Modular Progress Overview 3

I promised to make a new overview picture of the modular that I'm building. As you can see the center cabinet is almost filled up, but not everything in there is ready yet. Only the modules with all knobs on are done and tested. On the left extension there is still space for some MOTM style modules. I will build some more drum modules that will go in there. And on the right there is more room for 19 inch stuff. I'm still waiting for a power supply from MOTM and some power distribution boards. So not everything is powered yet. But when that stuff arrives that will be the first job I'm going to do. But for now I'm still working on finishing up a lot of modules that are halfway done or so. I think I'm also halfway the whole project now. So this picture is a nice landmark I guess for that :) You can click the picture by the way for a bigger version.

Oakley Multimix Module

Today I finished another Oakley module. This time it is a Multimix module. A versatile audio mixer module that you can build in different variants. I opted for the Stooge version since that fits the front panel that I got from Bridechamber. As you can see here from the back the wiring is quite easy. This one came with an extra PCB for the jack connectors and so you only have to make the interconnections between these two PCB. The options you can choose are done my jumpers you can solder on the PCB. Maybe you can see them when you click on the picture.

I found out by now that you can never have enough mixer modules. There are a lot of signals in a big modular setup like I'm building and somehow and somewhere they have to be mixed together. This mixer module is a bit different though than the ones I build from Yusynth. You can not only add the signals from the 3 inputs, but you can also subtract them. The zero position is actually in the middle of the potmeters. You can also tap the input signals without mix from the modules outputs again. Input 1 goes to Output 1, Input 2 to Output 3 and only Output 3 contains the mixed signal from all the inputs. If you look closely at the picture you can just see the power distribution board as well behind the module. I still need to wire the whole power system in the cabinet, but for now I have one of these boards in there.

Oakley Ring Modulator Module

I finished another Oakley module last week. This time it is a Ring Modulator module. It basicly multiplies two audio or CV signals with each other. It has an X and Y input both in AC (for audio) and DC (for CV signals) versions. And then it has one output where the multiplied signal comes out. As you can see in the picture there is not much wiring to be done. I made another MOTM style power cable for it. I'm getting better at creating those every time, so I plan to make much more of them. After the initial power test it was time to test it more and calibrate it.

And here is a picture of the finished module from the front. You can see it has 3 pot meters. The first two control the X and Y input level and the second one controls the Y inputs DC off set. On the PCB there are three trim pot meters. Calibration is quite easy. It is a matter of adjusting some offsets and finally there is a gain trimmer that makes sure the output level matches the input level. After this I played around a bit with it and it is good fun. You can make some freaky sounds with a ring modulator for quite common input signals.

Oakley Overdrive Module

Today I finished another Oakley module. This time it is an Overdrive module. Well actually you can switch between an Overdrive effect and a Distortion effect. I think these are the oldest effects around used to give electric guitars some extra punch and overtones. There are lots of guitar pedals around you could use for this as well, but Oakley made a nice 1U MOTM format module for it with two effects in one and of course it is more suitable for synthesizers. In the picture you can see that the wiring of this module is actually very simple. Just two jacks and one double pole switch to wire.

Well actually the whole module is quite easy and straight forward to build. There is no calibration to be done either. So after soldering the wires I hooked it up to the lab power supply to test it. I put a triangle wave on the input from the PC function generator. And if you look closely on the oscilloscope you can see an example what you can make from that. I haven't attached it yet to a sound source, but I believe what I see on the oscilloscope ;) I tested all functionality and decided it was done.

