Soma - LYRA-8 DIY Kit

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buttdispenser
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Re: Soma - LYRA-8 DIY Kit

Post by buttdispenser » Mon Jul 20, 2020 4:02 am

Hey guys, quick question: I don't have FR207 (2A max) diodes at my place, but a 1N4007 (1A max) should do the trick as well, right? Eventhough the max forward current of the FR207 is 2A, the PSU only delivers 1A at max. I mean, I'm a noob, but I don't see any reason for why this shouldn't work.

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Re: Soma - LYRA-8 DIY Kit

Post by Addam » Mon Jul 20, 2020 7:56 am

buttdispenser wrote:
Fri Jul 10, 2020 3:59 am
I was wondering whether it is possible to hook up only a part of the whole electronics to for instance just listen to the oscillators themselves. What needs to be connected together in order to achieve that? I would like to learn what the different arrangements of parts are achieving. How do I go about that? What do I need for that?
Without some good electronics chops you might be chasing your tail trying to figure this out without a schematic. Say, you think THINK you have it sort of figured out and something seems to not be working... you're not going to start desoldering based on a hunch right? I'd suggest you save your sanity and wait for the parts, especially considering how the boards need be linked (save the stress put on those connections for when you need to cram it into your enclosure).

If you haven't started on the wiring and pots/switches yet that is a couple months work right there to keep you busy :hihi:

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Re: Soma - LYRA-8 DIY Kit

Post by rationale_music » Mon Jul 20, 2020 8:37 pm

proximalterminus wrote:
Thu Jul 16, 2020 9:55 pm
Does anyone know how to modify the Vibrato depth?
Further up the thread is a pic I uploaded of the Lyra 4 board. The vibrato depth resistors are the four horizontal ones next to the whale logo that are connected to a nearby 4093 DIP IC that acts as the vibrato LFO. It won't be exactly the same on the Lyra 8 but you should be able to use that into to locate the same circuitry. You can tell which 4093 IC is the vibrato LFO by probing pin 14 of the chip and turning the Vibrato switch on and off, since this switch just controls the +12V to the IC.

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Re: Soma - LYRA-8 DIY Kit

Post by proximalterminus » Mon Jul 20, 2020 10:37 pm

rationale_music wrote:
Mon Jul 20, 2020 8:37 pm
proximalterminus wrote:
Thu Jul 16, 2020 9:55 pm
Does anyone know how to modify the Vibrato depth?
Further up the thread is a pic I uploaded of the Lyra 4 board. The vibrato depth resistors are the four horizontal ones next to the whale logo that are connected to a nearby 4093 DIP IC that acts as the vibrato LFO. It won't be exactly the same on the Lyra 8 but you should be able to use that into to locate the same circuitry. You can tell which 4093 IC is the vibrato LFO by probing pin 14 of the chip and turning the Vibrato switch on and off, since this switch just controls the +12V to the IC.
Amazing! Thank you so much. Just to be clear it’s these four resistors?
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Re: Soma - LYRA-8 DIY Kit

Post by rationale_music » Tue Jul 21, 2020 5:59 pm

proximalterminus wrote:
Mon Jul 20, 2020 10:37 pm
rationale_music wrote:
Mon Jul 20, 2020 8:37 pm
proximalterminus wrote:
Thu Jul 16, 2020 9:55 pm
Does anyone know how to modify the Vibrato depth?
Further up the thread is a pic I uploaded of the Lyra 4 board. The vibrato depth resistors are the four horizontal ones next to the whale logo that are connected to a nearby 4093 DIP IC that acts as the vibrato LFO. It won't be exactly the same on the Lyra 8 but you should be able to use that into to locate the same circuitry. You can tell which 4093 IC is the vibrato LFO by probing pin 14 of the chip and turning the Vibrato switch on and off, since this switch just controls the +12V to the IC.
Amazing! Thank you so much. Just to be clear it’s these four resistors?
That's right. Not sure where they are on the Lyra 8. I believe lowering the resistance increases the modulation depth.

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Re: Soma - LYRA-8 DIY Kit

Post by proximalterminus » Wed Jul 22, 2020 9:20 pm

Definitley a good idea to use IC sockets - I had Toshiba 4093s that I used initially but swapped them for the recommended TI ones and noticed the difference in sound straight away. And I am going to try some alternative delay chips.


This is very interesting, can you describe the sound difference at all?

