Archive of the former Yahoo!Groups mailing list: MOTM

I received some back-ordered Spectrol 148 linear pots today, and was shocked to
see they are ∗different∗ from what I've been buying for the last 8 years. Then
it dawned on me: RoHS has struck again! I have not received Spectrol pots
∗after∗ July 1st until this batch. I then downloaded the data sheet: yep, it was
∗changed∗ on July the 31st (better late than never, as Granny used to say).

I called Spectrol and talked to 3 different people for about 2 hours (I was
having an anxiety attack of sorts). Yes, they have redesigned the 148/149 pots
to be RoHS compliant. But then ∗old∗ 148/149 were also compliant. But, the new
ones are ∗made in France∗ by another Vishay division called Sfernice. I guess
this makes them "even more compliant".

There are 2 main differences, and 1 minor one

a) the pots are now white, not black

b) the torque (force to turn the shaft) is 'stiffer' than the other ones. Now, I
compared the specs (old versus new) and the ∗specs∗ are the same, but they have
a ∗WIDE RANGE∗ of 0.2 to 3.0 in-oz. (15:1). So, I guess the older (black) ones
are in the lower end of the scale and the new ones are bunched up toward the
upper end. If I was to make a comparison, the newer ones are more like the pots
in say my Frac modules, .com or Doepfer (they have a 'firmer feel'). But then
again, nothing prevents Sfernice from making a batch with 0.2in-oz which is like
the ones everyone is used to.

c) the pots are slightly 'thinner', but this will not effect anything.

So, what I am going to do is send in a formal request to Sfernice over in France
and see if I can get the pots made with a smaller range of rotational torque,
that is more towards the lower end of the scale. There are 3 possible outcomes:

1 - sure not a big deal
2 - yes, but you have to buy xxxx NCNR (non-cancellable, non-returnable) and the
price just went up yyy%
3 - errr....no.

I suppose the 'good news' in talking to Vishay is that these parts have a lead
time averaging 8-9 weeks versus 12-14 weeks (mostly 14 weeks) for the current
parts.
Also, their minimum order is only 100pcs, where the Spectrol was 600pcs. This
will allow me to get solder lugs instead of the long wires for the COARSE pot
used on the MOTM-300, making wiring a LOT easier. Of course ∗ALL∗ the kit
documentation is wrong....sigh........

So, here are my action items, as we say in the business:

a) send email to Sfernice, begging to get parts with a lower rotational torque
(this assumes the torque can be controlled to a degree, not just some random
value)
b) inventory of all existing 148/149 pots
c) see how many of the newer style is needed

Now, if I get response #3 above, there is a ∗small chance∗ I can get Clarostat
to sell me the older parts (Clarostat made them in Mexico for Spectrol). But
then again, they may want 5,000pcs minimum or some wild-assed number. I ∗may∗
find a Clarostat part that can sub, but in my experience, the Clarostat parts
are VERY EXPENSIVE, like 2X the Spectrol (and they are blue in color, like the
Bourns which makes the current documentation even more exciting).

The ∗probable outcome∗ is that I will have to accept the 'new' 148/149 pots from
Sfernice with whatever torque they send me. The performance will be the SAME,
they will fit in the same places on the pcb, and they have the same shaft length
and the same bushings. They may ∗all∗ be the 'stiffer' ones, they may all of a
sudden be like the current ones (because they will still fall within the spec).

I will update when I get an answer (probably in 10 days or so). In the
meanwhile, we will continue to ship as many kits as we can with the current
148/149 pots. Per my previous email: expect to see 148 pots substituted for 149
pots (EXCEPT in the VCOs). If we do have to change over, I would estimate 15% of
the modules ordered since July 1st would be shipped with the Sfernice parts.
Heck, there is the possibility that the Sfernice parts are ∗preferred∗ (shrug).

Paul S.
I need a nap