Lexicon LXP5 LXP1 pot and shaft replacement? Or not worth it?

[Farringdon]

I have an old LXP5 that has a broken knob/shaft, please see photos below:

I gather it is not super straightforward to get the right replacement parts, or am I wrong?  Perhaps it's not worth the trouble.  The reason I want to repair this is because I might sell the LXP5, LXP1 and MRC.

Would appreciate any help.  Thanks!

 

[pvision]

The input, output & mix controls are pots and they tend to go noisy. I don't know about the select switch, but I suspect the adjust control is an encoder

If it's like the pots it will be mounted on a separate PCB which will make life easier

If you can find an encoder of the correct type with the correct shaft you're in business

Nick Froome

 

[clintrubber]

The input, output & mix controls are pots and they tend to go noisy.

I guess everybody with a LXP1 or LXP5 recognizes this, unfortunately.

Correct me if I'm wrong, but at least some of these pots are 'not treated fairly'. Thought I saw opamps with BJT-inputs and DC-coupled pots. I figure that inserting a cap & subsequent bias-resistor should help for less scratchy pots. (Haven't tried it yet, not using the unit that much.)

Was surprised to see this 'assumed goof' in a schematic from a company  like L.

Bye

 

[Farringdon]

Thanks for the input.

Hmmm...I might not be worth the trouble as I think the LXP5 can be controlled by a midi software, though I've not tried it.

 

[Andy Peters]

Thanks for the input.

Hmmm...I might not be worth the trouble as I think the LXP5 can be controlled by a midi software, though I've not tried it.

LXP5 can be controlled by MIDI. I used to have a 1, a 5, and a 15, all controlled from a Lexicon MRC. It worked great until the buttons in the MRC stopped working, the LCD backlight died, and the pots in the effects devices went scratchy. The audio always passes through the pots, so if they go bad -- and the Lexicon pots always went bad -- you get noise.

I still have the LXP in a closet. I tried replacing the DC blocking caps that are in series with the audio level controls, and that didn't help. The pots are shot.

 

[Michael Tibes]

I had to fix an encoder on my tc m-one recently and the part itself was about 2 or 3 € at Reichelt. It was a bit tricky to identify, but at that price definitely worth it. It works like new now.

Michael

 

[clintrubber]

I tried replacing the DC blocking caps that are in series with the audio level controls, and that didn't help. The pots are shot.

In view of preventing scratchy stuff due to directly coupled pots to BJT-input opamps,
at least a few of those caps are 'at the wrong side' of the pot, like say top-left on this pic below.

There should a be a cap between the wiper & the opamp-input, or replace the opamp with a FET-input type.

Apart from commercial editors, I thought there was an old but working freeware Win program for controlling these. I should look up the exact name, but I recall it worked fine at least on WinXP.

Bye