Zorch's build progress

[zorch]

An unexpected benefit of having this thread has been that it has really been helping to keep me organized and prioritize things. This is a long one, so strap in!

Currently on the to do list:

Passive stripboard ring modulator

I did not have any luck with this one on the breadboard - but it still seems like something relatively easy to throw together that I would still like to have. I have been looking for ways of adding effects to existing sounds and this seems like it could be fun. Also, I can build it small and keep outside of the main case. I am running out of room in a hurry and I am not especially excited about making the new case part 2 just yet.

K25 subosc, glide, and attenuator
I have the parts to complete these and if I need a break from troubleshooting (of which there is a lot to do) I’ll pull these out. I am most interested in the subosc. I have a quad passive attenuator in my case right now so while the k25 one is snazzy looking it is low on the priority list. I might even give it away if someone wants it. The jury is still out. The glide seems less useful at the moment as my sequencer is acting up. Speaking of…

8 Step Arduino Sequencer
I have been slow to work on this. I have the arcade buttons now, but it is not going to be quick or easy to swap them all out. I am pining for the fact that the buttons are not orange too. I had some but stupidly returned them. Now I’m hemming and hawing about getting them back again. Functionally everything works as it should now with the backwards/forward switch doing what it should. The new problem is when the module is plugged in it has been mysteriously making my VCO’s drift. I hope the button replacement maneuver will fix the issue.

LMNC VCLFO & ADSR
I just realized that my 3rd + output socket on my ADSR is not working. Most likely its always been like this and have just never used it until now. The VCLFO has always seemed to behave a bit odd in the bank selector area. I should pull it and reflow everything on it, especially now that I have a bit more experience under my belt. It was one of my very first modules after all.

Buffered Ulti-Multi
Still having the crossover issues with the banks bleeding into each other. A bit stumped on how to solve the problem. I got the +12v 10 segment display audio indicator working after the PCB surgery but it still needs to be hooked into the bank selector along with the -12v display and the volt meter. Still not 100% sure how to ‘correctly’ attach the +/-12v meter. Also still searching for a way to get the -12v LED indicator to work. I think I can just plug it into the -12v rail as a reference but I have not tried it yet. Functionally it all ‘works’ but I’m hesitant to keep it in the system. I don’t want to add potential issues to the main case right now.

AO Dual Quantizer
Have made progress on this thanks to some much needed help but still have a ways to go before it is fully functional. This particular module poses the most existential of all the questions in my setup. I have not tuned anything in my system. Like at all. So I feel like having this fully functional might be a bit of a moot point right now. I’m curious to have other thoughts about this.

Stripboard Safety Valve
Have not touched this one in a while. Still hissing at me as I move near the tube. Kind of low on the priority list - especially since the solution isn’t particularly clear other than the usual “Check all connections and reflow”. I would like to add a line level LED in the system however…

Test PSU
Finished the stripboard and it all seems to be functioning nicely though I should put the oscilloscope to it. The cable tester on the other hand is a bit of a mess and might get added later after I print the enclosure.

Branches
Sitting in a box and ready to be assembled - though I have yet to decide on how to deal with the SMD bits. I am thinking I’ll use my flux pen, then solder paste, then my regular soldering iron (?). Another ‘afraid I’ll destroy it’ so I have been slow to tackle it. Faceplate is designed and ready to print!

Turning Machine
Faceplate is nearly finished being designed - I am adding some unnecessary flare to it because why not. Looking forward to building it.

Big Button
Got all of the components ready to go but I am not sure about the form factor. Its really not going to fit in my current case - even though that is where I would prefer it to live. I should just take a stab at the plate design and keep it in an external box for the time being. Once I have case #2 it will look pretty sweet next to the sequencer.

Mini/Micro Duck
To be breadboarded!

VCO #3
All parts accounted for! Waiting on assembly.

Clock Capture Module
So far down the list. So very far.

The Future!
Case #2 is still not more than a gleam in my eye at the moment. depending on how my test PSU works… I already have the parts for a least one more thanks to my tendency to over order things. The Twin T drums look fun but I think the Big Button is a better way for me to go at the moment. The MidiMuso seems neat but outside of the scope of my talents for the moment. Might pick up the DIY Herbs and Stones Liquid Foam kit though I don’t know if I want to deal with banana jacks. I am considering building a pair of stripboard OBA’s for my secret project. Though I think I might need more help with the Arduino aspect.

[Dud]

A lot of work here

For the real ring modulator, i’ve made it and the output level without opamp is very very low.
it’s on my future list to make it active (the Ken Stone version)

@zorch

The Twin T drums look fun but I think the Big Button is a better way for me to go at the moment

it’s 2 differents things, one is the sound and the other is the trigger.
They would be in fact complementary.
(maybe you have already some drum modules )

[willow2x]

Re:The BigButton train
Theres a Teensy module made by Otemrellik (I always read his name as Otter Milk =D) that has a decent amount of function for a Euro sized module, I think it would be nicely squashed into a 5cm Kosmo plate.

Sorry for giving you more modules to do, but with a bit of thinking it will take less space up (especially if you bastardise the Kosmo format and use 3.5 jacks), untill you get case 2 built =)

Teensy Eurorack Drum Module

[zorch]

Yes! I forget to mention that I consider the sound bank that Sam did in the other video as included in with this whole bit. I would not do one without the other.

[zorch]

Hm. It might be worth building the powered version after all. It is very possible that I built the breadboard version correctly and ended up with just too low of a signal.

Can anyone recommend diodes (preferably that are available on Tayda) for the ring?

[analogoutput]

Stone says “The part number of the Germanium diodes is not critical. Use whatever you can get.”

Tayda has two listings for germanium diodes, but 0 in stock for both.

