it's chassis ground. not used in my case; wooden case.
Soma - LYRA-8 DIY Kit
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Re: Soma - LYRA-8 DIY Kit
- Flounderguts
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Re: Soma - LYRA-8 DIY Kit
This has been brought up before.
It seems to be an artifact from an older version...ground plane hookup is the consensus right now.
The Lyra seems very sensitive to grounding issues.
It seems to be an artifact from an older version...ground plane hookup is the consensus right now.
The Lyra seems very sensitive to grounding issues.
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Flounderguts
Flounderguts
Re: Soma - LYRA-8 DIY Kit
and EM or static interference. while testing the previously working I noticed the ground hum would increase or decrease if I moved my hand away from or towards one side of the I/O board
Re: Soma - LYRA-8 DIY Kit
I'm nearly completed with my lyra but I haven't been able to find a good source for the thumbscrews. Does anyone know where I could get some or have some they would be willing to sell?
Re: Soma - LYRA-8 DIY Kit
If you want a cheap option you could buy some on alibaba (2 months shipping) and substitute standard M3 10mm or 12mm bolts while you wait
- Flounderguts
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Re: Soma - LYRA-8 DIY Kit
klenkstar, welcome to MuffWiggler!
Where are you located? There are several channels to find DIN thumbscrews...if you're in the USA, try computer shops. This style is often used with server racks.
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Flounderguts
Flounderguts
Re: Soma - LYRA-8 DIY Kit
Re: Soma - LYRA-8 DIY Kit
The quality seems good. These are the ones I ordered - https://www.aliexpress.com/item/4000145 ... 4c4dzHJQKZ
Re: Soma - LYRA-8 DIY Kit
Flounderguts wrote: ↑Mon Sep 14, 2020 7:53 pmklenkstar, welcome to MuffWiggler!
Where are you located? There are several channels to find DIN thumbscrews...if you're in the USA, try computer shops. This style is often used with server racks.
Thanks! I'm located in the US. There is a microcenter nearby I might scope out first before going the alibaba route. Thanks for the tip!
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Re: Soma - LYRA-8 DIY Kit
It's alive! WOAH man this thing sounds amazing.

Everything works perfect, EXCEPT:
The Hyper LFO doesn't seem to want to modulate the voices. It modulates the delay just fine, but when you flip the switch to "LFO" for modulation source on any of the voices (Total FB knob is turned down, as is Vibrato) the "MOD" knob just messes with the tuning of the voice slightly, and at its max position it pretty much silences the voice.
Everything else works great! Delay, Distortion, all the voices sound, hold knobs, the FM modulation between voices, everything! EXCEPT the Hyper-LFO modulating the voices. The LED also seems a little dim.
Now one thing to mention is I am still waiting on the headphone AMP IC (TDA2822), but I didn't think this would affect the Hyper LFO's ability to modulate the voices.
I've got proper voltages across the board, except where the TDA2822 chip should live. I'm assuming that will read properly right as soon as that chip is in there.
Any thoughts anyone?
EDIT: I re-seated all the dupont headers, now it's all working perfectly


Everything works perfect, EXCEPT:
The Hyper LFO doesn't seem to want to modulate the voices. It modulates the delay just fine, but when you flip the switch to "LFO" for modulation source on any of the voices (Total FB knob is turned down, as is Vibrato) the "MOD" knob just messes with the tuning of the voice slightly, and at its max position it pretty much silences the voice.
Everything else works great! Delay, Distortion, all the voices sound, hold knobs, the FM modulation between voices, everything! EXCEPT the Hyper-LFO modulating the voices. The LED also seems a little dim.
Now one thing to mention is I am still waiting on the headphone AMP IC (TDA2822), but I didn't think this would affect the Hyper LFO's ability to modulate the voices.
I've got proper voltages across the board, except where the TDA2822 chip should live. I'm assuming that will read properly right as soon as that chip is in there.
Any thoughts anyone?
EDIT: I re-seated all the dupont headers, now it's all working perfectly


- Flounderguts
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Re: Soma - LYRA-8 DIY Kit
It really is a very nice panel Flounderguts. I'm looking forward to seeing a completed unit!
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Re: Soma - LYRA-8 DIY Kit
Oh its a beauty panel, from our dear friends over at www.flundrton.com
They're even working on other cool panel concepts check it out:
viewtopic.php?f=17&t=234558&start=50#p3349177
The guy has some really cool stuff Flounderguts! You should check it out

