Yamaha D-1500
Digital Delay (1984?)

 

Classic rackmount digital monophonic delay unit with modulation.

RACKMOUNT EFFECT Main panel features a simple 7-segments LED display, a LED peak meter, 2 knobs and 18 buttons.

Terminal connectors:
- Midi interface
- modulation CV tension input
- 3 footswitch inputs (bypass, modulation and hold)
- delay out (-20/+4 dB)
- mix out (-20 / +4dB)
- input signal (-20 / +4dB)
- XLR I/O
- headphones (frontal)

 

TECH unit is based on 8-bit CMOS micro processing unit HD6303 (HD60303RP) family.
The D-1500 is a Monophonic delay unit, max time 1 seconds (1023 miliseconds to be precise) range frequency response from 20 Hz to 18 kHz with adjustable phase (a 180 degrees phase shift).

 

HEAR tweaking delay

 

FUNCTIONS the delay can be changed using 3 parameters:

- FEEDBACK sets the amount of repeated echoes - MIX is the balacing between dry and wet - TIME is displayed on the LCD.

 

 

TIME special HOLD function freezes the sound during 1 second cycling the signal.

HEAR bass delay + HOLD freeze

 

LFO single digital oscillator (shape: sine or square) modulates the delay pitch with variable depth- frequency range from 0,1 to 15 Hz.

TIP: CV the tension controls the internal LFO rate: relative voltage range from 0 to 10 V. HEAR Modulation

 

FILTER a basic low pass filter for the generated delay at 1 pole.

There are only 6 fixed cutoff values : 2,5/ 4 / 6 / 8 / 10 / 20 kHz.

MIDI Early Midi implementation: really limited and quite useless as it manages only the program change.

MAINTENANCE not much to say, quite reliable unit but missing segment on displays.

LEFT - Latest and only OS -seems- to be V.1.0. only eprom   - click to magnify pic -

MEMORY:
- 1 s. max sampling time.
- 6 rom presets (list)
- 16 patches setups.

- LEFT - Memory system works with a soldered 3V Cr-2032 lithium battery, replacement needs some basic skills. - click to enlarge pic -

AUDIO DEMO

	bass delay + HOLD freeze
	Modulation control by external CV synth
	tweaking delay (ceramic bells)
	guitar delay : too much feedback :)

VIDEO SELECTION demo1 demo2 demo3