Group Buy: High quality pots

[yldouright]

Inspired by the group buy for PEC carbon pots in another thread, I thought it would be a good idea to put the purchasing might of our membership to the task of finding a sub $20 audio pot solution for our projects. Members are encouraged to identify possible candidates and then the process can begin. Let the name dropping begin.

[GothWolf]

Originally posted by yldouright
Inspired by the group buy for PEC carbon pots in another thread, I thought it would be a good idea to put the purchasing might of our membership to the task of finding a sub $20 audio pot solution for our projects. Members are encouraged to identify possible candidates and then the process can begin. Let the name dropping begin.

I wish these messages were dated better.

Anyway - the problem I see here is some people want a direct volume pot (dual ganged, audio taper), while others might use a single pot that controls some other circuit to adjust the volume (even seen a single tube based circuit that noise filters a linear pot and does a log change of both right and left channels as equally as possible).

Other people may want a pot with a limit-switch-off when you turn it all the way down, and others may want a push-button. Some people want motorized for use with remotes.

Personally I want the limit-switch for on/off, a momentary contact when you push the knob, AND a motor, preferably with an LED in the knob (or maybe behind the knob with just a hole in the knob to let the light through and radiate from behind as well ... hmmm). Anyway - I'm not gonna get that without having them custom made (a possibilty - plenty of places would do it), but not at my needed quantity of 1.

I think everyone's application is too different to buy pots in bulk because everyone builds something different around the basic gainclone (which doesn't need a pot). You'd need a standardized preamp design.

-- Evan

[yldouright]

GothWolf
Your application is indeed esoteric but I would say that the majority of people here on this board need good stereo 25K log pots. They are versatile and can be ganged for balanced operation for those planning Pass Labs stuff too. An additional benefit is that purchased in quantity, I can match them into sets of pots which will track nearly perfectly and that is something that the individual purchaser cannot do economically.

[kilowattski]

yldouright

The problem you will have is what resistance Pot to order. Not all preamps have the same impedance and unfortunately one size does not fit all. Some of the Pass Labs preamps like the Aleph P 1.7 and BOSOZ need 5K pots.

[Variac]

BUT if you look over the PEC thread, you will see that the 25k pot is the most desired - because of gainclones I think, so there could still be a viable quantity fo a group order. It just wouldn't be for everyone, but what is?

[kilowattski]

Good Point!

[yldouright]

kilowattski, Variac, Gothwolf and others
This post does not exclude any pot. All it proposes to do is identify which pots are needed by our membership. The PEC 25k pot is desirable for the Gainclone but there are other phono stage and chip pre-amp projects which also like this value. If the X-BOSOZ requires a 5k pot, then another category could be started which can be included in the same group buy. The point here is to identify which pots are desirable for which projects and why they are. In this enterprise I expect to see a trend develop which will give us a list of the high quality pots and an estimation of the potential demand. The bigger the order, the more power we can have in getting the price we want to pay for those pots. At $40 delivered for the PEC pots, the ladder attenuator starts looking like a viable alternative and with that, you can make any value and log scale that you wish.

[Variac]

Ok, I agree that $40 is pretty steep, which is why we are here

In this thread carbon track /silver wiper pots from Alpha are mentioned and confirmed as pretty decent:

"Silver-Carbon" Pot ex Tawan - Photo - & ignore my ugly Pinky!

So I went to Mouser and found a different pot made by Alpha
with carbon and silver:


The one that is noted as having a silver wiper is the 17mm one
partly down the page:

http://www.mouser.com/catalog/620/433.pdf


So I am nominating this pot as a test case as a likely good sounding one. It comes in all relevent values and audio or straight taper.
Different shafts too!

[DSP_Geek]

Originally posted by yldouright
kilowattski, Variac, Gothwolf and others
At $40 delivered for the PEC pots, the ladder attenuator starts looking like a viable alternative and with that, you can make any value and log scale that you wish.

Funny you should mention that. Check out:

http://store.yahoo.com/triodeel/4pol24posals.html

$20 for a 23 position 4 pole switch ain't bad, as far as I can tell. Has anyone here done business with Triode Electronics?

Assume about 50 resistors at a quarter a crack, you're in the same ballpark as the pot. Does anyone have an opinion on series resistor ladders?


Francois.

[Variac]

That switch does look like the deal!
I'd like to know more about the contact material, but copper might be OK if the switch is used consistantly

Did I mention that the audio taper pots I mentioned above are $1.13 each? They have a built in switch, that is probably silver contacts too.

You can get linear ones without the switch and do the law faking thing.

Heck, maybe I 'll grow up and just order a few....