- Flounderguts
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Re: Soma - LYRA-8 DIY Kit
I'm working on an IO panel and enclosure for the standard DIY build.
Question: for the jacks on the back, which do you prefer; text right side up (see it from back), text upside down (see it when peering over from front), or text on top of main panel AND right side up?
And do we all like our power switch on the back?
This is what I've got right now...jacks right side up, power legend upside down. I just liked it, but it doesn't make a whole lotta sense...
Question: for the jacks on the back, which do you prefer; text right side up (see it from back), text upside down (see it when peering over from front), or text on top of main panel AND right side up?
And do we all like our power switch on the back?
This is what I've got right now...jacks right side up, power legend upside down. I just liked it, but it doesn't make a whole lotta sense...
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Flounderguts
Flounderguts
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Re: Soma - LYRA-8 DIY Kit
I stole your picture for my site too gnsk, fire me a PM if you want me to take it down. I credited you as well!
I'm going to be alllll over this. I was thinking of doing a clear acrylic, but if I can be one of the first "Standard Flounderguts builds", well that would be super cool.Flounderguts wrote: ↑Fri Sep 18, 2020 10:01 pmI'm working on an IO panel and enclosure for the standard DIY build.
Question: for the jacks on the back, which do you prefer; text right side up (see it from back), text upside down (see it when peering over from front), or text on top of main panel AND right side up?
And do we all like our power switch on the back?
This is what I've got right now...jacks right side up, power legend upside down. I just liked it, but it doesn't make a whole lotta sense...
Yes love my power switch on the back. Not sure what footprint your going for, but this guy seems pretty standard:
https://www.taydaelectronics.com/rocker ... ap-in.html
I'm a little biased because this is the switch I chose... But regardless, throwing my two cents in.
As far as the legend, I agree it doesn't make a lot of sense, but that is kind of going with the whole theme of the LYRA-8. It doesn't make sense, and that's how we like it

Re:
presumably to allow for a diversity of component choices. parts with different physical dimensions can all be "panel mounted" to the PCB without causing an issue. im still new to complex builds and found it quite straightforward to solder the control board using leftover resister leads as recommended.lasesentaysiete wrote: ↑Tue Jun 06, 2017 3:39 pmdoes anyone else find the control board design an odd choice? I mean that instead of having the pcb-mountable components mount to the pcb via regular footprints, we get this sort of smd type style with THT components. Anyone know why this is?
I actually don't mind it, btw. But it seems an unnecessary amount of work.![]()
Re: Re:
factory built is with pcb mount.
For DIY version, it it easier to swap pots and components.
For example, T18 pots to 6.35mm pots etc.
Just my thought.
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Re: Soma - LYRA-8 DIY Kit
She's finally finished! Behold the electric blue DIY Lyra-8. I took my time on this one and probably went overboard with the finishes but I'm more than pleased with the outcome. The panel is from frontpanelexpress and the case was custom made by a local wood & metal artist I found on Etsy. Today was final fabrication of the rear panel, cutting the wood, and mounting everything up. Onwards to FM feedback bliss!
Re: Soma - LYRA-8 DIY Kit
nice blue.digix wrote: ↑Sun Sep 27, 2020 2:51 amShe's finally finished! Behold the electric blue DIY Lyra-8. I took my time on this one and probably went overboard with the finishes but I'm more than pleased with the outcome. The panel is from frontpanelexpress and the case was custom made by a local wood & metal artist I found on Etsy. Today was final fabrication of the rear panel, cutting the wood, and mounting everything up. Onwards to FM feedback bliss!
Could you please let me know, where did you sourced the thumb screws? my screw from aliexpress has a little small diameter(< 12mm).
Thanks.
Re: Soma - LYRA-8 DIY Kit
Hi mate - I sourced the thumbscrews from Accu.co.uk (and paid stupid shipping to get them to me here in Australia)!
https://www.accu.co.uk/en/knurled-thumb ... ing=1&c=15
https://www.accu.co.uk/en/knurled-thumb ... ing=1&c=15
- Flounderguts
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Re: Soma - LYRA-8 DIY Kit
I've been looking pretty closely at the circuits of the Lyra, as I'm troubleshooting some weirdnesses.
The large pad on the IO board, which is connected on one side to the 5.1 ohm resistor, should almost certainly be connected to the chassis ground...NOT the ground rail on the main board or control board. It seems to act as a protective fuse in case of reversed polarity, and it should also help to remove noise from the headphone circuit.
The large pad on the IO board, which is connected on one side to the 5.1 ohm resistor, should almost certainly be connected to the chassis ground...NOT the ground rail on the main board or control board. It seems to act as a protective fuse in case of reversed polarity, and it should also help to remove noise from the headphone circuit.
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Flounderguts
Flounderguts
Re: Soma - LYRA-8 DIY Kit
Interesting - do you think this is necessary if one has a wood case? For mine the I/O board is mounted to a wood panel. I have quite clean signal from the main out but yeah - the headphone out has a bit of hiss and noise (does not sound like AC type constant hum, though).Flounderguts wrote: ↑Sun Sep 27, 2020 9:24 pmI've been looking pretty closely at the circuits of the Lyra, as I'm troubleshooting some weirdnesses.
The large pad on the IO board, which is connected on one side to the 5.1 ohm resistor, should almost certainly be connected to the chassis ground...NOT the ground rail on the main board or control board. It seems to act as a protective fuse in case of reversed polarity, and it should also help to remove noise from the headphone circuit.