Vintage Potentiometer repair DIY article

[analogmike]

Have fun!


http://www.analogman.com/graphics/astrotone/astrotone.htm

[Bernardduur]

Nice article. Thanks!

[petemoore]

Nice Read, great Pics, I couldn't make out any transistor types   .
 I've reclamped pot bottoms, sometimes it works out great, just the right set of slipjoint pliers made it pretty easy.

[Paul Marossy]

Oh darn, I thought you had some magical cure for a scratchy pot.  :wink:
I have tried rebuilding a couple of old pots, but the scratchiness never went away - but they were really clean and operated very smoothly after I was done with them!

[analogmike]

Hi,

The scratchiness may be impossible to fix without replacing the conductive ring in the pot. The carbon gets worn and causes scratchy sounds. The carbon rings are replaceable on the old ones if you don't want to change the pot's date code.

The transistors used in the originals and the clone I made are F (fairchild) button type 2N3566. I was able to get them at the electronics parts store 10 years ago (NOS). I have also seen metal can SM 07027 type in 1967 models.

Have fun!

[Paul Marossy]

The carbon rings are replaceable on the old ones if you don't want to change the pot's date code.

Really?! Well, how do you get some replacements?

[analogmike]

The carbon rings are replaceable on the old ones if you don't want to change the pot's date code.

Really?! Well, how do you get some replacements?

Same way you replace the plastic shafts on broken EH pots- cannibalism.

But you need the same pot value in this case so very tough to do.

[mudmen]

This letter with 'David Gilmour Music Limited' looks pretty interesting
Is it his pedal ?

[aaronkessman]

er, how exactly DO You replace the plastic shafts on broken EH pots? I've never seen a plastic shafted pot that big anywhere but EH boxes...

[analogmike]

This letter with 'David Gilmour Music Limited' looks pretty interesting
Is it his pedal ?

Not a very subtle hint, was it?  

I have had to use broken donor EH pedals to cannibalize the plastic shafts to fix other pedals. I dont know where you can buy those either but I bet CTS still makes them for someone...

good luck!

[Paul Marossy]

Same way you replace the plastic shafts on broken EH pots- cannibalism.

Oh, I see.  

[mudmen]

Not a very subtle hint, was it?  

Have you repaired any other pedals for him ?

[Doug_H]

It figures that one of the progenitors of "space rock" would need an "Astro Tone" pedal... :lol:

Doug

[mudmen]

Yeah, there's even a Floyd bootleg called 'The Band Who Ate Asteroids For Breakfast'

[analogmike]

Not a very subtle hint, was it?  

Have you repaired any other pedals for him ?

He has a pile of weak old fuzzfaces, was considering repair but rather than messing with them I sent him an NKT275 sunface and one with vintage BC108C, I hope he likes them!

[yeeshkul]

Guys does anyone have schematics for the Astrotone fuzz box above?

[alfafalfa]

Have a look on R .G. Keen's site !!

http://www.geofex.com/FX_images/samash.gif

Alfafalfa

[markm]

Although this thread is from last year, just wanted to say thanks Mike for a very interesting article.

[analogmike]

You are welcome!

Here is my NOS Sam Ash Fuzzz Boxxxxx along with a few more old fuzz pedals, rounded up for a FUZZ documentary last week.

[Marcos - Munky]

Wow, this is really a great pedal collection .