Lyra-8 DIY expansion and panels

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Flounderguts
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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Fri Sep 18, 2020 8:18 am

whyfarer wrote:
Thu Sep 17, 2020 2:49 pm
two questions:

1) anyone have 8 extra B5M 24mm pots I could buy?
2) if not, anyone want to go in on an order with me? Jameco seems to be the only supplier and they have a minimum order service charge bringing the order to $20 if it is below $20 (which 8 pots is). Instead of paying $25 to get 8 pots, I could do a mini group buy for those of us that are interested. Let me know - I'd like to order over the weekend if possible.
I have a bunch of them on the way...but you may not want to wait for that...
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Re: Lyra-8 DIY expansion and panels

Post by whyfarer » Fri Sep 18, 2020 12:44 pm

Flounderguts wrote:
Fri Sep 18, 2020 8:18 am
whyfarer wrote:
Thu Sep 17, 2020 2:49 pm
two questions:

1) anyone have 8 extra B5M 24mm pots I could buy?
2) if not, anyone want to go in on an order with me? Jameco seems to be the only supplier and they have a minimum order service charge bringing the order to $20 if it is below $20 (which 8 pots is). Instead of paying $25 to get 8 pots, I could do a mini group buy for those of us that are interested. Let me know - I'd like to order over the weekend if possible.
I have a bunch of them on the way...but you may not want to wait for that...
do you have an approximate eta? i need to order stuff from tayda and another supplier so I'll be waiting for a bit anyways...

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Re: Lyra-8 DIY expansion and panels

Post by whyfarer » Fri Sep 18, 2020 1:36 pm

better question: besides the price, any reason not to order these from mouser?

https://www.mouser.com/ProductDetail/Al ... tkJA%3D%3D

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Fri Sep 18, 2020 6:52 pm

Those look great.

R1 shaft, 300 deg turn, 15k cycles...not even that expensive at 100 pcs.
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Re: Lyra-8 DIY expansion and panels

Post by D.Tilbury » Mon Sep 21, 2020 11:03 pm

Hey, I havent checked in in a while. Been pretty busy....but, almost ready to solder the final touches on the build. I cut a snip off of some 1/4" nylon washers and used those to insulate from the pad switch closeness. Hopefully doesnt melt to bad once I solder it up. Dan, I am wondering if totally enclosing the unit with steel and grounding it is the key yo getting all the weird noise out of the picture.
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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Tue Sep 22, 2020 1:14 pm

D.Tilbury wrote:
Mon Sep 21, 2020 11:03 pm
Hey, I havent checked in in a while. Been pretty busy....but, almost ready to solder the final touches on the build. I cut a snip off of some 1/4" nylon washers and used those to insulate from the pad switch closeness. Hopefully doesnt melt to bad once I solder it up. Dan, I am wondering if totally enclosing the unit with steel and grounding it is the key yo getting all the weird noise out of the picture.
I have thought about this as well. I actually ordered a suitable steel enclosure (tough to find for 7u! easier for 6u) to try. However, grounding the switches as suggested by gnsk helped a LOT...and I'm experimenting with different LEDs on the LFO noise. The "diffuse" ones are noisier than the bright ones so far, but I have a few more to try...
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Re: Lyra-8 DIY expansion and panels

Post by RadHazard » Fri Oct 09, 2020 5:44 pm

Thanks for all the work you've done on this Flounderguts. I'll be ordering expansion pcbs, cap, rotary kit, etc., from you soon.

I'm working on my own version of the expanded front panel though and had a few questions.

I've basically taught myself pcb panel design with kicad over the last few days. I noticed you use EasyEda, is that just a preference thing or do you think there are benefits to it?

I also had the idea of using the pcb copper as touchpads and had a design in mind that would place contacts for voice pairs close to each other that would allow easily activating voice pairs with one finger. Though after seeing your mandala designs I may be tempted to just use those if you make it available.

I also had ideas for makenoise style backlit features. At the very least I would love to illuminate your lyra constellation design.

Last, I downloaded the gerbers for the extended panel and used one of the tools in kicad to convert them to a kicad project. One issue is, instead of having footprints for drill holes that have a defined center point and radius, holes are just made up of a large number of line segments approximating a circle. This obviously makes it difficult to tweak things (an example would be larger tune pot holes for high precision pots). Would you be willing to upload the easy eda project? I'm sure there's a way I could convert it to kicad or I could just learn easy eda.

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Sun Oct 11, 2020 3:22 pm

RadHazard wrote:
Fri Oct 09, 2020 5:44 pm
Thanks for all the work you've done on this Flounderguts. I'll be ordering expansion pcbs, cap, rotary kit, etc., from you soon.

