Synthesis Technology E520 User manual

E520 Effects
V1.1 – Nov 15, 2020
Menu Organization
Main Page
At power-up the Main Page is active. All effects are accesse in this page which is ivi e in five
separate areas:
1. Hea er area – contains the page title an several in icators, inclu ing the In/Out Filter status,
patch name, Mute status (speaker-slash icon) an EEPROM status light (green means
EEPROM is up-to- ate, re means EEPROM will be up ate with parameter changes within a
few secon s).
2. Menu area – contains four items which can be selecte via the rotary enco er:
1. Exit – select this item an press the enco er button to leave the Main Page an enter the Top
Page which allows access to other menus that control the E520.
2. Algo – select this item an press the enco er button to select the active effect. Selection uses
a pop-up scrolling menu.
3. P2 – rops own into the algorithm-specific settings page where you can change parameter
routing options, In/Out filter settings an a itional per-algo settings (if any).
4. P3 – rops own into the algorithm-specific patch page where you can loa an save
patches for the currently selecte algorithm.
3. Effect area – where the active algorithm ren ers its status
4. VU meters – L/R input an output volume in icators which show real-time signal levels on
input an output channels. When the VU meters show re then there is a strong likelihoo of
clipping istortion.
5. In icators for Fee back an Mix settings – four small sli er wi gets that show the current state
of the Fee back an Mix controls. When these controls are centere the ‘thumb’ of the wi get is
a fille circle, otherwise it is an outline. When Fee back controls are centere the amount of
fee back is zero. When Mix controls are centere the output will be an equal proportion of wet
an ry signal.
6. Buttons – legen s an status of the four UI buttons appear in this area. The three left-most
buttons are e icate to effect parameters while the right-most button is always a bypass
function that isables the effect an passes au io thru the E520 without mo ification.
Pg2
Pg2 (Page Two) off the Main page provi es a list of algorithm-specific settings inclu ing:

Items 1-6 are internal routing matrix settings that allow assigning CV inputs an internal LFOs
to the various parameters of the algorithm.
HPF In – a high-pass filter applie to the au io inputs prior to the algorithm. Can be use to
shape the way the E520 algorithm “sits in the mix”.
LPF Out – a low-pass filter applie to the au io outputs after the algorithm. Also useful for
sculpting the soun of the E520 for mixing.
Some algorithms have a itional parameters on Pg2 an these are escribe in more etail with
each algorithm.
Pg3
Pg3 (Page Three) off the Main page provi es six “Algorithm Specific” patches which use just the
current algorithm. These can be save an loa e using either the four buttons, or the enco er. As
shippe from the factory, at least one of these six will alrea y be efine as a “factory preset”, create
by our own Robert Rich to help emonstrate some of the unique capabilities of the E520.
Top Page
The Top page is use to select other functional pages. It provi es a short list of other pages that can be
entere by scrolling with the enco er an pressing the button. At the bottom of the Top page the current
firmware revision is isplaye .
Prefs Page
The Prefs page provi es a list of e itable parameters which are store in system EEPROM an control
various aspects of operation that are not irectly relate to algorithms an patching.
1. Time Display – select Secon s or BPM for isplay of some time values on the Main page.
2. Frequency Display – select Hz or BPM for isplay of some frequency values on the Main page.
3. Parameter style – select Pie, Arc or Bar for the visual wi get in icator of CV parameters on the
Main Page.
4. Input Level – select Mo ular (12Vpp) or Line (+4 Bu typical, +9 Bu max) for the max input
level on the au io input jacks.
5. Output Level – select Mo ular (12Vpp) or Line (+4 Bu typical, +9 Bu max) for the max
output level on the au io output jacks.
6. Aux Output – select “Algorithm” for auxiliary output from algorithms, or LFO1-4 to rive the
Aux jack with the output of one of the 4 internal LFOs.
7. CV Patch Loa – when “On” the Right Mix CV input can be use to select the active patch
from the 24 Global patches on the Patch page. When “Off” ( efault) the patches must be
selecte manually. Note that when this mo e is active the Right Mix function is still active from
this CV input but may be reassigne to another CV or a fixe value using the assignments on Pg
2.

