Question about power supply for D3a driver

[Tubenstein]

Hello!
I'm working on a SE amplifier that has D3a for the driver.

Here is the diagram for the supply.

6AU4 -> LC Choke -> 100uf -> 16H 12R -> 100uf -> 180v @20mA for D3a

Which value should I use for the LC Choke from either ISO (Tango) or Hashimito?

http://www.acoustic-dimension.com/iso-transformers/iso-transformers-choke-page.htm

http://www.acoustic-dimension.com/hashimoto/hashimoto-chokes-transformers.htm

Thanks in advance!!

 

[56085]

Is the supply you decribe for all the tubes in the planned amplifier? Or only for 2 x D3a? Or only for 1 x D3a?

 

[euro21]

If you use D3a with active load (CCS, gyrator), this HT smoothing is more than enough.
Active load PSRR -at least- about 40dB.

In my daily used (CCS loaded D3a, FET source follower, 300B) amp the HT "line":
5U4GB-4u7-33R-47u-10H-47u (to power stage and SF) -3k9-47u to CCS.

 

[Tubenstein]

Is the supply you decribe for all the tubes in the planned amplifier? Or only for 2 x D3a? Or only for 1 x D3a?

The planned supply is for 1 X D3a as it will be a monoblock amplifier.

 

[Tubenstein]

If you use D3a with active load (CCS, gyrator), this HT smoothing is more than enough.
Active load PSRR -at least- about 40dB.

In my daily used (CCS loaded D3a, FET source follower, 300B) amp the HT "line":
5U4GB-4u7-33R-47u-10H-47u (to power stage and SF) -3k9-47u to CCS.

I will have 1:1 Interstage transformer.

 

[56085]

The 6AU4 is a damper diode. I thought that with half-wave rectification choke input filters don't work like they normally do. Besides that, why use a choke input filter for a tube that runs in class A (and only consumes 20 mA)?

 

[astouffer]

The 6AU4 is a damper diode. I thought that with half-wave rectification choke input filters don't work like they normally do. Besides that, why use a choke input filter for a tube that runs in class A (and only consumes 20 mA)?

I've done choke inputs on purpose to drop a lot of voltage.

 

[sser2]

The 6AU4 is a damper diode. I thought that with half-wave rectification choke input filters don't work like they normally do. Besides that, why use a choke input filter for a tube that runs in class A (and only consumes 20 mA)?

There is one advantage of choke input: it is much quieter than capacitor input. The rectifier is full-wave (two 6AU4 tubes), half-wave won't work with power transformer.

 

[jhstewart9]

They said it couldn't be done?!?! Not recommended but here is the free wheeling diode in action.
The transformer is DC biased tho, not good. Notice the large negative overshoot when the freewheeling diode is unhooked.