I have been looking for an Alps RK27 or equivalent Noble 500K pot. Where do you get those things? I googled both and couldn't find anyone who sells them.

Have you tried >>> (www.partsexpress.com) or (www.audioasylum.com)

J

Can locate 100K and 250K ALPS Blue Velvet all over the place. 500K is a different story. One possible alternative is a stepped attenuator. Triode Electronics offers a 4 Pole 23 Position Alps make before break switch, usually used for making stepped attenuators. Includes little PC boards for mounting the resistors.
They even walk you through the resistor values you will need. The link is below.
http://store.yahoo.com/triodeel/controls.html

Why 500K? As the resistance goes up, the capacitance of your cables becomes more of an issue. At 500K it only takes 16pF of shunt capacitance to cause -3dB rolloff at 20KHz. To put this in perspective, a really good scope probe would have 11pF of shunt capacitance. I think there's a very good reason you can't find 500K volume pots; no one wants to use them!

I've been ordering from partsexpress for years now. They don't even carry a dual gang 100K pot. I've seen the Triode setup, I may go that route. The 500K is for the RCA 1963 RC-22. I built the two-stage input amplifier. I have an AES $2.50 alpha pot. I was wanting to upgrade. Where do you get the other Alps pots 100K blue or black ones?

Michael Percy Audio
www.percyaudio.com
has Alps pots
Angela Instruments
http://www.angela.com/
does as well and there are others as well.

Oh yeah, Angela. I went to the site some time ago and was scared off by the prices. Forgot about them. Who else?

A27, If you want a premium pot you are not going to get it for $5.00.
Another source is Parts Connexion.
http://www.partsconnexion.com/catalog/controlsswitches.html
Did you miss Michael Percy?

Here is an ebay auction with a BIN of 19.95 for two of them. I bought a couple for my Scotts off this seller with no problems:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3666&item=3490428970&rd=1&ssPageName=WDVW

:p: