Deckard's Dream DIY (Part 9)

The external 12V power supply brick has arrived. So I could finally finish the Deckard's Dream. First thing I did was again test all the voice boards individually. They all worked fine. I labeled them so that I know which board is which because they all have their individual tuning. Then I inserted them into the main board and attached them to each other with the spacers as you can see in the picture on the left. I was a bit surprised I had spacers in different lengths but it turns out that the distance between all the slots is not equal. I didn't expect that but luckily I had all the correct spacers in the parts kit. If I had ordered them myself I would have probably ordered all the same based on the first gap :)

And then an exiting moment. Testing the whole synthesizer. In this picture you see everything that is inside. Starting from left to right with the front panel, the hardware PCB sandwiched to the main PCB. The inserted in the Main PCB first the Power Supply board and the 8 voice boards. In the right bottom you see the output board and in the top right the external 12V 6A power supply brick. All tests went flawless and then I uploaded some patch banks I found online 4 banks in total, one of which hold some recreated Vangelis sounds. They sound so awesome :) I ended up playing a long time with them just with a little midi keyboard and my headphone on. Even without any effects. But I had to stop just there and do the last remaining bits. Everything still had to fit in the case. In the back of the case is a fan for cooling that should not be necessary but I installed it anyway. Luckily you can switch it on and off from the settings menu. So I'll start with it switched off and see if the Decard's Dream wont run hot in the studio.

Then you have to put the IO board in the back and attach the flat cable to it. The IO board is just attached to the case with the rings of the jack plugs for audio input and output. The fan is attached to the IO board with a connector. It is all vert well thought of in my opinion. So after putting it in the case again I tested it one more time and again I ended up playing on it for way too long. But last step left was to put it in the studio. I did leave room for it of course :)

And here it is in all it's glory. I think it looks great. In the studio I could finally put some reverb on it and use my Roli Seaboard to play with polyphonic aftertouch and wow! just wow! I was impressed before but when you start using polyphonic aftertouch on some of those Vangelis patches it really sounds so big and organic. I love it. I will surely use it on my upcoming album. There is one more thing to do. There is also an expander module from Black Corporation which makes the Deckard's Dream even better. It is a 1U unit that can fit right where the patch panel is now. It adds Ring Modulation, Chorus, Delay and Reverb and makes the unit stereo as well. I already ordered the kit from Black Corporation and also the parts kit and case. So that will be my next project in the near future and of course I will post the progress of that as well on this blog. OK that concludes this DIY series. I hope you enjoyed it. And if you want to build one yourself I'd be more than happy to share my experiences and answer your questions where I can. But do keep in mind this is an advanced project not very well suited for beginners.

Deckard's Dream DIY (Part 8)

 While waiting for the new external power supply I did something useful as well besides playing on the synth with 4 voices. I decided to put on the colored slider caps. Actually I wanted to wait to that it as a finishing touch when it was done, but I couldn't wait any more. I even read the manual since I didn't really understand what all sliders did, but it all makes sense to me now. Unfortunately the package with the power supply was delayed so more waiting .....

The next useful thing to do was put on the cooling blocks on the power supply. I was a bit surprised that everything so far was in the parts kit I bought from synthcube but not the m3 bolts for screwing these on. Luckily that is stuff I always have lying around at home. After that I started twisting the wires for the power supply. I did read that putting on these cooling blocks is not necessary when you change to TL062 and TL064 because the Deckard's Dream draws less current because of these and get less hot, but I decided that it wouldn't hurt either. More cooling is always better with electronics. I also took the rest of the case and started looking how everything should fit together. And then I found out the main board didn't fit in the case. Luckily there is a clear instruction about this on the build website. There is a 5 mm strips on both ends on the PCB that you can break of. There is a line cut into it to make that easier but I did it very carefully with some pliers trying not to damage anything on the main PCB.

Then finally the missing IC's I ordered arrived and I could finish all 8 voice boards. After that I started testing them by pairs. I run the calibration procedure for the voices and unfortunately one board did not wait to tune. So I put that one in solo and I could hear sound coming from it, but getting stuck on tuning. Later I found out that VCO B was running fine on the board and I did have a square and saw wave on VCO A but with a very low frequency. VCF and VCA seemed to work just fine. I started with a close visual inspection of the faulty board but couldn't find anything wrong. I started comparing it with another working board and all components were the same. Orientation of all components was the same. So I decided to swap components with a working board. Starting around VCO A. And bingo suddenly when I swapped the CEM3340 it worked! Luckily there as one extra in my parts kit, so I put the spare on on this board and voila. It worked like a charm. So now I have 8 working voice boards! Now only wait for the power supply to test them all at once.

