Ignorant Question About Electronic Parts

Danny Letz · Post by **Danny Letz** » 30 Oct 2023 12:31 pm

I say ignorant because I don't know anything about electronics. I have a Goodrich Matchbox 60 on which the control is broke. I suppose it's like a tone control. Are tone controls potentiometers? I found these numbers on it, 73A4N056S105A, 1MEG, Mexico 8833. Being it is obviously broken and has only two wires connected (Really no diagnosing involved) I can change it out. Anyone know where I could get a new one?

George Biner · Post by **George Biner** » 30 Oct 2023 1:36 pm

Yes, tone controls are usually potentiometers. how is it broken?

Is this image correct for the innards of the unit? https://images.reverb.com/image/upload/ ... 4p9bxq.jpg

In this schematic, the tone pot only has two connections: https://bb.steelguitarforum.com/userpix ... atic_1.jpg

I googled that part number, and not much is coming up. You might contact Kevin Ryan, the current owner of Goodrich, that's probably the quickest way.

George Biner · Post by **George Biner** » 30 Oct 2023 1:38 pm

Also, from the part number, it's a 1 megohm resistance, the "A" means audio (logarithmic) taper, and the 8833 is the date code showing the pot was made in the 33rd week of 1988.

Danny Letz · Post by **Danny Letz** » 30 Oct 2023 2:27 pm

It is broken as in come apart. The housing is plastic about 3/4 to 1 inch square and the cup part of it was connected to the top plate by 4 plastic pins that were braded by heat to swell the part of the pin that sticks thru. I would just glue back but I think something is missing that connects the knob shaft to the workings. The unit will probably still function but is not adjustable.

Danny Letz · Post by **Danny Letz** » 30 Oct 2023 2:32 pm

And yes that is the inside of the Matchbox but the body of the control is square and plastic. Your photo indicates that other shaped controls would also fit.

George Biner · Post by **George Biner** » 30 Oct 2023 2:43 pm

OK, well, any 1 megohm, audio taper potentiometer that will fit will work. but you have to match the shaft diameter and style to the existing knob, and match the mounting method to the hole in the chassis, both of these to avoid modifying the chassis, and the of course overall diameter / box dimensions. I personally would go onto DigiKey or Mouser and use their search tools to find one.

but, first, the fact that I get absolutely nothing from Google on the p/n indicates that you may have written it down wrong, you might re-check that

Danny Letz · Post by **Danny Letz** » 30 Oct 2023 2:54 pm

George, it turns out that my other Match Box 60 has a Clarostat JA1N056S504AA, 500K, Type J pot. That's a volume pedal pot isn't it? I may have one of those.

George Biner · Post by **George Biner** » 30 Oct 2023 3:02 pm

I can't say if that is a volume pedal pot, it's just a random pot to me, other folks may know.
It is a 500k resistance as opposed to a 1 meg, so that's different.
You can try it, nothing will blow up, see how it works.

Danny Letz · Post by **Danny Letz** » 31 Oct 2023 4:58 pm

I opened up the newer Matchbox 60 again and the mounting holes for the control and jack are different as well as the circuit boards looking different. May have to call Goodrich.

George Biner · Post by **George Biner** » 31 Oct 2023 5:02 pm

Yeah in my Googling I saw many different versions -- Kevin Ryan I'm sure will help out.