EMT 444 Time Delay Unit

Astonishing early 80s German technology and build quality. This thing is a monster with 6 outputs and a total of 7 transformers inside.

Note that we need to complete final testing on this unit and it will ship within 10 working days of purchase.

There is speculation that one of these was employed by Bowie/Visconti during the recording of Heroes at Hansa: we’d welcome confirmation or otherwise of this mystery online ‘fact’.

Here’s some info from the manual:

EMT 444 Electronic Time Delay Unit provides delay of audio signals and enables additional effects to be generated.

DELAY PROGRAM: The processed audio signal is available at 2,4 or 6 outputs, each selectable for any delay time between 0 and 255 ms in steps of 1 ms.

SPECIAL EFFECTS: Are possible, for instance:

• TIME DIVISION: The selected delay times can be multiplied by 0,5 / 0,25 or 0,125 , this allowing incrementing down to 125 µs.
• CLOCK VARIATION: Continuously variable delay time, manual or voltage control, for fine adjustment of the delay time or for generating frequency or phase modulation. Useful for vibrato, chorus, and phasing effects. TIME DIVISION can be additionally employed.
• ECHO FEEDBACK: Enables echo effects to be generated with repetition times between 0 and 255 ms, selectable in steps of 1 ms, and decay rates between 0,5 and 60 dB per repetition. TIME DIVISION and CLOCK VARIATION can be employed as well.
• LOOP: Permanent repetition of an initially introduced audio signal with a cycle time of 255 ms. Useful for scientific analyses, e.g. of spectra or of initial transients, as well as for special effects. TIME DIVISION and CLOCK VARIATION can also be employed.

COUPLING OF TWO UNITS: Two EMT 444 units can be cascaded for longer delay times or coupled in parallel to increase the number of inputs and/or outputs.

TECHNICAL DATA:

* Delay time: 1 to 255 ms, selectable for each output separately in 1 ms increments; switchable factors of 0,5 / 0,25 and 0,125 for fractional incrementing.

* Digital coding:

– internal: 14 bits
– A/D converter: 12 bits
– resolution: quasi-15 bit through threefold switching of the quantizing range

* Sampling frequency: 32 kHz
* Storage capacity: 112 kbits
* Input: balanced and floating
* Input impedance: more than 10 kOhms
* Input level: +6 dB / 1,55 V nominal level, adjustable between -10 to 15 dB

* Outputs: 2,4 or 6; balanced and floating (1,2 or 3 OUTPUT plug-in units)
* Output impedance: less than 40 ohms
* Output level: +6 dB / 1,55 V nominal level, adjustable between -10 to 15 dB
* Clipping level: 6 dB above nominal level

* Signal-to-noise ratio:

– RMS, unweighted – more than 78 dB
– Peak weighted – more than 72 dB

* Frequency response: 20 Hz to 15 kHz (+1/-3 dB)
* Harmonic distortion: less than 0,3% at nominal level and 1 kHz

* Coupling:

– Digital loop operation (1 unit)
– Analog feedback (ECHO, 1 unit)
– Digital cascade coupling (2 units)
– Digital parallel coupling (2 or more units)

* Power connection:

– 100 to 120 V
– 220 to 240 V
– 50 to 60 Hz

* Power consumption: approx. 70 VA
* Dimensions for rack mounting: 483 x 221 x 456 mm (W x H x D)
* Dimensions in tabletop cabinet: 505 x 255 x 525 mm (W x H x D)
* Weight: approx. 29 kg or 64 lbs