Deckard's Dream DIY (Part 7)

In the previous part I already said the Decard's Dream was coming alive. I had a menu on the display. Here is a picture of the display and knobs. I already put on the volume knob as well. The display is small but very high resolution so it is readable, but I do need my glasses for that :) So first I scrolled through all the settings to see what is there. I did find some interesting settings that I will try out later. But for now I especially want to know if everything works. I could not find a good test procedure on the build site so I started googling to see what other people did. And apparently it is a good idea to start testing all the knobs and sliders.

There is a special option in the menu to calibrate the sliders first. There are a number of sliders with a dent in the middle position. They go both up and down. Pitch course and fine. Balance between oscillator one and two, overall brilliance and the keyboard control sliders. You have to set them in the middle position before you start calibrating. Then there is a special option in the menu called 'debug' with this you can test all the sliders and know one by one. It reads out the value from 0 to 255. But I did see some stepping while doing this. I was a bit surprised. But I will figure that out later. For now all sliders seemed to work.

Nest thing to do was connecting the IO board back to the main board. It is connected via a flat cable. Here is the main output (mono) and also the midi connectors and the usb connectors. I hooked it up with USB to my notebook and then you get midi over USB. Next thing up was testing all the voice boards. I inserted a voice board in the first slot next to the Power Supply boards because I assumed that was the first slot. Then hookup up a midi keyboard to my notebook and used Midi-OX to connect the keyboard to the Deckards Dream. I expected to get some audio even though I would assume it would be out of tune or something, but nothing happened :( Then I read on the forum that you need to calibrate the voice boards, so I went in the menu and selected that option. Nothing happened. Like it didn't see the voice board at all. So i tried another voice board and same problem. I started panicking a bit and posted on the forum. But I was impatient for as answer and they I saw I made a very stupid mistake :) The slot next to the Power Supply board is actually slot 8 and now 1 :/ Duhh..

So then I calibrated the first board and it worked :) I had sound. After that I did all the boards I had complete since I still missed a couple of IC's. The supplied didn't send me the right amount. I had 6 complete boards and they all worked like a charm. They I wanted to hear the Deckard's Dream with multiple voices and inserted the 6 good boards, but apparently my lab power supply could not take that amount of power, so finally I got 4 running. I must say it sound fantastic :) Even mono and without any effects just on my headphones. So first thing to do was order a 12V external power supply that can deliver 6 Amp. I think the Deckards Dream has a high power on current, since with the four boards installed it only took 1 Amp on 12V, and my lab power supply should be able to deliver 3 Amp. We'll see when the power supply arrived. More next time.

Deckard's Dream DIY (Part 6)

Next thing to do was connecting the main PCB to the hardware PCB. After that I also did a quick power test and again the magic smoke stayed in :) I had some trouble determining how to mount the oled display so I didn't solder that yet. There is not much information available unfortunately about the mechanical construction of the Deckards Dream. I did look at some pictures online but still I didn't know for sure. So it was time to also screw on the front panel to see how it all fitted together. At first I had the spacers wrong so that the front panel was too far away. So this is a picture after the second attempt. And now I could also finally solder the oled display.

And then it was time for yet another exiting part of the whole build. Finally putting some software in the Deckard's Dream. You do need to buy a ST programmer for this and connect it a flat cable to the main PCB and with USB on your computer. You can freely download the programmer software. It did see my programmer right away and they you hit 'connect' to hook it up to the main PCB. There is actually a micro controller on the PCB. It is kind of a mini computer that controls everything and it needs software to run. You can download the 'bootloader' software from the Deckard's Dream build page and then you hit 'program' and it actually worked :) I got a success message. After this you disconnect the programmer and switch the Deckard's Dream of and on again. Some garbage appeared on the oled display. But then the manual said to hold the 'shift' button to boot it in USB mode. So I did and then the Deckards Dream acts as a USB drive and you can copy the firmware and factory sound banks on it. Reboot again and voila ! It came alive :) I had a working menu on the oled display.

