Hi, looks like you got the answer from analogoutput - I learned a bit myself.
I’ll amend the stripboard layout to make the diode orientaion a bit clearer. 1n5817 diodes would be ideal.
But you could just replace them with jumpers - if you’re confident you won’t plug it in upside down.
I’ll post a pic when I get the chance.
Cool, just updated my ‘To do’ projects folder ill add some 1n5817s on the order after next, should only need a few =)
Could you use this with a pickup rather than the piezo? what if. modular synth meets slide guitar? XD
You can plug a guitar to the input as there is enough gain to get the level - I tried it with a little electric lap steel guitar.
Tom Whitwell also designed the Electrophone which has a guitar pickup mounted on the panel.
It may or not be something to try - Check out his vid: https://youtu.be/2JwwlLcU29s
All the Modular Music Thing stuff is opensource with scematics etc on github.
Good luck with the build
Genius! Another damn thing for the “build this someday” list.
I forked Whitwell’s repository and added conversions of his old Eagle files to .fbrd and KiCad formats:
(my god Fusion 360 is a horrible pig)
There is quite a delay between you tapping the wood and the sound. What is causing that?
Nothing magic just clouds. I thought that would show of the sound better
Nice work on the stripboard lay out! I just made this and it works in upping the signal but there’s a really loud constant hum when its plugged in (the same type out get when a guitar jack is loose). Checked the jacks and they all seem secure… Any ideas what could be wrong?
THANKS!
Grounding problem, check that there’s a good ground connection from the piezo (or input jack) all the way to the power supply ground. If you have an aluminum front panel, make sure that’s grounded too. Other than that, the usual inspect and reflow circuit board connections, etc. …
I’m definitely glad I got a few of these things. Still one of my favorite modules.
Thanks for the quick reply dude! Let the grounding checks commence!! …Will let you know how I get on.
Hi
It sounds like a gounding issue. I had some issues when building it - In my case I’d forgotten a trace cut.
So I’d advise rechecking again against the layout.
I don’t think it’s important but I used a piece of blank pcb board for the panel.
If you send a photo I’m happy to have a look.
Also, are you using it with a piezo or with something plugged in? If the latter, does it make the same noise with nothing plugged in?
Thanks man! Originally I had a guitar jack for the input but I have replaced that with a 3.5mm jack & it seems to have helped a bit… Not sure why it should make a difference?
I just did a few tests on different signals:
BASS: small buzz which is reduced when i touch the strings or the eurorack panel
MUSIC THROUGH PHONE or MICROBRUTE: Works a treat with clear sound
PIEZO: very buzzy even when the level is turned all the way down.
Is this type of buzz normal or is there a way to at least reduce it?
Attached a couple pics. (I replaced R3 with a 50K & 5.1K resistors as I didnt have a 56K… THats why mine looks slightly different & has 1 more resistor on it)
I’ve noticed that cheaper 1/4" jack sockets can be a tad big in the ring and cause grounding issues.
Embrace the buzz, man. We’re DIY.
Hi Man
Thanks for sending the pics. I’ll get a chance to check tomorrow - but it sounds like you’re well on the way.
We’ll work it out though 
I’ve had a look and this looks the same to me apart from the the two resistors.
Had any luck getting rid of the hum?