8. Fee back Limiter – The fee back an filter resonance loops have an optional limiter to
prevent runaway overloa s (“explosions” or “screaming”). When the threshol lou ness is
excee e the gain in the fee back loop is iale own to prevent overloa signals. There are
four settings:
1. Soft. (Default) Threshol of -6 Bfs, 0.8s attack time, 1.6s release time.
2. Me ium. Threshol of -9 Bfs, 0.5s attack time, 1.0s release time.
3. Har . Threshol of -12 Bfs, 0.3s attack time, 0.6s release time.
4. Off. Limiter is isable . Allows irect control of fee back an can allow much longer tails.
Be very cautious with this setting as extremely lou outputs may occur if fee back or
resonance controls are iale up to the extremes.
9. Tempo Hysteresis – Sets the hysteresis win ow below which tap tempo jitter is ignore in some
elay-base algorithms. Values are 2, 5, 10 an 20ms. Use this setting if you’re riving the sync
input with a source that has significant jitter an you want to prevent the elay from constantly
rea justing. The “Tap” mo e of the Scope algo can be use to estimate the amount of jitter
present, then set the Tempo Hysteresis larger than that amount.
10. Wet/Dry mix type – selects the control curves for the Wet/Dry mix knobs:
1. Linear – curves are simple 0-100% ramps that cross at 50/50 in the center.
2. Const Pwr – curves are square-law that cross at 71/71 in the center.
3. Center Full – curves are flat to the center at 100/100 then linear.
11. Sync Rate – selects the sync input ivi er ratio:
1. Quarter – quarter note sync. 1:1 clock ratio.
2. Sixteenth – sixteenth note sync. 4:1 clock ratio.
3. 24PPQ – 24 pulses per quarter note. 24:1 clock ratio.
LFOs Page
The LFOs page provi es an overview of an access to four internal LFOs which can be use instea of
CV inputs to rive any one of the eight algorithm inputs. Each LFO allows control over:
1. Frequency from 100 sec / cycle to 10Hz.
2. Waveform – Sine, Triangle, Saw Up, Saw Down, Square, Slow Noise, Fast Noise, Triangle
Mo ulation, 5-cycle Sine, Full-Wave-Rectifie Sine, 10% pulse, Steppe Ran om an Slewe
Ran om.
3. Offset
4. Depth

A parameter wi get an a waveform isplay are provi e to help visualize the effects of the various
settings.
Patch Page
The Patch page provi es access to twenty four user- efine patches which can use any one of the
available algorithms. Quick access buttons provi e instant loa ing of any one of the first four patches
on the page. These patches can also be loa e via the CV Patch mo e escribe above.
To loa an existing patch, use the enco er to select it an then hit the “Loa Sel” button.
To save a current configuration as a patch, use the enco er to select the esire patch number, then hit
the enco er button to enter the patch naming process. Up to 8 characters may be use to name the patch
using the enco er an buttons to navigate an select letters. When the name is complete, use the Save
button to store the patch.
File Page
The File page provi es access to File Input / Output functions using the SD car slot. Several
operations are possible:
1. Directory – shows a irectory of all visible files on the SD car . If there are more files &
irectories than fit on the screen then scrolling is possible. Use the Top / Bottom buttons to
instantly jump to the beginning or en of the list. One level of irectory epth is allowe , so
clicking on a Directory in the top level (highlighte in a unique color) will rop own. While in
a irectory, one of the buttons becomes the “Dir Up” which leaves the irectory. A “Delete”
button is also available that will elete files an irectories.
2. Sys Save – saves the contents of the system EEPROM to a file on the SD car . Up to 8 letter
names are allowe . The file type is always “.EEP”.
3. Sys Loa – loa s the contents of a “.EEP” file into system EEPROM to restore previous state.
This allows the user to keep an infinite number of unique patch arrangements in separate .EEP
files.
4. Loop Save – Only visible if the current algorithm is Spectral Time Machine or Looper, an the
algorithm is in PAUSE mo e. When these con itions are met then the contents of the au io
buffer can be save on SD car as a stan ar 16-bit 2 channel (stereo) PCM .WAV file. The file
name can be user efine but the file type is always “.WAV”.
5. Loop Loa – Only visible if the current algorithm is Spectral Time Machine or Looper, an the
algorithm is in PAUSE mo e. Allows loa ing the looper buffer with previously recor e
material on the SD car .
Note that while in the File page the E520 au io processing will be mute an the “Speaker-Slash” icon
will be isplaye in the upper right.

Color Page
The Color page allows users to customize the screen colors. There are 10 color types use throughout
the GUI, an each one may be set to any one of 512 colors (eight brightness values for each of R, G
an B components). There are also a number of color presets efine :
1. Default – A cool slate & cream colore scheme that is use on initial power-up.
2. Warm Mo e – a tan scheme with warmer “ esert” tones.
3. Dark Mo e – a cool, ark scheme for use when the lights are low.
4. Bright Mo e – the original color scheme, similar to that use in the E352 an E370 Uis.
Moses Page
A picture of Paul Schreiber’s cat.
About Page
The About page isplays various bits of information about the E520 firmware, inclu ing:
The current CPU loa ing (in the upper left of the isplay)
The time / ate & version of the firmware.
A scrolling marquee of the names of the usual suspects.
The measure Vref voltage. 2.5V is normal
The measure CPU temperature. 30-50C is normal.
A status listing of all the CV an button inputs for iagnosing hookup problems.
About O erloads
In a multi-effects processor like the E520 there are an infinite number of ways to generate overloa s –
situations where the output signal “blows up” an generates maximum lou ness soun s that can
potentially amage equipment an cause iscomfort to the listener. To help avoi this, fee back
limiting is inclu e (see the escription in the Preferences section) which efaults to provi ing some
protection against this an supports even stronger levels of protection. Despite this it’s still possible to
create lou an unexpecte soun s, but this can be minimize with some simple steps:
1. Be careful when switching between algorithms – make sure that the Fee back an Filter
Resonance controls (if any) are not set to extremes.
2. Use the limiter feature provi e on the Preferences page – this applies to almost all algorithms
that support fee back, as well as all algorithms that allow resonant filters. Use extra caution if
the limiter has been isable (“Off” setting).
3. Some algorithms are especially prone to overloa ing:

1. Clean Delay – with both taps active an 100/100 mixing the output signal can naturally be
quite lou . With resonant filtering an strong fee back it will overloa very easily even
when limiting is enable .
2. Dual Mono – in Chain mo e it is very easy to overloa when using fee back.
4. When esigning new patches or just experimenting, be wary of setting fee back an resonance
controls beyon 75%.
Emergency Mute
If the E520 (or an upstream source) happens to generate un esire soun s, an “Emergency Mute”
feature is provi e that will quickly mute the output. Simply press any 3 of the LCD buttons
simultaneously an output au io will cease an a small “Speaker-Slash” icon will appear in the upper
right of the isplay to in icate muting is enable . Pressing 3 buttons again will unmute.

Description of E520 Algorithms
The following are in ivi ual escriptions of each algorithm in the E520. The algorithms are groupe
into several types:
Time Domain Delay effects
Time Domain Shift effects
Looping effects
Spectral effects
Miscellaneous effects
Time Domain Delay Effects
Time omain effects in the E520 are processe without the use of time/frequency transforms an use a
buffer rate that provi es a goo compromise between overhea an latency.
Resampling Mini Delay
O er iew
This effect is base on the E580 Resampling Mini Delay an encompasses or exten s all of its
functions. Stereo inputs are mixe own to a single channel, resample (ie – the sampling rate may be
re uce by a variable amount through a ban -limite interpolation process), pass through a elay line
with a fixe an variable tap, an are then resample to two separate outputs. Separate L/R fee back
controls allow fine a justment of recirculation on both the fixe an variable elay. Three mo e
settings emulate various classical elay characteristics.
CV Inputs
Four CV input parameters are supporte :
1. Tap Offset – controls the position of the variable elay tap. Range is from 0% to 200% of the
fixe tap position. Varying this control in real-time will cause granular cross-fa ing effects as
the elay amount changes. The parameter rea out shows offset as a percentage of the fixe tap.
2. Delay Time – this controls sampling rate over a 1:8 (48kHz-6kHz) range, smoothly varying
elay without granular artifacts but intro ucing consi erable FM. The parameter rea out shows
the time multiplication factor.
3. InMix – The original E580 is a monophonic effect, so on the E520 which is stereo the two
inputs are mixe accor ing to this. Full CCW is 100% Left channel, full CW is 100% Right
channel an 12:00 position is 50/50 mix. The parameter rea out shows percent L & R.
4. Multifunction – varies epen ing on mo e selection:
1. Clean mo e – no functions

2. BBD mo e – re uces SNR by a ition of noise.
3. Tape mo e – controls ran om elay time variation. Similar to unstable tape spee warble.
Buttons
Three button functions are supporte :
1. Range – Four elay settings for the fixe tap: 1x, 16x, 256x, 4096x allow elays from 0.196s to
~10min.
2. Mo e – Similar to the E580, there are three operating mo es:
1. Clean mo e – Basic elay function with no istortion or filtering asi e from the normal
resampling process.
2. BBD mo e – Emulates ol -style bucket-briga e circuit with rolloff starting aroun 4kHz.
The fourth parameter controls a variable noise floor.
3. Tape mo e – Emulates ol -style tape loop, inclu ing saturation istortion, slight peaking
an rolloff aroun 2kHz. The fourth parameter controls tape warble.
3. Freeze – Au io in the elay line is “frozen” an no new au io overwrites it. Fee back controls
on’t have any effect an the contents repeats at the elay rate.
Readouts
In a ition to the parameter rea outs there are four in icators:
1. Range – the range button selection
2. Mo e – the mo e button selection
3. Fixe Delay – the time elay on the fixe tap
4. Tap Offset – the time elay on the variable tap
Page 2 Settings
There are two Page 2 settings:
▪Tape NL - controls the type of nonlinearity applie in Tape mo e. Settings are None, 2n , 3r , 4th –
the exponential or er of the nonlinearity.
▪Tempo Ratio – controls an a itional ratio between the Tap Tempo an timing. Values are 1/1, 3/2,
2/1, 3/1, 4/1, 8/1, 16/1,2/3, 1/2, 1/3, 1/4, 1/8, 1/16
Feedback
Both fee back knobs are active in this effect.
Tap Tempo
Tap Tempo is active an controls the amount of fixe elay. Use the range button to return to the fixe
ranges. Tap Tempo status is shown in the upper left of the effect area: No in icator means tap tempo is
inactive, “...” means that some taps are etecte an the algorithm is acquiring the tempo, while “TT”

