Foxx - Select-a-Fuzz  [schematic]

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Foxx - Select-a-Fuzz

Postby digi2t » 22 May 2015, 02:10

Seeing as there are only two trace side gut shots, and no one is willing to post components, I took some time to look at this.

Image

Image

The pictures seem clear enough to make out what might be a resistor, or a cap. Cap polarities are fairly clear as well. Even a diode symbol can be made out. Wire connections to the board seem to be bigger solder blobs. Transistor E and C letters are there. So looking at, I get this;

Image

Two things that pop out at me, are the resistor/cap in series between B and C on Q2. Never seen that before. The Sustain pot set up is a new one for me as well. At least, the way I see it from the pictures it is.

Anyone interested in flinging some component values at me? I'm game to throw this on the breadboard and play with it.
No matter how many times I cut it, it`s STILL too short!

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Re: Foxx Select-a-fuzz.

Postby tabbycat » 23 May 2015, 11:33

major thanks for putting in the hard work, dino. this is a beast that needs to be released back into the wild.

i was looking at various foxx schematics and listening to clips last night and this schematic caught my eye because of the multiple-capped rotary switch.
http://www.harpamps.com/schematics/foxfzwah.pdf (thanks to harpamps for posting the schematic).
perhaps this or another foxx fuzz fuzz could be filtered through those caps? or those caps could be used as starting points for values?
it seems a lot of manufacturers in the old days readily recycled in-house circuit blocks and favoured components (shinei for example, the superfuzz spawning multiple variations, with and without wah) and maybe foxx were no different.

as an aside, that supersaturated overloaded slightly laggy fuzz sound reminds me a lot of the roland double beat ad50. that's to my ear. did foxx and roland have links or any crossover?
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"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).
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Re: Foxx Select-a-fuzz.

Postby tabbycat » 23 May 2015, 12:00

for what they are worth...

foxx sat 1.jpg


foxx sat 2.jpg
"be a good animal, true to your instincts" (d.h. lawrence).
"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).

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Re: Foxx Select-a-fuzz.  [schematic]

Postby digi2t » 23 May 2015, 12:41

Thanks Tab! Every little bit helps. I've had new info float in, including some corrections to the schematic. Here's the updated one;


I've seen the fuzz wah schematic, but in that case, the multi caps are there to adjust the voicing on the wah side. I think breadboarding will ultimately reveal what caps will sound best here.

I'm not aware of any links insofar as the Foxx/Roland thing goes, but what do I know? I'll have to have a look and see if there are any similarities in the two topologies. You never know.
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No matter how many times I cut it, it`s STILL too short!

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Re: Foxx Select-a-fuzz.

Postby TGP39 » 26 May 2015, 15:59

Great job digi2t!

Steve.
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Re: Foxx Select-a-fuzz.

Postby digi2t » 26 May 2015, 21:36

Thanks Steve.

Right now I have it on the breadboard. I've been confering with wiser people on this circuit, and they've been kind enough to supply me with possible/probable values. So far, I'm getting some pretty wicked fuzz, maybe too harsh though. I'm going to play around some more with it, and when I get something fairly decent, I'll post.

In the meantime, if anybody wants to chirp in with values, come on down. I'll try them out. If anyone knows how exactly the sustain pot interacts with this circuit on a real unit, please don't be shy, share.
No matter how many times I cut it, it`s STILL too short!
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Re: Foxx Select-a-fuzz.

Postby digi2t » 06 Apr 2019, 21:30

Finally!!

Breadboard test drive of the Foxx Select-a-Fuzz. Thanks to he-that-shall-remain-nameless. PCB's coming to DEFX soonish.


Link
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Re: Foxx Select-a-fuzz.

Postby digitalzombie » 15 Apr 2019, 16:39

Can you rehost all the images that seem to have disappeared from this thread?

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Re: Foxx Select-a-fuzz.

Postby toneman » 15 Apr 2019, 17:57

I'l like to 2nd digitalzombie's request for the schematic. :D

I luv old fuzzes!!!

8)
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Re: Foxx Select-a-fuzz.

Postby d312a » 15 Apr 2019, 18:17

Here is a verified vero layout over at tagboard forum.

http://guitar-fx-layouts.42897.x6.nabble.com/file/n46358/Foxx_Select_A_Fuzz.png
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Re: Foxx - Select-a-Fuzz

Postby modman » 15 Apr 2019, 20:13

I went on tagboard and stole the schematic back! Attached it to Digit's own post. Yeah, sue me.
"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)

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Re: Foxx - Select-a-Fuzz

Postby digi2t » 26 Apr 2019, 16:19

modman wrote:I went on tagboard and stole the schematic back! Attached it to Digit's own post. Yeah, sue me.


Right on!! Thanks!

Just for your own fun, you can really play around with all the input caps, make it as tame or sludgy as you wish. Lots of fun.
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