Then I put the knobs on and mounted it in my cabinet. As you can see there are three pot meters on the module. The top on is gain and that is on the input side, so with that pot meter you can determine how much signal is going in to the effect. In the middle is the timbre control that makes it possible to change the color (and so the shape) of the output signal and below is a dry/wet mix control. Which make is possible to regulate if you only want the input signal or add a little effect to it or by turning it all the way up you have the fully distorted signal. Then the switch to select on of the two effect modes and the input and output jack. All very straight forward, but a nice effect to have in the modular setup I think. Well that is all I can really say about it :)

Oakley VCO Module

Yesterday I finished another Oakley module. Here is the PCB that I had done already. Right in the middle you can see the SSM2210P Matched Transistor pair with the big Tempco resistor mounted on top of it. I used some heat sink pasta again to make the contact between the two more optimal. Further more you can see that this PCB has 7 trimmers in total. 3 multiturn for tuning purpouses and 4 single turn trimmers for waveshaping the Triangle and Sine wave. It is a nice versatile VCO and it is supposed to track over a large octave span.

And here is the finished module from the back. As you can see it also has extra PCB's like the Discontinuity to hold the jacks and extra potmeters. As before I hard wired the connection between these PCB in stead of using connectors. You can build them really quick this way since you don't really have to think what goes where. Just wire pin 1 to pin 1 and so on. And it also looks very neat because of the short wires that you can easily bundle with some tie-wraps. OK so far for the building. Now it is time for some testing and tuning.

For testing and tuning I hooked it up to the Oakley MidiDAC midi2CV converter I build before. A good chance to see how this combination works. First thing I did was adjust the wave shapers to get a nice Sine and Triangle output. Then I started the tuning procedure. It was quite alike the YuSynth VCO module I tuned before. I did it quite roughly this time because I didn't have much time yesterday. But I got it tracking over 5 Octaves quite quickly. After that I tested the other modulation inputs with an LFO and everything seemed to work fine. I will be building some more YuSynth and also some MOTM VCO's soon. It would be fun to compare them to each other. I will do that when I have them done and post something about it on this blog. After testing I played some melodies on the VCO on a midi keyboard. I ran the output through a delay and it sounded quite nice. Can't want to hook it up to a sequencer soon, but I still have lots of work to do before I can get to that. I'll keep you posted.

Oakley Discontinuity Module Graphs

I promised you to show a bit more about what the Oakley Discontinuity can do. To begin with here is a picture with the finished module in my cabinet. If you click on the picture you can read the text with the controls. The controls I used in the examples below are: Treshold, Fold, Discontinuity and Offset. I only use the normal output (so not the Clamp or Clip) and I put a Triangle wave from the PC function generator on the input. I'm not going to describe what all the individual control do. You can read the Oakley manual for that ;) But just some examples to let you see what it can do. I used my Velleman PC oscilloscope to capture the output signals btw. It has a nice 'save as' option for the image you have on your screen :)

So here is the signal that I put in:

And this is what came out:

I'm sure you can imagine that that will sound different :)

Oakley Discontinuity Module

Yesterday I finished another Oakley module. This time an module called 'Discontinuity'. Basically it is a Voltage Controlled Wave Folder. It changes the shape of the signal you put into it and it generally creates overtones. I will show you later with some examples. Almost all the parameters are also voltage controlled which makes it possible as well to keep a sound continuously moving. In the picture you can see the module from the back. As you can see there is a seperate PCB again for the potmeters and jacks. But on this picture the jacks are not installed yet.

And here is a picture of the finished module. Here you can also see the extra PCB with the jacks. I chose to hard wire all the connections between the PCB's. You could also use connectors so that you can take it apart easily, but I didn't see the added value in that. First of all I don't plan to take it apart. The PCB is even reachable from the back in case of a problem. Secondly I don't like putting these kind of connectors on wires. As you can see I wired the most right set of wires a bit too short. I couldn't even put a tie wrap around them anymore. But I decided to leave it this way, because it will work fine and desoldering will make more of a mess I guess.

And then it was time for some testing and calibrating. First the usual smoke test with no problems. Then I put a signal on this input from the PC Function Generator and tested if I heard something on the output. That worked fine. Then I tested the CV inputs and actually got three of them that didn't work. I started investigating by measuring on the PCB and found out quickly that I forgot to wire three wires :) Well keep reading that documentation sometimes ;) After I installed them I even found out that two of them were the wrong way around. And after I twisted that It all looked OK.

