Yusynth (Part 14)

Today I visited my old employer Bird Electronics again today to make some more Yusynth PCBs. In the picture you see my former colleague Marcel who did the nasty chemical bits. He put on his special clothes for this, because when you spill the etch material on your clothes the holes will eventually fall in. We made a lot of PCBs together. He helped me with my stuff, but we also created some PCB's for one of their customers. It was great fun to be there again and catch stories up a bit. I think the last time I was there was about a year ago.

My job today was to operate the UV light. The PCB layout is printed on transparent foil that is put on top of the PCB material. That in its turn has a photosensitive layer. So where there is ink on the PCB material the light gets blocked. Later on the unlighted parts will remain in copper while the rest will be etched away. Just leaving the copper lanes. He you see a case with left over PCB material. I can shop for my PCBs from there. All good stuff but only small pieces and big enough for the Yusynth PCBs.

And here are some finished PCBs drying. Next step is to drill the holes in them. I will return there on Monday to start working on that. I guess that will be a days work. I doubted recently by the way to try and make PCBs at home. You can buy all the needed kit online. But after today I'm happy that I didn't. First of all it is always a pleasure to visit Bird Electronics and secondly I wouldn't want these chemicals in my garage with the kids also walking in there and the cars being inside. So that idea is out of my head for good. I'll try to make some pictures on Monday as well.

Bridechamber Package Arrived!

Today finally my package arrived from Bridechamber!! Customs got me again and I had to pay import tax on it. Ah well. That's life :/ As you can see a lot of stuff was in the package. Especially some missing front panels and a lot of jacks! I also got a complete YuSynth Saw Animator kit so that one is complete for sure. I also got some multiple panels. I guess you can never have enough multiples on a modular synthesizer. And I also got a YuSynth CV standards panel with the necessary rotating switches. Well the coming period I don't have to get bored I'm sure :) I can finish up some stuff now :)

PC Function Generator (Part 3)

The PC function generator is all done now. Here you can see a picture of it in its enclosure. Looks nice doesn't it? You wouldn't know I build it myself if you see it like this. I'm very happy with it. All in all this kit only cost me 99 euro's and I think that is very cheap for a complete function generator with all the functionality that comes with this thing. I was almost starting to doubt if it could be something serious for this money, but I assure you it is. It is very complementary to my hardware function generator and now I'm able to chose.

I did some more testing on it. In the back you can see my other function generator that has a build in frequency counter. Or maybe it is more a frequency counter with a build in function generator ;) Well I set the output of the PC function generator at a 1Khz square. And here you see that the frequency counter measures 0.999999 Khz I think that is close enough ;) I did some more tests and funny enough it is every time this same result. Just under, but there is no way to calibrate this and I'm not sure even who is right :) Well it doesn't matter. It seems to do the job.

I found a spot for it under my keyboard. Later on I will place the PC oscilloscope next to it. I don't type much on that keyboard anyway so this way it doesn't take up to much space on my desk. I did some more test with the option to design your own waveforms. There is no graphical interface to do this by the way. You have to punch in values in a table, but here you see the result of a waveform I made. You can see it on the screen in the software and also the upper wave on the oscilloscope. Below that is the output of my other function generator. I used this setup to compare frequency output as well. And it seems that here everything looks good to. So I can close up this project as being succesful :)

MOTM 300 VCO's (Part 1)

I said before that I'm building a lot of PCB's at the moment. Among them are these three MOTM 300 VCO's. I thought since I'm building a MOTM compatible modular synthesizer there needed to be at least some MOTM modules in there. Of course I have build the two power supplies, but that doesn't really count right? They make no sound whatsoever. These VCO's are supposed to be very good. I read that they track over more octaves than a concert piano does. So they are very suitable for musical stuff. In the picture on the left you a start with the resistors on the PCB's.

Next to the PCB's I also ordered the special components kit from MOTM. It comes with some special transistor pairs and tempcos These parts are normally hard to find, so I advise you to get these as well if you are thinking of building the PCB's yourself. There are also some special resistor values on there that I have trouble finding myself. Like the 3M32 1% resistors. I have found them at Mouser, but that will cost me a lot of shipping costs. So I have them in my basket waiting until I need some more stuff from Mouser.

And here are the front panels that I also got in the same order. I still need to order jacks, potmeters, knobs and switches for them, but it is nice to have original MOTM panels. Maybe I'll get the front panel components also from Mouser to complete my order for free shipping. It will only take a lot longer that ordering from Farnell. They usually deliver the next day here. Well I'll keep you updated then I have more news on this project. For now my package from Bridechamber is finally at the post office so I can pick that up tomorrow to finish some other projects :)

The Perfect Apollo Studio Decoration

When I was young (in a galaxy far away) I used to build plastic model kits of cars, planes but also space stuff. My room was full with it. But when I got older I threw or gave them all away. One of the things I enjoyed the most was the big Saturn V rocket from the Apollo space program. And guess what? In celebration of the 40th anniversary of the moon landing Revell decided to reissue those kits. Yeah!! I ordered them all today and can't wait until they arrive. It will be fun to pick up another old hobby and this stuff will be the perfect decoration for my Apollo Studio :) This way I can also get into the mood for the Apollo project that I'm already working on. Hopefully this album will be done in the end of next year or so. I already have some music for it, but still a lot of work. Well I'll update you on the construction of the plastic models as well on this blog :)

AVRSynth 32 (Part 4)

Today I worked a bit more with my daughter on the AVRSynth 32. The next thing to do was to mount all the front panel components. As said before I had to drill the holes for the led holders a bit bigger. 8 mm turned out to be the right size. For the switches I puzzled a bit which ones to use. For the power I decided to go for a double switch so that I can switch both the power and the ground later on. The rest are single on of switches. The midi address selector switches are very close together so I had to leave the mounting ring of there. And because of that I decided to leave them of on the other ones as well.

Here you see a picture of the back of the front panel. I'm quite curious by the way about the material they used to make the front panel. It looks like PCB material but on the front it is black and white. If anyone has info on this stuff I'd like to hear more about it. The only thing I'm not sure about is the orientation of the switches. But I'll see about that when I start wiring and testing. The next thing to do on here is do the inter component wiring. But since my daughter already lost interest during the mounting of the components I wont do that now.

After this I did a little job on my own. Here you see how I'm applying pressure to get the header connector on the flat cable. I used a small bench vice for this since it is quite some pressure you need for this. I made a lot of cables in the past this way, but funny enough I couldn't remember anymore where pin 1 was supposed to go. So I looked up an good old IDE hard disk cable I made in the past to see how it was supposed to be mounted. Good that I save that kind of historic material ;) After this I also made two smaller 10 pin connectors on the left over flat cable.

And here is the end result of the cables and they are already in place on the PCB. The other end will be split up and going to the front panel components later on. I also found two left over components in the case. One resistor that I still have to mount on the bottom of the PCB. And a capacitor that should go on the X2 position (big crystal), but my kit came with a small crystal that is mounted in the X1 position. So now I'm not sure if I need to mount this capacitor or not. I'll have to find out somehow. Well I hope my daughter wants to work on it some more later on. I'd like to finish this project soon. I have enough other stuff laying around as well.

Synth.nl played on Elektroland #96 and #97

In the first two weeks of November music from my OceanoGraphy album was played on the Danish Elektroland Podcast by Bjorn Jeppessen. He has a very nice show with electronic music that is broadcasted on several radio stations in Denmark. His shows are archived online so you can still listen to them online. The reason I bring this to your attention is that he played my song 'Indico' twice. This track is not online on my website or my MySpace page so you probably haven't heard it yet if you don't have the album yet. I think it is a very nice relaxed piece and I think it is worth listening. It is one of my personal favorite tracks of the OceanoGraphy album. You can find Elektroland here: http://www.nattefrost.dk/elektroland

PC Function Generator (Part 2)

I finished the PC Function Generator PCB this afternoon. You can see the finished module in the picture on the left. I was a bit scared it had a serious problem, because when I attached the power supply nothing happened. Not even the power led came on. I quickly checked if any parts were getting hot, but nothing got even warm. So I started looking at the PCB again and found no problems there either. Then I started to measure on the PCB and didn't see power everywhere. I was very confused about this. Then I thought it was time to read the manual. (Who ever does that? ;) ) And it turned out that this module switches itself on when it is activated by the accompanying software :) After this I attached it to the parallel port of my PC and started the software.

