KR-8010 broken speaker selector shaft

Hello,

I am a noob at this vintage stereo world and took a leap.
This is my first "real" receiver since lusting my Dad's KR-5600 as a kid.
(pretty lights . . . sweet sound)

I picked up a KR-8010 this week and received it today. I took a few moments to explore the unit and had the speaker selector knob break off in my hand. One half of the shaft to the pot had broken off.

I would like to find a replacement and I don't know where to start, as I don't think I am going to find this part at the local electronics store.

Can any of you help get me started?

- after I find the part I will likely ask for any advice before I open up this beast.

thank you for any help or advice you can send my way,
David

I'm afraid that might be difficult to fix, short of finding a replacement selector switch on a parts unit. The good news is that a functional replacement might be found on several different models of receivers, since its function is pretty basic, but I don't know enough specifics to back that up. Also depends on how it's mounted. It's not that hard to find rotary selector switches, like might be used to switch pickups on an electric guitar, but you'd need something "dual" to switch both channels simultaneously. I think it'd almost have to come from another receiver or amplifier. I would hate to have to do it, but you might have to sacrifice the "C" speaker setting: "A", "B", "A+B" would be a lot more common, and make it easier to find a replacement.

I don't know what made it break, but if the integrity of the other "half" isn't compromised, it should have sufficient strength to operate the switch.... In other words, I might be thinking more along the lines of reworking the knob (set screw, new "insert", something like that maybe) to fit what's left of the shaft, instead of replacing the switch. Generally the shaft goes all the way through the switch and I'm just not thinking that it would be repairable. At least not by me. Perhaps a machine shop could make a new "extension" shaft that would attach to part of the original shaft on one end and then accept the knob on the other. That would require being able to move the switch "back" to make more room, however.

Don't know if that helped much- Just kinda thinking it over as I type.... I'm sure there are people on these forums who have dealt with similar situations. They'll have some ideas. I like those receivers, too, BTW.

If you have the other half (or if you don't, steal one off a junk pot), epoxy it to the intact half, using a spacer between them to make it fit the knob correctly, maybe a piece of circuit board, scrap of metal, or even cardboard (it will get soaked and strengthened with the epoxy).

I had to fix the exact same problem for a piece in a museum collection and here's what I did (not for the faint of heart). First I machined a plate about 2" in diameter with a 3/8" hole in the middle. The control was removed and installed in the hole in the usual way with its nut. The plate and control went back in the lathe (the plate is so the lathe chuck has something to grab) where the shaft was faced smooth and a 1/8" hole was drilled in the center. Then I cut the exact same style shaft off a donor pot and turned a 1/8" stub on the end. This got installed in the hole with a high strength Loctite bearing retainer product. Probably overkill, but it saved the original control and avoided messing with the knob.

The usual reason this happens is that somebody levers on the shaft with a screwdriver to expand it so the knob fits better. Those shafts are way more brittle than one might think and... snap!

Thank you, Gentlemen.

Great ideas to go with. I will follow both ideas.


David