Modular Progress Overview 4

I haven't build much recently, but I am testing all the modules that I have connected to the power now. Here I was testing the syncing of the clock of all sequencers. They all run very smoothly :) I also made some sound effects already on this modular setup. It is really great to patch on it. Since I'm working on a lot of new releases for later this year I don't think I'll have much time to work on the modular this year anymore. So for now the project is on hold. I expect that I will be working on it again from January on. So keep an eye on the blog for the progress :)

Yusynth (Part 26)

Yesterday I visited my old employer Bird Electronics again. We made some more YuSynth PCB's long time ago already, but I still needed to drill 0.8 mm holes in them. So that is what I did using the drill you can see in the picture. It was about 4 hours of work. After that I cut the PCB's to the right size. Usually there is always some excessive material around it to be able to hold it better and you don't want to loose the print on the edges when etching. After this is also drilled some 3mm holes for fastening the PCB's later on on the mounting brackets.

After that my former colleague Marcel helped me to wash the PCB's. There is a small layer of etch resistant material still on the copper that wasn't hit by the UV light. The material has to be washed of with thinner. And after drying from the thinner Marcel sprayed on a protective layer that also helps the solder flow better. And then the batch was layed outside to dry in the sun. While waiting we had a nice lunch over there and talked a bit about a lot of stuff. It was good old times again :)

And here is the end result. There are some PCB's on there that I made before like VCA's and Envelope Generators (ADSR's), but most of the stuff is new. Mainly logic modules like frequency dividers for the sequencer clocks, but I also made the PCB for the CV standards module that Yves made. I already have the front panel and everything for that, but I forgot that PCB in the last run. Well for now I have more than enough, because I guess this won't even fit in my modular desk any more. I'm looking into howto make some modules in Eurorack format now, because that saves a lot of space and I still have plenty of room left in the right 19 inch modular desk extension.

Modular Power Distribution (Part 2)

This morning I did a lot of work on the power distribution in the modular desk. Here you can see the power distribution board in the left part of the desk. As you can see there are quite some cables already attached. And all of those were hand made. By now I used about 200 meters of wire already and I'm about half way I think. On the right you can just see once of the YuSynth VCA modules I build. This gives a clear picture I think how everything is mounted and connected. It is really great that things a finally taking shape.

On the other side of the cabinet I still need to do a lot of work. You can see this also on the picture on the right. But I cannot continue at this moment because I ran out of black wire. I did calculate that black would go twice as fast as the other colours because all ground wires are double on the connectors, but it seems that twisting the wires takes up a lot of meters as well and then there is always some waste of course and you cannot go in a straight line sometimes from the modules to the power distribution boards. So I'll have to get some more cable to be able to continue.

So after this I started to create some patches to test if all modules that I connected also worked properly. I have tested them all prior to mounting them in the cabinet, but sometimes a wire can come loose of course when you pull them through the cabinet. But so far it looks like everything works. Not everything has a led either by the way, so for some modules you can't even tell if they are on or off. It was fun doing some patching on this big modular. I'm already working for a long time on the project, but was never before able to do this. So I'm starting to get excited about the whole thing now and can't wait until I can use it usefully in a track. That might even be the case on my upcoming album already. I'll let you know when I do of course :)

Modular Power Distribution (Part 1)

Yesterday evening I started work on the power distribution in my modular desk. This is the inside of the modular extension. On the bottom you can see the three MOTM power supplies that I've build and on the top right is another power supply that I will use to power the Synthesizers.com modules that I bought. I calculated that the MOTM-950 doesn't have enough power to take on all my modules. Especially the Q960 sequencers take 240 mA together on the +15V and the MOTM-950 only has 400 mA on the +15. On the top left is a power distribution board that I will use to convert the MOTM format connectors to the synthesizers.com power connector for some modules that go in the extension.