I'm working on my own version of the expanded front panel though and had a few questions.

I've basically taught myself pcb panel design with kicad over the last few days. I noticed you use EasyEda, is that just a preference thing or do you think there are benefits to it?

I also had the idea of using the pcb copper as touchpads and had a design in mind that would place contacts for voice pairs close to each other that would allow easily activating voice pairs with one finger. Though after seeing your mandala designs I may be tempted to just use those if you make it available.

I also had ideas for makenoise style backlit features. At the very least I would love to illuminate your lyra constellation design.

Last, I downloaded the gerbers for the extended panel and used one of the tools in kicad to convert them to a kicad project. One issue is, instead of having footprints for drill holes that have a defined center point and radius, holes are just made up of a large number of line segments approximating a circle. This obviously makes it difficult to tweak things (an example would be larger tune pot holes for high precision pots). Would you be willing to upload the easy eda project? I'm sure there's a way I could convert it to kicad or I could just learn easy eda.
I've been using EasyEDA because all the projects are automatically public. You should be able to search my folders (under Flounderguts) and see all sorts of confusing things!
I haven't been using KiCAD recently because some of the things I wanted to do with this are pretty difficult in KiCAD...they're not *easy* in EasyEDA, but I have workarounds that are reasonably quick.

EasyEDA is a bit like the original SketchUp...not really powerful, but it does all the basics, and there are workarounds for the tougher bits. For complicated traces and engineering, I find Altium to be much better...but it absolutely sucks for anything mildly artistic. EasyEDA is pretty good at doing things like importing fonts and simple graphics, and the keyboard shortcuts are simple and only require one hand.

I think I posted a DXF file of the drilling...you can import a DXF into KiCAD.

As far as the pads go, you can probably find my pads in the EasyEDA libraries...do a search for a "mandala" footprint in "user contributed." There is also a complete panel. I thought I posted the Gerber for that, but maybe there was something I wanted to check or tweak first...I try to make sure they are complete before posting them.

I'd avoid the LED thing. The LEDs are quite *noisy*, and the Lyra circuits pick up the sound very easily. They are also power hungry, and you will need a much larger power supply to run your Lyra. Those are the reasons I didn't add any of that. I am planning to have indicator LEDs on the gate-in PCB, though.

I'll try to find some time to tidy up my EasyEDA folders so that you can find the correct project. I tend to save my aborted projects, and my nomenclature and filing is a bit screwy...I'll try to normalize it a bit.

My wife hates my tool drawers labeled "pinchy things," "screwy stuff," and "Bulbasaur." I caved and just labeled the tape drawer "Tape."
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Re: Lyra-8 DIY expansion and panels

Post by RadHazard » Sun Oct 11, 2020 7:31 pm

Sounds great I'll look into the projects. I'm a software dev so I'm used to searching through unorganized directories with strange naming conventions ;)

I'm seeing what you mean about EasyEda. I gave it a try once I started trying to import custom graphics in kicad and found it to not be as intuitive as the "basic" feautures. The easy eda image feature was just so much slicker. I had an image that I traced in inkskape a while back that I thought would be perfect for a pcb. Didn't have much luck with kicad but was able to throw this together pretty quick in easyeda:
pcb render
Things aren't lined up perfectly but overall I think it's going to be a lot easier to do "non standard" things in easyeda.

Hmm, didn't think about noise. I've done a similar project (the MB6582). I had to deal with the noise introduced by using a vfd display there but (as I understand it) that was noise in the digital circuitry that wasn't making it to the audio output. I imagine the Lyra might not be so easy.

If I do backlit stuff It will be a separate circuit since I have an old arduino project with an led controller sitting around. Hopefully then I could place the arduino out of the way and just shield the LED wires. If I do have backlighting cutouts though I'll try to design it in a way where it won't look bad in case the LED's don't work out.

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Re: Lyra-8 DIY expansion and panels

Post by MemSens » Tue Dec 29, 2020 5:09 am

Hello,

I’m looking for any video of a working version of this amazing expanded Lyra-8 ?
Anyone knows where I can watch it ?

Thanks

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Tue Dec 29, 2020 11:04 pm

MemSens wrote:
Tue Dec 29, 2020 5:09 am
Hello,

I’m looking for any video of a working version of this amazing expanded Lyra-8 ?
Anyone knows where I can watch it ?

Thanks
Oof!

Yeah, I'll get on it. I got a little sidetracked.
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Re: Lyra-8 DIY expansion and panels

Post by Stoneyards » Wed Jan 06, 2021 11:46 am

I finished off this project (photos here) so thought I'd share some notes.

