Soma - LYRA-8 DIY Kit

[whyfarer]

I managed to keep the Attack, S Release, F Release on one board. The other has Voices, Delay, Distortion, and Vibrato. I'm going to go through the BOM one more time to make sure everything fits the way it should.

[gluepet]

Thanks Much, Wavy Davy - am about to start wiring portion and these will def help me out! Thanks also for the detailed pics!

I finished my LYRA-8 build, and am having a lot of fun playing with it.
A few notes on some mistakes, problems, and things I would do different with my build.

[Flounderguts]

The BOM. It's a work in progress...

All of the original parts in your Lyra BOM can be re-used in this. There are pads for the original electrolytic caps on voices 1-4, but they aren't actually necessary unless you want to use SMT aluminum poly caps.

There will probably be a lot of *other* electrolytic caps bodged in.

Please note, this BOM is *NOT* something you need to follow to the T. I made up the values based on what I have on hand, and what was cheaply available. If it calls for a 31K resistor, and all you have is a 27K, GREAT! Same goes for capacitor values. You don't really even have to be in the ballpark. Most of the minimum and maximum values are in line with Vlad's "tweaks" document, but not all. For instance, the Attack values are way out to lunch, but the suggested range is covered...and then some. Additional resistors on the attack may be recommended to make it useful, but we simply don't know until we try it!

Unfortunately, no one distributor has all of what is needed. I'm waiting on a quote from one of my distributors on a package deal in reasonable quantity, and if that works out we could all save a lot of money on shipping. I think if we can get 10 people on board (we're about half way) then a kit could work.

Here's the BOM

[Flounderguts]

Here are the final Gerbers, if anyone wants to get a head start or tweak them. I will be placing an order for boards in the next day or two.

[Flounderguts]

PDF files in case we have some crazies that like to etch their own.

The Attack Release board could be done single layer as is. The Voice board would need some rework to get it on to one layer.

PCB_Lyra 8 Expansion A V3.pdf

PCB_Lyra Expansion B V3.pdf

[Flounderguts]

Ok, some more on this. I'm just getting started on my front panel. A typical 19" rack isn't actually 19", it's something like 18 5/16".

I'm happier in metric, so let's call it 465.1 mm. The Lyra panel board is a titch under 255 mm, and my expansions are 92.71mm, which leaves about 24.68 mm. Uhhh...0.972" I think.

That could be the magic 1/2 inch that there was a question about.

In a rack, this will take up 6u...well, just under, but I can leave some space up and down for my panel, whew! Perfect, because the rack space I have for it is 7u...

[Alfrede]

Thanks for your files, is there a Chance to get the files as a Kicad Projekt?

[Wavy Davy]

Thanks for sharing your build notes Wavy Davy!

Is it just me, or does it look like two of the diodes on the main board are not soldered?

Cheers,
B

A few notes on some mistakes, problems, and things I would do different with my build.

IMG_1285.jpg

Thanks for the tip about missing solder on some diodes.
It only looks that way, because I did some of the soldering from the top side, and most from the bottom side.
Not everything soldered on the bottom side, flowed through to the top side, but still good connection. No cold solder joints.

An interesting side note: Photographing the blank boards, and then displaying them on a big screen TV, made it a lot easier to read the silk screen component designations, when I was looking for where to put the parts.
Same thing makes it easier, to examine the boards for mistakes.
It's like a giant magnifying glass

Also, I placed all the resistors in the same color code orientation, and all the ceramic caps facing the same way, to make it easier to troubleshoot, should that be needed.

Have a great day, and make some fun sounds

[Flounderguts]

Also, I placed all the resistors in the same color code orientation, and all the ceramic caps facing the same way, to make it easier to troubleshoot, should that be needed.

ALWAYS a good practice!

If you plan on more of this stuff, invest in a USB microscope! Well worth the cash.

Actually, I bought an endoscope/borescope for looking in motors and down plumbing. Turns out it's the same cam as on some of the mid-range SMT microscopes, so I just plug it into my laptop and hold it in a 3rd hand alligator clip.

It saves my aging trifocal eyes



Anyone know which font SOMA uses on the panels?

[Flounderguts]

Here's a DXF file for a 19" rackmount panel for (what I'm now calling) the Lyra-8+

DXF hole pattern

[Illywhacker]

Thank you so much for such a detailed response, WD.

