Lorre Mill Comb Room User manual

comb resonance - sets the feedback on the comb filter
itself.
comb rate - controls the clock speed of the comb filter,
sweeping the frequency.
envelope - controls the decay of the envelope follower.
mod - changes the amount of envelope signal which
affects either the comb rate or the room rate, selected
with the mod switch.
Lorre Mill 2023
input - controls the volume of the 1/4”, 1/8” and
banana inputs. The gain switch selects gain for the 1/4”
input, 10x or 40x.
comb return - controls the feedback from the comb
filter to the room circuit. Return banana jack will over-
ride the normaled comb output.
dry/wet - is the blend of effected and dry signal. The
select switch connects either comb filter output or room
output as the wet signal.
room rate - controls the clocks of the room circuit,
changing two echo lengths simultaneously.
Comb Room
lorre-mill.com/comb_room
inputs - 1/4” mono input with low/high gain switch and overdrive - 1/8” stereo input sums left and right channels to
mono.
power - 12v DC center positive 2.1mm x 5.5mm barrel 500ma minumum.
outputs - 1/4” mono output with selectable level (use a paperclip or pin to push the switch above the dry/wet
control) - 1/8” mono output on left and right channels.

comb
resonance
comb
return
return
dual delay
&
allpass filter
envelope
follower dry/wet
delta-sigma
comb filter
envelope
mod
room
cv
comb
out
select
room
out
room
rate
comb
cv
output
comb
rate
dry/wet
inputs
input
mixer
preamp
gain
40x 10x
The comb room effect combines a dual delay (room circuit) and a comb filter to make echo/reverb-type sounds
and resonant feedback. The comb filter is in the feedback path of the delays. An envelope follower gives move-
ment to either the comb filter or the room circuit. The comb resonance control in conjuction with the comb
return control can create self oscillation. The preamp for the 1/4” input has selectable gain of 10x or 40x and a
soft clipping characteristic. The comb and room circuits are both built around 1 bit delta-sigma converters. In the
case of the delays, the analog to digital conversion is done in the PT2399 echo IC. The comb filter uses a simple
and gritty A/D converter built of logic chips and op-amps. Which gives the filter a characteristic sound. Clock
noise can be heard at lower frequency settings. Patching the room output to the return will bypass feedback
through the filter, allowing all frequencies to echo.
PLEASE NOTE: Patching either the room output or comb output back into the input will bypass the feedback
limiting circuits and will result in higher volume feedback, this will not damage the device but be aware the
output will be louder and may clip.
Thank You! Enjoy!