FV-24. FV-1 based pedal.

deadastronaut · February 16, 2021, 12:49:25 PM

^ cool, cheers alex, so a couple of 1n5817's should be ok then...

: marc, hmmmm....maybe, i'll have to see how i go, i'm not a coder by any means, im just using spincad, then exporting a hex file to programme the epproms with pickit2.

but yeah, you never know...

Ice-9 · February 16, 2021, 12:50:58 PM

Hi Deadastro- The Fv-24 is looking really nice and sounds very nice as well. Congrats on getting it all built and working the way you wanted.

Regards the clamping diodes on the inputs of the FV-1 for p-p protection, I used to use BAT42 Schottky diodes but later pedal designs I ended up just not putting them in on newer designs as they are not really needed.

stallik · February 16, 2021, 01:08:38 PM

Really nice Rob. Do I need one? No. Will I build one anyway? Most likely

Digital Larry · February 16, 2021, 01:30:19 PM

Quote from: Ice-9 on February 16, 2021, 12:50:58 PM
Regards the clamping diodes on the inputs of the FV-1 for p-p protection, I used to use BAT42 Schottky diodes but later pedal designs I ended up just not putting them in on newer designs as they are not really needed.

The FV-1 reference schematic shows a 1k resistor in series with the inputs. This may well serve to limit the potential of "large" input signals to destroy or lock up the chip. It's just a guess. I know it's also part of some LPF at the input.

ElectricDruid · February 16, 2021, 02:04:59 PM

Quote from: Digital Larry on February 16, 2021, 01:30:19 PM
Quote from: Ice-9 on February 16, 2021, 12:50:58 PM
Regards the clamping diodes on the inputs of the FV-1 for p-p protection, I used to use BAT42 Schottky diodes but later pedal designs I ended up just not putting them in on newer designs as they are not really needed.
The FV-1 reference schematic shows a 1k resistor in series with the inputs. This may well serve to limit the potential of "large" input signals to destroy or lock up the chip. It's just a guess. I know it's also part of some LPF at the input.

Yeah, this makes sense too. The VCDO chip that I did used a 4K7 resistor in series like this to protect the ADC inputs. It limits the current that can flow through the *internal* protection diodes to a safe level, and thereby negates the need for *external* diodes. And (like in the FV-1 schematic) if you've got a resistor there, you might as well add a cap to ground and get some lowpass filtering to help remove any out-of-band noise.

bluebunny · February 16, 2021, 05:15:02 PM

Quote from: stallik on February 16, 2021, 01:08:38 PM
Really nice Rob. Do I need one? No. Will I build one anyway? Most likely

^ this <sigh>

Digital Larry · February 16, 2021, 05:57:58 PM

Don't sigh! I think of FV-1 projects as "solder once, tweak endlessly in code". It's the final frontier and all that.

jonny.reckless · February 17, 2021, 03:32:40 AM

Fantastic. I love those ambient sounds from around 7:30 onward and again around 9:35. So good.
It would be fabulous to have trails when switching presets.

bluebunny · February 17, 2021, 03:43:45 AM

Quote from: Digital Larry on February 16, 2021, 05:57:58 PM
Don't sigh! I think of FV-1 projects as "solder once, tweak endlessly in code". It's the final frontier and all that.

I was afraid of that... Software is my day job, so coding isn't necessarily my idea of fun. Having said that, I downloaded SpinCAD yesterday and had it up and running on Linux in no time... Must. Resist. . . .

deadastronaut · February 17, 2021, 05:08:13 AM

^ cool , yeah its great that you can use spincad with just a wave file....

excellent for previewing/ testing patches..

i use a guitar wave with staccato and long chordy stuff...

Digital Larry · February 17, 2021, 09:39:20 AM

Quote from: jonny.reckless on February 17, 2021, 03:32:40 AM
It would be fabulous to have trails when switching presets.

Can't be done with a single FV-1.

stallik · February 17, 2021, 01:56:22 PM

Yup. Decided I definitely won't be going down this rabbit hole.
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No hurry with my order Rob

deadastronaut · February 17, 2021, 03:12:44 PM

^ aha...its a good rabbit hole though....

Will pop in post ...

stallik · February 19, 2021, 04:51:41 AM

That was quick Rob, lovely looking board

stallik · December 26, 2021, 08:40:17 AM

FV-1 finally arrived a few days ago. Looking forward to finally play with this

deadastronaut · December 26, 2021, 08:57:08 AM

Cool, youll love it, i built 2 , the pedal, and put the other in a rack...

Look forward to your build..

caspercody · December 26, 2021, 07:28:19 PM

Very nice Rob

You should look into adding the 4049 clock module into your design. It adds more control to the effects. I added one on my FV project and a switch to be able to switch between the crystal and 4049 clock.

stallik · November 29, 2022, 04:06:24 PM

So, I've had this board for a year now and only just started populating it

Have a few parts on order but am looking forward to going down this rabbit hole in the new year.

With zero live experience but a little time playing with SpinCad, I have a question. This board is mono using the left output from the FV-1. Would it be possible to use the right output and the relevant circuitry after it and (perhaps using dual pots) create a stereo version usable with a dual amp setup? As I'm not using the FV-1 daughter board, there should be enough room to mount another board above the chip and still keep the same size enclosure.

Or, are patches which use such stereo effects going to be too limited by the processing power of the chip?

bartimaeus · November 29, 2022, 05:21:16 PM

Quote from: stallik on November 29, 2022, 04:06:24 PM
So, I've had this board for a year now and only just started populating it Have a few parts on order but am looking forward to going down this rabbit hole in the new year.

With zero live experience but a little time playing with SpinCad, I have a question. This board is mono using the left output from the FV-1. Would it be possible to use the right output and the relevant circuitry after it and (perhaps using dual pots) create a stereo version usable with a dual amp setup? As I'm not using the FV-1 daughter board, there should be enough room to mount another board above the chip and still keep the same size enclosure.

Or, are patches which use such stereo effects going to be too limited by the processing power of the chip?

depends on what you're doing. the max delay time is 1second (when using the normal crystal). so for stereo you only get 500ms of delay, and it takes twice as much code (since you need to write each channel individually). with only 128 instructions per program, you can run out of program space pretty quick too. a true stereo pitch shifter should be doable. a true stereo reverb will be tough to fit but doable. ultimately i don't think it's worth it, which is the reason nearly all fv1 designs are mono (despite the stereo in/outs).

what bugs me is hardly any of the mono designs i see use the stereo i/o pins for differential i/o. i guess pedals are always going to be noisy haha

Vivek · December 01, 2022, 08:48:49 PM

Congratulations and respects !

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FV-24. FV-1 based pedal.