aion HELIODOR AMP OVERDRIVE Руководство - Страница 2

Просмотреть онлайн или скачать pdf Руководство для Музыкальное оборудование aion HELIODOR AMP OVERDRIVE. aion HELIODOR AMP OVERDRIVE 11 страниц.

1 Project Overview

2 Introduction & Usage

INTRODUCTION

The Heliodor Amp Overdrive is based on the BOSS

to the OD-2r Turbo Overdrive.

The OD-3 continues in the tradition of the OD-2/r and BD-2 Blues Driver with BOSS's signature

"discrete op-amp" topology, using two JFETs and a PNP transistor to create a variable gain stage that can

be controlled like an op-amp but clips gracefully when overdriven. Unlike the two earlier units, though,

the OD-2 uses clipping diodes in the this stage to achieve a more traditional soft clipping.

Due to the circuit similarities with the BD-2, it's been theorized that the OD-3 was actually designed as

the successor to the Blues Driver, but that BOSS didn't want to make changes to such a commercially

successful pedal-and as a result, the OD-3 was released under the Overdrive umbrella.

Regardless of what went on in the product development meetings, the OD-3 does borrow ideas from

both the OD-2 and BD-2 and manages to improve on both of them from a design standpoint. The Blues

Driver may get more attention, but the OD-3 remains the crowning achievement of BOSS's discrete op-

amp topology.

The Heliodor is a direct adaptation of the OD-3 with no changes other than converting to true bypass.

The original OD-3 uses the 2SK184-GR JFET, a low-cutoff type similar to J201, but no longer made in

through-hole format. 2SK209-GR is the SMD version that is still in production and will perform exactly

the same as the originals. Each of the JFETs have extra pads for soldering SMD parts, but if you don't

feel confident in your SMD skills, Aion FX sells

through-hole applications.

USAGE

The Heliodor has three controls:

• Drive increases the gain of the discrete op-amp stage, which clips on its own as well as pushing the

second JFET stage into clipping.

• Tone is a passive treble cut before the output volume control.

• Volume sets the overall output of the effect signal.

HELIODOR AMP OVERDRIVE

11 Licensing

OD-3 Overdrive, released in 1997 as the successor

2SK209-GR pre-soldered to adapter boards

to be used in

TABLE OF CONTENTS