SYNTHELECTRO : synthesizers, electronic, retro-computing, etc...
Another problem that really annoys me when I want to quickly jump to a patch on a specific synth. is that it is never easy. You have to go to the PC to play with the mouse, or type on the series of control keys of a particular hardware sequencer. Or more simply, get up from your seat to change the patch directly on the machine.
I decided to create a small simple module allowing to select a MIDI channel as well as a change of patch on the selected channel.
Here is the result of my thoughts on the subject:
The second challenge consists in power the Patch selector from the MIDI bus. Indeed, such a device which must be inserted in a MIDI chain can be very quickly painful to use if in addition it is necessary to manage the power supply unit.
To do that, it is necessary to develop a system whose power consumption remains below 20mA, ideally below 15mA. this time, I chose a microcontroller that I haven't used for over 15 years but which turns out to be very energy efficient and above all very easy to program / debug.
At the stage where I am developing my little studio, I have now to decide for a mixing console. I would go for a RACK version because I don't have a lot of room in my studio!
What do you think of Yamaha's TF-R rack console?
The µPF--2
A few days after having ordered the realization of my printed circuit board, it has just arrived:
I am still waiting for the components, especially the switches and connectors, to carry out the first tests.
The adventure goes on. After having assembled an Omega MSX2 computer, an Easy Z80 under CP / M and a Maximite under Basic, this time I am attacking a clone of APPLE2, the RETRO] [ :
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| https://www.hackster.io/news/capture-apple-nostalgia-with-the-retro-computer-f0fc0ffda886 |
After starting by mounting the power supply, I actually noticed a problem with the two negative voltages of -12V and -5V.
Both of these power supplies have a small design error. Nothing very bad but this implies on the one hand not to mount the two regulators concerned, as can be seen on the previous picture, and on the other hand to make the corrections to the printed circuit board.
This considered, nothing prevents continuing to build what will ultimately only be a prototype since a final version involves making corrections :
The Sequential Circuits Prophet VS is a great synthesizer :
But it is also a machine that is not very well made. Poor quality components, perfectible printed circuits, spreading out of the processor buses inside the device, a PSU that heats up a lot, a very noisy transformer and above all a whole series of very poor quality connectors. Not to mention the 'famous' CEM5530 whose production at the time must be completely out of service today, reason why I had to develop a replacement clone years ago.
The copy I own has only really worked for a few years, after making a lot of changes. And yet, there would be more to do. And precisely, one of the really painful things in this machine, when it works and that one can use it, it is the very important noise which the power transformer generates: very boring.
So, I decided to replace the whole power system of this VS. There were several possible choices for creating a replacement PSU. I decided to create a generic power supply that can be used in other devices, and secure, without handling high voltages.
I created a low voltage switching power supply with linear regulators on the + 12V and -12V outputs:
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| Beta version. |
Output technical details:
I have to admit that it took me several versions to sort out the little issues that I encountered and thus obtain a very reliable and convenient power supply. To install this new PSU, the first thing to do was to remove all the concerned components on the Prophet motherboard:
