Rebis Audio RA226 User manual

Rebis Audio Ltd. RA226 Digital Sampler User Guide
CONTENTS Page
Caution 2
Powering Up 2
Controls 3, 4
Detailed Description
Input Level Set 5
Recording 5
Sampling 5
Multiple Samples 6
Editing 6
Playback 7
Delay Mode 8
Operation (brief)
Record 9
Playback 9
Editing 10
Multiple Samples 10
Drop-ins 10
Pitch Shift 11
Sample Length 11
Bandwidth 11
Delay/Echo 12
Phasing 12
Keyboard Control 12
Audio Trigger 13
Remote Trigger 13
Installation
Handling 14
Audio Connections 14
Phono Rack 14
Earthing 15
Memory Expansion 15
Remote Control 15
Pin Connections 16, 17
Specifications 18

CAUTION
The Rebis RA226 Digital Sampler contains Static Sensitive devices.
Handle only by the front panel unless in a suitable anti-static environ-
ment.
Store in the conductive plastic bag supplied until installed in a Rebis
rack frame.
POWERING UP
When the RA226 is used with the Rebis Modular Rack Mount power
supply and a selection of other modules in the same rack the power but-
ton on the power supply has to be pressed twice quickly to achieve the
full 40V required to drive the RA226.
The LED on the power supply will be bright when the output is correct.

CONTROLS:
LEDS: Indicate signal level at the input to the digital section.
Red LED indicates overload.
INPUT: Adjusts the input gain of the unit. (up to +20dBm)
MIX: Output blend control sets a balance between input and output.
FEEDBK: Sets the amount of output signal fed back to the input to
control the number of repeats in delay mode.
PITCH: In playback mode varies the pitch of the sample. Also sets
both the maximum sample and delay time and the bandwidth of the
processed signal.
START: Used to set the beginning point of the sample both in record
and playback modes.
END: Used to set the end point of the sample in record and playback
and the range and length of the delay time.
DELAY: Selects the echo mode ofoperation.On pushing this button
either 2 Seconds or full delay range is selected depending on the posi-
tion of the END control. The associated LED indicates when delay
mode is selected.
REC: Selects the sample mode of operation. When pushed it's associat-
ed LED starts flashing indicating that the unit is waiting for an input
over a preset threshold level. On receiving a signal over this level the
LED illuminates continuously and the input signal is recorded into the
section of memory defined by the positions of the START and END
controls.

LOOP: Joins the start and end of the sample to form a continuous loop.
Pushing a second time deselects the option.
LATCH: Changes play buttons from momentary to latching action.
Pushing a second time deselects the option.
REV: This button starts or stops the sample playing in the reverse di-
rection. It's LED illuminates while the sample is being played in re-
verse.
FWD: This button starts or stops the sample playing in the forward
direction. It's LED illuminates while the sample is being played for-
wards.
PITCH:
Bandwidth on the unit is variable and can be traded off against avail-
able recording time using the Pitch control. This control has the same
effect as the speed control on a tape machine, if it is used after a record-
ing has been made then it directly varies the pitch of the sound when
played back. The C.V. input to the module when used takes over con-
trol of this function so that samples can be played musically using any
keyboard which has a C.V. output. The front panel control acts a fine
tune when the C.V. input is being used.
When recording samples the Pitch control or C.V. if connected still
operate so these controls must be set to the centre of the required range
(by playing a suitable note on the keyboard with C.V.) if the full pitch
range is required on playback. If full bandwidth and a lower pitch range
is required then this control should be set nearer the clockwise end
(higher up the keyboard with C.V.).

Detailed Description of Operation
Input Level Set:
To obtain the best results with the RA226 it is essential to set the in-
put level accurately. This is adjusted with the input Level control and
correct operation is obtained when all three green LEDs are on for most
of the time with the red LED only flashing occasionally.
Recording:
Recording samples on the RA226 is made easy by an automatic
record function which is set internally at a preset threshold level
of -20dBm. Pushing the Record button starts the Record LED flashing
and the unit waiting for a suitable input level. When an input is detected
which is above the internal threshold level then the input signal is re-
corded into a section memory defined by the positions of the Start and
End controls.
While the signal is being recorded the Record LED stays on continu-
ously and when the section of memory is full the sample just recorded
is played back forwards, indicated by the FWD LED coming on.
Pushing either the Loop or Latch buttons will stop this automatic
playback if required.
Sampling:
The simplest way to get a feel for how to operated the unit as a sam-
pler is to record a full length sample of speech into the unit and then
play it back in all the different modes. To do this set the Start control
fully anti- clockwise, the End control fully clockwise, the Pitch control
to +.5 oct, the Mix control central and the Feedback control anticlock-
wise. Connect the unit to the insert points of a microphone channel and
set the Level control to obtain the correct reading on the LEDs while
speaking into the microphone. Now push the Record button and talk for
eight seconds.
The unit will playback the sample auto- matically when it has fin-
ished recording. You can now experiment with the different play modes
and Start and End edit controls as described in the Introduction section

