Help repairing old CMI Fuzz box?

[duck_arse]

How do you switch the battery off? Doesn't seem to be a TRS input jack.

top jack, lower extra lug, red wire.

[anotherjim]

But isn't that a normally closed contact? You plug in & it disconnects? Didn't know there were any Cliff sockets that work the other way. Suppose it must do, or it'd never work! 

[duck_arse]

well if it had the standard sleeve finger on both sides of the jack, they'd both rub up against the shaft of the inserted plug, shorting together, and power on. only my guess from the pics, tho.

I'd say a photo of the upper side of that jack would be the proover.

[crutter]

Thanks Marcos-Munky for the wiring diagram and the recommendation to try and disconnect the 4K7 resistor on the Fuzz pot to see if it improves things. I'll give it a go when I get a moment.
Also I'll see if I can get some shots of the top of the jack sockets, duck_arse. I was slightly perplexed by the power switch situation, too. Would it be 'always on' if the battery is connected?
Thanks
Chris

[Electric Warrior]

It's obviously a switched jack. Why would anyone doubt that? These were commonly used in british pedals in the 60's and 70's.

I'd leave the 4k7 in place. This circuit tends to work much better with it, especially with a treble booster behind it.

[ElectricDruid]

It's obviously a switched jack. Why would anyone doubt that? These were commonly used in british pedals in the 60's and 70's.

It's not that we doubt it, so much as we're curious about this old tech. That's not a "switched jack" as I usually understand it, and it's not the type of stereo jack with NC contacts that would do the job these days either. Clearly that's what it's doing, but the interesting bit is "how?".

[idy]

How do we know i'ts not a pair of TRS jacks? Are those period appropriate? They look undisturbed...

[Elektrojänis]

It's not that we doubt it, so much as we're curious about this old tech. That's not a "switched jack" as I usually understand it, and it's not the type of stereo jack with NC contacts that would do the job these days either. Clearly that's what it's doing, but the interesting bit is "how?".

Click open the bottom pic on the reply 10... It's from another unit, but look very closely to the metal contacts on the left side jack. To me it looks like the tip has a normally closed extra connection, but the sleeve has a normally open extra connection.

[duck_arse]

It's obviously a switched jack. Why would anyone doubt that? These were commonly used in british pedals in the 60's and 70's.

some of us have been around since the sixties, and yet have never seen a jack like that. it isn't obvious, as we can't see the mechanism itself, we can only infer function from what we see.

[anotherjim]

I've not seen one either, but I may never have seen a British assembled pedal either - but then I missed the '60s although I was there, I wasn't paying attention.

[Electric Warrior]

It's obviously a switched jack. Why would anyone doubt that? These were commonly used in british pedals in the 60's and 70's.

some of us have been around since the sixties, and yet have never seen a jack like that. it isn't obvious, as we can't see the mechanism itself, we can only infer function from what we see.

The more interesting jack is the one used in the Fuzz Face.
It not only connects the battery when a plug is inserted, but also lifts the tip from ground at the same time 

[PRR]

....

Teeny pictures. Giant pictures. Let's get it together.




Yes, these jacks seem to have an NO contact on the sleeve. (Yes, the image names are wrong.)

[Elektrojänis]

The more interesting jack is the one used in the Fuzz Face.
It not only connects the battery when a plug is inserted, but also lifts the tip from ground at the same time 

Almost immediately after spotting the contacts in the earliert picture in the thread I thought that this would be a clever use for it. I quess someone beat me figuring it out about 50 or 60 years earlier.