Proco Rat 2 Disassembly problem

[ewd]

I just aquired a ProCo Rat 2 that isn't working. Visually appears like new condition, still in original box, but with a burnt resistor -that I can see so far. I go to remove the knobs from the pots, so othat I can remove the pcb, and the knobs won't come off. No set screws or any other apparent retaining feature. Thinking that someone may have used a little goop to keep the knobs on the shafts, I use a screwdriver for some applied leverage with a wee bit of force, and the knob comes off WITH the pot shaft pulling right out of the pot! The other two knobs appear to be just as tight on their shafts. I've been working on assorted electronics for a while now, and I haven't seen anything like this before. Do I have to also destroy the other two pots to get the board out?

Ed

[ewd]

Update: Yes, the pots had to be destroyed to remove the knobs. Apparently, either someone at the ProCo factory or a previous owner took it upon themselve to use what looks like Super Glue on the knob shafts to hold the knobs on. I woulsd sincerely hope it was not the factory. Now I can replace the burnt resistor AND three 100k pots. Maybe I'll do the Ruetz mods also....

Ed

[Jazz P Bass]

Been there.
Done that.
It sucks.

[Enzo]

Are you sure they were not collet knobs?


Is ther a plastic insert in the top of the knob, typically a different color? Pry that out with a Xacto knife or something. Possible?


If so, there will be a nut inside that tightens down the collet around the shaft.

[ewd]

Enzo, I know what you are describing, and looked for that initially (thanks for the suggestion, though). After pulling the shaft/knobs out of the pots, I was then able to seperate the knobs from the shafts by using pliers to pull them apart. The shafts were normal splined/split shafts that the knobs were super-glued onto. I was able to then save the knobs (I think), but the pots were destroyed. Cost is pretty minor for the three 100k pots, it's just the aggravation factor that irritates me.

Ed

[bob p]

i ran into the same problem when i re-boxed some of the cheap danelectro stompboxes. some of them have really decent circuits, but the boxes all have glued on pots. hate it.

[Enzo]

Yeah, I later went to find a photo of the thing, and could see they were not collet knobs.

[ewd]

Now I've found that none of my normal supply houses carry these particular pots (Mouser, Futurlec, Jameco, etc.). Have an email into Proco Sound to see if they will sell the pots that will physically fit (with the correct values) onto the Rat 2 PCB........

[J M Fahey]

I suspect they are regular pots but with *long* , bent backwards legs, with direct-to-pcb ends.

Common in pedals because it simplifies manufacturing somewhat.

Try to get the original ones first, but if not available, you may add short brass wire extensions to the regular, easy to find ones.

[Jazz P Bass]

Are all three 100K log?
http://www.aronnelson.com/gallery/ma...serialNumber=6
http://www.beavisaudio.com/gg/images/Proco_Rat_2.jpg

[Jazz P Bass]

Small Bear Electronics has them.
Link: Results for Proco RAT Spare Parts

[ewd]

Yes, they are.

[ewd]

Thanks for the link for Small Bear. I had forgotten about them. I already ordered pots from Futurlec, but apparently missed the fine print they they were shipping from their distribution warehouse in Thailand. Found this out when I got an email from them today, after I let them know I hadn't received the order 12 days after the day they said it was shipped. May go ahead and reorder from Small Bear to see what arrives first.

[ewd]

Interesting results: Futurlec order - received 15 days from date notified parts were shipping (three days after placing order). Smallbear - notified next day after placing order that parts were shipping, parts received 4 days after placing order.