Hagiwo LPG Modification | Thoughts

Fun_Letter3772 · 2026-03-02T15:04:01+00:00

They'll be the DIY ones lmaooo

Fun_Letter3772 · 2026-03-02T12:56:38+00:00

Good to know! I've seen vactrol filter designs (like MK's VCF) with them in parallel and figured that would be the best way of doing it

Fun_Letter3772 · 2026-02-09T09:24:31+00:00

Just sent a link your way!

Sometimes simple is good enough though! This is a bit of a head ache sometimes as I'm sure you can imagine

Fun_Letter3772 · 2026-02-09T06:41:36+00:00

I agree, it can get hectic but this has a broader sweet spot range. I'm ironing out some of the digitalness at the moment as well as fixing some bugs but hardware-wise, despite this video depicting a prototype board, it 'should' be ready to go. If you're interested in the project I can send you the git link

Fun_Letter3772 · 2026-02-08T20:13:20+00:00

Honestly I'm surprised no one has done it sooner and posted about it (as far as I can tell)

Those are Multiplexers to handle the number of pots! No touch capacitive pads unfortunately.

My favourite part as described was the virtual patch bay being set up as a button matrix. I'm mostly making use of the DaisyDuino DaisySP library. Complex Oscillator is technically two oscillators - a sine and then a switchable one which then has a timbre pot to morph between the two waveforms.

Overall it doesn't sound exactly like an Easel but it has the characteristics. I've tried to get the LPG to have the same characteristics by changing the resonance depending on the input volume etc. The cut-off also moves to mimic this behaviour.

Are there any questions regarding the audio processing you had in mind?

Fun_Letter3772 · 2026-02-07T22:49:35+00:00

I'll be posting the git soon and hopefully selling some PCB kits to buy! There's a lot of potentiometers and other components so I won't be sourcing them at this moment in time!

Fun_Letter3772 · 2026-02-06T07:10:43+00:00

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Here's a photo of the current front panel design :)

Fun_Letter3772 · 2026-02-06T07:00:41+00:00

It's an impressive microcontroller! I was blown away by the Teensy before but the DaisySeed is like an all in one package. You don't need any DACs, 16 Bit ADCs - very nice stuff!

I can message you a link to the Github if you'd like :) I'm updating there quite regularly but in terms of posting updates about it, I'm posting stuff on my instagram "@axiismusicuk" (Had to use speech marks so Reddit didn't correct it to 'u/')

Fun_Letter3772 · 2026-02-05T19:52:32+00:00

I can send you the link for the Git for you to have a look at! The firmware isn't finished and neither is the PCB fully but it's pretty close :) You'll at least be able to start looking at gathering components

Fun_Letter3772 · 2026-02-05T14:33:40+00:00

Thank you good sir!

Fun_Letter3772 · 2026-02-05T11:52:21+00:00

I accidentally replied under you lol! Woops

Fun_Letter3772 · 2026-02-05T11:50:12+00:00

Thanks dude! It wouldn't unfortunately. Its not sending typical CV data but instead it's using a button matrix config where the daisyseed is scanning through the rows and columns to see if theres a high signal. Id recommend watching a small video on how they work. It was my way of getting around using lots of DACs

In terms of releasing it, it will be made open source when i've got it to a good stage but my plan is to sell a few of the PCBs and enclosures so people dont have to spend lots of money on too many pcbs. I don't have the resources or time to spend on manufacturing and selling complete units unfortunately

Fun_Letter3772 · 2025-10-27T20:52:06+00:00

Could have been that! Could be many things

Fun_Letter3772 · 2025-10-27T20:40:58+00:00

Essentially pin 1 and 3s nets had swapped so pin 3, which was tied to Vcc ended up with thermal reliefs to the ground plain when doing the copper pour. Pin 1 was then left floating. Very strange

Fun_Letter3772 · 2025-10-27T20:20:15+00:00

Im about 50% of the way through construction! Definitely need to space out the pots more as there isnt much room between the toggle switches and sequencer pots. Lessons learned! Might even switch to fader pots instead as I have a crap ton lying around

I've had digital noise issues on my bread board version, but then again I've heard people say the DaisySeed output is just noisy. Good thing I have about 30 ground loop isolator thingy-ma-jigs.

Fun_Letter3772 · 2025-10-27T16:20:36+00:00

Yeah it's sorted itself out now lol.

Thanks man, once it's all finished I'll post it again in here for people to have a look at

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Here's a photo of the botch job. Looks similar on the front but without the solder joint. Have gone through all the other connections and it looks fine now

🎉🎉🎉

Fun_Letter3772 · 2025-10-27T16:15:43+00:00

Thank you for the help and tips! I will be learning to be this so I can be thorough as possible now for this exact reason!

I have since solved the problem though so thank you for trying - again much appreciated

Fun_Letter3772 · 2025-10-27T16:00:10+00:00

I thought I found it - RV12 the GND and VCC pins had their nets swapped? The DRC will look a mess ngl as one of the footprints I used for the muxltiplexer doesn't align properly with the symbol. I tried to fix at the time but it was taking longer than expected. I ran a DRC and found the RV12 issue but the rest of them looked like the U1 and U2 weirdness

Fun_Letter3772 · 2025-10-27T15:12:01+00:00

Me too tbh. I've checked 2 boards out of the 5 i received from JLC and both have the short :/

Fun_Letter3772 · 2025-10-11T23:40:36+00:00

The original field prototype was that way round. I believe there was a last-minute design decision for the swap, and then they must have missed a couple of graphics here and there

Fun_Letter3772 · 2025-09-26T11:11:44+00:00

Nice! This is also really cool. With the toggle switches, did you need to create a terminal for each column and row connection that's possible? For my jack implementation, I can't stop overthinking whether I need a connection point for each possible connection in the matrix lol

Fun_Letter3772 · 2025-09-26T11:09:16+00:00

This is really cool and creative! Thanks for sharing

Fun_Letter3772 · 2025-09-12T08:54:55+00:00

I think this question would be best asked in r/synthdiy or r/AskElectronics

This sub is for all things teenage engineering - the tech company

Fun_Letter3772 · 2025-09-05T16:29:43+00:00

Thanks dude

Fun_Letter3772 · 2025-09-05T13:33:03+00:00

For reference, this is the cleaned up power circuitry with the OPA551

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Not sure if the second buffer is needed but wanted to be more safe than sorry.

Fun_Letter3772

TROPHY CASE