Tubelab Simple P-P Choke

[Einric]

I am in the process of building a Simple P-P and I have a couple of choices for chokes.
I have a C-12X 6H 165ma 160Ω and a 10H that is slightly larger but I don't know the ratings on it.
Will a 165ma 6H choke do the job for the simple P-P?

Thank You

 

[ronaldw441]

IIRC my PP's (have 3 of them) all pull between 185-200ma's so the C-12X would be a bit small. If you can wait a couple of days I'll measure the voltage drop across R1 to give you an accurate figure.

Ron

 

[Einric]

Sure, Thanks, I'm not in a great hurry since I don't have my Iron ordered.
The $30 to order an Edcore choke with won't break me.

But, by all means please let me know.

 

[ronaldw441]

I measured my 3 Simple PP amps in 5 different configurations with different power transformers. The average current through R1 was 192mA.

The amp that uses a 600VCT Edcor transformer had a current draw of 194mA.

 

[Einric]

Thank You, so a 200mA choke is what I need.

Simple PP @600VCT needs a 200mA choke under standard conditions.

 

[ronaldw441]

Einric,

Sorry for the delayed response. Yes the 200mA Edcor should be fine.

After searching in the basement for a couple hours I managed to find a choke close in specification to the Edcor. Connected to my board mounted Simple PP the choke improved the signal to noise ratio about 8dB versus the same amp with a resistor at R1. Impressive.

You'll probably have to be careful with output tube selection since the Edcor choke has half the resistance of the normal 150 ohm R1.

Ron

 

[Einric]

would anything be wrong with a resistor in series with the choke to make up the difference, or is that not really needed?

 

[Einric]

It looks like the Triad C-14X is perfect, 6H 200mA 150Ω.
Best of all it is $18 @ Mouser.

 

[ronaldw441]

Wow, that's a great deal & it should work great. Make sure you order it right away though. They only have one in stock.

 

[Einric]

Onlinecomponents.com has over 100 in stock for the same price.

 

[rfengineer2013]

FWIW, I used the Triad C-14x in my SSE build and it works great. The downside is that it isn't as "pretty" as one of the blue Edcors (the Triad is a plain-frame model) but I mounted the choke inside my chassis so appearance isn't an issue.

Best luck with your SSE - it's a solid performer.

Sam

 

[Einric]

Mine is the SPP and I was planning on mounting the choke inside the chassis anyway.
Thank you for your well wishes.