On 26/01/2010 4:51 a.m., Jim Lesurf wrote:
In , Ian Bell
wrote:
Jim Lesurf wrote:
In , Ian Bell


esr.co.uk do some centre and 41 position detent pots - they don't
mention the make.

Alas, they just seem to be the 'small pot with a detent collar'.


And how does that differ from the ALPS?

The Alps 40mm pots I am using are physically bigger and have tight and well
defined spec for things like level of attenuation for each step and the
tracking accuracy. I've used a number of them over the years and that has
satisfied me that they are reliable in terms of knowing what attenuation
you get, etc.

Simply putting a detent collar on any double gang pot doesn't automatically
provide that.

One reason for this is that smaller physical tracks would require greater
physical precison to obtain the same level of accuracy. But this also
depends on how well the pots are made. I have experience with the Alps
units, but have no idea in advance how well unknown makes will work.

Have you not seen any of the Alps 40mm type? if not, I can probably put up
a pic sometime. But clearly that won't in itself tell you the specs or how
reliable they are in long term use, etc.

Slainte,

Jim


I think I know exactly which pot you are looking for. It is the very one
that Quad used in their 44 Control Unit - 40mm Alps pot, Dual gang 500kohm
(stepped attenuator with 21 detents of approx 2db each ?). I've had a look
at one and the numbers on the back of the dual pot are :
024B-494.55K� x 2. Underneath this is another number : A3/12425

I've tried a search on these but haven't come up trumps but I suspect that
anyone wanting one could probably get them from Quad.

Mike

In article , Mike Coatham
wrote:
On 26/01/2010 4:51 a.m., Jim Lesurf wrote:
In , Ian Bell
wrote:



I think I know exactly which pot you are looking for. It is the very one
that Quad used in their 44 Control Unit - 40mm Alps pot, Dual gang
500kohm (stepped attenuator with 21 detents of approx 2db each ?). I've
had a look at one and the numbers on the back of the dual pot are :
024B-494.55K# x 2. Underneath this is another number : A3/12425

No, that isn't what I am using - although that have the same physical
appearance IIRC.

What I'm using is the 20k semi-log pot for volume as a conventional passive
potential divider.

I've tried a search on these but haven't come up trumps but I suspect
that anyone wanting one could probably get them from Quad.

Yes, I'd expect to buy the pot used by Quad from them. But it isn't what I
am using.

FWIW I have these Alps pots in 20k, 50k, and 100k values.[1] Also various
examples of the physically smaller ones, mainly with the law convenient for
balance with a center detent and no attenuation at center detent.

[1] Have them partly as 'spares' from my Armstrong days and blagged from
suppliers at various times. :-)

Slainte,

Jim

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