The Oakley Sound SE330
The Oakley SE330 is a 'mono in, stereo out' ensemble unit designed to mimic the behaviour of
the multichannel chorus and ensemble units of late 1970s and early 1980s. The SE330 uses
four channels of bucket brigade delay (BBD) lines and four voltage controlled low frequency
oscillators (VC-LFO) to achieve a sound reminiscent of the Japanese string machines, guitar
chorus pedals and studio rack effects of yesteryear. Unlike the original devices the SE330
allows greater control over the modulation depths, speeds and waveforms, as well as featuring
a wet/dry control.
The SE330 features three basic modes:
Quad ensemble:
All four delay lines are operating in this mode – with two BBDs and two
VC-LFOs being used for each stereo channel. This mode is at its most effective when the
wet/dry control is set to around 100% wet.
Stereo ensemble:
In this mode two BBDs are being used, one per stereo channel. Each BBD
can be modulated by its own pair of VC-LFOs. This mode is very effective when the wet/dry
control is set to around 50%.
Dimension
: Again, in this mode, two BBDs are being used. But this time both BBDs are
being driven from the same pair of VC-LFOs. However, one of the BBDs will receive the
inverted outputs of the VC-LFO pair. Like mode 2, this mode is very effective when the
wet/dry control is set to around 50%.
The four VC-LFOs are made from four separate circuits. Two of the LFOs produce sine
waves and two of them produce triangle waves. The SE330 is wired so that each stereo
channel's BBDs are controlled by one set of triangle and sine wave LFOs. Each pair of similar
waveform VC-LFOs are controlled by one set of speed and depth pots. So one set of pots
controls the two sine wave LFOs and one set controls the two triangle wave LFOs. Each pair
of similar waveform LFOs will therefore track each other but one is set to always run 20%
faster than the other.
An effective compander circuit reduces the inevitable noise created by the analogue delay lines
to a respectable level. A peak LED lights when the input signal is getting too big and
noticeable distortion would result.
Input and output level control pots are also provided to allow maximum flexibility in dealing
with a variety of input signal levels. Both the input and output connections are balanced but
can be used with unbalanced connections if desired.
The power to the unit should be a regulated split supply of +/-12V to +/-17V. Power is
admitted onto the main circuit board via a four way 0.156” (2.96mm) header of MTA or KK
type. The module can be powered by our own Rack Power Supply Unit (RPSU) or any other
MOTM compatible supply such as the Oakley PSU . Power consumption is +140mA and
-110mA at +/-15V
The printed circuit board size is 198mm (width) x 234mm (depth).
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