Here is another picture of the backside where you can see the sandwich of the main pcb the hardware PCB and the front panel. You can also see the correct spot and orientation of the Power Supply PCB in this picture. The only thing I find strange is that all the boards will be connected together in the end. I don't know how yet at this moment, but I'm sure I'll figure it out. There are all hanging horizontally though in the cart-edge connectors without any fixture. So that is a bit surprising to me. But we'll see later about that.

And finally here is a picture of the front of the assembly. Here you can see all the sliders and what they do and everything seems to fit fine :) I also soldered the headphone connector on now. I didn't do that yet again because I wasn't sure about the fit. The only thing missing now is the power switch. I will do that when I assemble everything together in the case.

 

Deckard's Dream DIY (Part 5)

 Like I said in the last part it was time for some testing. I did a visual inspection of all the boards and could not find anything that seemed wrong. The only thing is that there was an error found on the output PCB. Once of the Capacitors was actually wrong on both the PCB and the schematics. So before testing I decided to desolder it and turn it around. After that I attach the power supply to my lab power supply and applied 12V to it. The nice thing about a lab power supply is that you can limit the current it gives so I slowly turned up the current and the power supply lit up and all voltage led were OK. After that I measured all the voltages and everything was fine :) No magic smoke this time :)

After this I put the power supply board in the main board. First without the ICs as you can see in the picture on the right. Main goal here is to see if there are no shorts in the soldering or anything. It is very important to look for the right slot for the Power Supply since it is exactly the same connector as the slots for the voice PCBs, but they are not interchangeable. Also you have to watch the orientation of the boards. So my main board was also OK. After this I inserted all the ICs and did the same test. And I could see on my lab power supply it drew more current but everything still looked OK. The only problem is you don't see anything happening yet on the board. There are no leds or anything to indicate it is working. So more testing is needed for that.  After this I also inserted all the voice boards without ICs to also see if there was no shorts on these PCBs. Again no problems so far. Still always a scary moment to be honest powering up self soldered PCBs for the first time. Even after all these years of soldering.

After this I did another modification on all the voice boards. The advise was to solder two 1 mega-ohm resistors on the backside of the voice boards. It has something to do with the glide function and making it more like the behavior on the original CS-80. You have to be very careful here you solder them to the right pins of course which is a bit more difficult to see from the back side. But luckily there is a clear picture on the Decard's Dream build page. After this I compared them and actually I made a mistake on one board I had to correct.

Then I started inserting the chips on the boards. I did another modification here as suggested by the builder. My original components kit contained TL074 and TL072 IC's. Later on they suggested to change them for TL064 and TL062. I decided to this this. The advantage is that they draw less current. So the synthesizer will get less hot because of this. This results in that you can omit the fan in the case and you supposedly don't even have to install the cooling blocks on the power supply board. It was some extra cost but I decided to do it. Eventually you earn it back in power cost and I don't like noisy fans. Unfortunately I didn't get the right amount when the order was delivered so I had to contact the supplier and straighten that out. And that meant a lot of waiting. And I'm not very good with that so that was a bit of a struggle. But here is a nice picture of the whole stack of voice boards with all ICs inserted. More in the next part.

Deckard's Dream DIY (Part 4)

 The last board I had to do is the Hardware PCB. This is basically the 'human' interface of the synthesizer. It holds all the knobs and sliders and the display. Again the first thing to do is solder all the SMD capacitors. You need to apply flux first if you want the solder to flow under the components connecting surfaces. I have become quite handy by now, but I do need some magnifying glasses to see everything. Age isn't helping me here :) My eyes have been better in the past.

On this board there are also components on both sides. So you have to watch carefully for that. Eventually this board will be hooked up to the Main PCB they will be connected with the two double header connectors you see on the right. I did try if it fitted and it did so I guess that is OK. There are also some resistors and IC Sockets that go on the back side.

And here you see a picture with most of the sliders on there. I was a bit puzzled that some were different values than stated in the parts list, but since they are only voltage dividers it doesn't really matter which value you put in. I'm still looking how the display has to go in. I'm looking for some build pictures of other people for that. But I'm sure I'll figure it out in the end. Next time is actually testing the boards with the lab power supply and see if there are no shorts. First without the ICs and then a second time with ICs and see if everything stars. More about that in a next part.

Deckard's Dream DIY (Part 3)

 The next board I made was the IO board. This board takes care of the communication of the Deckard's dream with the outside world. The audio and midi connectors are on here, the power connector and also the USB connector. There is small SMD chip you have to solder on here and I was very confused about the orientation of this IC. So I asked on the Muff Wiggler forum and got some advice, but I'm still not 100% sure it is correct. I also read something about the Capacitors being wrongly oriented on the PCB and in the schematics. I guess I will have to be care full and do some measuring before I hook it up.

