To my shame, I have to admit that I sought out the following pic to confirm
the wiring to the Alps pots I received today for the purposes of mending my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was trying to remember
(specifically Earth on Pin 1 - both channels), but the labels read quite
clearly signal 'in' and 'out' - does this actually matter if the two
channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)

On Mon, 9 Nov 2009 20:33:53 -0000, "Keith G"
wrote:

To my shame, I have to admit that I sought out the following pic to confirm
the wiring to the Alps pots I received today for the purposes of mending my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was trying to remember
(specifically Earth on Pin 1 - both channels), but the labels read quite
clearly signal 'in' and 'out' - does this actually matter if the two
channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)



The picture is right - both channels must be wired the same. One end
of the pot is ground, the other end is the signal input. The centre
pin is signal output. Don't swap the input and output leads - it will
impose a bad load on the source equipment.

d

"Don Pearce" wrote in message
...
On Mon, 9 Nov 2009 20:33:53 -0000, "Keith G"
wrote:

To my shame, I have to admit that I sought out the following pic to
confirm
the wiring to the Alps pots I received today for the purposes of mending
my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was trying to
remember
(specifically Earth on Pin 1 - both channels), but the labels read quite
clearly signal 'in' and 'out' - does this actually matter if the two
channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)



The picture is right - both channels must be wired the same. One end
of the pot is ground, the other end is the signal input. The centre
pin is signal output. Don't swap the input and output leads - it will
impose a bad load on the source equipment.


OK, Don thanks for that and well done for pushing past the 'mild troll' in
the subject line! (No troll at all - just taking the P155 out of our good
friend *Nutter A* !! ;-)

I actually received a 50K and a 100K and understand from the Q&A session a
week or so ago that it won't make much odds which one I use (was a 50K,
IIRC) - unless I hear different, in about 20 minutes from now I will have at
least started to fit the 50K pot in, under the heading that will leave the
100K as a generally more useful spare?? Does that compute?

TIA, as ever....

On Mon, 9 Nov 2009 21:01:28 -0000, "Keith G"
wrote:


"Don Pearce" wrote in message
...
On Mon, 9 Nov 2009 20:33:53 -0000, "Keith G"
wrote:

To my shame, I have to admit that I sought out the following pic to
confirm
the wiring to the Alps pots I received today for the purposes of mending
my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was trying to
remember
(specifically Earth on Pin 1 - both channels), but the labels read quite
clearly signal 'in' and 'out' - does this actually matter if the two
channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)



The picture is right - both channels must be wired the same. One end
of the pot is ground, the other end is the signal input. The centre
pin is signal output. Don't swap the input and output leads - it will
impose a bad load on the source equipment.


OK, Don thanks for that and well done for pushing past the 'mild troll' in
the subject line! (No troll at all - just taking the P155 out of our good
friend *Nutter A* !! ;-)

I actually received a 50K and a 100K and understand from the Q&A session a
week or so ago that it won't make much odds which one I use (was a 50K,
IIRC) - unless I hear different, in about 20 minutes from now I will have at
least started to fit the 50K pot in, under the heading that will leave the
100K as a generally more useful spare?? Does that compute?

TIA, as ever....

Yup

d

"Don Pearce" wrote in message
...
On Mon, 9 Nov 2009 21:01:28 -0000, "Keith G"
wrote:


I actually received a 50K and a 100K and understand from the Q&A session a
week or so ago that it won't make much odds which one I use (was a 50K,
IIRC) - unless I hear different, in about 20 minutes from now I will have
at
least started to fit the 50K pot in, under the heading that will leave the
100K as a generally more useful spare?? Does that compute?

TIA, as ever....

Yup


OK.

I'm going outside now - I may be some time....

"Keith G" wrote


I'm going outside now - I may be some time....


And finally - a fade out and back in *on the knob*:

http://www.moirac.adsl24.co.uk/showntell/show.html


(Only needs me to post a pic of the white strip on my finger from the
soldering iron now and that's the whole shooting match! :-)

"Keith G" wrote in message
...

"Keith G" wrote


I'm going outside now - I may be some time....


And finally - a fade out and back in *on the knob*:



Okay, dammit - try this:

http://www.moirac.adsl24.co.uk/shown...ttenuate01.mp3


(Classic FM on FM!!)

In article ,
Keith G wrote:
To my shame, I have to admit that I sought out the following pic to confirm
the wiring to the Alps pots I received today for the purposes of mending my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was trying to
remember (specifically Earth on Pin 1 - both channels), but the labels
read quite clearly signal 'in' and 'out' - does this actually matter if
the two channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)

This is what you're actually doing - or should be. One channel only shown.

-------------------\
Input 3 /
\ Output
2 /---------------------
\
1 /
-------------------\----------------------
Ground

If you swap 1&3 (both channels) the pot will just work in reverse.
Swap 2&3 and you will likely get strange frequency response errors plus
possibly distortion near zero.

--
*A picture may be worth a thousand words, but it uses up a thousand times more memory.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in
message ...
In article ,
Keith G wrote:
To my shame, I have to admit that I sought out the
following pic to confirm
the wiring to the Alps pots I received today for the
purposes of mending my
'dog's bowl' attenuator:

http://www.moirac.adsl24.co.uk/showntell/alpswiring.jpg

Thankfully, the picture confirms what I suspected and was
trying to
remember (specifically Earth on Pin 1 - both channels),
but the labels
read quite clearly signal 'in' and 'out' - does this
actually matter if
the two channels are wired in the same fashion??

(I don't see how it can, but am I missing summat...??)

This is what you're actually doing - or should be. One
channel only shown.

-------------------\
Input 3 /
\ Output
2 /---------------------
\
1 /
-------------------\----------------------
Ground

If you swap 1&3 (both channels) the pot will just work in
reverse.

Meaning? Surely log pots need to be the right way round?

I've been a bit bemused by the argument that the value of
the pot doesn't matter much. Too late to argue now.

Ian

In article ,
Ian Iveson wrote:
I've been a bit bemused by the argument that the value of
the pot doesn't matter much. Too late to argue now.

In practice most modern solid state gear has a pretty low output impedance
and high (ish) input so not matched even without a pot added. If you
needed to attenuate by a very small amount a matching pad would be best -
but for this app it's not critical.

--
*Those who live by the sword get shot by those who don't*

Dave Plowman London SW
To e-mail, change noise into sound.