madbeanpedals Polytrog24 Manual

Polytrog24 Polytrog24
F
MODULATION
X Type:
Build Level: Advanced
Based On: EHX® Polyphase™
The 2024 version of the Polytrog has no circuit changes and minor layout tweaks. A bypass board
is now included with this version.
I don't think I can accurately describe just how much I grew to hate working on this project. Not that
it is a bad effect (it's actually one of the best sounding optical phasers around). Rather, it turned into
the longest development and most frustrating thing I've done for any pedal project, ever. I made
numerous mis-steps and errors, put it aside for months at a time and built maybe seven prototypes
to get it done. But, I never fully quit or gave up on it. Sometimes it does pay to stick with an idea
even when you really want to give up!
The Polytrog is a clone of the vintage (big box) EHX Polyphase. At its core, the Polyphase is a
six-stage optical phaser with a unique envelope control. This is the "quintessential" lush analog
phaser, even though that term gets thrown around way too much. The combination of optical-based
phasing with the high voltage operation puts the Polyphase in a unique category among many of its
contemporaries and successors and a successful build on your part will no doubt find a good home
on your pedalboard.
• ENV/SWEEP: The Polytrog has two modes: Envelope and Sweep. In sweep mode, the LFO is
automatic and the phaser is controlled by the RATE and FDBK pots. In ENV mode, the Sweep
LFO is disabled and a second, envelope driven LFO is enabled. Three controls (ENV SENSE,
ENV MOD and MOD RATE) are available to change the dynamic response of the new LFO.
• RATE: The speed of the automatic LFO. This works only in the Sweep mode.
• FDBK: The amount of feedback sent from the output of the phase stages back to its input. IOW,
a "swoosh" control. FDBK works regardless of what mode you are in.
• ENV SENSE: Controls the sensitivity of the envelope follower is in ENV mode. This is keyed off
playing dynamics. The higher the control, the more sensitive it is.
• ENV RATE: This sets the upper limit (speed) of the envelope controlled LFO in ENV mode.
• ENV MOD: The depth or intensity of the envelope controlled LFO in ENV mode.
• T1: This trimmer is used to set a fixed calibration point in the envelope circuit. See Notes.
• T2: This trimmer is to prevent runaway oscillation in the feedback path.
An older youTube demo:
Terms of Use: You are free to use purchased Polytrog24 circuit boards for both DIY and small commercial operations. You may not offer Polytrog24 PCBs for
resale or as part of a "kit" in a commercial fashion. Peer to peer re-sale is fine, though.
Technical assistance for is available via the
available to respond via email in a timely and continuous manner, and (2) posting technical problems and solutions in the forum creates a record from which other
members may benefit.
All copyrights and registered trademarks are property of their original owners. Any mention of trademarked or intellectual properties in this documents is purely for
comparative purposes.
Overview
Controls
https://www.youtube.com/watch?v=f2wQstrdrfo
madbeanpedals forum. Please go there rather than emailing me for personal assistance. This is because (1) I'm not always
Last Updated:
August 17, 2024 5:57 PM
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