CHORAL REEF

ANALOG CHORUS

COMING SOON

SCHEMATIC (PDF)

This pedal is discontinued. Please check our dealers or our Reverb store for any remaining stock.

The CHORAL REEF analog chorus pedal took 2 years and many failed attempts to perfect. The result was a no-compromise design built upon the MN3008 bucket brigade chip to satisfy VFE’s high standards for noise, headroom, and versatility. A whole host of chorus tones are available, including flanger and vibrato. The unique feedback circuitry lets you add a touch of resonance or dive into deep modulated chaos that rings on after you stop playing.

Click the different parts of the pedal to learn more.

Demos

How It Works

Features

Tech Specs

Story

Older

Versions

CHORAL REEF BLOCK DIAGRAM

Click on any section to learn more

FEATURES & CONSTRUCTION

TrueSoft  Bypass

All Analog Circuitry

Low Noise Op Amp

DualMode Switching

We combine durable true bypass relay switching with an effect-side FET switch for pure and smooth switching.

We use an out-of-production, expensive MN3008 chip for the lowest noise, highest headroom analog chorus.

A modern, high-speed op amp was chosen for its low-noise and high-fidelity properties.

DualMode Switching can convert the footswitch into momentary operation.

To use, wait 5 seconds, then press the sequence tap+tap+hold until LED flashes.

USA Made PCBs

Our circuit boards are made in the USA by Advanced Circuits (large PCB runs) or OSH Park (small PCB runs).

Custom Alpha Pots

We use a custom-designed SPEED pot for the widest possible range, but still easy to fine tune the modulation rate.

All VFE Pedals are built by hand in Puyallup, WA and include:

 

- Rugged diecast aluminum enclosures

- DualMode standard or momentary switching operation

- Industrial-grade Carling switches & Neutrik audio jacks

- Alpha pots soldered directly to PCB

- 5% WIMA film capacitors & 1% metal film resistors

- Ultra-pure, eutectic silver solder

- 1 year warranty on parts & labor

DIMENSIONS:

Enclosure dimensions: 2.37"W x 4.37"L x 1.16"H  (60 x 111 x 29mm)

With knobs & jacks: 2.6"W x 4.4"L x 2.1"H  (66 x 111 x 53mm)

 

POWER:

Standard 2.1mm, negative-tip 9V to 15V power supply or 9V battery.

 

INPUT IMPEDANCE:

1.8M-ohm

 

CURRENT DRAW:

~20ma continous

+30ma surge for 4ms during on/off switching

DIMENSIONS:

Enclosure dimensions: 2.37"W x 4.37"L x 1.16"H  (60 x 111 x 29mm)

With knobs & jacks: 2.6"W x 4.4"L x 2.1"H  (66 x 111 x 53mm)

POWER:

Standard 2.1mm, negative-tip 9V to 15V power supply or 9V battery.

 

INPUT IMPEDANCE:

1.8M-ohm

BY THE NUMBERS:

38 RESISTORS

30 CAPACITORS
1 INDUCTOR

4 TRANSISTORS

7 DIODES

2 OP AMPS

4 INTEGRATED CIRCUITS
8 POTENTIOMETERS
3 SWITCHES

3 JACKS
2 CIRCUIT BOARDS

CURRENT DRAW:

~20ma continous

+30ma surge for 4ms during on/off switching

HOW THE CHORAL REEF CAME TO BE

THE STORY

The first version of the Choral Reef was built in 2011, with the same basic design format as the current model. This early version was a modified clone of the original EHX Small Clone and its MN3007 chip. While the pedal sounded great and was very versatile, this original topology was limited, resulting in a lot of excess noise and a feedback control with a very limited range.

 

I spent more than a year after this initial small run to improve all aspects of the design, from the noise to the feedback circuitry and EQ. The result is a pedal that can play the role of chorus, flanger, vibrato, and many strange, seasick detuning sounds that will make your head spin.

-- Peter Rutter, founder of VFE Pedals --

Here is the list of versions of the Choral Reef circuit:

 

#1 - The original was a clone of the Electro-Harmonix Small Clone chorus. It added a DEPTH control and modified, variable MIX section. It has a 3-way switch & WIDTH control to adjust the delay range, plus variable feedback. Because it was a modified clone and used the original MN3007 bucket brigade chip, some settings had quite a bit of noise & the range of the feedback was very limited.

 

#2 - It took many revisions to get to the current version. During that time, I sold a few preview models at significant discount, some with noise issues in certain settings.

 

Here is what is new in the current version:

- MN3008 for increased delay range and less noise in comparable settings (design is tweaked to allow the user to stretch MN3008 to its limit, which will result in added noise)

- Improved tonal & volume balance of the modulated signal path

- Vastly improved range of the FEEDBACK circuit

- Dual-Mode switching