Questions on Synthwerks SP-4DP

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noisewreck
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Questions on Synthwerks SP-4DP

Post by noisewreck » Thu Jul 30, 2020 2:00 pm

These are perhaps a questions for James Husted, aka ersatzplanet. I could've sent a PM, but figured these might be useful for others as well who are looking for controller type modules...

So, trying to understand how the outputs on Synthwerks SP-4DP work in relation to the faders...
  • For outputs with the Up/Down arrows, is it a fair assumption that when the fader is up, voltage will increase on the UP output and decrease on the DOWN output? So, let's say if the output range is set to +10V, with the slider in the "UP" position, I'll get +10V from the UP output and 0V from the Down output, and in the middle I'll get 5V from both outputs?
  • Is +5v range bipolar?
  • What is the column identified with the <-> arrows for? Is that input or bipolar output?
Thanks in advance for the help

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ersatzplanet
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Re: Questions on Synthwerks SP-4DP

Post by ersatzplanet » Fri Jul 31, 2020 11:20 am

The SP-4DP is an active module. Each half of the 4 dual slide pots is normalized to a DV voltage, internally selectable
to either 0V-5V or 0V-10V ranges (approximately). The module can pass both AC and DC signals with output levels
proportional to the position of the sliders. The Jacks and slide pots are mounted to a 26 HP rotatable panel. The
panel graphics are so that the panel can be rotated to choose if the jacks are to the left or to the right of the slider
themselves, thus keeping the patch cables out of the way.

There are typically FOUR main ways to use the SP-4DP module. Each of the four slide pots in the SP-4DP are dual slide pots whose halves are electronically separate from each other, so each slider can do any TWO of these functions at the same time, to two different signal paths - eight signals can be controlled at once. The first type of function is to alternately send one signal (audio or CV) to two different destinations - this is called a Pan-pot function. The second type is to fade between two sources (audio or CV), sending the “mix” to one destination - this is a Segue function. The third type is to control the level of one signal (audio or CV) passing through the SP-4DP - This is an Attenuation function. The forth type is to generate DC control voltages and output them - the DC control voltage output function.

The jack are marked with arrows to denote the end of the slider that is "active" when the slider is moved to that end. The double headed arrow is the slider itself. So for example, if you were to put LFO-A into the up arrow jack, and LFO-B into the down arrow jack, the output from the double arrow jack would fade from LFO-A when closer to the up arrow side, and fade into LFO-B closer to the down arrow end. The reverse is true too. If you put a signal into the double arrow jack, it will get louder in the up arrow output when the slider is closer to it, and visa versa. The SP-4DP uses 100K dual linear sliders so if signals are very high, full attenuation may not happen is these modes. If you want to fully attenuate a sound, plug it into the end marked with the "+" sign (defeating the normalization to the +V) and read it from the double arrow jack. The opposite end of the fader from the "+" is normalized to ground, so this will assure full attenuation.

The CV-out mode with the SP-4DP by itself uses the normalization of the "+" inputs. You plug the destination into the double arrow jack and as you get closer to the jack with the "+" sign, the voltage will increase. Each dual slider's halves are wired opposite so one slider will output a increasing CV at the same time other is outputting a decreasing one.

As stated above, each hals of the slider can be connected with different functions at the same time and share the same control. You can have a DC voltage on one side, and a fade between LFOs on the other for instance. Any combo of the different modes.

The unit is not bipolar as is, but of course if you have a source of -V and +V, they can be patch into the jacks. The unit doesn't care if the signals are bi-polar or uni-polar, DC or audio. It is basically four dual pots with all 6 taps wired to jacks and configured as a voltage divider with a normalized DC voltage. It can be run as a purely passive unit too, just by not connecting it to the power bus. It also can output -V by just plugging the 10 pin end of the power connector in backwards.

Here is a link to the two owners manuals -
Manual for the assembled unit.
Manual for the Kit version
-James

James Husted - Synthwerks, LLC - www.synthwerks.com - info@synthwerks.com - james@synthwerks.com
Synthwerks is a proud member of the Mostly Modular Trade Association (http://www.mostlymodular.com).
Always looking to trade for Doepfer P6 cases

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EATyourGUITAR
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Re: Questions on Synthwerks SP-4DP

Post by EATyourGUITAR » Fri Jul 31, 2020 6:39 pm

this can do 4 stereo crossfaders then? 8 outs down the center column?
WWW.EATYOURGUITAR.COM <---- MY DIY STUFF

noisewreck
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Re: Questions on Synthwerks SP-4DP

Post by noisewreck » Sat Aug 01, 2020 3:34 am

ersatzplanet wrote:
Fri Jul 31, 2020 11:20 am
There are typically FOUR main ways to use the SP-4DP module....

Here is a link to the two owners manuals -
Manual for the assembled unit.
Manual for the Kit version
Thank you James for the detailed response! I’ll send you an email via your website to order the DIY kit.

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