SK109-Scale-bias

You are viewing an old revision of this post, from January 1, 2013 @ 15:09:25. See below for differences between this version and the current revision.

This module scales the input signal (gain from 0 ~ 1.2) and applies a bias to it (shift it up or down). It works from DC to video frequencies on both the signal and the CV inputs.

It allow s for nice stuff like signal multiplication, luma keys etc.. but is also very handy to get CV-signals into a more useful range.

Note: A negative biased video signal will pull down other channels on the mixer! We should probably add the possibility to clip the output signal between 0 and 1.4V volts, like it’s done on the original sk09-scalebias module.

Module Info

Inputs: – Siff (0-1V)
– Scale (0-1V / -1 – 1V)
– Bias (0-1V / -1 – 1V)
Outputs: Siff out
Power Draw on +5V: 22 mA
Power Draw on -5V: 22 mA
Frequency Response:

Schematic & PCB

View on Github

Parts List

Qty Value Device Package Parts Description
4 3,17/1,1 3,17/1,1 BIAS-IN, GAIN-IN, OUT-, SIFF-IN THROUGH-HOLE PAD
2 CPOL-EUCT6032 CT6032 C10, C12 POLARIZED CAPACITOR
5 100 R-EU_R1206 R1206 R102, R202, R302, R304, R305 RESISTOR
8 100k R-EU_R1206 R1206 R103, R104, R105, R106, R203, R204, R205, R206 RESISTOR
8 100n C-EUC1206 C1206 C100, C101, C103, C200, C201, C203, C300, C301 CAPACITOR
2 10k POT ALPS_RK09L1120 BIAS-POT10K, GAIN-POT10K
1 180 R-EU_R1206 R1206 R308 RESISTOR
8 1M R-EU_R1206 R1206 R113, R114, R115, R116, R213, R214, R215, R216 RESISTOR
3 1k R-EU_R1206 R1206 R207, R217, R303 RESISTOR
1 1k6 R-EU_R1206 R1206 R218 RESISTOR
4 20k R-EU_R1206 R1206 R108, R109, R208, R209 RESISTOR
1 22 R-EU_R1206 R1206 R307 RESISTOR
1 22-23-2031 22-23-2031 22-23-2031 X1 MOLEX .100″ (2.54mm) Center Header – 3 Pin
2 2k2 R-EU_R1206 R1206 R107, R117 RESISTOR
2 2u2tantal CPOL-EUCT6032 CT6032 C302, C303 POLARIZED CAPACITOR
1 300 R-EU_R1206 R1206 R306 RESISTOR
1 47k R-EU_R1206 R1206 R301 RESISTOR
2 4k7 R-EU_R1206 R1206 R101, R201 RESISTOR
2 50p C-EUC1206 C1206 C102, C202 CAPACITOR
1 75 R-EU_R1206 R1206 R309 RESISTOR
3 BAT54S-L44 DIODE_2CACA-SOT23 SOT23 D2, D6, D101 2 Diodes
2 LMH6643MA MAX4392ESA SO08 IC1, IC2
1 LT1228 LT1228 SO08 IC3

Photos

Observations

the “scale” side of things could have some more punch.

Revisions:

Changes:

January 1, 2013 @ 15:09:25Current Revision
Content
This module scales the input signal (gain from 0 ~ 1.2) and applies a bias to it (shift it up or down). It works from DC to video frequencies on both the signal and the CV inputs. This module scales the input signal (gain from 0 ~ 1.2) and applies a bias to it (shift it up or down). It works from DC to video frequencies on both the signal and the CV inputs.
It allow s for nice stuff like signal multiplication, luma keys etc.. but is also very handy to get CV-signals into a more useful range. It allow s for nice stuff like signal multiplication, luma keys etc.. but is also very handy to get CV-signals into a more useful range.
  <strong>Note</strong>: For better gain lift R215 from ground and connect to negative base of gain pot.
  <strong>Note</strong>: Pushing R307 to 220 Ohms and R308 to 1k8 seems to remove some tendency to oscillate
<strong>Note</strong>: A negative biased video signal will pull down other channels on the mixer! We should probably add the possibility to clip the output signal between 0 and 1.4V volts, like it's done on the original <a title="SK09-Scale-Bias" href="http:// synkie.net/modules/sk09-scale- bias/">sk09-scalebias</a> module. <strong>Note</strong>: A negative biased video signal will pull down other channels on the mixer! We should probably add the possibility to clip the output signal between 0 and 1.4V volts, like it's done on the original <a title="SK09-Scale-Bias" href="http:// synkie.net/modules/sk09-scale- bias/">sk09-scalebias</a> module.
  <h3>Parts placement</h3>
  <a href="http:// synkie.net/wordpress/wp-content/ uploads/2012/ 12/sk109-place.png"><img class="alignnone size-large wp-image-351" alt="sk109-place" src="http://synkie.net/ wordpress/wp- content/uploads/ 2012/12/sk109- place-1024x814.png" width="1024" height="814" /></a>

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