And guess what? It switched itself on :) So that mystery was solved. Here you see a picture I took from my screen. The software looks very basic, but there are some nice hidden features in it. But first things first. The function generator needs to be calibrated. Actually that process is quite simple. There is only one trimpotmeter on the PCB that adjusts the DC offset of the output. For this calibration you only have to attach a simple multimeter put on DC Volt measurement mode and adjust the trimmer until it reads exactly 0,00 Volts. So that is what I did.

After that I attached it to my oscilloscope to see the results of my freshly build apparatus :) And look a very nice sine wave! So it actually works :) After this I played a bit around with the software. You can load some freaky sound waves from a library and even design your own. I think this is very cool. You can also program it to cycle through different waves. So lets say 10 seconds of a 10 Volt Peak-Peak Sine wave at 200 Hz and then 10 seconds of a 5 Volt Peak-Peak Triangle etc. And also the Bode plot that I told you about that make a frequency response graph. I will try to show you all this functionality later on. Maybe also in a video.

After this it was time to put it in its enclosure. Here you see what it looks like with the lid of. I'm very happy that this project actually worked the very first time. Gave me my confidence back ;) Now I have to find a spot for this function generator and do some more testing. I want to see how accurate it is and compare it with my other function generator. Another cool thing I forgot to mention by the way is that is has a loop through connector for the parallel port. So the oscilloscope I build can be connected to this unit and operate both at the same time on the same parallel port. Very convinient. I think I'll fiddle around with it a bit more this evening. Well all in all a very productive day today :)

Electronic Snare Drum Project (Part 2)

I have been working on the electronic snare drum project from time to time in between waiting for components. But I missed a vital part for this project to. I had some trouble finding a 566 VCO The switch makes it possible to switch off the envelope for the filter and make the noise sound constantly. Later on I added a little mod replacing a 1M resistor for a pot meter to be able to adjust the length of the noise sound. I think this is a useful mod.

Last week I finally received the missing 566 from a seller I found on E-bay and I was able to complete the whole pchip. It is used for the shell generator. The shell generator will be build on the left part of the bread board. In this picture on the right you can see the completed snare generator complete with envelope generator, VCA and filter.roject. You can see it in the picture on the right. I did kill a 2N3906 in the process by the way because I mismounted it :) Ah well. I have enough of those. I played around with the potmeters and this drum module is actually very versatile. Not only suitable to make a snare drum sound, but you could also make a kick or toms with it. I'm very happy that it all works now. Always very satisfying :)

After this I ran the module through my Mooger Froogers for some fun results. As promised I will try to make a little video of it later on. What I need to do now is build this whole thing on a PCB off course and design a front panel for it. Too bad that I actually have to tear it apart for this, but well. At least I know it works and I really learned a lot from this project. Another thing I still need to do as well is add a manual trigger button that can work on the other modules as well that I'm building. I would like it to work next to the gate input. More soon on this project :)

PC Function Generator (Part 1)

The last Velleman kit that I'm building for now is a Function Generator that can be controlled by the same software that came with the PC Oscilloscope. They can also work together. The Function Generator will do a frequency sweep and the oscilloscope draws a nice graph of the result. In this way you can test a filter for example and get a nice graph of the filter response. Even though I also have a hardware function generator this one is also capable of generating much more complex waveforms that are very suitable for error tracing and testing audio equipment.

The kit looks a lot like the PC Oscilloscope. It actually has the same enclosure, just with different front and back panels. I started inspecting if I had all the parts and it looked OK. The first thing I noticed is that this thing has a lot of power regulators and that all the resistors are of the 1% type. Further more nothing special. The PCB layout is quite neat, but when I started soldering I found out soon that the ground isles are very big. I needed to heat the parts that are connected to ground way longer than I'm used to before the solder started to flow.

I started building this PCB today. Here is a picture where you can see the documentation in the back. It is very clear and again most components are on a roll in the right order. Even though I managed to solder R14 in the place of R41. They were actually next to each other. I took a lot of trouble to desolder the resistor and put the new one in place when I found out later that R41 had the same value. A lot of work for nothing. Well I learned one thing. Next time first check if it really needs to be taken out when I make a mistake.

