- Tuning, glide, pitchbend depth, and other global
parameters are here.
- The dual LFOs go into the audio range, and can be
used as extra oscillators.
- Oscillator 2 can be soft-synced or cross-modulated.
- The mixer has three modulation inputs for
hardwired signals, plus an extra signal input at
- Each filter has both lowpass and highpass/bandpass/
- These “mults” are for mixing signals and modulating
- The ADSR envelopes can treat the sustain portion as
a rising or falling slope, with adjustable rate.
- Panning can be modulated in the dual output
- Here’s where you patch in modulation sources
such as breath control and aftertouch.
I’m a big fan of Zebra, U-he’s flagship
softsynth. When I heard about ACE, I
thought, “Oh, that’s cute — a stripped-down
little brother for Zebra.” Boy, was I
wrong. ACE may have a modest price and
a modest list of modules, but its sound
palette is very broad, and the sound itself is
satisfyingly rich and “vintage.”
ACE’s design is very loosely based on
the fabled ARP 2600. It has a fixed set of
modules, all of which are immediately visible
on the panel. These are “normalled” to
one another for easy sound programming —
if you don’t do anything with virtual patch
cords, you get a familiar oscillator-to-filterto-
envelope signal flow. Like the 2600,
ACE also has numerous patch points. You
can interrupt the normalled signal path with
any other signal you choose, simply by
dragging a patch cord from an output to an
input with the mouse.
What sets ACE apart, though, isn’t just
the patching. Most digital and software
synthesizers use control signals (such as
the output of an LFO or envelope generator)
that run at a fraction of the audio sampling
rate. This saves on CPU power. In ACE,
everything runs at twice the sampling rate of your host DAW. The downside: ACE is
something of a CPU hog. The benefit: You
can jam an LFO up into the audio range
and use it as a third oscillator, or use it to
frequency- or amplitude-modulate one of
the other oscillators or a filter. Hence the
acronym: ACE stands for Any Cable
Installing ACE on my new Windows 7
computer was painless, and it ran without
problems in both Steinberg Cubase 5 and
Image-Line FL Studio 9. The factory presets,
created by well-known sound
designers Howard Scarr, Skippy
Lehmkuhl, and others, are plentiful, varied,
and high-quality. Basses, leads, keys,
pads, chord stabs, rhythm patterns, analog
percussion, modular madness — everything
is neatly categorized in the browser,
which also has a display pane for the
patch creator’s performance notes.
Learning my way around the ACE panel
took a couple of hours. The jacks aren’t
labelled, so I made a couple of wrong
assumptions — but also, the number of
ways to patch things together is vast! Getting
buzzy, grinding tones is easy, but I’ll
need a lot more time to explore the full
range of possibilities.
ACE has a four-position switch for
“quality” (presumably the internal sampling
rate). A “draft” rate saves on CPU cycles,
but may sound audibly thinner or have
aliasing. Three knobs you don’t usually
see are for slop, crosstalk, and even simulated
capacitor failure in the oscillators.
These all add to the analog instability of
the tone (and yes, like ACE’s other knobs,
they respond to MIDI control). These
knobs are on a second panel, called
Tweak (click on image below). This panel is also where the mapping
generator lives — see the “Mapper”
For fat sounds, up to eight voices can
be stacked and detuned to produce chorusing
or one-finger chords. (The voices
can’t be panned separately, however.) On
my system, using more than four voices
sometimes caused the signal to suffer a
short delay or breakup during its initial
attack, even with a very simple patch — but
since you can produce 16-note chords
with four voices, this is not a big problem.
ACE has two glide controls: VCO1
and VCF1 can glide at a different rate
from VCO2 and VCF2. With patches that
use oscillator sync or filter overdrive, this
can add some nice bite to the attacks of
notes that are more than a whole-step
apart, as the two oscillators will be sounding
different pitches for a brief moment.
Also available is an ARP-style duophonic
keyboard mode, in which VCO1 tracks the
lowest note you play and VCO2 the highest
note. Duophonic mode opens up
some unusual possibilities, especially if
VCO2 is soft-synced.
The factory presets (several hundred of
them) are incredibly varied. A couple of
one-finger chord patches turned into riffs,
which quickly became the basis of a new
piece that I’m planning to include on an
If you’ve ever patched an analog synthesizer,
you’ll understand the basics of sound
design with ACE, and we’re not going to
explain filter cutoff or ADSR envelopes in
this review. But ACE gives patching a few
A glance at the panel seems to show
two LFOs and two VCOs (tone oscillators),
but that’s a misleading impression. In fact,
the LFOs are full-range audio oscillators, so
what you’re really looking at are four oscillators,
each of which has different controls.
They have five frequency modes — semitone,
partial, subharmonic, Hertz, and clock
sync. In the first three modes, they track the
keyboard. These modes interact with an
unusually flexible fine-tune knob, which has
four modes — multiply, cents, 5Hz, and
beats. (Multiply mode can trip you up,
because you can set it to zero, which will
turn the oscillator off.) There’s also a suboscillator,
which always tracks the
frequency of VCO1.