Overall it was a lot of fun! The build guide was really helpful. Props to @flounderguts for such nice documentation. The boards are very high quality too.

Tips for builders:

One thing I'd suggest to everyone would be to add resistance to the attack side to bring it into the suggested range of 300k to 1M. I lit up some pots during testing as the attack resistance dropped to 0. Otherwise I used the suggested values in the build doc which worked as described.

The other suggestion I have is to get the stock Lyra working first, learn what it is supposed to sound like, then modify it. There's no schematic, and it is very challenging to troubleshoot.

A dupont crimper kit came in very handy in building jumpers and making removable connections between everything. Fly the jumper wires at a decent height above the panel to allow access to resistors and switches.

I mounted the power inlet and switch on perfboard which gave it some stability, but a chassis-mount would be better.

Overall it's been a very fun project and everything is useful as-is. I'm looking forward to further baffling my family and friends with my idea of "music." :-)

Some suggestions for future PCB revisions:

All this may be assembly error on my part, but many of the functions on board B seem like they're backward. The values for the distortion switch provide a good range, but turning the switch clockwise produces a less pronounced effect. Turning the range switches clockwise shift voices to a lower range. Vibrato frequency decreases as pots are turned clockwise, and left/"off" engages the expansion vibrato which was the opposite of what I expected, even though I followed the convention in aligning the switch notch to the empty dot on the panel.

Board B switches would be more intuitive to use if they were oriented vertically instead of horizontally, to match how they work on board A.

The PCB has components that extend across the whole rack width, with footprints and components within a few mm of my metal rack, so I worry a bit about shorts, and I imagine it's going to be tough to find a chassis to fit. The specified film caps on the distortion section are the most exposed, and they have very thin leads, so they tend to get bashed around a lot during assembly.

I stiffened the expansion board with aluminum angle fastened with 2 part epoxy which worked great. I think the main panel needs a bit of room on the bottom to accept a similar treatment since the panel tends to flex during use. Maybe a chassis will solve this problem.

Thanks again @flounderguts!

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Thu Jan 07, 2021 9:56 pm

Stoneyards wrote:
Wed Jan 06, 2021 11:46 am
I finished off this project (photos here) so thought I'd share some notes.

Overall it was a lot of fun! The build guide was really helpful. Props to @flounderguts for such nice documentation. The boards are very high quality too.

Tips for builders:

One thing I'd suggest to everyone would be to add resistance to the attack side to bring it into the suggested range of 300k to 1M. I lit up some pots during testing as the attack resistance dropped to 0. Otherwise I used the suggested values in the build doc which worked as described.
Yeah, on my initial build I smoked an attack pot, too. But I haven't had any issues since...hmmm. I'll revisit that!
The other suggestion I have is to get the stock Lyra working first, learn what it is supposed to sound like, then modify it. There's no schematic, and it is very challenging to troubleshoot.
PM'd you about that.
I mounted the power inlet and switch on perfboard which gave it some stability, but a chassis-mount would be better.
You're right, we need a better internal power solution.
Some suggestions for future PCB revisions:

All this may be assembly error on my part, but many of the functions on board B seem like they're backward. The values for the distortion switch provide a good range, but turning the switch clockwise produces a less pronounced effect. Turning the range switches clockwise shift voices to a lower range. Vibrato frequency decreases as pots are turned clockwise, and left/"off" engages the expansion vibrato which was the opposite of what I expected, even though I followed the convention in aligning the switch notch to the empty dot on the panel.
No, not error on your part. I noticed that on the first set of wings when I built it. The V.2 wings have the switch directions changed. It's easy to get turned around when you're placing footprints on the backplane! But on the V.1 wings, you could snake the contacts from the switches around using some of the many snipped legs.
:sstorm:
Board B switches would be more intuitive to use if they were oriented vertically instead of horizontally, to match how they work on board A.
Yep. I might have tried to be too fancy.
The PCB has components that extend across the whole rack width, with footprints and components within a few mm of my metal rack, so I worry a bit about shorts, and I imagine it's going to be tough to find a chassis to fit. The specified film caps on the distortion section are the most exposed, and they have very thin leads, so they tend to get bashed around a lot during assembly.
Yeah, that's legit. I had to grind away my rack a bit to get it all to fit!! I did manage to find a few more mm of clearance on the V2 wings and integrated panel. Also, I am in the process of swapping some ceramic caps in for distortion to see how they sound. If it's good, then the smaller blobs of ceramic might help there as well.
I stiffened the expansion board with aluminum angle fastened with 2 part epoxy which worked great. I think the main panel needs a bit of room on the bottom to accept a similar treatment since the panel tends to flex during use. Maybe a chassis will solve this problem.

