TS-808 Tone Control Pot

[smallbearelec]

I have been asked a few times to get this made, and I'm willing to do it. I need either:

--An accurate rotation/resistance curve drawing such as R. G. Keen has in "The Secret Life Of Pots" OR

--a working control salvaged from an otherwise dead pedal.

Given one of those, I will ask Alpha to make samples and then a production lot.

Can anyone help?

[amz-fx]

Steve,

It is called a G-taper pot.

It has audio taper at one end up to the midpoint then reverse audio from there to the other end.  It is described in one of the NatSemi handbooks.  I'll see if I can find it and send you a scan.

regards, Jack

[amz-fx]

They are also called S-taper according to NatSemi...

...an example is an Allen Bradley #70A1G032 R2035

-Jack

[smallbearelec]

Thanks! This is not one of the ones that Alpha lists in their catalog, so a graph that I can give them is really important.

[dosmun]

Hey Steve can you get any of the PC mounted pots like those used in the Ibanez 10 and L series pedals?  I need a 500kA pot for a Super Tube Screamer.

[amz-fx]

It is like the blue plot on this graph:

http://www.muzique.com/misc/pot.gif

Audio up to 50% rotation and then reverse audio from 50% to 100%.

regards, Jack

[Fret Wire]

That's good news Steve. The G/S taper in 100k would also be nice for the BMP and Rat. :wink:

Of course, it's easier said than done when you're not the one paying for a custom manufacturing run.

[smallbearelec]

Jack--

Thank you! I will ask at Alpha.

Fret Wire--

The cost of getting something made isn't always a fortune. If Alpha has the wafer already for a pot, for example, getting 1,000 pieces done is easy. I'm hoping that is the case with this pot.

Regards
SD

[Fret Wire]

The cost of getting something made isn't always a fortune. If Alpha has the wafer already for a pot, for example, getting 1,000 pieces done is easy. I'm hoping that is the case with this pot.
Regards
SD

Ah....that's right! I didn't even think about that. The wafer/track is the only difference, everything else in the pot stays the same. I'm sure they've made that taper before. Hopefully, Alpha will be able to do it for a reasonable cost.

[cb]

Looking at the graph, it appears that the turning the pot from 9 o'clock to 3 o'clock covers 90% of the tone change. What is the point of that, i.e. why not just use a linear taper pot?

BTW, I didn't know this was the taper for the TS-808 tone pot. Does the TS-9 also use this? TIA.

[Manolo Dudes]

It is called a G-taper pot.

It has audio taper at one end up to the midpoint then reverse audio from there to the other end.  

Isn't it what they call a "log-antilog" pot?

[smallbearelec]

I heard from Alpha. They have a standard wafer for a "4B" taper (maybe also called "W" taper):

http://www.smallbearelec.com/Projects/Alpha4B.pdf

Jack--

Whaddya think?[/img]

[amz-fx]

I heard from Alpha. They have a standard wafer for a "4B" taper (maybe also called "W" taper):
http://www.smallbearelec.com/Projects/Alpha4B.pdf
Jack--
Whaddya think?

I think that looks like the thing.  I saw a similar taper on the Clarostat site that was also called W-taper.

regards, Jack

[smallbearelec]

OK. Will take a few weeks to get samples. I will send for testing to you and J D Sleep, as he had also asked about this.

[federico]

Ask Alps http://www.alps.com as original Ibanez mount them (20k "W" tapering).
Look ts-808 inside at http://tubescreamer.digiteltlc.com/ts808_7.jpg and "W" taperig curves at http://tubescreamer.digiteltlc.com/RV_RESISTANCE.pdf
Let me know if you find other sources...
Bye