VCO2 can sync to VCO1 or be crossmodulated
or ring-modulated by it — or all
three at once, in varying amounts. Analogsounding
soft sync is produced when the
sync knob is turned up only part way. While
looking for a lead tone for a new piece, I
was twiddling these controls and stumbled
onto some overtones that were quite violinlike.
Nobody would mistake the patch for a
real violin, but it has a similar character. I
did it by soft-syncing VCO2 to VCO1 at
about 45%, setting the VCO2 coarse tune
knob to partial mode, and dialing the partial
up to about 7.6. These controls are quite
sensitive to small changes, so finding this
tone was a happy accident.
LFO1 has only one waveform (sine),
but it also has an input for sample-andhold
effects. LFO2 has five waveforms.
The LFOs can run in gate mode, in which
each new note starts its own LFO at a
point determined by the phase knob, or
in free-run mode, in which all voices
share one LFO.
Not enough LFOs to suit you? Use the
ramp generator. This has no inputs or waveform
selections, but it can either loop, producing
a repeating waveshape, or trigger
once and then stop to produce an attack
transient. Its up, hold, and down knobs can
sync to quarter-notes or whole-notes — or to
decimal fractions thereof, so if you need,
say, a five-against-four cross-rhythm, just set
a knob to 20 and you’re in business. This
feature is also available with LFO rates.
The filters each have two simultaneous
outputs. One output gives you a
choice of four lowpass modes (singlepole
through four-pole), while the other
has a choice of highpass, bandpass, or
notch. The filters can be overdriven at
the input with a gain knob. They can
self-oscillate and be modulated by
audio-rate signals for rich Minimoogstyle
The envelopes are basic ADSRs, not
multi-segment types, but each of them has
four input knobs, two each for time and
level control. The fall/rise knob turns the
sustain “level” into a rising or falling slope.
(Due to limited panel space, the fall/rise
rate knob is in the ADSR, while the fall/rise
amount is tucked away on the Tweak
page.) Envelope output can be controlled
via velocity. In addition, knobs for level and
rate control can accept inputs from various
Near the bottom of the panel are two
multiples. In a hardware synth, these would
often be needed to split a signal to several
outputs, but ACE can stack multiple patch
cords on any output. The multiples are
used to mix signals before sending them to
inputs, and also to modulate their amounts
in various ways, including crossfading.
The row of output jacks along the bottom
gives quick access to ten useful signals,
including MIDI key number, velocity, noise,
mod wheel, and aftertouch. At the other end
of the signal chain, ACE has dual output
VCAs, which can be panned separately.
The animated waveform display is a toy,
but it’s well-designed: It attempts to sync
to the fundamental of the waveform, making
it easier to watch the dancing squiggles.
More practical is that the numerical
value of each edit is shown in the display,
and you can move in finer increments by
ACE has one extremely useful module
whose concept is, frankly, digital. The mapping
generator (see Figure 1 above) can be
a keyboard zone mapper or a primitive step
sequencer, among other things.
The mapper provides up to 128 userdefinable
steps, which are edited graphically
on a nice big display. It operates in
one of four modes. In Alternate mode, it
moves to a new step each time you press
a key. In Key mode, each MIDI key selects
a step in the mapper, which means you
can have a different output level from
each key on the keyboard if desired. In
Map Smooth and Map Quantize modes, it
accepts a signal input and maps the level
of this signal onto an output in either
smooth or stepped fashion. This is useful
for setting up a nonlinear velocity
response curve, for creating a stepped
output from an LFO, and so on. Utility
commands let the data in the mapper be
randomized or quantized to clamp it to a
certain number of discrete values (four or
eight, for instance).
When the input is a repeating signal
from the ramp generator, the stepped output
produces a regular rhythm pattern,
useful for step sequencing. The mapper’s
output can also be used as a waveform
for LFO 2.
There are two main reasons to like ACE:
It’s highly patchable, and it sounds very
analog. Make that three — there’s the
very modest price. Patching with cords
(even when you do it with a mouse) is
much more fun than dialing up values in
a number-filled matrix. While the panel
looks simple, with everything plainly visible
on the surface, the voice design is
packed with unusual options — and yet
they’re easier to understand and deal
with than in some of the extremely feature-
rich soft synths I’ve looked at,
because the signal routing is always
For anyone who learned synthesis on
the ARP 2600, programming ACE will be
addictive. I had trouble tearing myself
away from it long enough to finish writing
this review — and for all the huge sound it
gives you for such a low price, it’s
certainly a Key Buy.
Surprisingly deep sound programming.
Great factory presets. “Real analog”
Needs a fast CPU.
CLICK HERE for an originial synth violin piece author Jim Aikin created in U-he ACE.
NEED TO KNOW
What types of synthesis does it
do? Modeled analog, including FM
Most unusual features? Audio-rate
modulation, mapping generator, oscillator
soft sync, duophonic keyboard
response, dual glide mode.
How are the effects? They’re basic:
You get a chorus/phaser, synced delay
line, and treble/bass EQ.
Do you get pulse width modulation
or oscillator sync? Yes and yes.
How about microtunings? ACE
loads Scala files for highly flexible custom
Formats and computer stuff: VST,
AU, and RTAS. Windows or Mac OS
10.4 or later. Intel Core2 Duo or better
Copy protection: Serial number entry.
Downloadable demo? Yes.