From the power supplies I am going to do cabling to a terminal block inside the big module. From there I'll wire the power distribution boards. The only problem I ran into is that I'm out of cable. So today I'll get some new one so I can continue. I'm very happy by the way that I can make those MOTM style twisted cables myself now. It looks really neat actually. After this I started removing modules from the cabinet to make room. And I needed some good spots to mount the power distribution boards.

And here is how I mounted them On the vertical support struts that are in the main modular desk. The boards you see here on the bottom is the same as in the extension before. It holds 3 synthesizers.com connectors, but also some MOTM style bigger 6way connectors. Those are also on the MOTM-950 power supply. The next problem I ran into was that I was short of synthesizers.com power cables. I did have connectors but no suitable cables, so in the end I cut existing cables in half and made new connectors on them. The cables I got were too long any way. All synthesizers.com modules are now connected and hopefully I can power them up tomorrow. I also ordered new MOTM connectors since I'm going to have to produce a lot of MOTM power cables for the rest. I'll keep you posted on the progress :)

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.

Yusynth (Part 25)

I finished two more Yusynth VCO modules. I got the front panels from Schaeffer again, but this time I corrected the mistakes I did on the first one. So everything fitted a bit better now. I used the first VCO I build a while a go as an example. That saves a lot of time. I used the same colors on the wires and the same routes as well. I think I build these two in about the same time that I build the first one alone. I also installed a MOTM style power connector on some nicely twisted leads as you can see. I did this for the existing VCO as well and decided I'm going to do all Yusynth modules this way.

After that I hooked them up to the lab power supply to do some initial tests. All looked well. Then I started with the calibration process. I didn't tune them yet, but I did the wave shape adjusting. On the oscilloscope you can see the output from the Sine Wave jack. This was as good as I could get it. I wondered a bit about the triangle wave. Those were not quite the same on the two newly build modules. But I will have another go at them when I am going to tune them. It was not that drastic by the way, but just some minor difference. Could be component tolerances I think.

I made one stupid mistake by the way. When I finished the first one of these two I put some cooling pasta on top of the tempco that is on the PCB and then I decided to put the cooling paste on the other one as well before I had wired it. Well never do that ;) You will hit the stuff with your wires or your hands and it is sticky. Another lesson learned today. Here you see a nice picture of the three Yusynth VCO next to each other. I still have one PCB left so maybe I will finish that one as well. I will have to order a front panel for that one then though. I'll let you know when I do.

Yusynth (Part 24)

I got my packege from Mouser last week including the 1M log potmeters I ordered. So today I finished the two Yusynth modules that I needed those for. They are envelope generator modules actually of the ADSR type (Attack, Decay, Sustain and Release). They most common type actually I think. I designed the front panels for these ones myself again and they were produced by Schaeffer. Like always just let me know if you want the .fpd files for Front Panel Express. I used a two pot bracket from Bridechamber.

Today my youngest daughter helped me assembling these modules. She is actually quite good with the small work. She cut some of the wires, put most of the tie-wraps on and she screwed on all the bolts and nuts. Not the easiest job actually. She is only 6 years old and she was clearly enjoying spending the afternoon with dad this way. It look like she is much more patient than my oldest daughter actually. She is easily distracted and then just walks away after a while. I tried to explain to the youngest one though what this module did, but she didn't really understand.

Then I hooked one of the Envelope Generators to a VCO so she could hear what happens with the pitch. As you can see in the picture on the left there is a red push button on the module the will manually trigger the envelope. Then I explained what all the knobs do and after that she got it I think. Well these modules are actually quite easy to build and work very efficient. No calibration whatsoever is needed. Just build them and they do what they are supposed to do. There are two outputs on the module by the way. A normal (positive) output and also an inverted (negative) output. And that makes it also quite versatile. I'm actually thinking in building two more of these since ADSR's come in handy everywhere. But I don't have any more PCB's, so I'll have to make those first.