In the process of hunting for the problem, disconnected the board, removed the face plate and after reassembly, works perfectly. So somewhat embarrassingly, have no real insight as to what was wrong. Suspect it was some weird grounding issue with the faceplate.

But jeez it sounds beautiful. So thanks to everyone here that has contributed knowledge and experience.

Now just to put finishing touches on the case, and then make some noise!...

[red-tin-dave]

Just though I'd say "Hi" - I got my PCBs a few weeks ago after they sat in the Parcel Force depot in Leeds for a couple of weeks. I have parts ordered - massive thanks to all the people on here who've contributed mouser/tayda/etc BOMS - they're been a great help. I intend to start soldering tomorrow and I'll be writing up my experience for a blog post on the RS Designspark website if anyone's interested.
I'm lucky enough to have access to a laser cutter at work so I'm planning on making an acrylic top panel with etched lettering in filled with wax - I can also bend acrylic so it may have bent front and back - anyway I'll share my experience on here.
Thanks again to everyone who's shared stuff.

[Wavy Davy]

Thank you so much for such a detailed response, WD.

In the process of hunting for the problem, disconnected the board, removed the face plate and after reassembly, works perfectly. So somewhat embarrassingly, have no real insight as to what was wrong. Suspect it was some weird grounding issue with the faceplate.

But jeez it sounds beautiful. So thanks to everyone here that has contributed knowledge and experience.

Now just to put finishing touches on the case, and then make some noise!...

Thanks for the followup post, to let us know you got your LYRA working.
Glad to hear it, and hoping my repair suggestions might help anyone else who has problems.

The more I play/experiment with my LYRA-8, while consulting the owners manual, the more interesting/fun noises I get out of it.
And the better I understand the signal flowing through the various knobs and switches.
Being a retired electronics repair tech, I really would love to have a set of schematics for my LYRA, to show me how everything works inside.
Lacking that, I plan to sketch out a signal flow chart, to make it easier for myself and others, to understand how the signals are passed around inside their LYRA-8 synths.
I also will share some changes to the front panel labeling, that I think will make it more logical/user friendly.

The owners manual is good, but a roadmap will help a lot too.

To all who have shared information, and all who have thanked me for doing the same,
I am grateful

[Wavy Davy]

LYRA-8 front panel notes ver-A.JPG

These are some changes/additions to the faceplate graphics that I have in mind.
Adding frames around all the text to make it more obvious what knob/switch it is connected to.
Adding "ON/OFF" to some of the switches to differentiate between, switches that select sources/destinations,
and ones that turn something ON/OFF.

Starting in the upper left hand corner and working left to right, top to bottom....
Moving "Hyper LFO, Modulated Delay, Distortion, and Output" labels, to above each section, for clarity.

Hyper LFO:
Changing the A/B Modulation Graphic to "BxA", "A+B" to make it clearer what is happening.
Adding the words "SOFT FM", "A>B", and "OFF", to indicate that the switch is turning "A>B SOFT FM" on/off.
removing the signal flow line, as I felt it was more confusing than helpful.

Modulated Delay:
Changing the signal flow lines to be more informative.
Adding "OFF" and "MODULATION SOURCE", to make that switch more informative.
Changing FB to "FEED BACK", to make that knob easier to understand.

Distortion:
Adding a line between DISTORTION and OUTPUT sections, to add clarity to what the knobs in those sections are controlling.

Output:
Adding "MASTER" to VOLUME pot label. labeling led as "POWER".

Hold knobs:
Adding "1,2,3,4" and "5,6,7,8" numbers for clarity.

Total Feed Back:
Adding "TO FM SW" above the sw. to make it clear that this switch is sending its output to the Frequency Modulation 3 way switches.
Adding "LFO" to the bottom switch position, to make it clear, what signal that switch position is sending, to the Frequency Modulation 3 way switches.

Vibrato switch:
Adding the words "ON" "OFF" for clarity.

Frequency Modulation 3 way switches:
Adding "FM" above the switches to make it more clear what they do.
Adding a comma between the numbers (3,4) (1,2) (7,8) and (5,6) for clarity.
Adding signal flow lines for clarity, to make it more obvious which direction the modulation was coming from/going to.
Adding "OFF" to the middle sw. position for clarity.
Changing the words on the bottom of the switches, to make it more clear what that position enables, "TOTAL FB", "LFO", "EXT CV IN".