signifies that tempo is active an overri es the Range setting. Tap intervals longer than ~5 secon s
cause the tempo calculation to reset.
Auxiliary Output
This effect has no auxiliary output.
Clean Delay
O er iew
The Clean Delay is a non-resampling elay (ie – the sampling rate is constant throughout the
processing) which always runs at the full 48kHz rate an intro uces no interpolation artifacts into the
signal while the elay length is stable. This is a true stereo effect in that there are separate elay lines
for Left an Right channels but they are processe i entically (same elay length, same filtering, etc.).
A switchable resonant 4th-or er lowpass filter is available in the fee back path if esire . Ping-pong
fee back between the two channels may be enable .
CV Inputs
Three CV input parameters are supporte :
1. Dly Len – this controls the length of the elay line. Varying this control in real-time will cause
granular cross-fa es as the length changes. The parameter rea out is in percentage of the full
range from 0-99%.
2. Tap Offset – controls the position of the variable elay tap which is mixe with the main elay
accor ing to the proportions selecte on a Pg2 setting. Range is from 0% to 200% of the Delay
Length from parameter #1. Varying this control in real-time will cause granular cross-fa ing
effects as the elay amount changes. The parameter rea out shows offset as a percentage of the
Delay Length. When set to 0% this tap is isable .
3. Filter Cutoff Frequency (when filter enable ) – controls the lowpass filter cutoff frequency. The
parameter rea out is in kHz from 0-24kHz. When the filter is isable this parameter is graye
out.
4. Filter Resonance (when filter enable ) – controls the lowpass filter resonance. The parameter
rea out is in percentage from 0-99% where 0% is no resonance. When the filter is isable this
parameter is graye out. Be careful – the filter may self-oscillate when this parameter is near
99% an can cause overloa s in some situations.
Buttons
Three button functions are supporte :
1. Range – Four elay ranges: 1x, 16x, 256x, 4096x allow elays from 0s to ~6min.
2. Swap – swaps the fee back paths of the L & R channels so that au io “ping-pongs” between the
two channels.
3. Filt – enables the filters.

Feedback
Fee back is active for this effect.
Readouts
There are five rea outs for this effect:
1. Range – 1x thru 4096x
2. Swap – on/off
3. Filter – on/off
4. Time – main elay time in secon s
5. Offset – elay time of the tap in secon s
Page 2 Settings
There two a itional Page 2 settings:
▪Tap Mix - provi es several options for mixing the main an aux taps – either 100/100, 90/10, 50/50
or 10/90. Use caution with the 100/100 setting as this, couple with extreme fee back or resonance
settings can easily result in overloa s.
▪Tempo Ratio – controls an a itional ratio between the Tap Tempo an timing. Values are 1/1, 3/2,
2/1, 3/1, 4/1, 8/1, 16/1,2/3, 1/2, 1/3, 1/4, 1/8, 1/16
Tap Tempo
Tap Tempo is active an controls the Delay Length. Use the range button or Delay Length parameter to
resume knob/button control. Tap Tempo status is shown in the upper left of the effect area: No in icator
means tap tempo is inactive, “...” means that some taps are etecte an the algorithm is acquiring the
tempo, while “TT” signifies that tempo is active an overri es the Range setting. Tap intervals longer
than ~5 secon s cause the tempo calculation to reset.
Auxiliary Output
This effect has no auxiliary output.
Resampling Delay
O er iew
The Resampling Delay is a variable-rate interpolating elay which allows control of both the elay line
length (for granular cross-fa e effects) as well as sample rate (for smooth elay changes an FM
effects). This is a true stereo effect in that there are separate resamplers an elay lines for Left an
Right channels but they are processe i entically (same elay length, same filtering, etc.). A switchable
resonant 4th-or er lowpass filter is available in the fee back path if esire . Ping-pong fee back
between the two channels may be enable .

