DJRND3 User's Manual

Specifications

- 42 track polyphony (21 stereo loops simultaneously)
- 64Mbyte SDRAM, for a total of 504 bars (4min 12sec @ 120 BPM, 5 min 36sec @ 90 BPM ... )
- 40 kHz sampling rate (32-48 khz once BPM re-synced for max. +/-20% pitch shifted tempo ratios)
- 16-bit stereo linear encoding
- 15VAC/DC 1A power supply
- MIDI CLOCK OUTPUT
- +/-0,05 BPM tempo accuracy
- Pitch bend loop recording
- 3 digital virtual volumes for phones, input and master lines
- 2 loops output levels : 0dB and +10dB
- Internal SCSI 3.6Gbyte hard disc drive to back up 1023 loops
- HDD analog loop player optimized "browser" immediately synced with the SDRAM loops

Introduction

DJRND3 is a 21-cyclic track audio recorder comprising 21 stereo loops spread in a 64-Mbyte SDRAM memory.
Digitally mixed together using a 3-row muting keyboard, loops spin in a common tempo which must be adjusted before sampling using a TAP TEMPO followed by a real time BPM adjustment called “TRIM TEMPO”.

Every loop has a pre-defined sample length value given in bars which can be double sized during recording for loops belonging to the first two rows of loopkeys.

DJRND3 provides 1 input line and 2 output lines : loops (0db +10dB) and phones. A “MASTER” input/output line for an external DJ mixer is also provided to be monitored by the DJRND3 headphones.

Three digital virtual volumes for master and input lines and phones can be adjusted with the potentiometer by holding respectively keys “MASTER” “IN CTRL” and “SYNC LOOPS”.

DJRND3 includes a SCSI 3.6Gbyte hard disc drive (HDD) to back up SDRAM loops by one loop at a time. The HDD OS software can save and play back up to 1023 loops which are automatically round crunched once the disc is full. Loops are played back automatically synced in BPM and bar with SDRAM loops according to the “SIGN” parameter previously recorded for every back up loop.

A 3.6Gbyte HDD is enough to give an average loop length of 32 bars for a total of 1023 loops, higher than the 24 bar value required for 504 bars spread in 21 loops. A HDD analog output line is provided in case of using DJRND3 with an external DJ mixer to crossfade between SDRAM loops and the internal HDD.

A MIDI clock output is provided on the rear panel to sync an external sequencer to SDRAM loops.

keys features description

“TAP/SIGN” : Tap Tempo/ Loop Signature :

- When “SYNC LOOPS” light is switched off : “Tap Tempo” to hit the input line beat rate displayed in BPM.
- When “SYNC LOOPS” light is lit up : “Loop Signature” to tap the beat rate of the selected loop to sign its beat circular position.

Loop Signature helps determining the bar (beat) synchronization between SDRAM loops and input line or HDD loop play back.

When light “SEL” is lit up, “TAP/SIGN” pressed displays loops tempo for a while.


“TRIM TEMPO” : When “TRIM TEMPO” light is lit up, to fine with the potentiometer the input tempo previously entered with the Tap Tempo. The input line tempo is obtained once an optimum beat coincidence is monitored in headphones.

Holding the “TRIM TEMPO” key helps scrolling larger tempo scales without exitting the “TRIM TEMPO” mode everytime the potentiometer reaches its limits.


“SYNC LOOPS” : To sync SDRAM loops in bars and BPM with the input line signals, or to sync the HDD loop play back in bars and BPM with the SDRAM loops, whether “HDD” light is switched off or lit up.

A “BpM” message is displayed when input line and loops tempos can not sync each other, otherwise an automatic pitch shifting according to the tempos ratio is achieved for this synchronization.

Loops are always monitored in headphones as long as “SYNC LOOPS” lits up.

When “SYNC LOOPS” key is hold, the potentiometer adjusts the phones level with a “Phon” displayed message.

When “HDD” lits up, “SYNC LOOPS” lit up helps to fine the HDD played back loop circular (bar) synchronization with SDRAM loops using the loopshift keys.


“IN CTRL” : Input line level control.

The input line is always monitored in headphones as long as “IN CTRL” light is lit up, thus displaying the input level on the 6-light dB level meter.

When “IN CTRL” key is hold, the potentiometer adjusts the input line level with a “InPu” displayed message.


“MASTER” : Master line control.

The phones exclusively monitor the master line signals as long as “MASTER” light is lit up.

When “MASTER” key is hold, the potentiometer adjusts the master line level with a “MASt” displayed message.