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Re: Soma - LYRA-8 DIY Kit

Post by proximalterminus » Wed Jul 22, 2020 9:23 pm

red-tin-dave wrote:
Tue Jun 02, 2020 4:49 am
gluepet wrote:
Mon Jun 01, 2020 7:57 pm
Finally finished this fantastic beast! Wanted to pass on some items that may be helpful:
...
• Tayda seems to be most economical source for majority components - they do not have everything, but mouser should have most of the rest. There are some useful shopping lists around pages 14-16 of this thread that others have shared
• Lay the big cap flat against the board - it is too tall for most enclosures to stand
• Source potentiometers that have solder "hole" contacts - not "tab" contacts - very tedious to solder and probably not as durable a connection
• Use cut leads from components for making "legs" for the switches on control board - see SOMA pics of inside factory build
• There may be an argument for not using IC sockets, but I wish that I had used them, instead of soldering directly to board, as I am curious to try out some different 2399 delay chips for comparison.

...
looks like a really neat job you've done there!
I didn't find the tab style pots too difficult to solder but I'm sure you're right about the hole ones being more durable.
Tayda seems to the cheapest source of stuff but it too for ever to get to me - my package went from Thailand to Turkey to Germany then back to Thailand then Singapore then Germany again before arriving in the UK! Tracking it was great fun!
Definitley a good idea to use IC sockets - I had Toshiba 4093s that I used initially but swapped them for the recommended TI ones and noticed the difference in sound straight away. And I am going to try some alternative delay chips.

And the CCCP style cap I used is taller on its side than the big one next to it is standing up! So lucky I was making my own case.

This is very interesting! Can you describe the sound difference between the 4093’s?

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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Thu Jul 23, 2020 8:43 pm

Oh man, I just got my order of resistors and caps from Digikey and started soldering on the mainboard and already I've spotted two discrepancies between the board and the BOM. There's at least 4x30k resistors needed not 3x like the BOM says and under "Total in the Synth" the BOM says there's only 1x43k resistor needed when there's at least 3x on the board. Is there even a place for the 62k resistor? Surely all the discrepancies must be documented somewhere.

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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Fri Jul 24, 2020 4:10 pm

I'm working on board V2.6 and using the 3.0 BOM. The BOM says the main board needs 27 x 47uF caps and 5 x 4.7uF caps. But I can only find 26 places for 47uF caps and 6 places for 4.7uF. Should I just go with the silkscreen or is one of the 4.7uF spots actually meant for a 47uF cap?
lyra4.7uf.jpg
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Re: Soma - LYRA-8 DIY Kit

Post by Flounderguts » Fri Jul 24, 2020 4:12 pm

Go with the silkscreen is what Max at Soma told me.

Where did you source those colored IC sockets?
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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Fri Jul 24, 2020 4:28 pm

Flounderguts wrote:
Fri Jul 24, 2020 4:12 pm
Go with the silkscreen is what Max at Soma told me.

Where did you source those colored IC sockets?
I got those in Akihabara Tokyo. Thanks!

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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Fri Jul 24, 2020 4:48 pm

lyra1uf.jpg
Seriously?! These 1uF caps are missing from the BOM too!? I'm going to post my spreadsheet of discrepancies once I'm done putting together this kit.
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Re: Soma - LYRA-8 DIY Kit

Post by LegWyne » Fri Jul 24, 2020 9:43 pm

Evicshen wrote:
Fri Jul 24, 2020 4:48 pm
lyra1uf.jpg
Seriously?! These 1uF caps are missing from the BOM too!? I'm going to post my spreadsheet of discrepancies once I'm done putting together this kit.
Much appreciated! About to get my order together for this. This thread has been so necessary

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Re: Soma - LYRA-8 DIY Kit

Post by Flounderguts » Fri Jul 24, 2020 10:54 pm

Evicshen wrote:
Fri Jul 24, 2020 4:28 pm
Flounderguts wrote:
Fri Jul 24, 2020 4:12 pm
Go with the silkscreen is what Max at Soma told me.

Where did you source those colored IC sockets?
I got those in Akihabara Tokyo. Thanks!
Ah, naruhodo...meka wa nani desu ka? Mendokusai, ne.
Boku wa sorera subite o jibun notameni hoshii!
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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Sun Jul 26, 2020 3:28 pm

LegWyne wrote:
Fri Jul 24, 2020 9:43 pm
Evicshen wrote:
Fri Jul 24, 2020 4:48 pm
lyra1uf.jpg
Seriously?! These 1uF caps are missing from the BOM too!? I'm going to post my spreadsheet of discrepancies once I'm done putting together this kit.
Much appreciated! About to get my order together for this. This thread has been so necessary
Here is my digikey cart of all the resistors and caps including the missing caps and sans the extraneous 62k resistor. I got one or two extras of each component. Only some of the IC's and transistors are included in this cart.
https://www.digikey.com/short/zb1bt4

Here is a spreadsheet noting discrepancies, things highlighted yellow just notes for myself telling me that I've soldered those parts:


Please let me know if I've missed anything. Still waiting for pots in the the post, so my kit isn't complete yet.

