Sonic Charge Echobode - Manual (Page 3)

I N T R O D U C T I O N
Echobode is a delay effect with a frequency shifter placed inside the feedback
loop. The frequency shifter algorithm is inspired by the classic Bode Frequency
Shifter (named after its inventor Harald Bode) . The difference between a frequency
shifter and a pitch shifter is that it shifts the audio spectrum linearly. E.g. an
overtone series of 100, 200, 300 Hz can be shifted by 50 Hz to 150, 250, 350 Hz,
making the overtones inharmonic. This effect in itself is great for creating
metallic bell timbres, but putting it inside a delayed feedback loop opens up many
other possibilities.
When a frequency shifter processes
audio, two "sidebands" are generated,
one that is shifted upwards and one that
is shifted downwards. The challenge in
creating a good frequency shifter lies in
suppressing one of these sidebands
(otherwise the effect sounds like a regular
amplitude modulator)
. We are proud to say
that Echobode features excellent
suppression over the range of 40 Hz to
20 kHz. If you want less suppression
there is a "sideband mix" parameter that
you can adjust, allowing you to create
amplitude and ring modulation effects.
Echobode features a unique "anti-
reflection" stage that removes "negative"
frequencies (frequencies that are shifted
down beyond 0 Hz and would otherwise
! © 2012 Sonic Charge! 3