View Full Version : Working on tube amp, need pot


swjanitor
09-16-2010, 05:36 PM
No... not 420... :nono:

What I need is a panel mount 1M linear taper with a 1/4" flattened (D) shaft about 7/8" long (although 1" or longer I could always cut to length). I'd even take an audio taper in a pinch.

Can't seem to find one at the usual places I'd check like Mouser or DigiKey.

Split shaft or solid shaft seem to be common... I may end up filing a flat onto a solid shaft if worst comes to worst. Fire up the ol' Dremel.

glen65
09-16-2010, 07:00 PM
Whats the make and model of the amp?

swjanitor
09-16-2010, 11:30 PM
Whats the make and model of the amp?

Motorola HS-544

I want to replace the original volume pot which has a resistor/capacitor network on the back of it with a plain ol' pot.

I've actually got a couple more of these amps, including a HS-621 (almost the same) and another HS-544.

glen65
09-17-2010, 10:43 AM
Motorola HS-544

I want to replace the original volume pot which has a resistor/capacitor network on the back of it with a plain ol' pot.

I've actually got a couple more of these amps, including a HS-621 (almost the same) and another HS-544.

You cant just eliminate the resistor and cap altogether.
You'll need to connect those in with the new pot.
You might try tubesandmore.com, quite a bit to choose from.

swjanitor
09-17-2010, 11:46 AM
You cant just eliminate the resistor and cap altogether.
You'll need to connect those in with the new pot.
You might try tubesandmore.com, quite a bit to choose from.

I think I can remove them w/o a problem. Look at the schematic for the HS-544/HS-621. There is actually a small ceramic circuit package attached to the back of the pot. Looking at this circuit compared to similar ones, say for example the Fender Deluxe 5E3, I should be able to just remove the pot with the attached resistor/cap network on the back and put in a normal 1M linear taper pot. It should improve the tone by not filtering the input as much. Maybe even increase the gain a little if I'm lucky.