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Projects => Build Reports => Topic started by: Aleph Null on July 24, 2025, 02:47:15 PM

Title: Clever Hans — Comparator Fuzz with EQ
Post by: Aleph Null on July 24, 2025, 02:47:15 PM
Clever Hans is the big brother of the One Chip Pony (https://youtu.be/ddcHft7HpVk?si=Rxl1XL4gpgR4ufhM). It's based on the same comparator engine, but the added EQ options make it much more versatile—truly a horse of a different color!

(https://live.staticflickr.com/65535/54671865841_0aa5cbf4dd_c.jpg) (https://flic.kr/p/2riaAYz)

I'm still looking for a way to label controls with hydrodip finishes. With simple layouts, labels aren't necessary, though

(https://live.staticflickr.com/65535/54672102684_72b3ef0c97_c.jpg) (https://flic.kr/p/2ribPo5)

I'm loving ribbon cables lately. I'd love to use another ribbon cable and I/O board for the jacks, but I havn't found a PCB compatible DC jack that will accept and external nut.

(https://live.staticflickr.com/65535/54672107619_3a8770e1fd_c.jpg) (https://flic.kr/p/2ribQRa)

The input stage is a mosfet boost with a heavy low-pass filter. This filter helps minimize string noise when the Gate is set high. This stage feeds the comparator. The comparator doesn't distort like most fuzzes. Instead of amplifying the signal until it clips, the signal is compared to the bias voltage. If the input is lower, the outup shoots up to the upper rail. If the input is higher, the output is slammed to ground. It's maximum fuzz and maximum compression all the time! The comparator then hits the EQ section. Contour is a simple input capacitor blend, but it's very effective. The Filter control is a multi-feedback low pass filter. This is actually similar to the filtering that a lot of PT2399 delay circuits use. This filter creates a resonant peak at the cut-off frequency of roughly 3–6dB. That peak keeps the signal from getting muddy, even with heavy treble attenuation.

The result is a powerful fuzz—with essentially no noise floor—that you can EQ to sit just right in a mix.

Here's a demo:


As always, I have extra PCBs. If you're interested, just DM me!
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: jimilee on July 24, 2025, 03:51:11 PM
Daaaammnnn I love it.


Sent from my iPhone using Tapatalk
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: NorthCoast on July 24, 2025, 04:38:18 PM
That finish looks fantastic! Sounds great, too.
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: Aleph Null on July 24, 2025, 08:39:12 PM
Quote from: NorthCoast on July 24, 2025, 04:38:18 PMThat finish looks fantastic! Sounds great, too.

Thanks! It's seaside, ocean mist, pistachio, and grape over a black powder coat.
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: LaceSensor on July 24, 2025, 10:02:27 PM
This is really cool. Congrats.
Ive been messing with comparators recently.
With this kinda application, is it right that its always super high gain? Any way to tame that?
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: Aleph Null on July 24, 2025, 10:44:36 PM
Quote from: LaceSensor on July 24, 2025, 10:02:27 PMThis is really cool. Congrats.
Ive been messing with comparators recently.
With this kinda application, is it right that its always super high gain? Any way to tame that?

All opamps are designed for super high gain. You can tame the gain with negative feedback, but then you have a regular opamp circuit and not a comparator.
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: LaceSensor on July 28, 2025, 10:43:56 PM
Fair. Im tempted to mess around with this circuit - thanks for sharing.
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: destro on August 04, 2025, 02:51:32 AM
This sounds like it has the potential to scratch the itch the ESR Graphic Fuzz left me with. Very cool!
Title: Re: Clever Hans — Comparator Fuzz with EQ
Post by: Aleph Null on August 04, 2025, 03:34:53 AM
Quote from: destro on August 04, 2025, 02:51:32 AMThis sounds like it has the potential to scratch the itch the ESR Graphic Fuzz left me with. Very cool!

That's an interesting comparison: they both have the resonances/filter thing happening, but the ESR is highly interactive with the pickups; Hans doesn't care what you put in front of it—it's going to get turned into a square wave!