Yusynth (Part 23)

A very small Yusynth update. This morning I completed another 1U Yusynth AD/DC mixer module. Since I already did a post on this one I didn't think I would show how it is build again. One thing that is different though on this one is that I was out of 50K potmeters and I had a lot of 25K potmeters left. So I sent Yves an E-mail to ask if that was OK. And he responded that this would work fine. So I build it using these potmeters and it works great. In the picture you can see the 3 Yusynth mixer modules I build so far. The right on is the 2U version. I still have one PCB left to build another 2U version and I think I will do that since they will come in handy for sure. I just need to order another front panel for that one then.

Yusynth (Part 22)

This evening I started calibrating and tuning the Yusynth VCO I build today. The calibration part consists of two parts. First you have to center the Saw wave around the zero Volts with a 25 Turn trim potmeter and prevent it from clipping either on the positive or negative part. You can only do this with an oscilloscope. Then you have to fine tune the shape of the Sine wave and Triangle wave with another trim potmeter. Again you can only do this with an oscilloscope. You can see what it looks like in the picture. This part is quite easy actually and I have done it before with LFO's.

The tuning part is a lot more complicated. First you need a trusted CV source. You could use a tested and tuned midi to CV interface for example, but I decided to use the CV keyboard from my Roland System 100m set. The only problem with that one is that there is a tune button on that as well. So I used a Volt meter first to make sure that its output was exactly 1V/Oct and I was quite confident that it was. Then I attached a frequency counter to meeasure the exact frequencies on the output. The calibration proces is very well explained on Yves website by the way.

Here you can see my test setup. On top in the middle is the Volt meter. You can see it reads 4.00 Volts and the frequency counter measures 440.1857 Hz. Then you drop an octave and the Volt meter should read 3.00 Volts then and the frequency should be half so 220 Hz. While doing this you change the V/Oct trim potmeter until it is correct. Then you repeat this over and over again until it is in tune over an octave or 5. That should be fine I guess. I also send the output to a pair of speakers so that I could tune a bit on hearing as well.

Here is another shot with 2.001 Volts on the CV input (close enough for me) and 109.9316 Hz in stead of 110. Well I've seen a lot of number like this. After about an hour or two fiddling around like this I was finally satisfied. Actually I don't even know if my frequency counter is that good. But it sounded quite OK :) I run it through some sound effects and played some melodies on the VCO. Well I'm quite happy with that sound and also how it tracks. So Yves did a very good job with this design. And I already decided that I'm going to build some more of his VCO's :) I can recommend it. You will have a very good oscillator for a very low price. And it doesn't get more analog :)

Yusynth (Part 21)

Today I finished another Yusynth module. This time it is a Voltage Controlled Oscillator or also called VCO. This VCO is quite versatile it has a Saw, Triangle, Sine and Pulse output. The Pulse output has Pulse Width Modulation and there is also a Sync input. Further more it has two V/Oct inputs to play melodies on it and it also has two Frequency Modulation inputs. One is Linear and the other is Exponential. Yves offers three versions of this VCO on his website. I build mine using SSM2210 Dual Matched NPN transistors.

In the picture on the right you see the finished module from the back. There are quite some wires on it, but as usual Yves has a very clear wiring schematic on his website. The only tricky thing on this PCB is that you have to put a tempco resistor on top of the SSM2210 (or whatever you chose). You can see it in the right top corner of the picture (if you click on it you get a larger version). I use special heat conducting pasta to make sure that the temperature is transferred as good as possible from the SSM2210 to the tempco.

After that I tested the module. As always first the magic smoke test. And after that I looked at the different output signals coming from the module. They all seemed to work. After that I tested all the inputs by putting a signal on them from the PC Function Generator. Everything seemed to work as expected. Next thing left to do is the calibration procedure for the wave shapers and after that the most important thing the tuning procedure to make sure it tracks 1V/Oct over a couple of octaves. I haven't done this before so that is new for me as well. I'll update you on the result.

Yusynth (Part 20)

I told you I had been busy today ;) I made two more modules actually. I also made a 1U version of the Yusynth AD/DC mixer. You can see it in the picture from the back. I will show the front later. I also build another Yusynth VCA. Since I already reported about that one in a previous post, I don't think it adds much value to show it again. I kind of made a copy of it so you can also look in the previous post ;) I used a Yusynt LFO module to test it. I reported about the spike in the signal that I saw. Unfortunately when used on this VCA module it is audible. Apparently the VCA is very very quick.