[fredrik]

Does it even matter? A lot of schematics seem to use 1n4148 (or 1n914, which is the same thing), and the first reference Google found (an Analog paper) basically said anything goes.

Maybe breadboard and try a few until you find one that sound right to you, dyi pedal builder style… (and then argue endlessly on the internet over which one is best, dyi pedal builder style…)

[zorch]

I see BAT41 and BAT46 on tayda…

[zorch]

In the stone article, it is mentioned that you can use 4148, but that germanium or shottky are preferable.

I should use them all and put them on different banks, because I need more complexity in my builds.

From the article.

“Even 1N4148 silicon diodes will work, though with greater distortion due to the larger voltage drop.”

[analogoutput]

Tayda also has 1N5817, which many of us have in our stash because we use two of them in every module (on the power rails).

[KardashevTypeII]

Kai,

This should be a Kosmo module. I’d tweak the sounds in my own.

-Fumu / Esopus

[willow2x]

Ive been working on breadboarding this one, just need some of the ICs (or subs, if any) once ive got more info and progress ill make a thread =)

[zorch]

Troubleshot (Troubleshooted? Trouble… shat?) the VCLFO and the ADSR. Replaced some pots with the type that have nuts so it feels a bit more solid now. The ADSR was just a loose wire.

Finished my PSU enclosure - the cable tester turned into a forest of wires, so that will be for another day.

The Mini Duck module has been fun to work on - I can see why Sam likes working with relays so much. I whipped up a quick faceplate for it - should be done when I get off work tonight. I voluntold a co-worker to be in charge of art for it. They were surprised.

[zorch]

After doing a little experimenting it seems that the power bus on my second supply was a not particularly well put together. Not a surprise considering it was one of my earlier bits. I pulled it out of the case and made sure everything was nice and solid. While that did seem to clear up the distortion issue I was having with my sequencer - now there seems to be some inference between modules that I didn’t have before. I think my two PSU’s are not getting along together very well since the issue seems to clear up when I unplug the second unit.

[zorch]

The more I play with my second PSU and bus board the more convinced I am that something is ‘off’ about it. It seems to be getting signals from modules that are not only not plugged into it but also not even patched! I can hear slight drifting that lines up with my K25 LFO as it cycles - which again, is on the first PSU and has no cables going to it other than power. Very strange.

The testing stripboard PSU I made seems to be working fine. And as tempting as it is to scratch build ALL of my future PSU’s I still might plunk down a few bucks and buy them FC anyway. While it would be cheaper to DIY - I’m wondering if the peace of mind/reliability trade off is worth it.

Meanwhile I think I got the quantizer and sequencer working - those were big projects that I am glad to have them working. I’m having a difficult time choosing the next project to focus on. I feel a little in the air as I wrestle with the PSU issues. I couldn’t resist getting this rhythm generator and I think having the big button and sound bank on hand and working when it arrives would be a natural next step. Most likely I will try to get the mini-duck finally sorted out and then troubleshoot the safety valve. I attempted to breadboard the DIY 808 kickdrum but sadly my breadboard-fu is weak so no love from that angle.

Meanwhile, here is a random patch:

Random patch

[zorch]

Fourteen hours, one power outage, and a spool change later, my wav bank plate is done printing. It’s my most ambitious 3-D printing project for my synth yet. I hope I got my tolerances right!

[zorch]

Time for another update!

I disassembled the entire rig to rework my power setup - replacing one of my FCPSU’s with a Routemaster. This let me clean up a few suspect bits of wiring well as get my power indicator LED working.

I know its a small thing but this light represents how far my knowledge has progressed. Heatshrink is a wonderful thing.

The real problem is that all after all of the work I did it still did not help the noise issues that I have been having. I need to do some more testing but I am beginning to believe that my issues can be traced to an under powered wall wart. Perhaps running the entire thing through just one is a bad idea. My issues sound suspiciously like @heckseven 's. The next step is to try running one PSU by itself and see how it reacts - and perhaps do some research to figure out how to get my oscilloscope to help me troubleshoot.

WAV Trigger:
This project is what made me think I just have an overall lack of power problem. As soon as I plug it in, both of my oscillators start chugging. The more banks I engage on it, the worse it gets.

Euclidian Rhythm generator, Turning Machine, Branches:
Next to build! Frankly I think having just these and the WAV bank will be a great deal of fun all by themselves.

Stripboard Safety Valve, Big Mult:
Still need troubleshooting. I am likely going to get an LMNC mult just to make sure I have one that works properly.

2 routemasters, Big Button, Real Ring Modulator, Clock Capture Module, Mixers:
These will likely end up being ‘second case’ project. I have everything for a 3rd VCO, but I might get a 1222 VCO instead.

[zorch]

After unplugging all modules from the second PSU, the WAV trigger still really crushes my VCO’s. I am a little stumped. Maybe I need a beefier transformer?

Also, is anyone willing to walk me through some oscilloscope 101? I have a vague idea of how to use the one I have - and I can see the audio rate wave forms with no problem. But using it on a PSU is proving to be tricky.

I’ve figured out how to get a voltage reading out of it anyway - so that is something.

[Sonosus]

Someone please correct me if I’m wrong, I haven’t used oscilloscopes on PSUs either, but try setting it to AC coupling and change the vertical scaling(V/div) to the smallest setting. This should centre and amplify the voltage ripple. Play with the horizontal scaling (s/div) until you see the waveform.

[zorch]

I have been giving this a shot but I am having a difficult time finding the wave form for some reason.

My scope has no problems with audio levels - I can see my VCO wave forms just fine. Every time I try to get a reading from a PSU, its just a straight line. Maybe this particular scope is not the right tool for the job?