EXAMPLE Developing a custom pcb for Daisy Seed - Funbox

[crashguitar]

Update on my build.

Parts arrived and I was able to finish soldering the board. I uploaded the Neptune patch via the web loader.

The bad news is that it is noisy and I am getting the dreaded 1 kHz whine. I tried a TL074 and the only other quad op amp on hand, which is a TLC274BCN. Same issue with both. I do not currently have it fully boxed up. The jacks and power are not soldered in place and I am using alligator cables to a breadboard for testing. Not sure if that is a factor or not. I think I might have had a similar issue with a Terrarium build that was fine once it was all boxed up, but I might be imagining that.

I will order some MCP6024 and finish boxing the circuit and see if either of these makes a difference.

On the positive side, the Neptune patch is really cool. I had fun playing with it while testing.

Thanks for the work on this. I will update when I can.

 

[keyth72]

Update on my build.

Parts arrived and I was able to finish soldering the board. I uploaded the Neptune patch via the web loader.

The bad news is that it is noisy and I am getting the dreaded 1 kHz whine. I tried a TL074 and the only other quad op amp on hand, which is a TLC274BCN. Same issue with both. I do not currently have it fully boxed up. The jacks and power are not soldered in place and I am using alligator cables to a breadboard for testing. Not sure if that is a factor or not. I think I might have had a similar issue with a Terrarium build that was fine once it was all boxed up, but I might be imagining that.

I will order some MCP6024 and finish boxing the circuit and see if either of these makes a difference.

On the positive side, the Neptune patch is really cool. I had fun playing with it while testing.

Thanks for the work on this. I will update when I can.

Ah man, yeah hopefully boxing it up and the new op amp will address that. If you are able to, you might want to use a probe to check if the line out from the Daisy Seed has the noise, or if it's only after the buffer stage. Thanks for the update!

 

[crashguitar]

Good news!
I finished boxing it up and both the 1 kHz whine and noise are gone. I have a TL074 in for the IC and it seems dead quiet to me. I haven't tested it into a bunch or amps or anything, just into my cab sim with a headphone out (Neunaber Iconoclast). That is what I use to record, so I feel pretty confident that if there was noise it would be present in this format.

I also swapped out for a different Daisy Seed with the Pluto patch with exactly the same results. Noisy and whiney before it was soldered to the jacks and quiet as a mouse when soldered up.

Not sure what this means for others.

Thanks again for sharing this project and the patches.

I think you mentioned earlier that you did not have an option for the right position of the speed toggle for the Pluto patch. Is it possible to have a mode where the speed option is removed? The loop just plays forward at 1x speed?

 

[keyth72]

Good news!
I finished boxing it up and both the 1 kHz whine and noise are gone. I have a TL074 in for the IC and it seems dead quiet to me. I haven't tested it into a bunch or amps or anything, just into my cab sim with a headphone out (Neunaber Iconoclast). That is what I use to record, so I feel pretty confident that if there was noise it would be present in this format.

I also swapped out for a different Daisy Seed with the Pluto patch with exactly the same results. Noisy and whiney before it was soldered to the jacks and quiet as a mouse when soldered up.

Not sure what this means for others.

Thanks again for sharing this project and the patches.

I think you mentioned earlier that you did not have an option for the right position of the speed toggle for the Pluto patch. Is it possible to have a mode where the speed option is removed? The loop just plays forward at 1x speed?

That’s great!! Very happy to hear that, I wish I knew a bit more about electronics to understand why, but I guess either proper grounding or shielding? I’m glad you didn’t get the toggle noise like I got with the pcbway board, the oshpark boards seem higher quality ( they should be for how much more they cost) but I don’t know if that’s the root cause.

Yes that switch position on Pluto is available, and yes you could make it a locked mode that only plays 1x speed, absolutely. I think it would be a fun exercise to show how one would do that, so maybe later this weekend or early next week I’ll do a quick write up on it.

My idea for that toggle was a “random” mode that played random segments of the loop out of order, but I haven’t given much thought on how to code it up yet.

Share some pics if you want!

