help w replacement pots…

[beatsnblunts]

D shaft..

 

[JohnRoberts]

Came across this...

https://messageboard.tapeop.com/viewtopic.php?t=75894
Those are Noble pots made in Japan, I used them on the Rhodes Mk7 pianos.

Yes, Aphex still has stock of these parts. Unfortunately, the new owners are rather dense when ordering these parts. Therfore you must be thorough and double check the order. I would also send Aphex a pic of eack pot for ID. I ordered some 15 C pots and got A's from them!

15A = 10% audio taper

15C = 10% reverse log taper

15B = linear taper.

Jim Williams
Audio Upgrades

I doubt Noble (or anybody) manufactures inexpensive pots in Japan... they may design them in Japan but generally manufacture in mainland China to be cost competitive. A couple decades ago Alps (major Japanese pot maker) moved production to Brazil in an attempt to be cost effective, since then they moved their production to mainland China.

Back last century while at Peavey I encountered problems from a major US pot maker who moved their inexpensive pot production to China and messed up the recipe. They stopped selling pots to Peavey because they said we were too picky...

JR

 

[beatsnblunts]

thanks everyone for their conversation here! i appreciate the help.
cheers!

 

[beatsnblunts]

Well.....

i got the pots but had a hard time finding them in the shaft that i needed so i got solid shaft and made them into 'D' or flatted shafts with the help of a grinder. and yes 16mm is the correct size. would have been easier to get new knobs that fitted knurled or slotted shafts.

 

[JohnRoberts]

OK here's today's TMI about pots and knobs. At Peavey we enjoyed the luxury of tooling custom knobs for our products, something small companies only dream about. Collet knobs and set screw knobs give you adjustability, but extra labor in the factory at final assembly is undesirable (expensive). Let me skip ahead to today's TMI story. Sales reps are whiny cry babies (slight exaggeration) and I recall several EU reps complaining that our powered mixers were just not competitive with one EU based competitor's model, side by side at point of sale (sorry I don't recall who). Since the buck stopped with me as engineering manager over all Peavey powered mixers so I had to bring the subject mixer into my lab to kick the tires.

It took me a few bench measurements to suss out what was going on, but when tone control pointers were set to flat, the EU competitor had a measurable HF and LF boost. Not a lot, but enough to be audible in close side by side listening tests. Digging deeper it turns out the tone controls had splined shafts but were using custom tooled knobs whose pointers didn't register centered at 50% rotation (knob was probably tooled for a different application). Their choice was to install the knob 1/2 spline hot, or 1/2 spline cool. They went for hot, and our low expectation reps ASSumed that the sound difference they heard was better performance from the competitor.

Not the first time I had to wrestle with low expectations and poor brand perception even inside the castle walls.

JR

 

[beatsnblunts]

OOps!
well, i though it was all good-passed audio, no noises then i started to adjust the ratio- if i barely turn up the ratio the reduction meter goes full on and i get no audio- until im at the other end of the knob-full CW.

Any one have any thoughts on this?
wrong taper? bad soldering(i did lift some of the pads when de soldering)
un related issues that i forgot this had?

thanks ya’ll!
-SteveMc

 

[beatsnblunts]

bumpy bump-

 

[scott2000]

OOps!
well, i though it was all good-passed audio, no noises then i started to adjust the ratio- if i barely turn up the ratio the reduction meter goes full on and i get no audio- until im at the other end of the knob-full CW.

Any one have any thoughts on this?
wrong taper? bad soldering(i did lift some of the pads when de soldering)
un related issues that i forgot this had?

thanks ya’ll!
-SteveMc

You could put a meter on the pot to see if it's whacky from damage or factory error. There are also ways to measure taper if you think that is a possibility. What pot/ taper value was it? What did you replace it with?

Could jiggle the pot while in use to see if it possibly behaves which would mean a sorta bad connection . Or study your work really well to see if something stands out like moving joints or whatever.

 

[beatsnblunts]

thanks Scott, i replaced with same pot(but am double checking that) re flowed the solder and still issue-will get to poking around soon.
S