Pitch knob:
Adding the numbers "1,2,3,4" and "5,6,7,8" to make it more obvious what they control.

The 34>56 78>12 FM structure switch:
Adding "FM LINK" above for clarity.
Changing to "1,2<7,8" above "3,4>5,6" to make it more intuitive, what voices/oscillators are modulating in what direction.
Commas between numbers for clarity.
Adding "OFF" in bottom switch position, for clarity.

Modulation Amount Knobs:
Adding the word "AMOUNT" for clarity.

Wave Shape Knobs:
Changing the word SHARP to "WAVE SHAPE" for clarity, and adding the triangle and square wave graphics, for added information as to what the knob is doing.

Fast switch:
Adding the word "SLOW" to the top position of the sw. for clarity.

Touch pads:
Making the numbers bigger/bolder, to help with identifying, what the numbers on the rest of the control panel, are referring to.

All these changes and additions are purely a mater of my personal preference, so that when I sit down to experiment with my LYRA-8, I can quickly know what I am doing, without referring to the owners manual.

It will probably go through some changes before I settle on a finished version.
I will share a better front panel image, when I print the final version for my LYRA.
Nice thing about using printed paper face plate graphics, is I can change it fairly easily.

Any comments, corrections will be welcome and appreciated.

[Flounderguts]

These are good suggestions, and timely...as I am currently designing my own front panel.

I've been pretty disappointed by Altium, when it comes to doing anything except routing. It simply refuses to succumb to my gentle tweaking to give me decent fonts, graphics, or patterned pours. I find myself going back to clunky old EasyEDA, just because I know how to accomplish something, rather than taking an entire day to fail at a single task.

Any Altium gurus around?

[Flounderguts]

Question:

On the IO board, there is a pad between the external in and the out jacks. It is a large pad, connected to a 5.1 ohm resistor, but nothing else.

There is no silkscreen on the backside of this to show if a component goes there, but in the photos of the inside of the Lyra, there seem to be pins coming through. Anyone know what this is? Am I just really stupid?

[woodster]

They're just VIA's, very big VIA's as far as I could tell. I Didn't put anything in there and my build is fully functional as far as I can hear or see.

[Watson1983]

Hi friends,

Would there be any problem if I change the 0'1m ceramic capacitor at the in/out board for one mylar of same value?
I don't know what happened, but I've got one cap less.... I've asked my dog, but she doesn't know anything about it.


Thanks

[Flounderguts]

Hi friends,

Would there be any problem if I change the 0'1m ceramic capacitor at the in/out board for one mylar of same value?
I don't know what happened, but I've got one cap less.... I've asked my dog, but she doesn't know anything about it.


Thanks

Should be fine, as long as it's of the same voltage range. Better, actually.

[gluepet]

Question:

On the IO board, there is a pad between the external in and the out jacks. It is a large pad, connected to a 5.1 ohm resistor, but nothing else.

There is no silkscreen on the backside of this to show if a component goes there, but in the photos of the inside of the Lyra, there seem to be pins coming through. Anyone know what this is? Am I just really stupid?

I have the same question - Anyone know if the following from assembly instructions is regarding this large pad/via?:
"Pay attention that CV VOICES socket use ground pins for automatic CV switching when a jack plugged to the socket. It can be important if you would like to rearrange it to another socket's type."

[woodster]

No, not related.

[woodster]

It really is a wonderful thing

IMG_20200417_203610(1).jpg

[gluepet]

It really is a wonderful thing

IMG_20200417_203610(1).jpg

Looks great - Congrats! Nice LED’s

[Watson1983]

Hi friends,

Would there be any problem if I change the 0'1m ceramic capacitor at the in/out board for one mylar of same value?
I don't know what happened, but I've got one cap less.... I've asked my dog, but she doesn't know anything about it.


Thanks

Should be fine, as long as it's of the same voltage range. Better, actually.

The ones I've got at home are 0'1mf 100v,should it be fine or it'll be better if I wait and get the proper one?

[Poldenstein]

The ones I've got at home are 0'1mf 100v,should it be fine or it'll be better if I wait and get the proper one?

As a general rule: use caps that are at a voltage rating that is equal or higher than the one recommended, avoid lower voltage rating