Non fuzzing fuzz - ELK Fuzz Wau

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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fuzzbuzzfuzz
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Post by fuzzbuzzfuzz »

**please move if in the wrong forum spot thanks**

Repair help requested if possible.

Picked up a "junk" fuzz on Xmas day - an ELK Wau Fuzz. It's an early 70s large treadle monster with a tone foot switch. It should by rights produce a clanging octave fuzz noise as underneath its guts are essentially a Shin Ei 6 transistor super fuzz. But as of now it's simply out putting a mild overdrive. I've had the multimeter over it - no obvious voltage black holes.

Any potentially obvious solutions spring to mind before I delve deeper?

Perhaps a dodgy transistor? Irvtepkacevthosebold caps?

I spent a good few fruitless hours today frustratingly stumped by it!

Thanks all in advance!
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fuzzbunny
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Post by fuzzbunny »

1) Cleanup solder traces on pcb
2) Verify with matching schematic
3) Follow singnal path with Audio Probe

4) Have fun!

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lolbou
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Post by lolbou »

I would audioprobe first. And have a look at these electros then...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.

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fuzzbuzzfuzz
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Post by fuzzbuzzfuzz »

Thank you for your input gentlemen. This one is proving a challenge.

I measured the voltage across the circuit and located a few dead spots or low voltage points. In lieu of that I saw a couple of transistors had almost no volts running across them. I socketed two. I also recapped the electrolytes. Slight improvements. The annotated diagram is before I socketed the transistors.

Whilst fiddling I noticed that by gripping the board by one corner (lower left in the picture) with my thumb connecting the circuit trace points for a green cap and resistor - that a full fuzz sound emerged albeit noisy. Without applying pressure unfortunately silence. I replaced that cap then the resistor alongside but the same effect.

..and then a high pitched squeal emerged and I quit for the night!! I now also see a full voltage across a socketed transistor which can't be correct..

Two steps forward and several back it seems.

The high pitched squeal noise - bad soldering?

My thumb connecting the two components...grounding them?

Any thoughts much appreciated as always.
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fuzzbuzzfuzz
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Post by fuzzbuzzfuzz »

Note: The "X" in the lower left is one of the resistor points measuring 0 volts. Below is a .047 greenie cap (now replaced). The next point up is also a .047 cap.

Do green caps leak and require replacement due to aging?

What is a good method of cleaning up the board traces?

In soldering a few trace connection points lifted but I believe I rescued them. It's s messy old board with poor soldering all over.


I need to remember to have fun with it though!

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ljn
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Post by ljn »

I don't think those green caps go bad with age. At least, I haven't come across a bad one yet.

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