Archive of the former Yahoo!Groups mailing list: MOTM

----- Original Message -----

From: rob

To: 'MOTM litserv'

Sent: Thursday, May 24, 2007 3:33 PM

Subject: RE: [motm] Spectrol 248J pots?

Hi Paul,

Why not try the plastic shaft 248's? They are in stock in a number of suppliers, rather than plated brass. In my experience the plastic bushing is not a problem, unlike Omeg. I do find some 1/8" shaft Spectrol 248's are DOA, but I have never had that with 1/4".

 

The electrical and mechanic rotation of the 148 and 248 are very similar.

 

148 is 300 degree machnical and 270 electrical

248 is 295 degree mechnical and 265 electrical

 

Rotation life is the same, although resistive tolerance is higher on the 248. And yes the 149/249 have some advantages over 148/248 but also a shorter life span.

I can't see a major problem with switching to 248's.

 

Regards

Rob

www.emulatorarchive.com

 

 

 

 

a) the part I would potentially use is: 248J-9-10-104 (I could also use
248J-9-10-503 which is 50K)

b) I have not seen stock of these anywhere. If somebody has seen stock, please
contact me.

c) the parts have 2 "issues"

1 - the plastic bushings can be easily stripped. And I mean ∗easily∗ you have to
be very careful
2 - the shaft rotation is not the standard 300 degrees, which is what the front
panel graphics are laid out for.
Instead the 248/249 uses 270 degrees, so the '0' and '10' ticks will not ever
align (meaning, when the pot
is fully CCW, instead of on the '0' tick the knob pointer is on the '1' tick).

See how thrilling and exciting synthesizer design can be??!? :)

I'm not as concerned about (1) as I am about (2).

Comments? Anybody even locate the 248Js?

Paul S.