After that you really need an oscilloscope to do the calibrating. In the picture on the right you can see an example of what it looked like when I put a triangle on the input and twiddled around a bit. I will do another post later on with some more examples so you can see what it can do. I have a speaker on the output all the time and you can really hear the difference. Normally a triangle sounds very soft just like a sine wave. After putting it through this unit it really sharpens up the sound and you can make some interesting stuff from very basic waveforms. OK. As promised more later. But for now it seems to work fine :)

Oakley MidiDAC Midi2CV Module

I know that I'm posting updates on finished modules very rapidly after another now. But that doesn't mean I all build them so quick :) I have build a lot of PCB's the last two years and just now I have all components for some modules. So that is why I'm able to get them finished so quickly because now I finally have the potmeters or the front panels. Here you see the PCB of an Oakley MidiDAC midi to CV converter. It is supposed to be very good so I'm very curious how it will track later on. I should eventually hook my midi setup up to my modular through this unit.

Oakley thought very well of the layout of the PCB in correlation to the position of the front panel components. They can do so of course because the PCB is front panel mounted through the potmeter so you will actually know where they go :) But because of this the wires are all quite short which makes it look very tidy. I just couldn't use my regular led holders because one of the leds is exactly behind the PCB. I guess that is the downside of this construction for me. I used more simple black plastic led holders for this unit and decided to just solder wires to the leds in steads of bending the legs and soldering them on the PCB itself.

Then is was time to hook it up and to some testing. At first I didn't get any response but found out quickly that this was because the Midi channel was set wrongly. The DIP switch worked just the other way around as I expected. Then I hookup up a midi keyboard and started to test all the signal outputs. As you can see there is a lot of them and that is also what makes this Midi to CV converter great. Next thing was to check the switched and potmeters and that all worked fine. So then it was time for some calibration. Of course this module must tune and to 1V/Oct.

Calibrating isn't even that difficult on this module. You just put the tune potmeter in the middle. Then there is an initial trim potmeter. And then you measure the Voltage on the Pitch output. Select the lowest note possible and it should read 0 Volts. Then you go to the highest midi note possible and then turn the V/Oct trim potmeter until it read 10,58 Volts. And then it should track. And I verified that by hitting notes across different octaves and it tracks perfectly. I was expecting this to be much more work, but actually it tuned in about 5 minutes :) After that I played around a bit on the VCO I build recently. I was thinking to recalibrate that VCO soon using this MidiDAC since I think it tracks even better than the Roland CV keyboard that I used back then. If you are interested in this module visite the Oakley Website at: http://www.oakleysound.com/mididac.htm

Oakley Equinoxe Voltage Controlled Phaser

Tonight I finished my first Oakley module. It is a Voltage Controlled Phaser module called Equinoxe. And it is called after the Equinoxe album by Jean Michel Jarre, because it recreates exactly the phasing of the originally used EHX Small Stone I guess. It is a fairly simple unit to build and luckily I had some components in stock for it like the LM13700's that I got long time ago already. As you can see this module is not on a potbracket like my other modules. Oakley uses PCB mounted potmeters that come with special brackets to make them stronger. And you can use them to hold the PCB in place.

For this module I got the PCB, potmeter kit and pot bracket kit from Oakley and I got the front panel and knobs from Bridechamber. The rest of the components I could source through my regular electronic component suppliers. You can get the documentation for this module on the Oakley website by the way. After applying power to the module (usual smoke test) I started testing it. I think I did what everyone does with a phaser the first time. I put some noise in it and put everything to full and the modulation speed very low. Then you get a very neat wind sweep sound. And it did that perfectly so I guess I can say it works. I still need to see if some trimming is necessary. I didn't look at that yet to be honest. I was happy enough it worked.