 

[keyth72]

New demo, last one for awhile! Ventured into synth land for this one:

 

[keyth72]

I think you mentioned earlier that you did not have an option for the right position of the speed toggle for the Pluto patch. Is it possible to have a mode where the speed option is removed? The loop just plays forward at 1x speed?

You should be able to use the stepped mode (first toggle at center position) and put the speed knob to noon to always get 1x speed, but if you want a separate toggle for 1x speed, this is how you modify the code.

To add a 1x speed mode for the Pluto's 1st toggle, right position, make the following two changes to "pluto.cpp":

After line 436:

} else if (switch1_action == 2) { // Switch1 right = random TODO // <--This is line 436,

speed_inputA = 1.0; // <-- Add this line to lock in 1x speed with 1st toggle in right position (currently is a blank space)​

} else { // Switch1 center = stepped // TODO Verify that I don't need some kind of midi check here

After line 486 :

} else if (switch1_action == 2) { // Switch1 right = random TODO // <--This is line 486,

speed_inputB = 1.0; // <-- Add this line to lock in 1x speed with 1st toggle in right position (currently is a blank space)​

} else { // Switch1 center = stepped // TODO Verify that I don't need some kind of midi check here

That's all, just add those two lines to set the loopA and loopB speed input to 1, and recompile with "make".

 

[crashguitar]

Thank you very much! I really appreciate your sharing of this.

I also like the idea of random, as I was thinking of pairing it with an OBNE Ramper. The new version has a random mode.

Also, pretty cool that you made a midi synth out of this. You are on fire!

 

[keyth72]

I also like the idea of random, as I was thinking of pairing it with an OBNE Ramper. The new version has a random mode.

That looks like a useful little pedal! I didn't know anything like that existed. You should be able to accomplish the same thing over midi on the Funbox as well, if you had a device or plugin that sent ramping/random midi cc values.

 

[keyth72]

New planet module, Venus! I think I had said there wouldn't be a new one for awhile, but last week I stumbled on an open source example of running a STFT (Short Time Fourier Transform) on the Daisy Seed, and from that I was able to do some interesting things inspired by a jsfx Reaper plugin called "Atlantis Reverb". Here's the Venus demo:

 

[rwl]

I took a short trip to Venus this morning. Beautiful! I think it may be my favorite so far.

 

[crashguitar]

Just finished watching it (after a break to do yard work before it becomes unbearably hot). Another very cool patch!
The freeze function is awesome as are the lo-fi and drift functions.

I may have to make a decision between this and Jupiter until I the budget allows for another run.

 

[keyth72]

New video, just me explaining the project and github repo, so probably a bit dull unless you are actually building one. I go through the main points of the KiCad design file and code:

 

[Heavygroove]

Excellent, just incredible! Just finished a Terrarium build, but the noise is starting to annoy me. Currently using the Seed effects package from your Git and I'm thoroughly impressed. I've been toying with trying the low pass filter mod, or going line level through my FX loop, but now thinking I should move on and do a Fun Box build. I'd like to go through Oshpark and I'm trying to get an idea of cost. Which service are you using (prototype, after dark?) and what's the final all in on the min of 3 boards? looking forward to putting one together, Thanks!

I just discovered your build guide, which very nicely answers all my questions. So, thanks and nevermind!

 

[keyth72]

Excellent, just incredible! Just finished a Terrarium build, but the noise is starting to annoy me. Currently using the Seed effects package from your Git and I'm thoroughly impressed. I've been toying with trying the low pass filter mod, or going line level through my FX loop, but now thinking I should move on and do a Fun Box build. I'd like to go through Oshpark and I'm trying to get an idea of cost. Which service are you using (prototype, after dark?) and what's the final all in on the min of 3 boards? looking forward to putting one together, Thanks!

I just discovered your build guide, which very nicely answers all my questions. So, thanks and nevermind!

Haha awesome, glad the guide could answer your questions! With Oshpark I've only used the purple prototype boards, which I think are the cheapest option. Let me know of any feedback you might have throughout the build process, hopefully all goes smoothly.