CV Inputs
Four CV input parameters are supporte :
1. Dly Len – this controls the length of the elay line. Varying this control in real-time will cause
granular cross-fa es as the length changes. The parameter rea out is in percentage of the full
range.
2. Delay Time - this controls sampling rate over a 1:8 (48kHz-6kHz) range, smoothly varying
elay without granular artifacts but intro ucing consi erable FM. The parameter rea out shows
the time multiplication factor.
3. Filter Cutoff Frequency (when filter enable ) – controls the lowpass filter cutoff frequency. The
parameter rea out is in kHz from 0-24kHz. When the filter is isable this parameter is graye
out.
4. Filter Resonance (when filter enable ) – controls the lowpass filter resonance. The parameter
rea out is in percentage from 0-99% where 0% is no resonance. When the filter is isable this
parameter is graye out. Be careful – the filter may self-oscillate when this parameter is near
99% an can cause overloa s in some situations.
Buttons
Three button functions are supporte :
1. Range – Four elay ranges: 1x, 16x, 256x, 4096x allow elays from 0s to ~6min.
2. Swap – swaps the fee back paths of the L & R channels so that au io “ping-pongs” between the
two channels.
3. Filt – enables the filters.
Page 2
There is one a itional Pg2 setting:
Tempo Ratio – controls an a itional ratio between the Tap Tempo an timing. Values are 1/1,
3/2, 2/1, 3/1, 4/1, 8/1, 16/1,2/3, 1/2, 1/3, 1/4, 1/8, 1/16
Feedback
Fee back is active for this effect.
Readouts
There are four rea outs for this effect:
1. Range – 1x thru 4096x
2. Swap – on/off
3. Filter – on/off
4. Time – time elay in secon s

Tap Tempo
Tap Tempo is active an controls the Delay Length. Use the range button or Delay Length parameter to
resume knob/button control. Tap Tempo status is shown in the upper left of the effect area: No in icator
means tap tempo is inactive, “...” means that some taps are etecte an the algorithm is acquiring the
tempo, while “TT” signifies that tempo is active an overri es the Range setting. Tap intervals longer
than ~5 secon s cause the tempo calculation to reset.
Auxiliary Output
This effect has no auxiliary output.
Prime Delay
O er iew
The Prime Delay is an emulation of the Lexicon Prime Time rack-mount elay. It is a resampling elay
which allows control of both the elay line length (for granular cross-fa e effects) as well as sample
rate (for smooth elay changes an FM effects). As the original, this is a mono effect in that there is
one elay line whose input is an equal mix of Left an Right channels an separate output taps for Left
an Right channels with in epen ent elay lengths that are selectable from a pre- etermine set which
inclu es elays that have relatively prime ratios. Controllable 4th-or er lowpass filters are available in
the fee back path if esire . Buffer lengths well beyon that of the original Prime Time effect are
available an the two outputs may be mixe own to mono if esire .
CV Inputs
Four CV input parameters are supporte :
1. Delay Set A – this controls the length of the A elay line. Varying this control in real-time will
cause granular cross-fa es as the length changes. The parameter rea out is in millisecon s
assuming the VCO is in “Cal” mo e. There is a limite list of elay values, some of which are
“prime” which is in icate above the control.
2. Delay Set B – this controls the length of the B elay line. Varying this control in real-time will
cause granular cross-fa es as the length changes. The parameter rea out is in millisecon s
assuming the VCO is in “Cal” mo e. There is a limite list of elay values, some of which are
“prime” which is in icate above the control.
3. VCO A j – this varies the sample rate over a 1:2 range. Fully CCW is consi ere “Calibrate ”
an an in icator above the control will reflect this. As the control is rotate CW the sample rate
is increase by up to 2x an the in icator will show “Uncal” to reflect that the sample rate is
not locke own at a precisely known rate. The parameter rea out is in percent from 0-99%.
Note – the E520 har ware oes not support the full VCO range of the original Prime Time unit,
so in the 1x Mult range the VCO A j control oesn’t exten higher than 50%.
4. Rolloff – controls the lowpass filter cutoff frequency. The parameter rea out is in kHz from
0.8kHz to 15.0kHz (the full range of the original Prime Time).

Buttons
Three button functions are supporte :
1. Delay Mult – Four elay multiplier ranges as in the original Prime Time: 1x, 2x, 4x, 8x. These
settings re uce the effective sample rate by the selecte amount.
2. Buf Len – three buffer length controls which enable elay settings beyon those of the original
Prime Time. The 8k setting is equivalent to the original, while the 64k an 256k setting allow
much longer elays.
3. Mix – Allows combining the Left & Right output channels.
Page 2
There are no a itional Page 2 settings for this algorithm.
Feedback
Fee back is active for this effect.
Readouts
There are four rea outs for this effect:
1. Delay Mult – 1x thru 8x
2. Buf Len – 8k thru 256k
3. Mix – L+R (mixe ) or L/R (separate)
4. A: – blank or Prime
5. B: - blank or Prime
6. VCO – Cal or Uncal
7. Repeat – Highlighte when in repeat mo e (buffer freeze)
Tap Tempo
Tap Tempo is repurpose to enable/ isable the Repeat mo e. In Repeat mo e the au io input is
isable an the buffer recirculates with the previous contents until Repeat is isable .
Auxiliary Output
This effect has no auxiliary output.
Re ersable Delay
O er iew
The Reversable Delay is a reversing an resampling elay which allows control of both the elay line
length (for granular cross-fa e effects) as well as sample rate (for smooth elay changes an FM
effects). This is a true stereo effect in that there are separate resamplers an elay lines for Left an
Right channels but they are processe i entically (same elay length, same filtering, etc.). A switchable