And here is the mixer module from the front. As you can see this 1U version has only 3 inputs and no Gain and DC Bias pots. The PCB is actually the same only with some components left of. So when you make this PCB you can choose whether to make the 1U or 2U version that I showed in the previous post. Again there is no calibrating to be done. I only tested it with two AC signals this time from the PC function generator and another from a synthesizer. It all worked fine. I also designed this front panel As you can see I put the led in another place to balance the design out a bit.

I mounted the two VCA's in the cabinet. Starts to look great in the mean time :) On the right on the two VCA's you can see the multiple panel that I build. On the left are two ADSR front panels for modules that I didn't build yet. I actually ordered the wrong potmeters for them. They should have been 1M logarithmic but I ordered linear by mistake. In the next round I'll order the right ones and the linear ones will be necessary somewere soon for sure. I also still have to build some Yusynth VCO's. I already build a couple of PCB's and I have 1 front panel. I'm very curious how it sounds, so I guess I should start with it soon. But I also have a lot of other stuff laying around. A while you have to make choices in your life right? :)

Yusynth (Part 19)

Today I was quite productive again. It is very cold outside here and snowing, so nice weather for DIY stuff :) I finished a Yusynth mixer module today. Yves made two versions actually. A 2U version and a 1U version. This is the 2U version. It can mix DC and/or AC signals. It has 4 inputs with level control, a general gain for the two outputs. One of the outputs is inverted by the way. And you also have a pot for DC bias. I think it is a very versatile module. It is quite straight forward again. Here you see the PCB with the wires attached and the front panel from the back.

And here is a picture with all the wires connected. I'm think it looks neat doesn't it? Well I used a 2 pot bracket from Bridechamber again for mounting the PCB. These things are so handy. After this I applied power and did the usual routine checks. All looked good and then I attached some input signals to it. One from the PC Function generator and another from a synthesizers. And it mixed alright. Nothing to calibrate at all on this module actually. It just works :) Then I played a bit with some DC signals and they added up as well. Nice for mixing CV signals I think.

And here is a picture of the finished module. The led in the middle lights up with the output signal. It is a nice kind of volume indicator. I designed the front panel on this module myself and it was made by Schaeffer like all the other front panels I made myself. Again if you would like to have the .fpd file just send my an E-mail. I like this module. I think I might actually make another one. I still have another PCB left, so it is not too much work. Only my modular setup is filling up quickly. So I have to look if I will have space left for it. I like the stuff that Yves makes a lot. It is all very clear and you can't really go wrong. I can highly recommend his stuff when you want to start with DIY youself. Just look at his website: http://www.yusynth.net/ and click on the left on 'Modular Project'

Yusynth (Part 18)

Today I finished another Yusynth module. This time a Steiner VCF module. It is quite a versatile filter module that you can switch between High Pass, Low Pass, Band Pass and All Pass using a rotary switch. So actually you get three filters, because the all pass is kind of the same as your input signal :) Besides that it has two CV inputs with a potmeter to regulate the amount and also a potmeter for the input signal. I was wondering if this was the first module Yves designed by the way since it looks just that little bit different than the other modules that I build so far.

So here is the module all wired up. It is all quite straight forward. Yves provides a really neat wiring scheme on his website that makes wiring so easy. He even included the correct marking for the rotary switch so you don't even have to think :) Well after wiring it was time for testing. I applied power to the unit from my lab power supply and for the first time my current restriction kicked it. Lucky that I have it otherwise that would have meant magic smoke I guess ;) I did a quick visual check and found out quite quickly that I mounted the IC socket for the TL072 the wrong way around :( Luckily it was on a socket so I could turn it quite easily. But what a stupid mistake this time :(

