Dizzy boards are back in stock

[Synthbuilder]

Issue 3 Dizzy boards are now in stock from Paul at Krisp1.

Issue 3 PCBs are identical to issue 2 but have less Oakley Buss headers available. I've restricted it to eight 0.1" three way headers now. Issue 2's thirteen was somewhat excessive for a distribution board containing 16 power headers.

Tony

[nerdware]

Great news! Thanks.

16 power headers? So you've added another 4 headers? Excellent!

[krisp14u]

Sorry but there are still only 12 Power headers and now 8 buss headers

[Synthbuilder]

Ah, my abilities to count to twelve have always been very much overstated.



Tony

[nerdware]

LOL

[Leverkusen]

Hi Tony,

I am transitioning from using just a dotcom harness to building some extra Dizzy boards to further expand my system. While going through the guide I found this and wonder if I just got something wrong or if there might be mistake:

The midiDAC, however, generates the CV and gate lines for your modular so this should have two wires connected on its buss connector. Both pins 1 and 2 are used on this module.

Shouldn't it be pins 1 and 3 and pin 2 not used?

The middle location, pin 2, is ground on the module and this should not be connected to the Dizzy or midiDAC modules. Connecting the two grounds in this way could induce earth loops and introduce hum or crosstalk in your system.

Also I have a bit of a hard time to understand under wich circumstances I should connect the optional links R1, R2 and R3 (I see that you ommited them on Dizzy 4). My system is mostly built of Oakley modules plus a few other brands (Haible, MOTM, Yusynth, CGS, Barton,...). By now I have built everything with dotcom style connectors and used diy MOTM adapters where needed. Also I have some Dizzy 3 and some Dizzy 4 boards in the drawer to use.

So I guess I will have to connect panel ground and 0V as I did not the modules. I am not sure though if this has to be done on the Dizzy board, on the modules, on both or anywhere but not on both...

[Synthbuilder]

Shouldn't it be pins 1 and 3 and pin 2 not used?

Yes. I'll get that corrected. Thanks for pointing it out.

I have a bit of a hard time to understand under which circumstances I should connect the optional links R1, R2 and R3

In a standard set up you would only connect R3. You can ignore R1 and R2. R3 simply connects the middle pin of the Oakley Bus header to 0V and is used to electrically isolate the noisy gate signal with the more delicate CV line. If you are not using the Oakley Bus then you can omit R3 too.

R1 connects pin 2 and pin 3 of the power headers together. This should ideally be done at the PSU, so R1 is not normally needed. However, you should always connect both pins 2 and 3 of the Dizzy's power inlet, with two separate wires, back to 0V on the PSU. If you have an Oakley PSU, they'll simply go back to pins 2 and 3 on the PSU's out connector.

R2 connects the second 0V to the one of the mounting holes on the Dizzy PCB. Again, you can ignore this as your panel is should be grounded via the power supply. If you are mounting the Dizzy on a wooden case then R2 will not do anything anyway.

The smaller Dotcom power connectors are inferior to the MOTM/Oakley standard which uses a bigger connector so you can use larger diameter wiring, and dedicates two lines to 0V. It's best to use the MOTM header if you can on any modules.

Tony

[Leverkusen]

Thank you for the support, Tony! Got it now.

Of course you are right about the dotcom connectors. It's just the power supply I found used at a good price when I started expanding my former COTK system and did not feel confident enough to built one by myself. It also came with a nice power inlet/power switch module. So I built my first 15 Oakley modules with that dotcom connectors before I incorporated other DIY brands in my system and transitioned to MOTM. I guess I go with it until the whole system is finished and think about changing the connectors on all 15 modules then - not really looking forward to crimp those 60 wires for the MOTM connectors by hand...

[Synthbuilder]

not really looking forward to crimp those 60 wires for the MOTM connectors by hand...

I use Molex KK 0.156" connectors rather than MOTM's MTA156 system. You don't need an expensive tool, just an ordinary Molex style crimper, the housings are cheaper, and I think it's a better connector too.

It's still a bit of a bore making up a bunch of leads but it's easy enough to do.

Tony