of this manual. In addition you can try varying the pitch of the sample
whilst in playback with the Pitch control.
Sampling: (cont)
Samples can be recorded into any part of memory by setting the Start
and End controls to define the section before pushing the Record but-
ton,but make sure that the End control is set more clockwise than the
Start control.
Multiple Samples:
Multiple samples can be recorded into memory by adjusting the Start
and End controls before recording each sample. These samples can then
be played back independently by resetting the Start and End controls to
the original settings before pushing the FWD button.
Samples can be 'dropped into' any section of an existing recording by
defining the section beforehand with the Start and End controls.
A special remote control unit will soon be available which will allow
up to eight user defined sections of memory to be played back instantly
in either direction.
Editing:
All of the recorded material can be heard by setting the Start control
fully anticlockwise, the End control fully clockwise and pushing the
FWD button. Any recorded sample can be edited down to individual
notes by the use of these same controls.
If the Start control is set later in memory than the End control when
the sample is played then the whole of memory is played except the
section between the controls. This is useful in editing out part of a sam-
ple which is not required.
Setting any controls or operating any buttons except Delay and
Record will not permanently alter any sample in memory but merely
select a different section to be played back. Feel free to experiment with
the edit controls and playback modes described later, you cannot dam-
age your sample, it will all still be in memory if you require it.

Playback:
There are four different playback modes which can be used in either
direction and are defined by the state of the Loop and Latch switches in
combination as follows:
1. Loop and Latch off.
The sample plays once only in the selected direction while the play
button is held down. Pushing either play button at any time always
starts the playback from the selected end.
2. Latch on.
The play buttons only have to be touched to start playback in the se-
lected direction once only. Touching the opposite play button before the
end of playback reverses playback from the point reached.
3. Loop on.
The sample is played for as long as the play buttons are held down in
a continuous cyclic loop in the selected direction. The sample is played
each time from the point last reached.
4. Latch and Loop on.
The play buttons only have to be touched to start continuous cyclic
playback in the selected direction. Touching the same play button again
stops the playback, touching it again restarts playback from the end se-
lected. Touching the opposite play button whilst in playback reverses
the playback from the point reached.
A few minutes experience with the RA226 audibly demonstrates that
these play modes simply provide a vast range of sample effects.
the same as the maximum sample time and is dependant on the number
of expansion boards installed.
Once the Delay button has been pushed and the Delay LED is on
then the End control sets the actual delay time obtained as a percentage
of whichever maximum time has been selected.
When the maximum delay time is 1.3 seconds the delay mode uses
the last 1.3 seconds of memory only, any samples stored in memory up
to this point will not be affected by using the Delay mode. However
when the full delay time is selected all of memory is used and any sam-
ples will be lost.

Delay Mode:
The delay mode is selected with the Delay pushbutton and when
pushed one of two maximum delay times are selected depending on the
setting of the End control.
Before selecting this mode you should decide whether you require
any more than 1.3 seconds delay (at 16kHz bandwidth), if you do then
you must set the End control clockwise before pushing the Delay but-
ton. If 1.3 seconds is adequate set the End control anticlockwise and
push the Delay button.
When the maximum delay time is 1.3 seconds the delay mode uses
the last 1.3 seconds of memory only, any samples stored in memory up
to this point will not be affected by using the Delay mode. However
when the full delay time is selected all of memory is used and any sam-
ples will be lost.
The Mix control should be used to obtain the required blend of input
and output signals. If an echo send line is being used to drive the unit
then none of the input signal will normally be needed at the output and
the Mix control can be turned fully clockwise. Alternately if the unit is
wired into the insert points of a mixing console then the amount of echo
mixed with the input will be controlled on the RA226 by setting the
Mix control near it's centre.
The delay time is now variable with the End control from two milli-
seconds (anticlockwise) to the maximum time selected (clockwise).
The Feedback control is used to set the number of repeats, from one
with it anticlockwise to almost an infinite number with it fully clock-
wise.
The Pitch control will set the bandwidth of the delayed signal and can
be useful in making echoed signals sound more natural. This control
also has an effect on the delay time and can be used as a fine tune if a
particular time is required.