Well nothing was damaged luckily. After applying power again everything looked OK and I started testing. I put a noise signal on the input from the PC Function Generator. I tested all three filter modes and that all worked like expected. There is only on 1 turn potmeter on the PCB for 1V/Oct tuning, but when I wanted to fiddle around with that I noticed something strange. When I up the resonance to get auto oscillation it didn't work at first. But only when I also fiddle with the cuttoff pot as well. I tried it several times and the same result. Maybe Yves can shed some light on this? His other modules start auto oscillating by only putting the resonance to 95% or so. And usually there is a trimpot to calibrate this. Ah well no big deal at all. Then I put a square wave at the input and actually got some very neat results. It is not a very clean filter, but that makes it exciting I think :) So I hope I didn't make any mistakes except for the wrongly mounted IC socket. It pretty much works like I expected besides the auto oscillation thing.

Yusynth (Part 17)

And this morning I finished another YuSynth module. It is a YuSynth Saw Animator module. As you can see this is a factory produced PCB. I this as a complete kit from Bridechamber including the components. While inspecting the components I found there were 2 resistors missing and there were 1 uF elcos supplied in stead of the polyester capacitors that should be there, but I could easily get them from Farnell. I didn't really bother to contact Bridechamber about it. One nice thing about this PCB is that the component values are on the silkscreen of the PCB. So documentation is close at hand :)

Wiring PCB is becoming standard production work here in my studio the last days :) So I got this one wired very quickly again. Actually this module is a dual module. There are two Saw Animators on the PCB. So you have wiring for module 1 and module 2 being an exact copy. There are also two LFO's standard on the PCB. The LFO's output is normalized to the Mod Input and is disrupted when you insert an external jack. Saw Input 1 is also normalized to Saw Input 2. So if you input a saw on input 1 it is replicated to input 2 automatically.

And here is the completed module. Calibrating is easy. You apply a 10V Peak Peak saw signal and then adjust one trim potmeter to get the output saw aligned and using another trim potmeter you balance the DC offset to get it nicely around the zero. Then you do the same for the output of the other part of the module. If you input other signals than a saw you get some neat output results as well by the way. Also when you don't input a full 10V peak peak signal the output is different. Quite funny what you can do with this fairly simple module.

And here is the finished module from the front. The leds you can see indicate the speed of the internal LFO. As said before you can override those with an external signal. But what does it do then? Well you can 'animate' or 'modulate' a boring saw into an alive one. It thickens up the sound. I heard my PC oscilloscope is back by the way. Maybe I'll grab some signal pictures with it later on so you can see what it does. I hope Gerrit comes back soon with the modified piece for my cabinet so I can finally screw some modules into place and start working with them. For now I'm going to look what is next on my backlog pile :) I'm sure I don't have to be bored the coming days. As always I'll keep you updated on the progress.

Yusynth (Part 16)

Today I finished two YuSynth LFO modules. Again I made everything myself on these modules including etching the PCB's and the front panel designs. I also had these front panels made by Schaeffer. And I used a bridechamber 2 pot bracket as you can see in the picture on the left. I had some more holes to drill on these brackets since the PCB has 6 fastening points in stead of the usual 4. I guess because it is a long PCB and you don't want it to short circuit on the pot bracket when it should bend. I keep having trouble to drill these holes exactly on the right spot. Just clumsiness I guess ;)

And here is a picture of the wiring I did. As you can see there are quite some wires on this PCB. 6 of them already go to the rate selection switch. Which is kind of a cool features because it increases the frequency span a lot. Of course I had the wires correctly the first time on the switch, but doubted that later on and after switching them I found that they had to go back again ;) Ah well this way you learn to test better. The reason I started to fiddled with the wires was actually because it didn't function when I was calibrating the first one.

The first thing I did after that was comparing the PCB's of both LFO modules. And after about 10 minutes of studying and measuring a bit, I found that I had two resistors wrong. On one PCB were two 2k7 resistors and on the other two 8K2 and there were supposed to be one 2K7 and one 8K2 on both of them. I had to remove the PCB's again from the pot brackets to desolder these resistors. Since this is a single layer PCB that is doable with just a desolder pump. I maned to do so even with saving the resistors and just switching from one PCB to the other.