And here is another picture with all the IC sockets in place. I decided to deviate from the instructions here and solder them before the capacitors. If you look closely at the picture you will see that there are two very odd size IC sockets on there. I never saw those before. But they will hold two IC's as well that I never saw before. Well so far it is all very straight forward and I hope it will work. I'll try to finish it as soon as possible because I can't wait to get it finished. Somehow after the problem with the oscilloscope I lost confidence a bit and I'd like to prove it wasn't me I guess ;)

VU Meter (Part 2)

I showed you the front panel before that I made for the Velleman VU meter kit that I build. Well here you see the front panel with the led holders and leds in place. Looks nice doesn't it? Can't wait to see it working. I did make a very little mistake. You can see that the space between the lower two leds and the rest is a bit larger. Probably I skipped 1 click on the grid. Well I don't really care it is not worth producing a whole new front panel only for this. I'm still missing jacks they are also in the Bridechamber package that is still in customs.

Here is a picture of the back of the front panel. I'm still figuring out how to attach the PCB to the front panel. The normal Bridechamber pot brackets won't work here. I think I'll see if I can find some thin aluminum or steel sheets so that I can make my own brackets. Then I won't have to wait on them any more as well. I'll let you know when I figure it out. If anyone has any idea's I'm open for them. I could not get the AD converter for the Oscilloscope by the way. So I decided to send it to Velleman and let them figure it out. I can only wait and see what they come up with.

OceanoGraphy Fan Movie

And here is another fan movie made by Mike from Cosmic Frequencies:

Two More Front Panels

Today two more front panels arrived from Schaeffer. I designed them both myself. Left is the panel for a stereo mixer I'm building based on the MFOS stereo mixer PCB. On the right is the front panel for the VU meter project. I showed you the design before and here is what it looks like. I was a bit anxious that the holes for the led holders were to close, but I just tried it and it fits perfectly :) I saw on the tracking system that my Bridechamber package is now in customs, so hopefully I will be able to start finishing some modules again soon. I need potbrackets especially and they are in that package. In the mean time I'm building a lot of PCB's. I'll update you soon again.

Headphones Repaired

When I'm in the living room I often work with my headphones on, listening to some music. I have a pair of closed headphones for that so that my surrounding isn't bothered by me and vice versa. Usually I prefer open headphones btw, but anyway there was a lose wire in the somewhere because sometimes on one ear I lost sound and when I fiddled with the cable it worked again. So I decided to take it apart. One of the wires was loose on the plug, but the wires were to short to solder them back. So I extended them for about a centimeter, put it back together and it works perfectly again :)

Digital PC Scope (Part 2)

After I completed the PCB and build it in the case, I started the calibrating process. I had a little trouble and didn't really understand why. I fiddled a bit more with the trim potmeters and finally calibration succeeded. But it didn't go as planned actually. Then I hook it up to my function generator and saw that it actually did some very strange stuff. I used my other oscilloscope to find out what was wrong, but I could only find correct signals on the PCB. I'll try to explain to you what I saw by showing you three pictures from the software. The input is a pure sine wave:

As long as I stay below the 0 Volt line everything looks OK.

When I try to center the image by shifting its Y position a bit up this is what happens:



You can see that part of the positive signal is actually shown as negative values. Very strange. I measured the whole analog circuit and up to the A/D converter it all looked good. I looked on the support desk of Velleman and found a post with the same problem. There it turned out the AD converter chip was broken. Well I couldn't find the same chip easily so I decided to contact Velleman about it. I'll keep you posted on the progress. I don't think I can solve this problem myself since I don't have spare parts and I have no idea what happens in the digital domain.

WWF Tweet about OceanoGraphy

Recently I handed my OceanoGraphy CD to the Dutch brand of the WWF (WNF -> Wereld Natuur Fonds). It seems that they listened to it by now and liked it a lot :) I'm very proud to see that they did some communication about it to their contacts over Linked In and also over Twitter. I hope this cooperation will grow to be something very nice. I would love to hear my music in some nature documentary in the future. Well we'll see :)

Pacifico Fan Video

Hi, my #1 USA fan Mike from Cosmic Frequencies made this very nice video for me. Enjoy :)

Digital PC Scope (Part 1)

This is the other Velleman kit that I found, that I was very enthousiastic about. It is an digital oscilloscope that you can build yourself. It connects to a PC through a printer port and comes complete with software. It has the option to record signals and also has a spectrum analyzer build in. And of course the great thing is that you can save images from the screen. That would be great to post on this blog from time to time. I was very curious so I started building it right away when I got home with it.