resonant 4th-or er lowpass filter is available in the fee back path if esire . The unique features are
that this elay can be run forwar or backwar s an it can be “frozen” to keep playing the current elay
contents without changing.
CV Inputs
Four CV input parameters are supporte :
1. Dly Len – this controls the length of the elay line. Varying this control in real-time will cause
granular cross-fa es as the length changes. The parameter rea out is in percentage of the full
range which is fixe at 5.4 secon s.
2. Delay Time - this controls sampling rate over a 1:8 (48kHz-6kHz) range, smoothly varying
elay without granular artifacts but intro ucing consi erable FM. The parameter rea out shows
the time multiplication factor.
3. Filter Cutoff Frequency (when filter enable ) – controls the lowpass filter cutoff frequency. The
parameter rea out is in kHz from 0-24kHz. When the filter is isable this parameter is graye
out.
4. Filter Resonance (when filter enable ) – controls the lowpass filter resonance. The parameter
rea out is in percentage from 0-99% where 0% is no resonance. When the filter is isable this
parameter is graye out. Be careful – the filter may self-oscillate when this parameter is near
99% an can cause overloa s in some situations.
Buttons
Three button functions are supporte :
1. Reverse – pressing this button switches the irection of recor ing in the buffer memory. Soun s
alrea y in the buffer will play in the opposite irection an new soun s recor e into memory
will go in reverse.
2. Freeze – pressing this button enables/ isables Freeze mo e, wherein no new soun s are
recor e into the memory an the contents of the memory will continue to play out unchange .
3. Filt – enables the filters.
Page 2 Settings
There are four a itional Page 2 settings for this algorithm:
1. Glitchy (On/Off) – “On” ( efault) isables the controlle transitions but may intro uce clicks
an pops. When in “Off” mo e changes to the length of the elay line use crossfa es to smooth
the transition, but intro uces some lag in responsiveness, especially if the Dly Len parameter is
changing frequently.
2. Rev Src – allows selection of the source for the Reverse comman . By efault this is controlle
by Button 1, but may be controlle by any CV input crossing a threshol .
3. Frz Src – allows selection of the source for the Freeze comman . By efault this is controlle
by Button 2, but may be controlle by any CV input crossing a threshol .

4. Tempo Ratio – controls an a itional ratio between the Tap Tempo an timing. Values are 1/1,
3/2, 2/1, 3/1, 4/1, 8/1, 16/1,2/3, 1/2, 1/3, 1/4, 1/8, 1/16
Feedback
Fee back is active for this effect.
Readouts
There are four rea outs for this effect:
1. Reverse – highlighte when in reverse mo e.
2. Freeze – highlighte when in freeze mo e.
3. Filter – on/off
4. Time – time elay in secon s
Tap Tempo
Tap Tempo is active an controls the elay length. A just the Delay Length parameter to switch control
back to that parameter. Tap Tempo status is shown in the upper left of the effect area: No in icator
means tap tempo is inactive, “...” means that some taps are etecte an the algorithm is acquiring the
tempo, while “TT” signifies that tempo is active an overri es the Range setting. Tap intervals longer
than ~5 secon s cause the tempo calculation to reset.
Auxiliary Output
This effect has no auxiliary output.
Diffusion Flanger
O er iew
The Diffusion Flanger is short elay which allows smooth control of the elay line length over intervals
of 0-5ms which makes it particularly useful for Flanging an Karplus-Strong effects. This is a true
stereo effect in that there are separate elay lines for Left an Right channels but they can be processe
i entically. The unique feature of this algorithm is the inclusion of an 8-stage allpass iffuser at the
input with control over mix an length which can be use to “thicken” up the soun prior to flanging.
A itional features are that the elay control can be one either in linear time or exponential frequency,
an that the output can be set into “flanger mo e” which makes comb-filter soun s easier to achieve.
CV Inputs
Four CV input parameters are supporte :
1. Diffuse – this is a two-mo e control which varies the mix an length of the iffuser. Use button
1 on the right of the isplay to select control of either the mix or the length – the uncontrolle
parameter will be hel at its last value (the value is save uring reset / power-cycle). Mix
ranges from 0-99% an operates like a wet/ ry control. Length rea out is isplaye as

