Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #98666  by mgbills
 Fri May 27, 2011 12:35 pm

Here is a link to the Alpha dual ganged linear pots. They are a bit cheaper than they are from Tubes and More. They still need to be disassembled/reassembled. Has anyone found these from CTS, or some non-Chinese manufacturer. I have a fair amount of scepticism about manufacturing in that part of the world. Severe polution. Dyes in rivers. Slave labor. The usually Hippy Hibble-Dribble. Small Bear sent me a great pdf of the detail on these. PM me, and I'll forward it to you. Looks like the ones from Small bear have a shaft diameter of 6.35mm. It's a very detailed schematic, and I'm not a real electrical engineer...I just play one on TV.

Anyway...Peace to all. Thanks to all your crazy folks out there for all your hard work.
 #105735  by TI4-1009
 Mon Nov 28, 2011 6:11 pm
Just a word to the wise if you want to do the dualie swap. Alpha makes (at least) two sizes of dual 250 and 500 pots. I bought a few of the 24mm figuring bigger, beefier, better. When I finally popped the bottom off I was surprised that there was no "wafer" on the bottom- it was just a round piece of aluminium. The "waffer" on these is internal and peened onto the bottom of the rotating shaft. There may be a way to get the element off and replace it with the other one without breaking anything, but with my luck I elected not to try that.

The smaller ones are about 16mm in diameter and have the phenolic resin wafer as the bottom of the pot itself- external. Doing the swap took like 90 seconds as demonstrated on Waldo's Excellent Video. Here are two photos of the two different pots:



I got the smaller ones at smallbear. On the meter they all go up a little higher than either 250 or 500, but they feel smooth. Plus with limited space in the control cavity the smaller size should be a benefit (24mm is almost a full inch)- not to mention the height.