 

[Heavygroove]

Just placed a few orders! Went with the powder coated 125B and drill job thru Tayda, along with the majority of the components. For the boards, I ended up going with the Oshpark, but picked the After Dark service, black W/clear mask (added a few days to the job, but had to go with the black!). Looking forward to it! Only things I've noticed so far, and minor at that: CVS Bom - C1, C2 are shown as 100, no unit. Obvious assumption is pF. Also has description as rectangular film, but build pics show MMLC's. Assumed MMLC's are correct, oversight on BOM? Would film caps be inappropriate if I wanted to use them there? Like I said, really minor. Should be fairly intuitive to someone capable of the build. I'll let you know if I notice anything else. I'll try to remember to get build pics, I always seem to think of it after build is finished. Thanks!!

 

[keyth72]

Just placed a few orders! Went with the powder coated 125B and drill job thru Tayda, along with the majority of the components. For the boards, I ended up going with the Oshpark, but picked the After Dark service, black W/clear mask (added a few days to the job, but had to go with the black!). Looking forward to it! Only things I've noticed so far, and minor at that: CVS Bom - C1, C2 are shown as 100, no unit. Obvious assumption is pF. Also has description as rectangular film, but build pics show MMLC's. Assumed MMLC's are correct, oversight on BOM? Would film caps be inappropriate if I wanted to use them there? Like I said, really minor. Should be fairly intuitive to someone capable of the build. I'll let you know if I notice anything else. I'll try to remember to get build pics, I always seem to think of it after build is finished. Thanks!!

Yes, 100pF is correct, good catch! I’ll update the BOM, and either type should be fine, but I’ll also update to specify MMLC since that’s what I used. Good luck with the build!

 

[keyth72]

Next Funbox module, Saturn! Saturn is a "spectral delay", which is turning out to be one of my favorite effects. There are a handful of audio plugins that are advertised as spectral delays, but I have never seen one in pedal form. It works by using a STFT (short time Fourier transform) which lets you operate in the frequency domain, as opposed to time domain (same as the Venus module). The STFT breaks up the input signal frequencies into groups and delays each group by different amounts of time. Each group contains a frequency range of about 47Hz. The result is fragments of your guitar sound coming back at slightly different times, which to me kind of sounds like windchimes. There were a couple of techy blog posts that guided my code development on Saturn, so I'll share those here for further reading if you're interested:

Spectral Delay effect for guitar with Pure Data

In this post I’ll show you how to unleash the power of DSP (digital signal processing) to make your guitar sound like never before. The spectral delay is one of my very favorite effects, and …

guitarextended.wordpress.com

CEC — eContact! 11.4 — Spectral Delay as a Compositional Resource - John Gibson

And here is the video demo video for Saturn:

 

[crashguitar]

Another cool patch! I love that you are playing with the SFFT and making something unique. I am back at work, but I will load this up and have some fun.


Somewhat related and I am not a programmer at all, so I apologize if this is a dumb thought. I believe that chorus, flange, and phasing are all applications of short delays mixed with dry signals that result in wave construction/deconstruction to produce their distinctive sound. Is this something that this spectral approach could applied to?

 

[keyth72]

Another cool patch! I love that you are playing with the SFFT and making something unique. I am back at work, but I will load this up and have some fun.


Somewhat related and I am not a programmer at all, so I apologize if this is a dumb thought. I believe that chorus, flange, and phasing are all applications of short delays mixed with dry signals that result in wave construction/deconstruction to produce their distinctive sound. Is this something that this spectral approach could applied to?

You could probably take a spectral approach for chorus/flanger/phaser, but off the top of my head I'm not sure how. I think it would be much heavier on the processor than the traditional approach, but maybe there's some interesting things you can do in the frequency domain for those effects. Definitely something to think about!

 

[Heavygroove]

Just received my boards from OSHPark today! For anyone interested, this is what the After Dark (black substrate w/clear mask) boards look like. They are the same price as the Prototype Purple. Ordered them on 8/8, so just over 2 weeks to having in hand.