Vintage EHX Polychorus needs help !

[charlje]

Hello everyone,

That's my first time posting here. I was advised to come ask here by Analog Mike from Analog Man.

The thing is I own a vintage EHX Polychorus that needs some fixing. The 4 positions MODE selector (rotary switch) is dead and I'm trying to replace it.
Here are some pictures to point out the part I'm looking for.







Does anybody could me help find the name/reference of this part ? Or where to find the schematics with the name indicated ?

My mistake is I firstly figured it should be a 2P4T rotary switch( 2 Poles 4 Tracks ??) which I ordered on Ebay. When I received it, there were only 3 positions, instead of 4...
Anyone has an idea ?

Thank you!

[Scruffie]

It is a 2P4T switch... just to be sure, there is only 3 clicks on a 2P4T switch as you have a starting position, so start, click, click, click (end) i've made that mistake before.

Otherwise, I think Tayda sells them.

[Granny Gremlin]

Yeah, those aren't hard to find.  There's a coupe local places I can get those at.

The best way to make sure you are getting the right number of poles and throws is to count the number of solder pins on the bottom (2 rings of pins; inner = poles and outer = throws*poles). you might have to mount it off PCB because you might not be able to find a switch with the same pin spacing/layout (which pin is located where - e.g. 12 o'clock on the outer ring might be pole 1 Throw 1 or it could be pole 2 throw 4).

Note also that the enclosed (B&W plastic) Alpha rotary switches have the ability to set the number of usable throws with a special washer around the shaft, so if those fit you can use one with more throws than you need, just snip the unused pins (if it fits the PCB spacing)

[Govmnt_Lacky]

Otherwise, I think Tayda sells them.

BE SURE to look that it is "Break BEFORE Make" The switches that Tayda sells that look like these are "MAKE before Break"

[charlje]

wow !
that's great ! very fast answers, precise and helpful it seems 
thank you

I will check if the ones I already have couldn't actually (!?) be a fit...

Otherwise, I think Tayda sells them.

BE SURE to look that it is "Break BEFORE Make" The switches that Tayda sells that look like these are "MAKE before Break"

sorry, but what does this mean ? it sounds like there's something subtle to get, that I unfortunately don't

[charlje]

Otherwise, I think Tayda sells them.

BE SURE to look that it is "Break BEFORE Make" The switches that Tayda sells that look like these are "MAKE before Break"

sorry, but what does this mean ? it sounds like there's something subtle to get, that I unfortunately don't

Think I found an anser :
"Q3. What is the difference in Shorting and Non-shorting?
A3. A shorting contact is also known as "make before break" and describes the action of the contact as you select your switch positions. The switch will momentarily "short" postion 1 and 2 together when you rotate from position 1 over to position 2. A non-shorting contact is also known as "break before make". The connection is momentarily broken when you rotate from position 1 over to position 2. "
from http://www.electro-nc.com/faq.shtml

so this would mean I have to make sure the switches don't make a short before going to the next connection... otherwise it could damage some components I guess

[Govmnt_Lacky]

so this would mean I have to make sure the switches don't make a short before going to the next connection... otherwise it could damage some components I guess

Correct!