Another important board is of course the Power Supply. I still need to fix the cooling blocks but further this is not a very difficult PCB to create. The downside is though that it sticks in the same slot on the main PCB as the voice boards and you definitely do not want to mix them up. There is only one slot where the Power Supply should go. I also got the advise on the forum to test all the boards separately and the same goes for the Power Supply. Better test them all first with as less components inserted as possible. Also first test the PSU on the Lab Power Supply where you can limit the current to make sure you don't have any shorts. 

And here is a picture of the Main PCB where you can see the blue slots that will fit the voice boards and the Power Supply. The SMD components on this board were already preinstalled. I wonder why they didn't do this on the IO board. As you can see the rest is pretty straight forward. The only board left is the control PCB with all the sliders and knobs for the front panel. More about this in the next part.

Deckard's Dream DIY (Part 2)

After soldering all the capacitors on only one thing is left and that are all the IC sockets. After that I did a careful inspection for the orientation and checked for missing components. As you can see if you inspect the picture closesly there are some resistors not in place. So I started reading on that and it turns out this is meant to be this way. They were put in by the designer to have the possibility to do some changes to the filter afterwards in case that was necessary without having to design a new PCB. I didn't put in the IC's yet. I read on the Muff Wiggler Forum that it is better to test the PCB for shorts first and then put the IC's in later. So I decided to do that as well. It is always a good feeling when you finish a PCB like this, but then also the worrying starts if you made no mistakes. But we'll see about that later. I followed the instructions closely so at this point I can't see what could have gone wrong.

And then 7 more of these boards to go. Here is a picture when I finished three of them. After the first one it usually goes faster. I could finish a complete voice board one day actually. Creating all the voice boards took me about 10 working days where I also did some other work in between. My girlfriend also helped comparing the boards to see if they were all identical. And so far we could not find any differences between them. So so far everything looked great.

And here is a another picture I took during the building of the voice boards. I actually didn't make a picture yet with all the voice boards, but that will come later when I start testing and assembling. Now I need to look at the rest of the PCBs because there is a lot more. I also acquired the case by now and started looking for assembly pictures, because there is only a build document for the voice PCBs not for the rest. So you are kind of on your own there. Even though there are some nice people that really provide excellent information and help on the Muff Wiggler Forum. If you plan to build one yourself you should really create an account there and read up on the whole thread about the Deckard's Dream. By now I have all the 8 voice PCB's done. More in the next part.

Deckard's Dream DIY (Part 1)

 If you follow my blog you know I like to build my own synthesizers. Unfortunately due to my divorce I had to sell a lot. Also some of my DIY stuff. But as you know after 2,5 years I have a small studio again. Luckily I still had a DIY kit that I saved. It is a Deckard's Dream which is actually a clone of the famous Yamaha CS80 that was heavily used my Vangelis one of my favorite musicians. I did have a CS60 in the past and that came close. So I'm really looking forward to this synthesizer. But the build is a lot of work and not the easiest to build. First thing up is build  the 8 voice boards. In the picture you see the back of the first one. You have to solder a lot of very  small SMD capacitor on there to begin with. I never really did that and my eyes used to be better ;) So that was quite a challenge.

After that you start with the resistors and diodes. There are a lot actually and you need to pay attention to the correct value going in the right spot. Usually it is quite a puzzle, but luckily some made a build document that made life a lot easier. It is divided with a drawing that highlights all the resistors of one value and where they need to go. That actually saves a lot of time and mistakes. And one thing I learned myself is using to multi meter to measure the resistor values before I put them in and not rely on what is printed on the bag you buy since sometimes the supplier makes mistakes too. It is a lot of work, but actually I find this work very therapeutic and relaxing :) So I don't mind.

After This the capacitors go on. Just like the diodes here you have to watch the orientation too. Getting this far for the first board was about a days work. So time to stop and also the sun light was going away. Unfortunately I don't have very good lighting in my temporary work place which is actually the dinner table in our living room. So time to call it quits. 

And already I'm worrying if I didn't make any mistakes. But I decided to build the 8 voice boards one by one so when they are finished I can compare them to each other. It would be weird if I made the same mistake 8 times over. But well you never know ;) I will update you with part 2 soon.