Multiplikand is a compact routing utility module for Eurorack in 6HP. It takes Audio and CV, with optional DC filtering.

At its core, Multiplikand offers four active precision multiples, married to a unity-gain mixer.

Clever normalisation and a switch allow you to configure how the signals are summed.

Here's a look at the front panel.

We wanted both Multiple and Mix functionality in the same Module.#

When we use our Modular, we often record the dry signals into seperate tracks, plus an audio path with effects.

This allows us jam to our hearts content and still be flexible in editing.

Multiplikand is perfect for this: patch the incoming signals into one multiple each, split the dry tracks directly into an audio interface, then send Multiplikand's Mix into an effect.

#

We wanted it to work for Audio and CV.#

The Eurorack world offers plenty of passive multiples - which work fine for some patches, but are fraught with potential signal loss.

We designed Multiplikand as an active multiple, which means it can deliver a much more accurate copy of the signal.

That makes it suitable for duplicating signals that require a high amount of precision, such as pitch CV.

#

Multiplikand limits the Voltage it lets pass to its output - when you add very hot signals, they get clipped at +12V / -12V, suitable for Eurorack Audio and CV.

This is to keep you from overpowering the inputs of your other Eurorack modules with signal levels that are too high.

Jumpers on the back of the module let you opt-in to filter DC offset per channel, if you want to use Multiplikand exclusively for Audio.

Multiplikand takes a standard 2x5 pin Eurorack power cable. We have included one with your kit.

The red stripe denotes -12V and is clearly marked on the PCB print on the back of your module.

Make sure you pay attention to the orientation of the cable both on your power bus and the module itself before you power up your system.

Multiplikand has four channels of active multiples, arranged in four identical-looking blocks at the top and bottom, left and right.

Patch an Audio or CV input signal into the jack at the top of the block, and you will get a copy of the same signal as an output from the three jacks beneath it.

A single channel of the active multiple looks like this.

The bottom jack of each block holds a special function - it allows you to configure how the signals are summed.

Set the switch to the right position, labelled 1+2+3+4.

If you now patch four signals into the top of each block, so there is a signal present on In 1, In 2, In 3 and In 4, it will be output as an equal gain sum 1+2+3+4 on the bottom jack of the fourth channel, on the bottom right.

If you patch a cable to the bottom jack of channels 1, 2 or 3, that channel is removed from the sum on output 4.

Set the switch to the left position, labelled 1+2 / 3+4, to group the mix into two groups of two channels instead of one group of four.

An input signal on In 1 and In 2 will now be output as a sum 1+2 on the bottom jack of the second channel, on the top right.

An input signal on In 3 and In 4 will be output as a sum 3+4 on the bottom jack of the fourth channel, on the bottom right.

Now, if you patch a cable to the bottom jack of channel 1, that channel is removed from the sum on output 2.

And if you patch a cable to the bottom jack of channel 3, that channel is removed from the sum on output 4.

2x2 channel mode allows you to easily set up Stereo FX Send - Return patches. For this patch, set the switch left to 1+2 / 3+4 mode.

This type of routing is really helpful if you have a stereo signal and a stereo effect, and you want to mix both but still have extra patch points that carry the dry and wet signals - e.g. to record them as stems.

Patch the left channel Audio into In 1 and the right channel Audio into In 3. For each of these, patch a cable in to the jack below the input to get a duplicate of In 1 and In 3.

These will become your FX Send L and FX Send R, sending dry audio to your effect. Let's assume it's a Delay. Patch these into the L and R input of your Delay module and set it to 100% wet.

Patch the L and R output of your delay into In 2 and In 4. This will effectively make them your FX Return L and FX Return R.

On Out 2 and Out 4, you will now have an equal gain mix of wet+dry for left and right channels respectively.

Multiplikand's input pinheaders are half-normalled with the input jacks in the front:

If you patch a cable into the front input jacks of channels 1, 2, 3 or 4, the signal from pinheaders 1, 2, 3 or 4 is removed from the input signal path.

The pinheaders come in pairs of signal and GND; If you have nothing connected to one or more of the input headers 1, 2, 3 or 4, it is imperative that you close the connection to GND with a jumper.

An open connection will make the module succeptible to noise and ground hum.

Multiplikands output pinheaders duplicate the signal from the front jacks:

A signal on the front output jacks of channels 1, 2, 3 or 4, will be equally present signal on the pinheaders 1, 2, 3 or 4.

When prototyping ideas, nothing is more fun than whipping up a quick sketch on a prototyping platform.

Writing a few lines of code, then uploading your sketch to an Arduino, Teensy or Daisy, allows you to play with your DSP idea in the physical world.

Multiplikand enables you to bridge the gap to Modular: pinheaders in the back allow you to patch jumper wires from your proto board to Multiplikand's inputs.