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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Sun Jul 26, 2020 3:30 pm

Flounderguts wrote:
Fri Jul 24, 2020 10:54 pm
Evicshen wrote:
Fri Jul 24, 2020 4:28 pm
Flounderguts wrote:
Fri Jul 24, 2020 4:12 pm
Go with the silkscreen is what Max at Soma told me.

Where did you source those colored IC sockets?
I got those in Akihabara Tokyo. Thanks!
Ah, naruhodo...meka wa nani desu ka? Mendokusai, ne.
Boku wa sorera subite o jibun notameni hoshii!
Augat makes them. I always spend way too much time and money in those electronics stores. I get lost in them for hours.

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Re: Soma - LYRA-8 DIY Kit

Post by red-tin-dave » Sun Jul 26, 2020 4:07 pm

proximalterminus wrote:
Wed Jul 22, 2020 9:20 pm
Definitley a good idea to use IC sockets - I had Toshiba 4093s that I used initially but swapped them for the recommended TI ones and noticed the difference in sound straight away. And I am going to try some alternative delay chips.


This is very interesting, can you describe the sound difference at all?
The Toshiba ones sound a bit "thinner" if you know what I mean. A bit less substance to them. They'd be ok if they were the only ones you could get.

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Re: Soma - LYRA-8 DIY Kit

Post by LegWyne » Sun Jul 26, 2020 10:51 pm

Thanks Evicshen! I need to do a second order to get non Tayda bits, your list defs helps.

Struggling to find solid dimensions of the control/main board for some reason. Does anyone have the precise dimensions handy? Are they exactly 10x10"/25.4cmx25.4cm?

I'm asking as I'm planning to do some but not all of the documented mods (Vibrato, voice range and delay distortion) and I'm trying to find an appropriate case that isn't too much wider. This 14x10x3 Hammond case looks great but I'm not sure there is enough clearance to get the boards in. Would be handy to have good measurements. https://au.mouser.com/ProductDetail/Ham ... vn8A%3D%3D

[Edit:] Using the screw holes visible in one of the 12x12 finished images I can see the control board is just about exactly 10x10 which means a 14x10 enclosure with an internal width of 9.9" wont work :( back to the drawing board.
Last edited by LegWyne on Mon Jul 27, 2020 12:24 am, edited 3 times in total.

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Re: Soma - LYRA-8 DIY Kit

Post by LegWyne » Sun Jul 26, 2020 11:33 pm

I don't live in the US/Canada but if I did I'd seriously consider getting something like this:
https://www.barkerdoor.com/ProductDetai ... 2DDOVETAIL

They do custom ply boxes for cheap and they've got a sale on. Like $15 USD for machined dovetailed box parts you assemble yourself. Would be a nice easy option.

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Re: Soma - LYRA-8 DIY Kit

Post by Flounderguts » Mon Jul 27, 2020 11:05 am

You need 266 x 266 mm to fit the board comfortably. in a box. Height can be fudged a bit, but 55 mm looks to be minimum.

I'll make a box template to go with the front panels (which should arrive today!)
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Re: Soma - LYRA-8 DIY Kit

Post by Flounderguts » Mon Jul 27, 2020 12:03 pm

Panels are in! Photos in the panel thread...

viewtopic.php?f=17&t=234558
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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Thu Jul 30, 2020 2:32 pm

IT'S ALIIIVVE. I breathed a big sigh of relief after the moment of truth. Are there any tutorials on how to methodically test each part of the synth? Also has anyone put any thought into making this battery powered? Perhaps with a few LiPos in series or some 9V batteries?
2020-07-30 (1).jpg
2020-07-30 (2).jpg
2020-07-30 (3).jpg
Playing with different knob configurations.
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Re: Soma - LYRA-8 DIY Kit

Post by whyfarer » Thu Jul 30, 2020 2:58 pm

awesome panel! did you etch, cut, print, or make it in some other fashion?

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Re: Soma - LYRA-8 DIY Kit

Post by Evicshen » Thu Jul 30, 2020 3:02 pm

whyfarer wrote:
Thu Jul 30, 2020 2:58 pm
awesome panel! did you etch, cut, print, or make it in some other fashion?
Laser cut plywood! It was supposed to be a prototype but it may end up being the official face plate for a while. I may try staining it. I would like to try acrylic or steel if I have time.

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Re: Soma - LYRA-8 DIY Kit

Post by Flounderguts » Thu Jul 30, 2020 4:35 pm

Evicshen wrote:
Thu Jul 30, 2020 2:32 pm
Also has anyone put any thought into making this battery powered? Perhaps with a few LiPos in series or some 9V batteries?
12 V is what you would need, probably higher as it requires 12v for stable operation...maybe a 14.4v Lithium Ion battery?
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