Vintage RS Slider (100k Value) Question

Moderator: VelvetGeorge

Post Reply
sine_wave
New Member
Posts: 31
Joined: Tue Jul 16, 2013 5:40 pm
Just the numbers in order: 13492
Location: New York

Vintage RS Slider (100k Value) Question

Post by sine_wave » Fri Sep 26, 2014 4:02 am

Hey,
Someone is offering me an old (NOS) RS slider/potentiometer (just like the ones that were used on the original Marshalls). Now, I know that the bias trimmers for the 12,000 build is somewhere in the 20K-25K ballpark, yet I saw a schematic that George posted a while back of an amp that was only a few serial numbers away from the EVH holy grail amp and the value for the trimmer was 100k. :what:

My question… Is it not worth it to bother with a part with a value like this (100K) for my 12,000? Also, if I do use the 100K, are there any ways for compensating for it with maybe a change in one of the resistor values, etc? I really need help here, especially since I don't know what was generally used in the Plexis of yesteryear. I appreciate any help.

- John

User avatar
bill bokey
Senior Member
Posts: 485
Joined: Sun Jan 02, 2011 2:54 pm
Just the numbers in order: 13492
Location: France
Contact:

Re: Vintage RS Slider (100k Value) Question

Post by bill bokey » Fri Sep 26, 2014 4:12 am

What's wrong with a 25k trim pot ? So much easier to use than those old sliders !

User avatar
Strat78
Senior Member
Posts: 3093
Joined: Fri Aug 03, 2007 12:38 pm
Just the numbers in order: 13492
Location: though I'm standing still, I'm in a moving place.

Re: Vintage RS Slider (100k Value) Question

Post by Strat78 » Fri Sep 26, 2014 9:28 am

27k to 500k will work fine. I have a RS 27k slider in my 12 series and used a 5.6k bias resistor (next to the diode) to get it into a good range. Although with your typical 27k Alpha trim pot you usually have to use something around 33k, not sure why that is.. I love the sliders, if you don't grab the 100k, I'd be interested, so let me know. :toast:

Post Reply