going bananas again?

[Harry Bissell]

Hi Roel:

Roel Das wrote:

> Hello everybody,
>
> I just finished and tested my first part ever. I
> rebuild one of my older(between 15-20 years old) toy
> keyboards to a CV keyboard using the schedule from
> efm's cookbook. (one 'switch' per key, the switches
> are actually metal wires that bend and make contact
> when pressed)
> Now i need to buy connectors and stuff. So, help me
> out:
> * Are there any standards in keyboard connectors or
> tips?

Beats Me...

>
> * The same for powerconnectors (-12,0,+12 between the
> modules)

John Blacet has a standard that (i think MOTM) others use. I use a power
supply strip with screw terminal strips for +-15 volts
and ground... (but if I was 'new' I'd go with the Blacet standard). Not
because the 'Blacet' standard has any special engineering merit, but
(uhh well... ) because its standard. :^)

>
> * I read the banana stuff, so the modules will be
> 1/4", but what's the difference between switched and
> other 1/4" females?

Switched connectors are good for two things...
1: you can automaticly "ground" an unused input to reduce noise and
crosstalk
2: you can make a "normalled" connection, i.e. Run the Keyboard Control
Voltage to a VCO frequency input <unless> you patcg another cord into
it...

<FLAMEWAR BAIT HERE :^)>  IMHO the "normalled" connection is the RIGHT
THING to do in cases where you almost always need the connection...
1) Keyboard CV to VCO and VCF (esp with attenuator in the VCF CV...)
2) VCO Waveforms to Mixer inputs or switches (I like thumbwheels...) If
you have a mixer... if not
3) VCO Waveforms to VCF inputs
4) VCF Outputs to VCA inputs...
5) Envelope Generator to VCF CV inputs (esp with attenuator)
6) Envelope Generator to VCA CV inputs (esp with attenuator)
7) LFO outputs to VCO, VCO PWM, VCF, and VCA (esp. with attenuator)
8) all other 'normal' connectors needed to perform basic synth
operations...

If you put the 'normalled' jacks just before the attenuators (pots) then
you have easy cordless control for the most USEFUL functions...

I make the normalled conncetions with a Molex (you use what works for
you) connectors behind the modules so that you can still unplug a single
unit for more DIY etc...

I even put toggle switches so I can select either (lets say) ENV 1 or
LFO 1 to VCO PWM... Three way switches are even more powerful...

(FIE ON THOSE WHO DISAGREE....  :^) This does not "remove" any options,
lock you into a way of thinking, or eliminate the 'purity' of modular
synths...
You can still feed the VCA output to the VCF input to the VCO... It just
doesn't make noise that way...

IMHO Plugging outputs to outputs is a bad idea unless it is designed
that way... I trust JH to do it but not most folk...

No offfence is meant by any of this... I'm just not getting enough mail
to read this weekend... This aughtta shake some loose...

>
> * What type of cases/frontpanels(for the modular,
> 19inch) are available, and which one should i actually
> buy? The cheapest?

Lots... search SKB Cases... I like the pop-up mixer case especially, 12
spaces high and very portable... Some like the Frac-Rac (PAiA) oothers
the MOTM rack... Do what you like...

>
> * Should i put fuses in the power source? Is the one
> on EFM's cbook ok enough? Any mods necessary?

I like an input fuse (though I don't have one)... If the supply
regulators have massive heatsinks you will usually smell the
"something's wrong" smell before damage occurs. Supply should be output
short circuit protected...
Fuses if used should be easy to see...get at... change...etc.

>
> (http://www.xavax.com/efm/synth/cbook/pics/pwr2a_sd.gif)
> * Any other things i should start worrying about at
> this point?

(Yeah... like I said... A Flamewar...)
:^) Harry

>
>
> Thanks.
> Roel
>
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