percentage with a maximum of more than 1 secon . Current values of both parameters are
isplaye in a rea out near the top of the screen.
2. Delay Time - this controls the elay over a 0-5ms range when in Time mo e an a 20Hz-20kHz
range when in Frequency mo e, smoothly varying elay without granular artifacts but
intro ucing consi erable FM. The parameter rea out is in percent of maximum but the actual
Time or Frequency value is isplaye in a rea out near the top of the screen.
3. LFO Freq – this controls the frequency of the integrate low-frequency oscillator. The
parameter rea out varies from 100 sec-1sec/1-11Hz in an exponential curve that provi es
greater sensitivity in the low frequency range.
4. LFO Depth – this controls the amplitu e of the LFO waveform as it is summe with the Delay
Time parameter. The parameter rea out varies from 0-99%.
Buttons
Three button functions are supporte :
1. Diff Sel – toggles between CV1 controlling either the mix or length of the iffuser.
2. T/F Mo e – toggles between CV2 controlling elay time in either Time or Frequency mo e.
3. Out Mo e – toggles between pure elay output an “Flange” output which performs a 100/100
mix of the elay line input an output. Flange mo e provi es for the eepest comb notches
which enhances the soun of the classic effect.
Page 2 Settings
There are no a itional Page 2 settings for this effect.
Feedback
Fee back is active for this effect.
Readouts
There are three rea outs for this effect:
Time / Freq – isplays the elay length as either time or frequency.
DMix – the current value of the Diffuse Mix parameter.
DLen – the current value of the Diffuse Length parameter.
Tap Tempo
Tap Tempo is active an controls the LFO rate. A just the LFO rate parameter to switch control back to
that parameter. Tap Tempo status is shown in the upper left of the effect area: No in icator means tap
tempo is inactive, “...” means that some taps are etecte an the algorithm is acquiring the tempo,
while “TT” signifies that tempo is active an overri es the LFO rate setting. Tap intervals longer than
~5 secon s cause the tempo calculation to reset.

Auxiliary Output
The elay time value (with offset an LFO) is available on the auxiliary output.
Chowder Delay
O er iew
The Chow er Delay is use to chop/slice incoming au io into “chunks” which are ran omly reor ere
in time with optional reversing an pitch shifting. Various parameters provi e control over the chunk
size, probability of chopping, reversing an shifting, as well as the time span of reor ering. Clean 5ms
splices are create between chunks to avoi unpleasant clicking transitions. Tap Tempo is use to set
the base time rate.
CV Inputs
Four CV input parameters are supporte :
1. Chop Div – Chop Division controls the size of the chunks. Tap Tempo establishes the uration
of a quarter note an the Chop Div parameter scales that from whole notes to 1/64th notes.
2. Sttr Prb – Stutter Probability controls the probability that a chop/slice operation will occur. At
full CCW rotation chopping will never happen. At full CW rotation every chunk will be
choppe .
3. Chop Or – Chop Or er controls how far back in time to go when fetching alternate chunks to
insert into the output stream. From full CCW (0%) the range increases up to the limit
etermine by the Buf Mult button setting. Beyon 50% to full CW the probability that the
chunk will be reverse increases from 0 to 100%.
4. Ptch Prb – Pitch Probability controls the probability that a pitch shift will be applie to any
chunk.
Buttons
Three button functions are supporte :
1. Buf Mult – selects one of four possible maximum elays over which the Chop Or control
operates. Range is 4 chunks to 32 chunks.
2. Stutter – manually forces a repeat of the most recent chunk. Overri es all ran om operations.
3. Freeze – toggles Freeze mo e where no new au io is recor e in the elay buffer. Chopping
still takes place but only on material alrea y in the buffer.
Feedback
There is no fee back an the controls are repurpose in this effect.
Left Fee back – Repeats. Controls the maximum number of repeats ran omly applie to any stutter
operation. CW from center varies from 1-15 while CCW from center varies from 1-15 an also forces
reverse play.

