Module Controls & Ins/Outs
sr01w.JPG (21781 bytes)

SR01 Spring Reverb with VCA

Inputs:
Audio In
Wet Mix Level CV 0-12V

Outputs:
3.5mm audio out
6.35mm audio out

Power: +/-12V

Controls:
Input Level, Treble, Wet Mix, Dry Mix, Output, Level

Size: 12HP

Spring Specification:
Dual spring, length: 160mm x2. Feedback/shock reducing mountings.
Output Level Rever time approx. 2 to 4 seconds (frequency dependent).

Introduction

Natural reverbaration is caused by reflected sounds, and in a normal room most of these reflections come from the walls and Ceiling. It is important to differentiate between reverb and echo; an echo is heard as clear repetition of the original sound, whereas reverb consists of numerous reflected sounds which normally come only marginally behind the original sound.

Reverbaration tends to enhance sounds by giving depth and colour, and artificial reverbaration is understandably a very popular effect. There are several non-digital ways of producing artificial reverb, but one of the best methods that produces excellent results at a low cost is the spring-line system as used in the SR01. Spring reverb is the same type of reverb found built into the EMS VCS3 and ARP2600.

A spring-line normally consists of 2 long springs mounted side by side, and having an input transducer at one end and an output transducer at the opposite end. A signal applied at the input transducer results in sound waves being transmitted down the springs, and these are desinged so that there is a significant delay time. Also, in order to produce a more realistic effect it is normal for the springs to give different delay times. The sound waves produce an output signal when they reach the output transducer, but some of the energy is reflected back to the input transducer, and then back to the output transducer where further output signal is produced. In fact, the energy will be reflected up and down the springs numerous times, gradually diminishing until no significant output is produced.

This is obviously analogous to sounds being reflected around a room, and for such a simple system, can give a very realistic effect.


Fitting Details (full details in manual)

Remove spring line from cardboard box. The spring is small enough to fit inside most 3U and 6U cases. To keep mains hum to a minimum, mount spring as far away as possible from the mains transformer. Make sure there is enough clearance for the module PCBs, and that it is clear from the power supply. Ensure no cables interfere with the spring.

General Use

Everything self explanatory really. Feed audio into the spring reverb, take it out into your mixer. All controls self-explanatory. The Wet Mix CV input has a 0-12V range to vary the wet mix level. When using the wet mix CV input, the wet mix control becomes a level offset.

The treble cuts the top end before the signal enters the spring.

Feed you VCO straight into the Reverb, with dry mix to minimum, and wet mix up high. If the pitch is kept constant the VCO takes on a new timbre - strange and metallic. With subtle triangle LFO modulation on the VCO pitch, you start to get a chorusing effect.

Echo Effect

Set-up the reverb as normal. Feed a gate/clock or square LFO waveform signal into the wet mix CV input, and turn the wet mix to a low value. This way the reverb affect sound will be gated as it decays away, creating an echo style effect. (Thanks to Tim Hannigan for this patch).

Weird Effects

Bashing the casing or scraping the springs (not a good idea when spring is mounted inside new to the power supply) is very avant garde.