Issue History
Issue 1 was the first version and is easily identifiable by its use of the green plastic Omeg E16
pots. During 2003 it was reported that some Omeg pots were failing in the field and, indeed,
some had even been supplied to us from the factory as faulty. During that year we completely
revamped the whole Oakley modular range to use a more reliable and expensive part.
The new issue 2 PCBs were made to support Spectrol/Vishay 248 pots and used our specially
made and somewhat expensive Oakley ‘Spectrol’ pot brackets.
The new issue 2 also corrected the small fault in PCB legending which showed Q2 the wrong
way around. It also incorporated two ‘PAN’ pads to allow for easier wiring to the sockets.
The LFO and LFO-NC outputs which had to share a pad on the old issue board now have
their own buffered and isolated output signals. Any loading on the LFO output would not now
affect the depth of modulation to the Equinoxe phaser.
The LED driver was made more complex. The issue 1 design simply relied on a resistor to
control the current through the LED. When the LFO output was very low the LED would
blank out completely. The issue 2 design controlled the LED through a constant current
source. Therefore, although the LED will still vary in intensity and colour with the triangle
waveform output, it never actually goes out. This gives a more useful and pleasant display.
With issue 3, released in 2006, the circuit board was now fully RoHS compliant and was made
using a lead free process. The OTA devices were now two LM13700 instead of four CA3080.
The CA3080 was made obsolete by Intersil, formally Harris and RCA, and in any case was not
available in an RoHS form. Even with this profound change in devices there are no discernible
differences in sound between the issue 2 and issue 3 designs of the Equinoxe.
Also included with issue 3 PCBs was the ability to make the LFO output inverted or non
inverted. However, this was done by fitting certain components and therefore had to be done
at the construction stage. The TUNE trimmer was given a bigger usable range and was made
easier to set.
Issue 4 boards were released in 2009. These were identical to issue 3 but for the addition of
Synthesizers.com power headers.
In late 2009 it was decided to move over to another type of pot. Vishay had pushed the prices
of their old Spectrol range up to such a degree it was not economic to continue to use them.
The BI 260P pot was a useful alternative but stocks were hard to find and the log taper pots
had a poor performance. Issue 5 boards use the Alpha 16mm pots, which are good quality
clones of the standard ALPS 16mm pot.
Issue 5 also incorporates a jumper to select between LFO modes and features a six way header
for expansion to the Deep Equinoxe daughter board.
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