DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: analogmike on August 13, 2005, 03:06:43 PM

Title: Vintage Potentiometer repair DIY article
Post by: analogmike on August 13, 2005, 03:06:43 PM
Have fun!


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

(http://www.analogman.com/graphics/astrotone/topassembledsml.jpg)
Title: Vintage Potentiometer repair DIY article
Post by: Bernardduur on August 13, 2005, 04:11:01 PM
Nice article. Thanks!
Title: .
Post by: petemoore on August 13, 2005, 06:55:53 PM
Nice Read, great Pics, I couldn't make out any transistor types  :D .
 I've reclamped pot bottoms, sometimes it works out great, just the right set of slipjoint pliers made it pretty easy.
Title: Vintage Potentiometer repair DIY article
Post by: Paul Marossy on August 13, 2005, 09:46:09 PM
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!
Title: Vintage Potentiometer repair DIY article
Post by: analogmike on August 14, 2005, 02:19:18 PM
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!
Title: Vintage Potentiometer repair DIY article
Post by: Paul Marossy on August 14, 2005, 06:07:28 PM
QuoteThe 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?
Title: Vintage Potentiometer repair DIY article
Post by: analogmike on August 14, 2005, 10:49:45 PM
Quote from: Paul Marossy
QuoteThe 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.
Title: Vintage Potentiometer repair DIY article
Post by: mudmen on August 15, 2005, 07:47:24 AM
This letter with 'David Gilmour Music Limited' looks pretty interesting ;)
Is it his pedal ?
Title: Vintage Potentiometer repair DIY article
Post by: aaronkessman on August 15, 2005, 10:49:46 AM
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...
Title: Vintage Potentiometer repair DIY article
Post by: analogmike on August 15, 2005, 11:00:01 AM
Quote from: mudmenThis letter with 'David Gilmour Music Limited' looks pretty interesting ;)
Is it his pedal ?

Not a very subtle hint, was it?  :D

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!
Title: Vintage Potentiometer repair DIY article
Post by: Paul Marossy on August 15, 2005, 11:14:44 AM
QuoteSame way you replace the plastic shafts on broken EH pots- cannibalism.

Oh, I see.  8)
Title: Vintage Potentiometer repair DIY article
Post by: mudmen on August 15, 2005, 11:40:40 AM
Quote from: analogmike
Not a very subtle hint, was it?  :D

Have you repaired any other pedals for him ? :)
Title: Vintage Potentiometer repair DIY article
Post by: Doug_H on August 15, 2005, 12:05:58 PM
It figures that one of the progenitors of "space rock" would need an "Astro Tone" pedal... :lol:

Doug
Title: Vintage Potentiometer repair DIY article
Post by: mudmen on August 15, 2005, 12:12:08 PM
Yeah, there's even a Floyd bootleg called 'The Band Who Ate Asteroids For Breakfast' :)
Title: Vintage Potentiometer repair DIY article
Post by: analogmike on August 15, 2005, 02:48:58 PM
Quote from: mudmen
Quote from: analogmike
Not a very subtle hint, was it?  :D

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!
Title: Re: Vintage Potentiometer repair DIY article
Post by: yeeshkul on October 01, 2006, 10:00:14 AM
Guys does anyone have schematics for the Astrotone fuzz box above?
Title: Re: Vintage Potentiometer repair DIY article
Post by: alfafalfa on October 01, 2006, 10:25:37 AM
Have a look on R .G. Keen's site !!

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

Alfafalfa
Title: Re: Vintage Potentiometer repair DIY article
Post by: markm on October 01, 2006, 11:19:16 AM
Although this thread is from last year, just wanted to say thanks Mike for a very interesting article.
Title: Re: Vintage Potentiometer repair DIY article
Post by: analogmike on October 01, 2006, 12:27:12 PM
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.

(http://www.analogman.com/graphics/fuzzes.jpg)
Title: Re: Vintage Potentiometer repair DIY article
Post by: Marcos - Munky on October 01, 2006, 12:40:31 PM
Wow, this is really a great pedal collection :icon_eek: :icon_eek: :icon_eek: :icon_evil: :icon_evil: :icon_evil:.
Title: Re: Vintage Potentiometer repair DIY article
Post by: Mark Hammer on October 01, 2006, 01:56:42 PM
I only *wish* I had a nickel kickback for every time I mentioned this but old pots with worn carbon CAN be rejuvenated with this Stabilant contact enhancer I keep going on about.  It forms a conductive layer on the resistive strip and wiper, and bridges that little 2-micron gap between wiper and strip that makes for the scratchiness that plagues us all.  It is chemically stable so it won't break down over time.  I have successfully used it to rejuvenate lots of pots, and I keep harping to folks that I don't know why boutique outlets don't tout it as a quality performance feature the way they make a big deal out of switchcraft jacks and true bypass switches.
Title: Re: Vintage Potentiometer repair DIY article
Post by: Harry on October 01, 2006, 02:24:58 PM
Quote from: Mark Hammer on October 01, 2006, 01:56:42 PM
I only *wish* I had a nickel kickback for every time I mentioned this but old pots with worn carbon CAN be rejuvenated with this Stabilant contact enhancer I keep going on about.  It forms a conductive layer on the resistive strip and wiper, and bridges that little 2-micron gap between wiper and strip that makes for the scratchiness that plagues us all.  It is chemically stable so it won't break down over time.  I have successfully used it to rejuvenate lots of pots, and I keep harping to folks that I don't know why boutique outlets don't tout it as a quality performance feature the way they make a big deal out of switchcraft jacks and true bypass switches.
A quick search; you've suggested this at least 18 times!  :o
Title: Re: Vintage Potentiometer repair DIY article
Post by: yeeshkul on October 01, 2006, 06:20:54 PM
Thanks for the hint.  :) Is there any difference between Astrotone and Sam Ash fuzzz boxx?
Title: Re: Vintage Potentiometer repair DIY article
Post by: analogmike on October 01, 2006, 06:58:21 PM
Quote from: yeeshkul on October 01, 2006, 06:20:54 PM
Thanks for the hint.  :) Is there any difference between Astrotone and Sam Ash fuzzz boxx?

No, but some will sound great and others poor.

I remember hearing about Stabilant years ago, have not heard of it in a long time. Are there any distributors in the usa? I think it would be great to use it on some things, and to restore some old gear.
Title: Re: Vintage Potentiometer repair DIY article
Post by: Gilles C on October 02, 2006, 10:15:58 AM
In Canada, we (where I work) buy it from http://www.e-sonic.com/acc/products.aspx?partID=STABILANT+22A&partIDExt=256&command=detail

or elsewhere http://www.stabilant.com/sizes01h.htm

Gilles
Title: Re: Vintage Potentiometer repair DIY article
Post by: britelite on October 02, 2006, 01:47:22 PM
USA Distributo: rhttps://www.micro-tools.com/store/item_detail.aspx?ItemCode=22 (https://www.micro-tools.com/store/item_detail.aspx?ItemCode=22)

Peace
Title: Re: Vintage Potentiometer repair DIY article
Post by: Noplasticrobots on October 02, 2006, 06:36:02 PM
Love the enclosures on those old Sam Ash pedals.