Operating Instructions (brief)
Record
1.Set MIX control midway.
2.Adjust INPUT control
(optimum level = +10db).
3.Set START to 0%.
4.Set END to 100%.
5.Set PITCH to +1.
6.Press RECord button.
RECord LED flashes while RA226 waits for input.
LED steady indicates RA226 is recording.
Sample will playback automatically when memory is full.
If sample is satisfactory turn MIX control to OP to disable input.
The automatic playback can be stopped if necessary by pressing LOOP
or LATCH.
Playback
Momentary - Press FWD or REV buttons for momentary
playback.
One Shot - Engage LATCH button first for single touch
playback of entire sample.
Continuous Loop - Engage both LOOP and LATCH buttons.
Step - Engage LOOP button only to step through
looped sample.

Editing
The START and END controls define which part of the recorded sam-
ple will be played.
1.Turn the START control CW to edit from the front of the sample.
2.Turn the END control ACW to edit from the end of the sample.
Swap the positions of these two controls to remove a "window" from
the sample.
Note: START/END settings are scanned at the moment the sample
starts to play therefore adjusting the END control while sample is play-
ing will have no effect until next play.
To save time when editing long samples it is advisable to adjust the
end point first. i.e.Set the START control a little before the required end
point to save playing the whole sample.
It is also worth considering use of the REVerse and PITCH controls to
assist precise editing.
Multiple Samples
The START and END controls can be adjusted prior to recording a
sample to define the memory zone which it will occupy.
This facility can be used to reduce the time taken to record short sam-
ples. It also allows several samples to be stored in memory simultane-
ously and short samples to be inserted in longer ones.
Drop Ins
The RA226 can be switched in and out of record to perform orthodox
drop ins.
1.Set mode, LATCH on, LOOP off.
2.Play sample with FWD button held down.
3.Press REC button and RA226 will start recording. (Both buttons can
now be released).
4.Press REC button to drop out of record.

Pitch Shift
A sample recorded with the PITCH set to +1 can be transposed down
through two octaves by rotating the PITCH control anti-clockwise be-
fore or during playback.
If playback at a higher pitch is required the sample must be recorded at
a lower PITCH setting.
e.g.1 Record at PITCH 0 to allow playback to be transposed through
one octave up or down.
e.g.2 Record at PITCH -1 to allow playback to be transposed up
through two octaves.
Using the PITCH control will have an effect on the bandwidth of re-
cordings. See table 1.
Sample length
Sample length can be increased by up to 400% by using a lower
PITCH setting when recording. This will result in a proportional reduc-
tion in bandwidth. Extra memory cards, RAM5S, can be installed to
increase storage capacity to a maximum of 22 seconds @ 16kHz (88
seconds @ 4kHz).
These cards can be switched out at times when finer edit resolution is
required. See Memory Expansion.
Bandwidth
The effect of the PITCH control on storage time and bandwidth are;
PITCH CW 5.5 Seconds @16kHz
PITCH Centre 11 Seconds @ 8kHz
PITCH ACW 22 Seconds @ 4kHz

Delay/Echo
To enter delay mode set START control to 0%, MIX control to IP, and
press DELAY. With the PITCH control set to +1 the RA226 will now
provide up to 1.4 seconds delay at 16kHz bandwidth. The END control
adjusts delay length and repeat echo can be introduced with the FEED-
BACK control.
The dry signal can be removed by turning the MIX control to OP.
In this mode only the last 1.4 seconds of memory is used, so samples
stored in the rest of memory will not be erased.
If you wish to use the entire memory, set the START control to 100%
before selecting DELAY.
Phasing/Tube effects
Set MIX control midway
Adjust INPUT control
Set START control to 0%
Set END control to 0%
Press DELAY
Manual phasing can now be created with the PITCH control.
Turn MIX control to IP
Add FEEDBACK
PITCH control now gives resonant tube effect.
Both these effects can be controlled musically by using a CV keyboard
instead of the PITCH control.
Keyboard Control
Any keyboard or sequencer equipped with a 1 volt per octave CV and
gate outputs can be used for musical control of samples.
When the keyboard is connected it takes over the role of the PITCH
control during recording as well as playback.
The last key pressed before recording will define the PITCH setting.
This key will be the reference point for play back of the sample from
the keyboard. (Refer to Pitch Shift section). The PITCH control itself
now acts as a fine tune control.

Audio Trigger
Samples can be synchronously triggered by an external audio source
by feeding signal to one of the audio trigger inputs.
If the track being used to trigger the sample contains excessive cross-
talk it should first be gated using a frequency conscious gate such as the
Rebis RA224.
Audio trigger input 1 operates like the FWD play button, and obeys
the LOOP & LATCH mode settings.
Audio trigger input 2 plays all the edited sample and will not retrigger
until the sample has finished playing. Thus a sample lasting for 2 bars
can be triggered from a snare drum playing 4 to the bar.
Remote Trigger
* Play : Connect to FWD or REV play switch remotes as required.
* +5V : Available on Pin 4 of outer card.

