Astro Tone Fuzz

Analog Man Guitar Effects

In 2010 we came out with the Analog Man Astro Tone fuzz, a new fuzz based on the old Sam Ash and Astrotone fuzzes but improved for better sound. For more info, see

Vintage Effect Pot Repair

By Analog Man

Here is a pedal we got in for repair and some fabrication work in Aug 2005, from the UK. We have to do this sort of work often on old pedals like E-H pedals due to pot damage from being stepped on. This pedal has a recessed knob area so very rare for this sort of damage but somehow it happened (blame Roger).

This pedal arrived with no bottom plate, no battery clip, and not working. There was some internal rewiring also, as a British Fuzzface jack had been replaced the original grounded output jack. A ground wire was running around inside from that jack which we removed when we added the original switchcraft jack.

I have a mint in box Sam Ash Fuzzz Boxx which is the same pedal, made by the Astro Amp company in '66 - '67, so I could make sure I restored it with the correct parts. The Astrotone knobs seem to be unoriginal but I will leave them on. We have had several of these pedals over the years, there is one version without the recessed knobs, we had a 1967 model like that.
The Sam Ash Fuzzz Boxx is the first pedal I ever cloned, in the early 1990s. Here is the one I made at left, build into a CRAZYTONE fuzz box that I got from Angela Instruments (remember their crazy catalogs!). Mine was really a clone, down to the artwork on the board and the board mounted pots. Works pretty well!

Here are the insides, after I replaced the output jack and rewired it like mine. His is an early 1967, you can see the 1966 pot codes below. My red one has 1966 pot date codes too, but seems to have different type capacitors (film vs ceramic) and circuit board material. Mine also has an original plastic input jack. The input jacks have a built in switch to disconnect the battery (+) side when you unplug, it was before they figured out the simpler method of using a stereo jack with the battery (-) wire going to the RING connection.

After rewiring and installing an old blue battery clip that I found in my drawer, it worked but not well. Looking closely we saw that the VOLUME pot was falling apart. It is the one at the left, note the space under the metal cap and the crimp legs bent out. This happens when someone steps on the knob. EH pedals used nylon pot shafts which often broke before the pot would open. If that happens, and you have a donor EH pot of any value with a nonbroken shaft (good luck), you can follow the steps below and install a new shaft and rotor into the old pot.

First we had to unscrew the knobs and pots to remove the board from the case. Then we needed to remove the pot from the board, as it was impossible to recrimp it as it was. Also we could clean it up nicely after removing it. At the left you can see the three solder lugs desoldered and lifted up to allow removing the pot. The traces are very fragile so it was done carefully but the top one broke a bit, not a problem as the tab would about reach the next wire. I added a short jumper wire to the next pad anyway, hidden by the solder, just to make it stronger.

After removing the pot, I carefully dissassembled it. Some later pots will not come apart but this style usually does. I cleaned out the pot with a Qtip and red DeOxit spray cleaner/lubricant, and added a dab of grease on the top cover to make it turn smooth like a new pot. When you sprayclean pots, the cleaner loosens the grease and that is why the pots will turn too easily after spray cleaning. The black part has the shaft and rotor, and will come off on this style of pot for rebuilding.

Then I put the pot back together and crimped two of the legs so I could test it. You can use long needleneck pliers but I have a STRAIN RELIEF plier that works really well for recrimping pots as it reaches around a bit like a C-Clamp. I then tested the pot with an Ohm meter to make sure it was working over it's full range with no dropouts. It was fine so I crimped the other 2 legs and popped it back in the board.

Here is the pot reinstalled and soldered back in.


Here is the top of the pot installed, nice and tight now. You can see the date code 1376647. 137 = manufacturer (CTS), 66 = 1966, and 47 = 47th week of 1966. Last digits on the other set of numbers are 10K meaning a 10K pot.

Next was the bottom plate. They were made from sheet aluminum (or aluminium as they say across the pond) so it would not be hard to make a good reproduction. I had some scrap aluminum from a box, just big enough so traced my Sam Ash bottom and cut one out. Laying it on the handmade sandcast ASTROTONE, I trimmed off some excess. Then used a large flat file to get the sides straight and deburred, and round off the corners. Finally when it fit well, I used scotchbright (synthetic sandpaper pads) to make the edges smooth and safe, and make both top and bottom very smooth and clean.
Hope you enjoyed this repair as much as I did, and can use the info to repair some vintage effects in the future.

Regards, mike ~^v^~ aNaLoG.MaN ~^v^~ vintage guitar effects