Here is the content of the box again in the picture on the right. In front you see the PCB and the software on CD. And behind that a neat looking plastic case with aluminum front and back panels. Like the VU meter kit most components are on a roll again in the correct order. But this kit is a lot more advanced for sure than the VU meter kit. I would not recommend this for an absolute beginner. The good news though is that they also sell these completely assembled. So you can just but them when you are looking for a cheap oscilloscope.

After a few hours of work this was the result. The PCB is finished already. You can see the BNC connector on the front. This is the input of the oscilloscope on the right is a test point that is needed for the calibration process. I need to get a 9 Volt power adapter for it. That was obviously not included. Next thing was to build it into the casing. There was a little tricky thing there because another power regulator needed to be attached to the back panel and then soldered from the top of the PCB. I managed, but it was not very easy to reach.

Here you see the PCB in the case. There is a piece of foil included that needs to be wrapped under and over the PCB to get rid of outside interference. I think they could have done a bit better on this, but well when it works it's fine by me. It is inside the case anyway so you won't see it. OK next thing is hooking the power up and see if the unit wants to communicate with the PC. But not today :) I had enough for one day. I'll let you know the results very soon. Good night to you all.

More Front Panels Arrived

After my initial test with the YuSynth VCO front panel that I ordered through Schaeffer, I decided to make some more panels for projects that I'm building. In the picture you can see this VCO panel with the potmeters already in place together with a front panel for a Buchla clone of a resonant low pass gate that I'm also building. I'm still waiting for jacks and mounting brackets from Bridechamber thought, but Scott has confirmed me now that they have been shipped. So hopefully I can finish them soon.

And today this stack arrived. On the bottom is a front panel that I designed for the Hip Bass Drum project that I did. And on top of that two YuSynth LFO front panels and two YuSynth ADSR panels. They all look great. I'm so happy that I can do this on my own now. The only thing I still can't do on my own is creating PCB's. Soon I'll go to my old employer Bird Electronics again to etch some PCB's. But I'd like to be able to do this on my own as well. So I'm looking into what I would need for that as well now. But first I'm going to do another nice batch of YuSynth PCB's next week at Bird Electronics. I'll try to take some pictures again in the process.

VU Meter (Part 1)

Last week I visited my local electronics shop again to pick up some parts and found out that they also sell a lot of nice electronics DIY kits from Velleman. I never though much of those, but when I browsed through them recently I did find some interesting stuff. To start with I found a stereo 15 led VU meter kit. I though what would be neat to integrate into a mixer module I'm building, so I decided to check it out. As you can see it comes in a neat box so it looks promising. So time to unpack.

And here is the content of the package. It is all very well documented and even suited for beginners I think. What is especially neat is that all the PCB components are on a roll strapped together in the right building order. So you can't even go wrong picking a wrong component value as long as you stick to the documentation. It also came with a plastic kind of front panel that I didn't think was very suitable to fit my modular. But more about that later on.

And construction was very easy, but then I hooked it up to my electronic snare drum project and saw that only the left side was working. After close inspection I found that while bending one of the Elcos I damaged a PCB trace. So I repaired that with some wires on the bottom of the PCB. And then it worked like a charm. It is nice to have some kind of level indication in a modular setup I think. The only problem with this kit is that there are two potmeters on the PCB to calibrate it and they are 1 turn. So it is very touchy. I think 25 turn would have been better there.

I was thinking about integrating this VU meter into a mixer that I'm building, but I found out quickly that 15 leds in a led holder takes more space than I thought. So I decided to design a separate front panel for it. You can see that in the picture on the right. I just hope I left enough room between the led holders. Well we'll see :) I gave it also outputs so that I can easily chain it somewhere in between an audio signal path. I'll let you know how it turns out eventually. If you are interested in any of the front panel designs I'm doing by the way just let me know and I'll send you the FPD files. This was a nice in between project while I'm still waiting for parts to arrive to finish up some other projects. I already picked up another Velleman kit as well that I will tell you about very soon. If you are interested in them just look at http://www.velleman.eu