Analog Vintage Style Phaser

A beautiful sounding phaser based on the original vintage EH "SmallStone" phaser guitar effects pedal. It has been expanded from 4 to 12 stages, with unique switching which allows stages to be individually selected for both the Output and Resonance return paths. It can be used in Mono IN, Mono Out mode or Mono IN, Stereo OUT mode, with the Stereo outputs taken from the Stage and Emphasis paths rather than the more usual inverted signal only method. We have added CV voltage control of Phasing depth and Emphasis (Resonance) levels, so that these can be fully controlled from other Eurorack modules or external voltage sources.

In addition to a manual Frequency control it includes two separate Frequency CV inputs; FCV1 and FCV 2, and the latter includes an attenuverter function. An inbuilt, wide ranging LFO is normalized to FCV 1 input, and the LFO has its own external output too. Unique "Wet" output and second Input with level control, which allow external effects to be patched into the Emphasis loop to create a second Emphasis path.

The Mega-Phase 12 uses a clever arrangement to generate a stereo output using a single, mono input. To create a true stereo phaser would require either two Mega-Phase 12 units, or for a single unit all of the circuitry would have to be doubled to 2 x 12 stages, this would dictate a much larger circuitboard to accomodate all of these extra parts, and the module grow from 18hp wide to over 30hp wide! And of course the cost would be higher too because of all of the extra components.

A common "cheat" to create a stereo phaser is simply to add an inverter to the right hand outputs, so that the output is 180 degrees out of phase with the Left output, however this is not particularly convincing or versatile. Because we have added switchable taps to the phaser stages, we are able to connect the Right output to the Emphasis stage rather thant the main output stage, which is the case for the Left channel output. So, if the Emphasis stage is set differently from the Main stage, the output sigmals are as follows:

• LEFT OUTPUT - Main Stage output plus (if emphasis control is set above zero) Emphasis added from Emphasis Stage
• RIGHT OUTPUT - Emphasis Stage output plus (if emphasis control is set above zero) Emphasis from Emphasis stage
• As an example, lets see what happens when we set the Main stage switch to 8 and the EMP-Stage is set to 11
• First, with Emphasis control set to zero:
• LEFT OUTPUT - Output taken from Stage 8
• RIGHT OUTPUT - Output taken from stage 11
• Next, if we set the Emphasis control to 25%
• LEFT OUTPUT - Output taken from Stage 8 plus 25% resonance added from Stage 11
• RIGHT OUTPUT - Output taken from Stage 11 plus 25% resonance added from Stage 11

It can be seen that because we can tap the phaser stages separately this allows is a much more versatile Stereo capability.