Emax & Emax II

User's Group

Emax Information
Emax II Information
visitors since 09/05/1996

The Emax II was originally released as a 1Mb mono 16 bit sampler. That was quickly changed to 2Mb and stereo. Most early models were retrofitted to stereo, but there are still some mono units out there. Though it's maximum sample rate is only 39kHz it does have the ability to playback samples created at 44.1kHz. The Emax II filters are not analog, they are digital. But, unlike the Emax with it's fixed 512k of memory the Emax II could be expanded from 1Mb-8Mb though to go beyond 2Mb required the addition of a daughterboard. For more information on Memory Upgrades view the Repair/Upgrade section. The Emax II also had (at the time) a more robust SCSI implementation which meant it was compatible with more peripherals such as Syquest removable media, MO drives, CD-Rom drives and a variety of hard drives. It's maximum partition size is 540Mb.

Operating System

  • Emax II OS 2.14


  • Model: 2201 1 Mb KEYBOARD
  • Model: 2202 1 Mb RACK

  • Model: 2203 1 Mb KEYBOARD (W/HD)
  • Model: 2204 1 Mb RACK (W/HD)
(The original models were concluded in June of 1991)

  • Model: 2212 2 MB KEYBOARD
  • Model: 2213 2 MB RACK

  • Model: 2205 4/8 MB KEYBOARD (W/HD)
  • Model: 2206 4/8 MB RACK (W/HD)

The details of when E-mu actually cut over from 4 to 8Mb RAM or from 40 Mb to 105/127Mb Hard Drives is not known.

The Basics

  • 5 Octave velocity sensitive keyboard C to C or 3 space rack
  • 14 Velocity curves
  • Velocity can control VCA level, VCA attack, VCF cutoff, VCF attack, and VCF Q.
  • 3.5 inch floppy disk drive (uses double sided, double density (DSDD) floppy disks)
  • Internal and external SCSI connection (internal HD power supply)
  • 32 Character Backlit LCD
  • RS-422 connection
  • MIDI In connection
  • MIDI Out/Thru connection
  • Programmable Arpeggiator
  • 16 track "scratchpad" sequencer
  • Clock In (Clock In can accept 24, 48, or 96 ppq, the pulses should be at least 1ms wide and 1 to 5 volts.
  • Clock Out (Clock Out sends a 24 ppq which is 5 volts and about 6ms wide)
  • 2 Programmable wheels for real-time control over pitch, filter cutoff, AHDSR attack rate, level, LFO modulation index, etc.
  • 2 Footswitches
  • 1 Footpedal
Audio Out and In
  • Headphone
  • Mono Mix
  • Main Out (L and R stereo)
  • Sub A (L and R stereo / Tip-output and Ring-effect return)
  • Sub B (L and R stereo / Tip-output and Ring-effect return)
  • Sub C (L and R stereo / Tip-output and Ring-effect return)
  • Sample In (stereo / Tip-Left and Ring -Right)

Sample Rates and Times

For stereo samples, divide time in half

Time (seconds)
Sample Rates 1Mb 2Mb 3Mb 4Mb 5Mb 6Mb 7Mb 8Mb
20.000kHz 26.1 52.5 78.6 104.9 131.1 157.3 183.5 209.7
22.050kHz 23.7 47.6 71.3 95.1 118.9 142.7 166.4 190.2
27.778kHz* 18.9 37.7 56.6 75.5 94.4 113.2 132.1 151
31.250kHz* 16.8 33.5 50.3 67.1 83.9 100.7 117.4 134.2
39.0625kHz 13.4 26.9 40.3 53.7 67.1 80.5 94 107.4

* Sample rates shown in bold have a maximum continuous sampling time equal to that of the 39kHz rate. Emax II performs automatic sample rate conversions on the sample, then frees up the additional memory for subsequent sampling.


Audio channels: 32 (16 Stereo)
Max Output Level: +4 dB into 600
Input Impedance: 5 kHz
Output Impedance: Stereo 100k
Mono 2.5
Audio 600
Data Encoding: Input 16-bit Linear
Output 18-bit Linear
Max Input Sampling Rate: 39kHz
Signal To Noise: 90 dB
Dynamic Range: Input >90 dB
Output >102 dB
THD+N: >.05%
Stereo Phase: Phase Coherent +/- 1 degree at 1 kHz
Power Requirements: 45 Watts


Voice Architecture

Each of the 16 Stereo voices has it's own set of the following:

  • Dynamic digital lowpass filter (VCF) with AHDSR envelope generators
  • Digital amplifier (VCA) with AHDSR envelope generators
  • LFO with adjustable rate, delay, and speed variation

The Emax II CAN chorus its voices without loss of polyphony.

Digital Processing
  • Truncation
  • Looping (Crossfade and Equal Power)
  • Digital combine
  • Sample reversal, as well as rate and pitch conversion
  • Transform Multiplication tm
  • Splicing
  • Advanced Split and Layer
  • Individual tuning and attenuation for each sample

Transform Multiplication:
Transform Multiplication is a digital effect which merges together 2 sounds in such a way that frequencies common to both sounds are accentuated while uncommon frequencies are discarded. It works best on harmonically rich sounds.

Spectrum Synthesis:
Emax II's Spectrum Synthesis allows you to specify up to 24 complex waveforms, (called Spectrums) and to either step or fade through them during the course of a sound. The 24 waveform locations are called Time Slices, since they represent the waveform at that slice of the sound. This method allows more complex and interesting sounds to be created. In addition, each partial (sine wave) can have a 24 point envelope that determines the pitch of that partial over the course of the sound.

Each Emax II voice can consist of two synthesized timbres, a synthesized timbre and a sampled sound, or two sampled sounds. The resulting voice can then be processed using the Dynamic Processing features and placed anywhere in the stereo field.

Portions of text taken from the Emax II Owners Manual © 1989 E-mu Systems Inc.