Sunday 30 April 2017

Hornby Skewes Shatterbox

The Hornby Skewes Shatterbox is another stupid rare fuzz/booster made in the 60's, need I really say any more? In case I do, info is not really available on this monster, but here's what I found:

Skewes Shatterbox Produced in Leeds circa 1966, the unit combines two effects; The JHS Zonk fuzz and a Treble Booster circuit, the original unit was produced in exceptionally limited numbers and was famously used by Mark Bolan T-Rex.



Layout 1: Original PNP



Layout 2: NPN Version


Layout 3: Original with LED


Layout 4: NPN with LED

 

16 comments:

  1. Please excuse my being thick - so you join the two switches together at "5"?

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  2. Are the labels for input jack and input board the right way around?

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    1. Yes. The switching is odd, so I added the wiring to the switches. Just connect the locations with the same labels together. So on the switch there's a wire that says input board means you connect the input wire on the board to that lug of the switch. Same goes for the boost wire and boost on its respective switch.

      I labeled two of the lugs "5" because they are connected together and they are both lug 5 of their respective switches.

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  3. I think input board and input jack are inverted in the switch.

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  4. How do you connect LEDs for indication of on/off?

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    1. the original didn't have LEDs. i just made 2 new layouts with switching for LEDs that i'm confident will work right.

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    2. Brilliant, thanks Zach.

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  5. Swell 2 and 3 should be reversed, dontcha think?

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    1. nope, not according to any of the multiple schematics for the zonk. the swell control is exactly as it's indicated in the layout.

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  6. Anybody verify this yet? Itching to build it if it works!

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  7. I could not get this to work (built the regular zonk ii today without incident). This one just motorboats.

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  8. Just looked inside my original 1960's Shatterbox and it has two 125uF capacitors. I thought someone might find that interesting/useful.

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    Replies
    1. Actually, there's a lot that is different. The fuzz switch is DPDT but only one side is used(so it's SPDT), boost is DPST. The input resistor is 470k, not 27k. There's a 4k7 trimpot between fuzz control pin 3 and chassis ground. I'll be able to see more if I need to remove the circuit board to complete the repair(it hasn't worked since about 1973, lucky my dad never threw it away!).

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    2. hey man. can you post pics of the top and bottom with component values in the forum? if you can trace it i'll gladly do it and make an updated layout based on your original. cheers man.

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    3. Will do. I'm also planning on making a youtube video of the repair. I'm not well at the moment so it may take me a couple of days to get round to it.

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