Zonk Machine fuzz, trouble shooting help needed!

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Reg18
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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

Bg wrote:
Sun Sep 27, 2020 4:15 pm
You need to show the track side, do a close up, just in case theres any bridging
Image

I put in a BC147 and a 2n3904 and the noise is almost gone, but the tone isn’t as good!
Looks like it might a simple case of transistor swapping untill I get it right.
Last edited by Reg18 on Sun Sep 27, 2020 4:58 pm, edited 1 time in total.

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

I switched to a Les Paul and I actually quite like it now. Video below.
I’ll have to measure where the 100k pot is set (in place of the 33k resistor) because it does squeal in a few spots on the dial and the gain changes a bit too, there seems to be a sweet spot.....ill laugh if was actually 33k!

https://youtu.be/skavWRSnP-g

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

I’ve finally got it stable and sounding good.
Although the transistors I used have lowered the gain a bit,
I found using a higher gain one for Q1 and lower for Q2 seemed to fix the squeal and be a happy medium for tone and gain.
BC548 for Q1 and 2N3904 for Q2, any other suggestions for transistors to try for this circuit?

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Re: Anyone built a Zonk Machine fuzz?

Post by Lostininverness »

Good result! It's pleasing when these things work out eh??!!

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

Ok so I may still need some help problem solving my Zonk.
I did manage to get it working without squealing with a BC548 and 2N3904 transistors however the gain is low and it’s a little muddy (although it sounded great stacked with a Timmy at band practice this week) I love the sound with 2 x BC548 transistors but it’s more gain and starts squealing again. Can anyone tell from
The schematic/strip board layout what things I could try to fix it?

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

After many attempts and some breadboarding I gave up and built a MK1.5 Tomebender instead....the circuit is virtually the same with some minor tweaks which tells me the transistors are possibly the issue for my Zonk.
Can anyone help with some Germainum NPN Transistors with a low gain around 60-120?

I am very happy with how my silicon Mk1.5 Tone bender has turned out, took some tweaking to get it sounding smooth but it’s very Usable and cuts really well with a band as well.
Still determined to get a good working Zonk Machine though. Would love a good supply of low gain Transistors to mess with, who’s got some they could part with?

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Re: Anyone built a Zonk Machine fuzz?

Post by jeremyb »

You could get a PNP like an AC128 which is easily found and reverse the power supply?

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

jeremyb wrote:
Thu Oct 29, 2020 6:05 pm
You could get a PNP like an AC128 which is easily found and reverse the power supply?
Yeah I might have to look into how to build a charge pump
To get it to work with a normally daisy chain power supply, is that what you mean by reverse power supply?. In the last few weeks I’ve sucsessfully built a MK1.5 Tonebender, Lovepedal JTM clone, Lovepedal Les Lius clone, Super hard on boost and a Fuzz Face....this bloody Zonk is giving me a head ache though, I’m Determined to get a good working proto if nothing else!

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

https://www.instagram.com/p/CHRyUZQHB7j ... e4j9jt9fhx

After Paul WD kindly donated some AC128 transistors I finally have a good sounding proto of the Zonk Machine mk2.
Turns out getting some proper germainiums sorted out the squealing as well.... not sure how but it did.

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Re: Anyone built a Zonk Machine fuzz?

Post by FuzzMonkey »

Reg18 wrote:
Sat Nov 07, 2020 5:55 pm
https://www.instagram.com/p/CHRyUZQHB7j ... e4j9jt9fhx

After Paul WD kindly donated some AC128 transistors I finally have a good sounding proto of the Zonk Machine mk2.
Turns out getting some proper germainiums sorted out the squealing as well.... not sure how but it did.
The correct transistor gain range and properly biased?

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

FuzzMonkey wrote:
Mon Nov 16, 2020 8:12 pm
Reg18 wrote:
Sat Nov 07, 2020 5:55 pm
https://www.instagram.com/p/CHRyUZQHB7j ... e4j9jt9fhx

After Paul WD kindly donated some AC128 transistors I finally have a good sounding proto of the Zonk Machine mk2.
Turns out getting some proper germainiums sorted out the squealing as well.... not sure how but it did.
The correct transistor gain range and properly biased?
One AC128 is around 140 hfe the other around 220.
Probably too high but they work pretty well. I’m not sure what is a good range for a Zonk Machine?
Biasing is set with a trim internally for Q1 and a 20k pot externally for Q2, I haven’t actually measured it at the collector of either.

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Re: Anyone built a Zonk Machine fuzz?

Post by FuzzMonkey »

Reg18 wrote:
Tue Nov 17, 2020 4:00 pm
FuzzMonkey wrote:
Mon Nov 16, 2020 8:12 pm
Reg18 wrote:
Sat Nov 07, 2020 5:55 pm
https://www.instagram.com/p/CHRyUZQHB7j ... e4j9jt9fhx

After Paul WD kindly donated some AC128 transistors I finally have a good sounding proto of the Zonk Machine mk2.
Turns out getting some proper germainiums sorted out the squealing as well.... not sure how but it did.
The correct transistor gain range and properly biased?
One AC128 is around 140 hfe the other around 220.
Probably too high but they work pretty well. I’m not sure what is a good range for a Zonk Machine?
Biasing is set with a trim internally for Q1 and a 20k pot externally for Q2, I haven’t actually measured it at the collector of either.
If it works and sounds good; that's all that matters.

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

Image
Image
Image
Couple of Zonks in proto type stage

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Re: Anyone built a Zonk Machine fuzz?

Post by FuzzMonkey »

Nice work Reg.

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Re: Anyone built a Zonk Machine fuzz?

Post by Reg18 »

Zonk MK2 prototype, bias and bass additional to the standard swell and gain


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