In article , Ian Bell
wrote:
Jim Lesurf wrote:
In article , 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

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:
In article , Ian Bell
wrote:
Jim Lesurf wrote:
In article , 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 don't think I have seen them. I had a look on their web site and found
some rather smaller detent pots but no 40mm ones I could see - does this
mean they are no longer in production?

Cheers

Ian

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

Jim Lesurf wrote:

Anyone know who imports/sells the Alps 40mm detent pots in
the UK? I've
been trying to find out via google but not found anyone
who does these as
stereo 'log law' pots, and sell small quantities or
one-off.

FWIW I still have some pots for my own use. But one of the
projects I'm
working on may involve one, and I might then want to
publish details so
readers can make something similar if they wish.

The market for decent audio pots must have declined
considerably due to the ubiquity of encoder/chip/display
alternatives.

Consequently, possibly, switched attenuators seem quite
fashionable, and may fit into a 40mm space. Google reveals
quite a few. "Dale Vishay" look less of a lash-up than some,
but I haven't seen one in the flesh. Expensive, but good
pots aren't cheap either. DIY is tedious but doable, if you
can find a good switch.

If, on your travels, you come across a rotary encoder-based
module that remembers where it was before it was switched
off, and that has a ring of LEDs rather than a numeric
display, that's what I'm looking for.

Ian