards, you would set up the CCS for double the mA that each triode needs. Ex. 6mA paper triode would have the CCS set at 12mA.

If you would normally use two red LEDs for bias, but you parallel the triodes in a tube like the 6CG7, would you use 4 red LEDs?

Thanks!

Blair

No. But your current will be 2x one triode.

Shannon

OK,

It looks like you have the phase inverter CCS on the Poseidon board set to around 6.5-7mA. Does that not put each triode at 3-3.5mA?

Thanks!

Blair

Blair wrote:It looks like you have the phase inverter CCS on the Poseidon board set to around 6.5-7mA. Does that not put each triode at 3-3.5mA?

Correct. I guess I should ask what is the proposed application for the LED bias to answer your question better.

Shannon

Hi Shannon,

I was just going to do a parallel Anode Follower using a 6CG7. I figure around 12mA total for both triodes. Would I need to half the anode load resistor?

Thanks,

Blair

Here's a simulation from Tube CAD to help you visualize it all. The -3.63V bias would be two red LEDs.

Shannon

Thank you Shannon!

How much is TubeCad? That looks pretty nice.

Sadly, it is defunct software due to conflicts with the newer 64-bit versions of Windows. I run mine emulated in XP through VirtualBox. Maybe email John Broskie if he'll sell you a copy, as the resellers weren't carrying it anymore last we checked around here.

Shannon

You could look at this:
http://www.beigebag.com/v5_features

No idea if it is affordable for a hobbiest.

I run B2 Spice for the day job.
It has a wizard for creating tube circuits and has extensive models for tubes. JB is/was one of the authors.

Cheers,
Ian