And here is the finished module between some unfinished ones. As you can see it has a build in LFO. You can also apply an external CV signal for modulation, but for normal operation the internal LFO works fine. You can also use the output of the LFO to modulate an external module to have them run in sync. The other controls are Frequency, Emphasis and Modulation Depth. Next thing I should try I guess is run the Eminent 310 through it and see how it compares to the EHX Small Stone. But on the other-hand I have an original EHX Small Stone (even a Russian one) so why should i? :) Ah well just for the fun of it I guess. I have some more Oakley PCB's ready so I hope I can show them to you soon. I'm done for today :) Going to watch a movie now. Good night :)

Modular Backlog Update

I promised to make a blog posting as well about the stuff that I still have to finish. In the picture on the left you see a stack of PCB's. Some are fully populated some not. On the left are some MOTM boards that will be used inside the modular for power distribution. Next to that are some CGS PCB's and on the right are a lot of Yusynth PCB that I made myself. Some of them are also spare. I made a lot of those twice while I will only completely build one. Maybe I will sell the other PCB or maybe keep them for spare for the future. Below the stack of Yusynth PCB's is also some MFOS stuff.

And here is another stack of PCB's. The stuff you see here is mostly populated as well. Most of them are Oakley PCB's but on the left is also a Mega Percussive Synthesizer from Electro-music.com also designed by Thomas Henry. Below is the Snare drum project on the breadboard. I'm saving this to make some video before I put it on a experiment PCB. In the picture on top you see also a front panel laying in the bottom of the picture. That is the Front Panel I designed for my Hip Bass Drum module. That one is quite complete so I can finish that very soon I guess.

There here some stuff I have laying on the floor right now. These are mostly front panels I'm populating. You will recognise the Klee Sequencer panel that I posted about before on the left and behind that is the MFOS Stereo Mixer I'm building. You can also see the VU meter panel on the bottom and some more Yusynth stuff that will come soon. On the far top left are the synthesizers.com Q960 sequencers. Hopefully my furniture builder Gerrit will fix the modular desk on Wednesday so that I can start installing and testing them. I can't wait for that :)

And here the last picture. On the top left is a Bridechamber multiple panel where I already put the jacks in. Then on the bottom next to the roll of black wire is an Oakley MidiDAC that will funtion as a Midi to CV converter in my modular desk. And on the right are three MOTM 300 VCO front panels. All in all quite some stuff I still have to finish, but I nearly got all the parts. Now I'm missing some potmeters that I will get from Mouser soon and I already used up all the jacks so I ordered some more of them too. I thought I had enough. But apparently I didn't ;) Well now you have seen everything, so I hope you can see why I'm a bit busy at the moment :)

Modular Progress Overview

Since I'm working a lot now on my modular project and I only showed you some PCB's and loose panels I thought it would be nice to post a little overview of the modules I have finished now. In the bottom of the picture on the left you can see the Yusynth filter modules I build and the Wogglebug. On top are three modules I bought on E-bay. On the left is a MOTM-120 Sub Octave Multiplier that adds subharmonics, next to that a MFOS Quantizer and next to that the Oakley Noise and Dual filter module that I used to test my other filter modules.

In this picture you see the two MOTM 900 and 950 Power supplies that I build. And also the VC-LFO that I repaired earlier. It has an Oakley front panel, but is actually a MFOS. I do plan to build an Oakley one and swap panels somewhere in the future. On the right you see the Yusynth Random module I build with noise generator and sample and hold. I still haven't fastened any module in the cabinet yet, since I'm still not sure where everything should go. I need to make some kind of plan for that I guess.

And maybe you spotted this front panel in a previous post as well. Here you see it together with the PCB's that go with it. This will become a Klee sequencer from Electro-music.com. It looks really great in this circular setup. I got this front panel from Bridechamber and it was designed by Thomas White. I studied the documentation for this project last week and I ordered all the PCB components. Hopefully they will arrive on Monday and then I can start building this beast :) I can't wait to see it working. This project is the most complex module I build so far. But we all do need a challenge don't we :) I'll keep you posted on the progress as always of course.