The dpFX Stereo Effects Mixer is a parallel mixer designed for stereo pedals & pedalboards and is also compatible with line level signals. It can be used as a summing box that can take up to 3 stereo signals and combine them into a single stereo output.
It features high-impedance TRS inputs (buffered with JFET op amps) that can be driven by instruments (guitar, bass etc) or line level signals as well. It makes use of low distortion, low noise op amps and each input has a volume knob that goes from mute, up to +6dB gain.
The output impedance is very low ensuring the best interconnectivity with the rest of your gear.

dpFX Pedals

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3-Channel Stereo Mixer

PINAX Stereo Matrix Mixer 4x4, aktiv.
Dies ist ein aktiver STEREO 4x4 Matrix Mixer mit Schaltern für unipolaren/bipolaren Modus für jede Ausgangsspalte. Die TRS-Ein- und Ausgänge des Geräts sind AC-gekoppelt und so konzipiert, dass sie jede Art von Übersprechen zwischen ihnen aktiv unterdrücken.
Es ist für Instrumente (Gitarre, Bass usw.), Synthesizer, Eurorack-Signale und jede Art von Line-Level-Signalen geeignet.

Unipolarer Modus: In diesem Modus verhalten sich alle Potentiometer, die den jeweiligen Ausgang versorgen, normal, d. h. wenn der Knopf ganz gegen den Uhrzeigersinn gedreht ist, gelangt kein Signal vom zugehörigen Eingang in den Mix. Wenn der Knopf im Uhrzeigersinn gedreht wird, gelangt ein größerer Teil des Signals in den Mix. (Bei maximaler Position gibt es eine Einheitsverstärkung.)

Bipolarer Modus (Phasenumkehr): In diesem Modus hat jeder Knopf in der Mitte seines Bewegungsbereichs eine Nullposition. Durch Drehen des Knopfs gegen den Uhrzeigersinn wird ein zunehmender Anteil einer negativen (phaseninvertierten) Version des Signals am entsprechenden Eingang hinzugefügt, während durch Drehen des Knopfs im Uhrzeigersinn ein zunehmender Anteil des Originalsignals zur Mischung hinzugefügt wird.

PINAX Stereo Matrix Mixer 4x4, Active.
This is an active, STEREO 4x4 Matrix Mixer with switches for unipolar/bipolar mode for each output column. The device's TRS inputs & outputs are AC-coupled and designed to actively reject any kind of crosstalk between them.
It is suitable for instruments (guitar, bass, etc), synths, eurorack signals and any kind of line level signals.

Unipolar mode: In this mode all pots feeding the respective output behave in regular fashion, that is when the knob is fully counter-clockwise, no signal from the associated input passes into the mix. As the knob is advanced clockwise, a greater portion of the signal passes into the mix. (At max position there is unity gain.)

Bipolar mode (phase reversal): In this mode, each knob has a zero position mid-way through it's travel. Turning the knob anti-clockwise will add an increasing portion of a negative (phase inverted) version of the signal at the corresponding input, while turning the knob clockwise will add an increasing portion of the original signal to the mix.

4x4 Stereo Matrix Mixer

With this device you can mix two signals into a single output and still be able to use the original signals since they pass unchanges through the splitter to the respective outputs.
e.g.: You can mix the L & R channels of a stereo signal down to mono and still be able to use the original stereo signal.

Stereo Splitter & Mono Mixer with Pan Control

This is an all analog Stereo Parallel Blender that offers two independent loops and a Dry blend and is able to handle signals varying from instrument level up to higher line level (~24Vpp max).

All jacks are TRS. The device is compatible with mono signals as well.

Dual Stereo Blender

KRAMA-3 gives you the ability to split your signal, route it through three separate loops (A,B,C) and blend them all together with your dry signal. The dry volume and the volume of each loop can be controled independently through the pots A, B, C, DRY.

Three phase reverse switches ensure that you will overcome any case of phase cancelation during the blending process when using pedals that reverse the phase. The phase reversal is applied after the signal enters the RETURN jacks. 

KRAMA-3 can also be used as a three input mixer with volume control, phase reverse and mute ability. Just connect the three signals that you want to mix to the Returns A,B,C and take the resulting mixed signal from the output. A fourth signal can be connected to the Input as well. 

Krama-3 Triple Loop Parallel Blender