Urgent question:
A Gain-fader of the Resonator section got out of function and I’ve found out that it has got broken. It’s section is fully working.
I’ve been told by my tech that I need a: 10kOhm logarithmic (“Audio” or “A”) for replacing. I’ve two in stock and there’s written on either: 10k 7a, and the other one 10k 7b.
Is the first the right one I’ve to put in or are both not fitting. What means the number “7” ?
Thank you in advance
It might be Ta or Tb, rather and not 7a and 7b ?
If that’s the case, there are two meaning depending on where the sliders were produced:
In Europe Ta means linear taper, and Tb means audio taper or log taper
In USA Ta means audio taper or log taper, and Tb means linear taper
You can test it with a ohmmeter and check the behavior of the slider. If the values change constanstly from one end to the other of the slider, it’s linear and that’s not what is needed.
If the values change faster at one end of the slider, it’s an audio or log one.
Disclaimer: The above info is based on my personal experience and might not be entirely accurate. 
Thank You so much. I’m knowing this with the European letters vice versa and the measuring.
But what made us confused was the “7a,7b”, or as you said the “Ta and Tb”. We don’t know this signification, and I believed this is a completely different type probably for other functions in the Poly.
So I only just want to know, if I can take them ???
Listen, try them both inside the Polymoog and see how they behave. If they’re 10K Ohms like you said, they’re the right value. Only the way they work will differ. And if they’re the wrong type, all that will do is not produce the desired behavior when you move them, but it will absolutely not risk damaging anything. That I’m sure of.
I would try the Ta (or 7a) first.
Maybe I’m being captain obvious, but isn’t any of this in the service manual?
Or can’t a slider be easily checked with an ohm meter?
I quickly looked in the schematics and it showed an audio output slider of 10K audio for the filter.
Not sure if it’s the same for the resonator section.
If you’re talking one of the gain sliders IN the resonator section, I’d guess just compare one channel to another.
Sorry… maybe I’m missing something here.
What size (in mm) are the originals? I have a J.H. triple resonator that was built with sliders (all 10K of various types), now parted with and placed in a MOTM panel; my point is that I have a pile of Sliders and could mail you one if it will fit/help you out.
Let me know. (unfortunately, I cannot post a picture here otherwise, I would).
Thank you SO much, you’re SO lovely ! 
I’ll begin to fight with that bugger in a few days and I hope I won’t get hung in the wire-jungle of the rearside of the panel. Comitting suicide would be the more comfortable way, I think… 
I think it would be more easy to fix the electronics of a control-panel in Cape Canaveral than to swap a slider in a Poly…
Sorry abou this:
I observed, I’ve made a little mistake. the second slider has NOT the signification “7b”, it has “7g” (Tg ?)…
Now parts arrived yesterday from a very lovely guy in England. He has sent me almost all I needed for replacement and spare.
On one side of both sliders is written: 28411 1
And on the other side of one: D 10kOhm 7A
And on the other: D 10 kOhm 7G
I measured yesterday guided by my tech and we found out both are logarithmic, but the 7G is a “reversed”. That’s it.
Now this weekend i’ll begin the big struggle and will put the first in. I’m very curious what is written on the broken one.
Well, it had been really a tough work taking out the non working slider and we’ve found the bug. The carbon surface has a hair crack that could only be seen with a magnifire. This led to the interruption of the working-line.
BTW I was advised to swap all the contacts on all boards into gold-ones and I’ll do, as this is the most severe sickness on the Poly.
In spring when I’ll get my upgraded Memorymoog, I’m thinking of building a second Fort Knox around my house because of all of the gold. 
One good thing about big synths like the Memorymoog or Elka Synthex, or worse a Yamaha CS80: because of their sheer size and weight, burglars will always settle for easy items such as cash and/or jewelry instead of carrying a 200 lbs analog beast out of a house!! 
YES, ABSOLUTELY.
And this is about to be prctised in our town and country day by day. This makes me kinda sleep well. But there are exceptions.
Burglars are coming and stealing your items in that moment when you’ll never expect. That’s the the bad surprising we always have to fear.
It had been some years ago when one man had been taken by surprise when trying to open up the door at the neighbours one floor below.
Bad thing for music making is, we can hear a needle falling down on the floor, but good for keeping the burglars away.
Very true. Every theft I heard about from musician friends, the items stolen were stuff that one person can easily carry - mics, cymbals, guitar amp heads, guitars, small mixers and processors. Trailers are a popular target too. Most thefts are carried out by a single person. Look around any pawnshop and most music items are small stuff.
I cart my stuff in Anvil cases. They’re heavy enough to discourage theft. Same with my racks. I make it a point to gig with anything that no single person can easily run away with. That’s a little harder with guitars, so I use guitar stands that you can’t easily or quickly free at the neck. When packing up, I usually put stuff on top of the guitar cases so you can’t easily grab them.
I leave my Yamaha P-90 at the rehearsal room, but I always take my guitar and vocal mic.