The master line is only usefull with an external DJ mixer in order to monitor the whole DJ set-up from the single DJRND3 headphones connector.


“HDD” : Hard Disc Drive.

When “HDD” light is lit up, the HDD plays back a loop automatically synced in bars and BPM with SDRAM loops. The HDD loop length is displayed in bars.

The HDD loop can be selected among 1023 loops using the potentiometer and the loopshift keys.

When “SYNC LOOPS” light is switched off, the loopshift keys helps to select a group of 32 loops in which the potentiometer browses the selected loop. 1023 loops back up on the HDD gives 32 possible groups of 32 loops.
Once the loop selected, “SYNC LOOP” can be lit up to adjust the bar synchronization with SDRAM loops using the loopshift keys.

Holding “HDD” key when starting power supply erases every loop on the disc after a countdown of 10 seconds.


“REC” : To be armed to start recording, "rEc" message is displayed until the loopkey to record is pressed. Loops recording can be stopped (cancelled but altered) by pressing “REC” again.

- “REC” and “SAVE/+” pressed together arms the back up process to save a loop on HDD. “SAvE” message is displayed until the loopkey to back up is pressed.

- “REC” and “JUNC/-” pressed together arms the loop junction computation. “Junc” message is displayed until the loopkey to junction is pressed.

- “REC” and “SEL” pressed together erases all SDRAM loops except during a loop back up process.


“SEL” : Selection key :

When holding “SEL” key, any pressed loopkey inverts the corresponding loop mute status until “SEL” key is released.

“SEL” keypressed switching light “SEL” off makes light “ALL” lit up meaning any loopshift keys action affects every loop simultaneously. When light “ALL” switches off, loopshifting keys only affect the selected blinking loop.

“SEL” keypressed forcing light “SEL” lit up allows either :

- to select a loop to wheelslide using the loopshift keys, or to adjust the loop volume using the potentiometer, or
- to set the 6-light loopshifting scale directly to its 1/64 limits by pressing keys “JUNC/-” / “SAVE/+”, or
- to displays SDRAM loops tempo value by pressing “TAP/SIGN”, or
- during a recording process, to select the next loop to record or to double the length of the recorded loop among the two lower rows of loopkeys.


“8-4-4-2-2-2-2”; “128-32-16-16-16-16-16”; “128-32-16-16-16-16-16” : 21 muting loopkeys.

Any muting loopkey mixes its corresponding loop level adjusted by the potentiometer.
The muting loopkey mode depends on the “SEL” key mode : holding “SEL” key makes a loopkey inverts its loop mute status as long as “SEL” key is hold, the final mute status being obtained once “SEL” released.

Without pressing “SEL” key, any loopkey definitively inverts its mute status at each press.

Loops status light stand for “recorded loop” or “mixed loop” whether “SEL” light is lit up or switched off.

The loopkey number stands for the maximum sample length in bars a loop can record.


“BACK/FORW” : Backward and Forward loopshift keys.

To wheelslide loops in terms of colunns (32 colunn = 1 bar).
The 6-light binary scale determines the number of colunns affected by the loopshift keys to the parameter as follows :

- When “ALL” light is switched off, loopslide forward or backward the selected blinking loop
- When “ALL” is lit up with light “HDD” off, loopslide forward or backward the whole set of SDRAM loops.
- When “ALL” and “HDD” lights lit up with “SYNC LOOPS” light off, select a group of HDD loops.
- When “ALL”, “HDD” and “SYNC LOOPS” are all lit up, loopslide the HDD played back loop.

During recording with a 6-light binary scale equal to 1, loopshift keys acts as a pitch bend effect affected on SDRAM loops in order to keep the bar synchronization during sampling.


“SAVE/+” :
- “REC” key released, “+” mode to increase the 6-light binary scale value for loopshift keys.
- “REC” key hold, “SAVE” mode to arm the HDD back up process. Once pressed, a SDRAM loop is saved on HDD unless the loop has not been previously signed using the “TAP/SIGN” key with “SYNC TEMPO” lit up.


“JUNC/-” :
- “REC” key released, “-” mode to decrease the 6-light binary scale value for loopshift keys.
- “REC” key hold, “JUNC” mode to arm the junction computation process. Once pressed, the junction of a SDRAM loop is filtered to cancel any glitch around the loop junction after recording.


