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Quirks
Given the large amount of functionality packed into the Memory Lane, there
were bound to be a few...umm...quirks in the design.
1.
Modulation depth: in tap mode, the modulation depth control provides a
more limited range of modulation depth than in modulation mode. In
modulation mode, depth can be set to much more extreme and 'effect'
like settings which can be conveniently turned on and off with the foot
switch. Just one small note here – at the very highest and extreme
modulation depth settings on the depth knob, very faint modulation may
still be heard with the mod footswitch toggled off due to the soft-switch-
ing nature of the right footswitch mechanism.
2.
LED color and tap/modulation feature modes: this is a really quirky one,
and was simply a case of us running out of board space to add more
control circuitry. In an ideal world, the right LED would have turned red
whenever modulation was on, regardless of whether you are in tap or
modulation modes. Given our limited board space, we made the follow-
ing compromise: with the small feature switch set to tap mode, the right
LED stays flashing green even when modulation is manually turned on,
done so by turning the modulation depth knob clockwise past its 'click'.
However, with the small feature switch switched to modulation mode,
the LED stays flashing green and modulation stays off until the right
footswitch is toggled (regardless of the setting of the modulation knobs),
at which point the right LED turns to flashing red to indicate its 'on' sta-
tus. This turns on whatever modulation setting is set on the modulation
depth and speed knobs. An important note: if modulation is turned off at
the depth knob (fully counterclockwise and clicked off), the footswitch
will still toggle the LED between red and green, but there won't be any
change in modulation. Very quirky indeed. The easiest way to think
about it: when in the modulation feature mode, click the right footswitch
to red, set the depth and speed as desired, then use the footswitch to
toggle that modulation off and on as necessary as you would a separate
effect pedal. It's kind of like having an effect pedal where you may be
able to set its controls to have no audible effect on the signal, but you
can still turn it 'off' and 'on' with the footswitch.
3.
Delay ranges: to provide the highest degree of tap tempo accuracy, in tap
mode the available delay range possible to be tapped is restricted to
between 250 and 550 ms approximately. With the feature switch set to
modulation, the full 40 ms to 550 ms range is available via the delay dial.
A few more words about normal operation. The ongoing appeal of bucket
brigade delay devices can be partly attributed to their somewhat lo-fi sound
quality. Two things in particular contribute to this as a result of using slow
clock rates to achieve longer delay times:
a.
high-frequency rolloff in the delay path – a combination of both the capaci-
tive signal loss as the signal is passed bucket-to-bucket, and the 5th
order analog low-pass anti-aliasing and reconstruction filters required to
fulfill Nyquist theorem requirements to minimize aliasing noise from the
bucket brigades.
b.
noise – each element of the bucket brigade contributes a small amount
of noise to the delayed signal as it is passed on. With 8192 elements
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