02 July 2008

Yusynth (Part 4)

I'm very busy at the moment working on my new album, but I did some more work on the Yusynth project in between. I got some more components from my local electronics shop, but they don't have everything on stock. There were also some components they could not get at all. I ordered them from Farnell.com Like the thermistor you see in the picture on the left. It is a resistor that is temperature sensitive. It's value changes when the temperature changes. It is used to keep the oscillator in tune when the temperature changes. I mounted it right on top of the IC for optimal result (I hope).

In the picture on the right you can see how far I am with the VCO's. They are almost done. I still think it is amazing that music will come from these PCB's. But eventually it will be the case :) I'm very curious how they will sound. There is only one thing I haven't figured out yet. On one place there are two 1N4148 diodes that need to be matched. But I have no idea how I should do that. Maybe I should ask Yves about that. But if anyones reads this and can help me out, please do :) In the mean time I also started building the LFO modules. I will post an update soon, but I still need to make pictures of this progress.

I picked up a special lab power supply to be able to test my projects. It has three independent very stable power sources. Two of them are variable from 0-30 Volts and one is fixed on 5 Volt. With the two variable sources connected together I can make the +15 and -15 that is necessary to for the Yusynth modules. It is also short circuit proof. I gues for testing that is a bit better than blowing up a freshly self build power supply ;) OK now back to working on my album :)

9 comments:

yusynth said...

Hi

Here is how to match the 1N4148 :

first case : you have a DMM (Digital multimeter) that offers the diode measurement option. That's very easy then, test the diodes on the special diode position and select pairs of diodes which match better than 3mV (by this I mean both diodes have measured values that do not differ by more than 3mV)

second case : you have no magic diode option on your DVM. Here is how to proceed . You need a 10k resistor, a 9V battery and a millivoltmeter. Connect in series, the battery, the resistor and and the diode (in direct polarisation). Then measure the voltage drop at the leads of the diode. You should get a value in between 550mV and 750mV. The matching procedure consists then in selecting the diodes with the same drop voltage with a maximum tolerance of 3mV.

That's it

Synth.nl said...

Hi Yves,

Thank you so much! You're even quicker than I could write you an E-mail :) Fantastic!

Michel, Synth.nl

vinnui said...

I'm building the same 4 PCBs, and i want to say that the work Yves has done is absolutely fantastic, and inspirational. Thanks for the hard work!
I want to build all of the YuSynth modules.

Synth.nl said...

OK cool. I would be interested to see your progress too :)

vinnui said...

I've posted a blog entry of my current progress:

http://vinnui.blogspot.com/2008/07/yusynth-vcos.html

I'm suprised, when I saw you are building the YuSynth VCO's too, because everybody choose the MFOS, or Catgirl's synth version instead. I'dont know why. YuSynth PCB's are single sided, while MFOS are double sided.

I'm subscribed to your RSS feed long ago, to track this project and other good things.
Happy soldering! :)

Synth.nl said...

OK cool. I subscribed to yours too now :)

yusynth said...

I suppose that people choose MFOS because they can buy the PCBs and spare themself the burden of etching and drilling. These have been available from Ray Wilson from a while now and it's quite logic they are popular. Up to now, one had to DIY ones YUSYNTH PCBs. It is only very recently that I had an agreement with Bridechamber to distribute YUSYNTH PCBs, only a few module PCBS are yet available but soon this number will grow. I expect then that yusynth module will grow in popularity too ;-)

Cheers

Synth.nl said...

Nice :) Do you also have plans for front panels? I still have no idea how I'm going to do that.

yusynth said...

Scott Deyo of Bridechamber will offer panels for yusynth modules in the MOTM and Euro format. I have asked him if he would also propose DOTCOM format panel and he told me that he might if should there be requests enough...
Therefore, if you are interested I invite you to get in touch with Scott.

Cheers