Right Fee back – Pitch Shift. Controls the amount of pitch shift applie to any stutter operation. CW
from center is upwar shifts while CCW from center is ownwar shift. Repeate stutters will
compoun shifts up to one octave an then wrap back to no shift.
Readouts
There are three rea outs for this effect:
1. repeats – isplays the number of repeats selecte by the Left Fee back.
2. pitch – isplays the pitch shift selecte by the Right Fee back.
3. Flashing Chunk In icator – a ot in the upper center flashes at the chunk timing rate.
Page 2 Settings
There are 3 a itional settings on Pg2
1. Chl Diverge – Channel Divergence. When set to “Off” the right an left channels will have
i entical chopping operations applie . When “On” the channels are in epen ently processe
an will behave ifferently epen ing on the ran om probability settings.
2. Ptch Quant – Pitch Quantization. When “Off” the pitch selection on the Right Fee back is
unconstraine an can select any pitch shift amount between +/- 800 cents. When “On”, only
multiples of 100 cents are allowe .
3. Sync Phase – Controls the timing phase of the chopping process relative to the Tap Tempo
input. Values of -10ms, 0ms an +10ms are allowe an control alignment of the chopping
point. Default is -10ms but a value of 0ms will most often ensure that notes are not choppe
uring their attack.
Tap Tempo
Tap Tempo is active an controls the basic quarter note timing. A just the LFO rate parameter to switch
control back to that parameter. Tap Tempo status is shown in the upper left of the effect area: Current
tempo is always isplaye , “...” means that some taps are etecte an the algorithm is acquiring the
tempo, while “TT” signifies that tempo is active. Tap intervals longer than ~5 secon s cause the tempo
calculation to reset. Tempo rate is save when switching algorithms or powering own. Apply a
continuous quarter-note clock (as from a sequencer) to keep the chopping process in sync with the
external source.
Auxiliary Output
This effect oes not rive the auxiliary output.
Pattern Delay
O er iew
The Pattern Delay is a stereo tappe elay line with CV-controlle tap patterns. Each channel (left /
right) has its own separate elay line with two sets of taps – Primary an Secon ary. The patterns are
chosen from a set of 64 an the length of the patterns can be a juste via buttons. Mixing between

Primary an Secon ary, filtering an fee back all allow control over the complexity an ynamics of
the output. Tap Tempo is use to set the base time rate an a selectable multiply/ ivi e ratio can scale
the rate.
CV Inputs
Four CV input parameters are supporte :
LPri Dnsty – Left Primary Density. This selects a pattern for the left primary taps. Density of the active
taps increases with increasing voltage.
RPri Dnsty – Left Primary Density. This selects a pattern for the right primary taps. Density of the
active taps increases with increasing voltage.
2n Dnsty – Secon ary Density. This selects a pattern for the left an right secon ary taps. Density of
the active taps increases with increasing voltage.
P/S Mix – Primary / Secon ary mix. This allows proportional mixing of the Primary an Secon ary
taps into the final output for both left an right channels.
Buttons
Three button functions are supporte :
Len Sel – selects one of six possible length parameters to a just:
◦L Pri – Left Primary pattern length
◦L Sec – Left Secon ary pattern length
◦R Pri – Right Primary pattern length
◦R Sec – Right Secon ary pattern length
◦L FB – Left Fee back tap position
◦R FB – Right Fee back tap position
Len A j – Cycles through 1-16 for length parameter selecte by Button 1.
Tap Mult – Cycles through Mult/Div ratios for tap tempo. Possible values are: 1/1, 3/2, 2/1, 3/1,
4/1, 8/1, 16/1, 2/3, 1/2, 1/3, 1/4, 1/8, 1/16
Feedback
Fee back knobs are active an control both fee back an filter cutoff frequency. Top center position is
isable as usual. Turning CCW enables fee back AND filtering. Turing CW enables only fee back.
Readouts
The pattern settings are isplaye above the CV wi gets in two groups. Left channel patterns in the left
group, Right channel patterns in the right group. Each group consists of three lines:

Top line – Primary pattern
Mi le line – Secon ary pattern
Bottom line – position of fee back tap
Within each line are three types of symbols:
Fille circle – active tap
Empty circle – inactive tap
Dot – beyon length of pattern, or fee back position.
Page 2 Settings
There are 4 a itional settings on Pg2
Pri Filt – enables / inverts / isables lowpass filter on primary taps.
Sec Filt – enables / inverts / isables lowpass filter on secon ary taps.
L FB – enables / isables Left channel fee back.
R FB – enables / isables Right channel fee back.
Tap Tempo
Tap Tempo is active an controls the basic timing interval. Tap Tempo status is shown in the upper left
of the effect area: Current tempo is always isplaye , “...” means that some taps are etecte an the
algorithm is acquiring the tempo, while “TT” signifies that tempo is active. Tap intervals longer than
~5 secon s cause the tempo calculation to reset.
Auxiliary Output
This effect oes not rive the auxiliary output.
Resonators
O er iew
Resonators is an array of four tunable elay line resonators with several ifferent ways to assign pitch.
Tap Tempo an Sync inputs can be use to stimulate the system for Karplus-Stong effects. This is a
stereo effect with separate resonators for left an right channels which are tune to follow each other.
CV Inputs
Four CV input parameters are supporte an their functions change with the selecte pitch mo e. Pitch
sensitivity is approximately 1V/Oct – as close as is possible with the uncalibrate CV input paths on
the E520 when the attenuator knobs are turne fully CW.
Buttons
Three button functions are supporte :
Quant : Selects the type of pitch quantization use for assigning pitch to the resonators