Friday, 2 February 2024

Reeves Electro Zo:

 A modified and improved Hornby Skewes silicon Zonk 2 that goes for big bucks.

Schematic and a breadboard session(!) is avaiable HERE.

It seems that silicon transistors in the 150-200 hFe range works best in this circuit.

*Update 240203* Reeves Electro got in touch with Gray Bench since two of the pot values was incorrect in the trace. Layout and schematic is updated.


 

 
Schematic
 


 


28 comments:

  1. Tag it! Used PN2222's at 165 hfe and it sounds massive!

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  2. Notice some contrasting info from Markus in the comments about the swell and drift values. Haven't tried it yet, but like it the way it is.

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  3. Built it using <100 2n5135. I tried 2n2222a as well but found they were a little gated in this circuit. Thank you Anders!

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  4. Great sounding fuzz. Thanks for the layout.

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  5. Works nicely, but how much output are we getting out of this? I'd say it's probably only slightly above unity for me, using 2N2222As.

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  6. I used a 2n3906 for q1, hfe was 197 and 2n2222A for q2, hfe was 180. Not tried any other transistors yet as happy with this combination. Plenty loud and sounds great.

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    1. 2N3906 is PNP, a 2N3904 is the NPN equivalent but if it sounds ok then I guess leave it in

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    2. Just checked my board and I have the 2n3906 orientated the opposite way around to the layout. Guess I had a stray 2n3906 in my 2n3904 bag.

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  7. I've been LOVING this. Just wish there was a bit more output to it. Thoughts on boosting it a bit?

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  8. Great layout, tried 2n5550, mpsa06 & bc337 all around 150 ish hfe, the Texture pot really makes this shine over the original

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  9. Just tried Fairchild BC547A 110-220 hfe, sounds great! A huge thanx for your well balanced layouts!!!

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  10. Hello, thank you for this, would anybody be able to draw up a tagboard layout for this? real noob asking here. Thank you all

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    1. Often times when this happens, the culprit is a tiny solder bridge or fleck of copper trace bridging on the underside where it shouldn't be. I keep a magnifying glass and exacto knife handy for board inspection no matter how many times I'v built a circuit. If you've used all the right value components and potentiometers and got them all in the right places (this is something I also triple check every time), then I would ask what transistors you used? These primitive fuzz circuits can sometimes be really finicky with transistor choice, which is why I always use sockets. Also, it is not the cheapest tool, but getting a Peak semiconductor tester (if you don't all ready have one) helps out a lot. I follow all this with the caveat that, sometimes, a stripboard build just doesn't work. MANY times, I've started over and had NO problems the second time, even when I wasn't able to diagnose the problem on a nonfunctioning build the first time. I'm, quite obviously, not a scientist. Good luck!

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    2. Fixed the mistake, I should have removed the flux better. Thank you.

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    3. Congratulations! Seriously - getting something perfectly right the first time is great and all - but I personally am more proud when I f*ck something up, diagnose it, THEN fix it. Building circuits like this has been the single greatest lesson in patience that I have ever undertaken.

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    4. You are damn right. I've been doing diy's fx for a while now and every time its struggle. But often I have success.

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    5. some of my diy's
      https://harlywake.blogspot.com/2024/05/diys-by-my-design.html

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    6. Nice work - the old school BMP-style enclosures look really great!

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  12. 470pf is 10 times too big ....... ask me how i know =]

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  13. i see a suggestion for a cap switch mod, thx!

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  14. Thanks for doing this! I have been looking over this build quite a lot (the point to point build). There are a few things that seem to stand out (and i could very well be wrong!) The schematic calls for 2 x 220k Resistors. I can only ever see one in any variation that markus builds. There is a 220k off the swell pot leading into the 10nf cap. The resistor on the other end appears to be a 1m - which is in the schematic but is this a strange place for it to sit? (i assumed it woud be on the input) The other resistor seems to only appear in some versions. Most seem to be 5 resistor versions but sometimes there is a resistor on the texture pot lug 1 to power. I think this resistor is 820ohm or 10k??? i can also see the 47k, 680 and 3.3k. I also cannot see a diode or 100uf cap in his point to points but i also know they are not essential.

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  15. The polarity protection & power supply filtering are an added to every layout here, whether they’re in the schematic or not?

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    1. Hi Brian, i didn't know that - but i also added I knew they were not essential. It was probably an add on comment to my main questions/queries. Markus looks like he dropped using the 100uf in later builds.

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  16. Some think it’s overkill, but really it safeguards the circuit from voltage spikes & noise.

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