Thanks again @flounderguts!
You might be right. I did end up making a set of integrated expansion panels after seeing how flexy the IO panels were! I'm hoping to get a second PCB attached down there for the gate in mods (which I'm trying to make backwards-compatible with the IO panel) which will help stiffen stuff up on both styles. You bring up a good point about the chassis. Maybe I can figure out something that would brace the main board mounts against the rack uprights, but I worry about the strength of the little blobs of epoxy at the bottom of the posts.

But I see no way of getting all of this into a chassis (which is only 17" inside) without major changes.

Thanks for the kind comments! The whole thing *is* a bit of a kludge, but I wanted to sort of honor the experimental nature of the original instrument. I am eager to get more feedback from you when you've had more time with it!

one of the ideas I've been kicking around is that there is a bit of a gap between the long release of the "FAST" mod, and the short release of the "SLOW" mod. My thinking is that I could eliminate the "FAST" release section altogether, and instead spec a pot with a very short release value on one end...then when you switch it from FAST (on the central panel) to NOT FAST, you get a mod circuit that covers the entire range of release values from very snappy to as long as you want to make it (I have both 15M and 20M pots)
That would free up almost an inch, and if I tightened things up on the B side, I could perhaps get all the mods on a single board, and perhaps inside the 17" chassis limitation.
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Re: Lyra-8 DIY expansion and panels

Post by Stoneyards » Sun Jan 10, 2021 4:45 pm

Great comments here on revisions. Even with board B switches turned around, I find the experimental nature of Lyra means that the impact of these inconsistencies are totally fine. It's not like it's a filter cutoff where there's muscle memory.. The sounds are out there, and the interface is too..

I think that the idea to eliminate the fast release section, picking the smallest safe value there - will solve a handful of layout/size issues together all at once. That it will fit in a chassis will solve for flex, and I'd guess it would also ease construction and wiring on that wing.

I had one other thought: From a musicality perspective, I find myself wanting direct outs, even just for voice pairs. Maybe an idea for a V2 I/O panel or an expansion panel? I'm in the process of building Kijimi, and am having some of Janne's PCBs made for individual voice outs and a stereo output bus with manual panning for each voice.

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Sun Jan 10, 2021 8:35 pm

Stoneyards wrote:
Sun Jan 10, 2021 4:45 pm
I had one other thought: From a musicality perspective, I find myself wanting direct outs, even just for voice pairs. Maybe an idea for a V2 I/O panel or an expansion panel? I'm in the process of building Kijimi, and am having some of Janne's PCBs made for individual voice outs and a stereo output bus with manual panning for each voice.
I saw the stereo output thread for the Kijimi! I was thinking of a better IO, certainly with stereo, since I think that's something that the Lyra really needs. Do you think 4 stereo pairs with a pan would be a good idea? I could certainly integrate that with the gate circuitry. Or maybe a switch for stereo out per pair to mono-per-voice? And then a summed output in stereo, with it's own pan?

I like the idea, because by splitting out the voices I can control the level of each pair...which is something I think would really lend itself to the musicality of this as a standalone instrument.

I also wonder about eliminating the headphone output jack.

Given the extra real estate from eliminating the fast release section, and a modest re-jigging of the layout, I think I could fit it all into the 7u that is currently on the panel, and perhaps find a suitable backplane chassis as well.

Fun idea. Keep them coming!
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Re: Lyra-8 DIY expansion and panels

Post by grm » Mon Jan 11, 2021 7:11 pm

Flounderguts wrote:
Sun Jan 10, 2021 8:35 pm
4 stereo pairs per pair
do you know where the individual voice out wire taps would have to be connected? very interested.

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Re: Lyra-8 DIY expansion and panels

Post by Flounderguts » Mon Jan 11, 2021 11:23 pm

Not positive, but there are basically 4 quad opamps on board...3 TL074 and one TDA2822.

There are some summed voices there, and I think they go to the pins marked FMxx, and then to mixdry1 and mixdry2. Then it goes through the filter circuit, and then to final out. The mixing balance seems to be at the TDA2822.

Mostly I think it will involve some probing with an audio output jack. I probably won't have time for this until February (I'm still away from my studio for another 10 days), but I don't think it will be too hard to find where to tap the signals. The issues are more to do with the pan. Also the filter section is decidedly mono. I'm not exactly sure what strategy to use, there!

Maybe we should invite @guest to take a look at the Lyra...he's probably the best circuit analyzer guy around here that I can think of!
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