How to replace volume pot in Dynaco Pas

Viridian: Do you think I should use a 100k pot? I am not using the loudness feature.I have been looking at the math and I am unsure.
The low level input is 50k and the high level input is 250k and the output is 1k.

I have been reading up on pots and attenuators and I will admit that I am a little confused.I was never very good at math and the equations (as expressed in the white paper I am reading) are beyond me.I understand the concepts but am having a problem putting numbers to formulas.

If you or anyone has experience with this or a recommendation I would be very grateful.

rank beginner hack

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I would, and have, gone with a 100K pot. The problem being, if you use the phono stage, you will have to replace several of the caps and resistors on the board with different values to return the RIAA curve to being flat. This is not a bad idea, as the original design pretty much sucks and even with the upgrades, you will find that it is probably not up to the quality of the line stage.

BTW, here is a link to a simple graphic by Joe Curcio that shows the mod. Again, once modded, this will only be flat into a 100K volume control:

http://db.audioasylum.com/cgi/m.mpl?forum=dynaco&n=14226&highlight=RIAA&r=

Finally, as Ralph pointed out, moving the time constants to the board will make the first three inputs all phono inputs, which is kinda cool. No more "tape head" and "special".

Thanks guys. I will change my order on the attenuator.

This mod doent' look too bad to perform.

Do you guys recommend any particular caps?

e

Ralph would be the expert on caps, for sure. I can say that I don't like the sound of orange drops, but there are really nice caps in all price ranges. For $1 to $2 there are the polypropylene and tin foil Daytons from Parts Express, which are surprisingly nice. Some like the Solens as well. For $5-$6 the Russian K40 caps are fantastic but a bit larger than many other caps. The sky is pretty much the limit from there if you have the budget.