The CP-70 was a portable electric piano invented during the
seventies by the japanese company Yamaha, also makers of
renowned fine classic grand pianos. It was made for the touring
musician who wanted to take an acoustic piano on the stage. It's a
rock solid instrument that splits into two parts for better
transportability. The structure is based on the keyboard and
mechanics of a classic grandpiano but with a smaller harp, less
strings and shorter than a classic baby grand. There's no
soundboard, and every note has its own piezoelectric pickup. The
main preamplifier offers a basic 3-band equalizer and a tremolo
effect. This piano had a significant role in the pop music of the
seventies and the eighties, featuring in songs by well known
musicians like Stevie Wonder, Genesis, George Duke, Simple
Minds, etc. It is now back on the stage thanks to the british band
"Keane", you can see it in the video of the song "Everybody's
changing". Every modern digital keyboard offering a wide variety
of timbres has a patch inspired to the sound of the CP piano, and
sometimes it's still preferred in genres like rock and pop where the
producers want a brighter and more prominent piano sound.
EG70 is a physical modeling simulation of a CP-70 electroacoustic baby grand touring piano.
- Full Polyphony (73 notes)
- Adjustable sympathetic resonances
- Realistic response to keyboard dynamics
- Adjustable global tuning
- Four dynamic curves available
- Realistic control panel with active EQ and Tremolo effect
- Stereo tremolo mode (auto-pan)
- Adjustable note decay and release lengths
- Built-in stereo digital reverb
- On-screen help tips and readout values
- Low memory and CPU power needed
- Easy MIDI-Learn feature
EG70 has a very natural response to keyboard dynamics and to player's style. You'll hear the
benefits of physical modeling mostly when the sustain pedal is in use. The sound is warm and
metallic at the same time, unpredictable, rich and natural like only a real piano can be.
About Physical Modeling
Although physical modeling synthesis is a well known concept nowadays, it's good to point out
some of the differences that make a modeled instrument, like a piano, preferred over a
sampled one. As we all know, physical modeling is a technique to recreate acoustic phenomena
in the digital world by means of math formulas and other complex algorithms, but in practice it
takes the musician to a compromise: while samples offer true realism, being an actual
photography of a specific sound, just like a photography a sampled sound stays still, never
changes over time and doesn't react to external variations. On the other hand, a modeled
sound may lack of realism or may be somehow imprecise regarding little details, but it's alive,
does react to musician's playing style, adds color and vitality, is never static and takes full
advantage of the power of modern digital systems.
Speaking of a piano, which is one of the most expressive instruments ever invented by
humans, using samples is a bit of a contradiction. Can you quantize the dynamics of a piano
and establish a limit? You can't. Can you consider all of the variables and combinations that
may happen with different numbers of notes played in as many different situations? You can't.
Can you create resonances using samples? You can't. This is why, sometimes, physical
modeling can be preferable over sampling, so that the virtual gets closer and closer to the real.
Now let's have a look at how EG70 benefits from physical modeling. First thing: the polyphony.
In EG70 you have a full polyphony of 73 notes. One note available per each single key. This
could seem obvious but it isn't. Many times you see digital pianos with 88 keys but offering
128 or even 256 notes of polyphony. So, what's the point of having more notes than keys?
Because with sampling you need a note per each sample playback. If you press the sustain
pedal and hit the same key twice or more times, you employ a new voice each time, so you
can even use all the available voices for a single key, because samples start playing one on top
of another, summing phases and amplitudes, resulting in an unnatural behaviour for a piano.
In EG70, when you hold the sustain pedal down and hit the same key more times, the virtual
hammer always strikes the same
(virtual) strings adding or subtracting
vibrations according to the phase of
the string in the very moment when it
gets struck by the hammer. One key,
one voice. This is exactly what
happens in a real piano, and every
time you hit the key you can hear
subtle differences from other strikes
of the same note. Also, this extends
the limit of the 127 velocity values
available in the MIDI protocol.
Another example: the resonances. A baby grand piano like the CP-70 has no soundboard, so
the actual resonance is very limited, but still there are 131 strings that are free to vibrate
when the dampers are released, 15 of which are large round-wound strings that produce a
high number or overtones, and the last 8 keys (for a total of 16 strings) don't have dampers at
all, and are free to resonate all the times. So, when the player keeps a key down when the
note has reached a full decay, he's keeping the damper away from the string(s) setting them
free to resonate if other keys are played. This is called “sympathetic resonance”. When the
sustain pedal is down, all dampers get away from the strings, so a single note played may
spread its resonances through the whole harp. This is what happens in a real piano and in the
CP-70 electric piano, and is perfectly emulated by EG70.