And here are the two finished LFO modules. As you can see in the picture they have another neat feature called Sync. This makes it possible to synchronize two modules to each other of to for example to a sequencer clock or any other signal. Further it has an FM input making it possible to do frequency modulation on an external CV signal. I tested all the features and it works like expected. The only thing I see is a little dip just on the crossing point of the uppper and lower part of the Triangle and Sine wave. I'm not sure if this is normal, but I can't get it away using the trimmers anyway. Actually I don't think it is a big problem either. Well all in all a productive day and two new modules :) More to come soon. I'm on a roll now :) I'll let you know soon.

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 2

I'm working very hard now on finishing some modules for my big modular. So I thought it was a nice moment to post another overview of the current status. I know some of you are following this blog for my DIY stuff and some of you have no idea what it is all about :) So from time to time I will show what it is becoming. In the picture on the left are the modules that I have finished or nearly finished. I'm working at the moment on the YuSynth LFO's and Saw Animator. So you can expect a post on those soon. If you click on the picture and zoom in you can see what it all is. Every module has a text label.

And here is the big overview picture of the hole modular desk. As you can see there is still a lot of empty space, but that will become all filled some time to form one big modular synthesizer. Most stuff will be self build, but there will also be some pre-build modules in there soon like the Synthesizers.com modules I bought recently. On the top left you see the ASM-2 that I'm also still building and in the middle on top is the Elektor Formant that I still need to restore as well. I tried to repair the old power supply that came with it, but it is so damaged that I decided to go for a new power supply for it actually.

And there is lot to some soon. I have been working on a lot of modules the last year that all are missing parts. 95% of the components on the PCB's is very ordinary and cheap stuff that I can find in my local electronics shop, but some parts are very difficult to track down and sometimes quite expensive. So I have a huge backlog of stuff I need to finish right now. I will do a post about that as well later on so you have an idea. I'm still enjoying especially the DIY stuff a lot, but the whole modular is still not in any state to produce music with it. So I'm really eager to create some sounds with it soon, that is why I'm working very hard now to finish enough stuff to be able to hook it all up soon :)

Yusynth (Part 15)

I finished another module today. I had this PCB lying around for a long time. It is a Yusynth VCA module. There is one tricky thing you need to do while building this module and that is to match two BC547C transistors. It is only possible to do this when you have a multimeter that is capable of measuring the HFE (amplification) factor of a transistor. The reason this is necessary is that they will work in pairs.

Building this module even though it is not that complicated was special for me, because it is the first module that both has a PCB that I made myself and a front panel that I designed myself. Again I used a 2 potmeter bracket from Bridechamber. After this it was time to start wiring again. I started as usual with the wiring to connect the front panel components. After that the wires on the PCB. Because there is no silk screen on the PCB, I made sure to use different colored wires to be able to tell what is what later on.

Then it was time to test and calibrate. Yves has a nice calibration procedure on this website, but I misread it. I spend over an hour trying to calibrate it, but it didn't work like I expected. The first thing to do is put the front panel potmeters for the audio and CV input to maximum, but I also put the Gain potmeter to maximum while it should have been on the minimum position. After I found that out calibration was a piece of cake actually :) It is a nice VCA, quite quick actually. I even used the LFO to do audio rate stuff with it.

Here is the finished module in my modular desk. As you can see I still haven't fastened any of them. I have been looking for nice black screws for a long time. I think I found them now. Actually guitar screws for mounting pickups to a guitar body. They have a big head and are not too long. I found them on E-bay somewhere in the UK from a guitar shop. Another thing I'm still thinking about is how I should layout all the modules so that it is kind of logical. Because I'm screwing them directly into the wood of the cabinet I don't want to move them too much since I'm sure that the wood will get damaged and after a couple of times it won't hold anymore. Well next up are the two Yusynth LFO modules you also see in the picture. I'll update you soon.