Darkglass - Duality Fuzz Engine  [traced]

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andregarcia57
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Post by andregarcia57 »

aionios wrote: 28 Nov 2021, 21:12 Hmm, you're right. I didn't catch that in prototyping but it does appear those two are backwards. Thanks for pointing that out.

Here's the updated schematic -


darkglass-duality-trace-schematic.png


Easy fix if you've built one already, just reverse wired 1 & 3 for both of those pots. If the direction doesn't bother you, the tone and taper is exactly the same, it's purely a "user interface" issue.

I've got a new version of the PCB on the way that will have this fixed, probably late December.
What transistors? Q1 and Q2 and diodes flip?
Thanks

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aion
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Post by aion »

Since they're only used for switching I didn't bother to check. 1N914 and J111 would be the best options that would perform identically.

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x-tn
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Post by x-tn »

aionios wrote: 28 Nov 2021, 21:12 Here's the updated schematic
darkglass-duality-trace-schematic.png
I think the C16 should be connected at the other pin of the R20 (=IC6 pin3).

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aion
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Post by aion »

x-tn wrote: 07 May 2022, 13:41 I think the C16 should be connected at the other pin of the R20 (=IC6 pin3).
It looks like an error, but it's actually correct to the original unit... here's a closeup:

Image


C22 is my C16 (cap to ground), R30 is my R20 (resistor to +) and C16 is my C17 (cap to -). It's a bit low-res, but the traces are all connected along the top row and there are none on the underside of the board.

It definitely looks like a mistake... especially considering that this section is very similar to the Microtubes which has the cap at the noninverting input. Darkglass may have made a mistake in the Duality design or it could have just been a quick & dirty fix to change the filter frequency without any extensive changes. But either way it's correct, and seems to have persisted across seven different revisions so it's just part of the unit's sound now.

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JácintBenkovics
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Post by JácintBenkovics »

aionios wrote: 13 Nov 2021, 02:25 All right, y'all were patient - here's the full schematic.


darkglass-duality-trace-schematic.png


I believe the most recent schematic from this thread is accurate other than the missing capacitor values. The only structural difference is R11 in my schematic, which was not present in the unit I traced (revision 4-K) but was in the one from this thread (revision 7).

Since the resistor values all match up with mine, I think it'd be safe to backfill the Rev7 schematic with the Rev4K cap values and assume they're the same.

Full tracing journal:
https://aionfx.com/news/tracing-journal ... zz-engine/

PCB:
https://aionfx.com/project/binary-dual-fuzz/
May I ask why did you use only one CD4049 in your version, while the original has two?

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Post by jhergonz »

JácintBenkovics wrote: 20 Feb 2023, 09:23
aionios wrote: 13 Nov 2021, 02:25 All right, y'all were patient - here's the full schematic.


darkglass-duality-trace-schematic.png


I believe the most recent schematic from this thread is accurate other than the missing capacitor values. The only structural difference is R11 in my schematic, which was not present in the unit I traced (revision 4-K) but was in the one from this thread (revision 7).

Since the resistor values all match up with mine, I think it'd be safe to backfill the Rev7 schematic with the Rev4K cap values and assume they're the same.

Full tracing journal:
https://aionfx.com/news/tracing-journal ... zz-engine/

PCB:
https://aionfx.com/project/binary-dual-fuzz/
May I ask why did you use only one CD4049 in your version, while the original has two?
i believe Darkglass uses cmos for switching.

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tommymariot
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Post by tommymariot »

Hi guys, a friend of mine bring me his pedalboard for a new wiring so today I compared my Duality clone with the original I used for this thread (Rev 7). I found my version has less bass freq and little bit less volume (maybe the pot taper is a bit different from the original).
What do you think could be the cause?
aionios wrote: 28 Nov 2021, 21:12
Here's the updated schematic -


darkglass-duality-trace-schematic.png
have you had the opportunity to compare your clone with an original?

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aion
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Post by aion »

tommymariot wrote: 26 Mar 2023, 21:21 have you had the opportunity to compare your clone with an original?
Nope, mine was thoroughly destroyed in the trace, but others have A/B'd and said it was spot on. But with 7 revisions of the Duality it's certainly possible there were a couple of tweaks along the way - in addition to standard component tolerances, especially going between SMD and through-hole.

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