12AU7 CD Linestage CHoke Value.

[Gizmo2]

Hi,

Building a 12AU7 cathode follower line buffer after a stock 2 volt cd player.

Want to run a simple C-L-C using (2) Solen 47uF PPE caps.

Told to buy a Hammond 5H choke.

My power supply is 125v-125v, 12.6v heaters.


There are so many different values of 5H chokes

http://www.tubesandmore.com/scripts/...RC&PAGE=SUBCAT

Want to end up with 95-100 vdc B+

What choke should I buy?

[Bill Fuss]

50 ma is plenty. You're in the wrong forum.

[kevinkr]

I'd repost this query in the tubes forum or ask a mod to move this thread there.

You might want to try Duncan Amplifiers PSUD2 power supply design software - with a little work to understand the software it will tell you pretty accurately what the value of the input capacitor and the dcr of the choke needs to be to hit your target voltage.

Ask questions there and other forum members will pitch in with their advice which may also include some negative comments about the 12AU7's linearity. (It's not the best, but in CF operation probably won't contribute significant distortion if the load impedance is reasonable.) In case you are interested (and it is not necessarily the case that you should be.. ) the 5687 is a commonly available alternative, has better linearity and much higher transconductance making it a very good cathode follower.