Potentiometer : Digital potentiometer used to adjust different parameters as follows :

- to adjust the headphones volume with “SYNC LOOPS” key hold,
- to adjust the input line level with “IN CTRL” key hold,
- to adjust the master line level with “MASTER” key hold,
- when “TRIM TEMPO” is lit up, to adjust the input line tempo previously tapped in using “TAP/SIGN” key,
- when “HDD” lits up with “SYNC LOOPS” light off, to browse HDD loops among a given group of loops,
- in other cases, to adjust the volume of the selected blinking loop if this loop is not muted off.

“Init” erase all status

Once power on, default loops tempo is 100 BPM and loops are all erased : an “Init” message remains displayed as long as no loop is recorded. Except during a HDD back up, every loop can be erased at any moment by pressing “REC” and “SEL” together. In that case the previous loops tempo value is kept.

Input line tempo adjustment

To adjust the input line tempo, switch off light “SYNC LOOPS” and starts tapping the input beat using the “TAP/SIGN” key. Once the entered BPM value is stabilized, lit up light “TRIM TEMPO” to adjust the tempo more accurately with the potentiometer to obtain the best beat coincidence in headphones.
When the potentiometer reaches its limits, hold “TRIM TEMPO” key while the potentiometer is set back to its middle position.

HDD loop play back

To play back HDD loops, press key “HDD”, scroll the loop to select with the potentiometer in the group of loops which can be selected using the loopshift keys. Once the right loop selected, press “SYNC LOOP” key to wheelslide the HDD loop play back in comparison with the SDRAM loops using the two loopshift keys and the 6-light binary scale.

Recording loops

Either input line or HDD loop play back can be re-sampled in SDRAM simultaneously with some loopsliding beat effects made with the loopshift keys. The SDRAM sampling process is the same for both, except the analog input line requires its tempo to be properly adjusted before sampling starts in order to obtain perfect beat looping, which is not the case with the HDD loop play back which is automatically BPM matched with SDRAM loops.

First, recording must be armed by pressing the “REC” key before the first loopkey to record : “REC” and “SEL” light lit up with loopkeys light showing recorded loops, “rEc” message is displayed until the first loopkey to record is pressed. During the recording sequence, a beat countdown is displayed counting from the number of bars the loop to record.

To double size a loop during its recording countdown, arm “SEL” and press again the loopkey : the same initial amount of bars will be added to the current countdown bar value, except if the recorded loop belong to the 3rd row (8-4-4-2-2-2-2) where loops can not be double sized.

To select another loop to come next into the recording sequence during the loop beat countdown, arm “SEL” and press the next loopkey to record. The recording sequence stops when the last recorded loop is done, or when “REC” key is untimely pressed to stop recording.

The last recorded loop is by default the selected blinking loop which level can immediately be adjusted with the potentiometer if necessary. The blinking loop stands for the selected loop for level adjusting or loop shifting. Only one loop blinks at a time, except during recording when two loops can be waiting (”IIxx” displayed).

Loopshifting (wheelsliding)

The selected blinking loop can have its level adjusted with the potentiometer when the loop is muted on, and can be wheelslided with the two loopshift keys with light “ALL” switched off.

To select a loop without changing any mute status, press “SEL” key before. Once a new loop selected, press “SEL” key twice to lit up light “ALL” so wheelsliding does not concern the selected blinking loop anymore to spare the right beat circular synchronization of the loop. Loopshifting loops each others sometimes helps optimizing bar synchronization when loops have been recorded out of a commun recording sequence.

The number affected by the loopshift keys is given by the 6-light binary scale controled by keys “JUNC/-” and “SAVE/+”.

Loop bar signature

To sign a loop circular position, lit up light “SYNC LOOPS” and hit once the “TAP/SIGN” key when the selected blinking loop restarts the beginning of its phrase. “SiGn” message is displayed each time the “TAP/SIGN” key is hit with light “SYNC LOOPS” lit up.

Loop back up on HDD

To back up a SDRAM loop which has been previously recorded and bar signed, press “REC” and “SAVE/+” together before pressing the loopkey to save on HDD. “SAVE/+” light will be lit up until the loop is totally back up on HDD.

Loop muting keyboard

Each muting loopkey mixes the corresponding loop level adjusted by the potentiometer. The muting keyboard mode depends on the “SEL” key mode : holding “SEL” key makes a pressed loopkey inverts its loop mute status as long as “SEL” key is hold, the final mute status being obtained once “SEL” released. Without pressing “SEL” key, a loopkey definitively inverts its mute status at each press.
Loops status light stand for “recorded loop” or “mixed loop” whether “SEL” light is lit up or switched off.

During loops mixing with the muting keyboard, always the last muted on status blinks as the default selected loop. To select a different loop without changing any loop mute status, just lit up “SEL” light before.

Loop level adjustment