[sdiy] Dynacord Boomer Sampler PSU

[Synthusiast]

Hi Dave,

Here's the pinout of the transformer Dynacord used for the Percuter (S), 
Boomer and Big Brain:

pin 2: 18V AC @ 0,6A
pin 6: 18V AC @ 0,6A
pin 5+4: 9V AC @ 1,2A
pin 3+1: 9V AC @ 1,2A

So basicly it's a tranformer with a 18V and a 9V output.

The onboard UV lamp is very interesting indeed. I don't know of any other 
similar device offering that feature. With the Boomer you can create custom 
sound cartridges, which can be triggered from Dynacord's Percuter drum 
system. The Percuter can hold up to 8 sound cartridges. The Big Brain is a 
sequencer/trigger to MIDI/MIDI to trigger interface. You can connect two 
Percuters to it and it routes the 16 trigger inputs of the Percuters to 16 
different MIDI channels and it can route those MIDI channels to the 16 sound 
cartidges of the Percuters. And it can record up to something like 1 million 
notes. That's probably the reason why they called it the Big Brain.

The Percuter, Boomer and Big Brain were originally designed by Hans Peter 
Baumann, who sold the designs to Dynacord. Baumann built analog modular 
synths and drummachines in the 70s and 80s under the BME brand.

I own all three of them.

Regards,
Martijn


> Hi y'all...
>
>
> So I walked into this store, browsing for new gear, and came across a
> weird box. It says "Dynacord Boomer Digital Sound Programmer". I asked
> wat it was. They said all they knew was that it used eproms. They gave
> it to me for free. Joy! It turned out to be a sampler.
> http://www.synrise.de/images/dynacord-boomer.jpg
>
> Although its specs are rather 1984 (8 bit/12kHz/1.3 seconds of
> memory), I'd like to get it to work. It seems to be in good shape, but
> the transformer is missing. So, now I need one or two transformers. I
> traced the PSU board to figure out what I need. I got confused.
>
> It uses  4 pins of a 8 pin DIN type plug:
> http://pinouts.ru/connectors/din8cf.gif
>
> pin 4&5 and 1&3 go to the two ~ terminals of a great (diode rectifier 
> ring)
> pin 2&8 go to the - terminal.
> The elcos here are 16volts and 24volts max.
> So far so good, but the odd thing is that the + is going to two 7805 ICs!
>
> Pin 7 goes to 3 diodes.
> diode one: goes via an elco to ground.
> diode two:  goes to a 7815
> diode three (in opposite direction) goes to a 7915
> The elco's are 40volts max.
> To me, this method of getting a symmetrical PSU is not familiar.
>
> All 78xx/79xx share the 0 as ground. And just to be sure, I checked
> that this 0 is the gound on the sound in/out terminals.
>
>
> Does anybody know what type of transformer I need?
> Or can anyone guess the voltages I need from this information?
>
>
> BTW: The machine has an onboard UV lamp to erase the eprom memory! :-)
> I'll look more healty with your help! ;-)
>
> thanks,
>
> Dave
>