CV Tools Module

CV Tools

Sadly CV Tools is now out of production but I will leave this here for reference

Overview
The CV Tools Module is a 12HP Eurorack all-analogue module and is compatible with the Doepfer™ A-100 modular synthesizer bus standard. 

The CV Tools Module is a versatile voltage processor intended for control voltage manipulation such as adding, subtracting, attenuating, amplifying and offsetting.  It can also be used with audio signals to great effect.

A review by SR (a VICMOD member); bought as a kit: 
"An excellent simple tool. Great for cascading polyrhythms. Really easy to use and very surprising differences depending on where you tap the signal." 

For further feedback and comments from users see the feedback page.

Checkout the videos and soundfiles at the bottom of the page.

Download the latest CV Tools User Manual from the support page

4-channel Polarizing Cascade Mixer Section

Essentially this section is a 4-channel mixer but with two main differences:

The first and most significant difference is that it has a cascade architecture. This has a summing stage at each of outputs OUT2, OUT3 and OUT4 (denoted by the Σ symbol);  OUT1 is added to OUT2, OUT2 is added to OUT3 and OUT3 is added to OUT4.

Consequently OUT1 is just from channel 1, OUT2 is the sum of channels 1 and 2, OUT3 is the sum of channels 1, 2 and 3, and OUT4 is the sum of all four channels. However, when a patch lead is plugged into any, or all, of outputs OUT1 to OUT3 it disconnects that output from the next channel’s output summing stage.

The second main difference is that it is a polarizing mixer which allows an input signal’s level to be adjusted or inverted. Each channel has a basic gain of 2 and therefore an input signal can amplified by up to a factor of 2 or inverted and amplified by up to a factor of 2 (i.e. -2). This is useful for adding and subtracting signals in varying degrees.

Slew Limiter 

This could be used to add portamento to a VCO control voltage; blending one pitch into the next. This is also called lag or glide on other synthesizers. In the MIN position there is no noticeable slewing but in the MAX position it takes just over a second to ramp up or down to the next voltage step

CV Tools Specification

4-channel Polarizing Cascade Mixer

Channel 1

Input: 3.5mm jack IN1

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT1 - Normalled to Channel 2 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 2

Input: 3.5mm jack IN2

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-16kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT2 - Normalled to Channel 3 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 3

Input: 3.5mm jack IN3

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT3 - Normalled to Channel 4 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 4

Input: 3.5mm jack IN4

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, A-100 Bus CV or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable - jumper selectable to ±2 (±3%) or 1 (set by RV7)

Output: 3.5mm jack OUT4 and Slew Limiter input

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Slew Limiter

Input: 3.5mm jack IN

Input impedance: 1MΩ (±1%)

Normalled input: Channel 4 output OUT4

Slew range: 0.5ms-1000ms

Gain: 1

Output: 3.5mm jack OUT

Output impedance: 0Ω (±1%)

General

Dimensions

3U x 12HP (128.5mm x 60.6mm), depth 52mm

Power consumption

+12V @ 20mA max, -12V @ 20mA max, +5V is not used.

Reference voltage (VREF)

Jumper selectable at each mixer input. 
Channels 1-3: 5.00V (set by RV6), 0.5V-2.5V (set by RV8)
Channel 4: 5.00V (set by RV6), CV from A-100 bus.

A-100 Bus utilisation

±12V, 0V and CV used; +5V and Gate are not used.

Contents

CV Tools Module, 200mm 16-way ribbon cable, 4 sets of M3 cap-head socket screws, nylon washers and a 2.5mm hex key.

Users' video and sound files

 last of the flies by neilbaldwin
The bassline on this track uses CV Tools.


The Dioder from Neil Baldwin on Vimeo.
A novel application: Here CV Tools is being used to scale and invert RGB control voltages for Ikea Dioder LED lights (via a DIY interface).

Here are a couple of videos showing a comparison between the ARP2600's Voltage Processor and CV Tools (i.e. the thing that was the inspiration for CV Tools).