INSTALLATION
Handling
There is a slight risk of damage to some of the devices in the RA226
in areas prone to high static build up. To eliminate this risk it is advisa-
ble to take a few simple precautions when handling the module.
1.The RA226 is supplied in a conductive plastic bag. Do not remove
it from the bag until you are ready to install it in the rack frame.
2.Make sure that the rack frame is securely connected to mains earth.
3.Immediately before handling the module touch something which
you know is connected to mains earth to discharge any static build
up.
4.Always make sure that the power to the rack frame is disconnected
before inserting or removing the module.
5.Always return the module to its conductive plastic bag if it has to be
removed from the rack - especially if repacking unit for shipping.
Audio connections
Screened cable should be used for signal connections, the screens be-
ing connected to 0 volts at the edge connector only for the inputs and at
the jackfield only for the output.
A separate wire should join the Rack 0 volts to the main jackfield 0
volts.
Phono Rack
When the RA226 is plugged into a RA14RP phono type rack frame its
input and output will appear on the phono sockets behind the left hand
module slot. Before inserting the RA226 check the PCB on the rear of
the rack, earlier models have a track link between pins 5 and 6 on each
slot and pin 8s on each pair. These links must be broken before the
RA226 is installed.
If other connections to the RA226 are required then the racks rear con-
nector board can be suitably modified by your Rebis dealer or a quali-
fied engineer.

Earthing
When installing the module in a Rebis Rack Frame ensure that it is
firmly screwed in and that the rack is earthed, as it is essential both for
safety and screening that the front panel is ultimately connected to
mains earth.
Memory Expansion
RAM5S memory expansion cards are simply installed by removing
the screening plate, plugging the new card into the existing memory
card and securing it with the two screws provided. The double switch
located on the bottom edge of the central PCB should then be adjusted
as follows;
Standard Module - 1 ON 2 ON
Plus one expansion card - 1 OFF 2 ON
Plus two expansion cards - 1 ON 2 OFF
Plus three expansion cards - 1 OFF 2 OFF
On occasions when finer edit resolution is required memory cards can
be bypassed using the above settings.
Remote Control
Most of the functions of the RA226 can be quite simply remote con-
trolled as shown in the connection diagram.
To enable remote control of the START/END functions the switches
located on the rear edge of the outer PCB should both be switched off.
Important: These switches disable the front panel START/END con-
trols.
Rack Mount Power Supply
When the RA226 is used with the Rebis Modular Rack Mount power
supply and a selection of other modules in the same rack the power but-
ton on the power supply has to be pressed twice quickly to achieve the
full 40V required to drive the RA226.
This is due to the surge current limiter built into the regulator and is
not a fault.

PIN CONNECTIONS
Connector 1 (analogue board, outer PCB)
1) Keyway slot
2) +5 volts out for pots
3) 0 volts out for pots
4) +5 volts out for remote
5) START pot in from remote
6) END pot in from remote
7) Audio trigger input 1
8) keyboard gate in
9) Main 0 volts
10) +40 volts in
11) Clock out to remote
12) C.V. in
13) C.V. screen
14) Audio output
15) Input screen
16) Audio input

Connector 2 (digital board, centre PCB)
1) Keyway slot
2) DELAY switch remote
3) RECORD " "
4) LOOP " "
5) LATCH " "
6) REV " "
7) FWD " "
8) RECORD LED remote
9) Spare
10) "
11) DELAY LED remote
12) LOOP " "
13) LATCH " "
14) REV " "
15) FWD " "
16) Audio trigger input 2

SPECIFICATIONS
Maximum Input level: +20dBm
Maximum Output level: +20dBm into 600 ohms
Input Impedance: 100 kilohms
Output Impedance: Less than 50 ohms
Control Voltage Range (CV): 0.5V to 2.5V
Frequency Response: L.F. -2dB @ 20Hz,
H.F. Variable between
-3dB @ 16kHz @ 5.5 Secs and
-3dB @ 4kHz @ 22 Secs
Distortion: Less than 0.2% THD @ 1kHz @ +10dBm
Dynamic Range: 85dBm
Delay/Storage Time: Variable between 5.5 and 22 seconds.
Expandable to between 22 and 88 seconds with three RAM5S
expansion boards.
Trigger Input: Audio input for FWD play
Power Requirements: +40 volts @ 175mA standard, 250mA with three
expansion boards (RAM5S)
Dimensions: 5.25" x 2" x 7.9" behind front panel