Roland SBF-325 User Manual

vrLn?

1

.After
the
the POWER switch0at ON

2

.Use the INPUT LEVEL switch0and

the output level control of the instru­ment or external preamp to adjust the
signal level so that the green LEVEL
INDICATOR
cator lights, the input level is too high
and distortion might be caused

making

BYPASS

I

wi'

the connections,

switch0at

0

lights

set

OFF

and

.

. If the red indi-

.

3

.Set the EFFECT MODE switch

at OFF and set the OUTPUT LEVEL
switch

. Control the output sound level by

4
means of the volume control on the
device (mixer, amplifier, etc
ed to the SBF-325 output

m

as needed

.

.

0

.) connect-

5

. Try the EFFECT MODE switch
the MODULATION Section controls,
the FEEDBACK control

PHASE switches

sounds

.

6

. When volume adjustment is neces-

sary, it is preferable to adjust in the
units connected to the SBF-325 out­put

.

0,

0 0

0 ,

and the

for various

NAMES AND FUNCTIONS OF THE CONTROLS

INPUT SECTION

CHANNEL A INPUT Jack

CHANNEL B INPUT Jack
Low level signals such as guitar or bass

guitar require the use of a preamp such
as the Roland SIP-300 or SIP-301

When only one input jack is used, the

input is automatically connected to
both inputs

.

BYPASS SECTION

BYPASS Switch Q
The BYPASS switch0makes direct

connections between the inputs and
outputs

. This means that the POWER

switch0may be left at OFF when the

SBF-325 is in the BYPASS mode and
that the gain in the BYPASS mode is

unity

. With the BYPASS switch

OFF, the gain will depend on the set­ting of the INPUT LEVEL switch
and the OUTPUT LEVEL switch

(see diagram)

.

0

.

INPUT LEVEL Switch
Set to match the output level of the

input

.signal

.

INPUT LEVEL INDICATOR

The green indicator shows the presence
of an input signal

lights when the input level is high
enough to produce distortion

0

0

; the red indicator

.

0

(CAUTION

ance, the BYPASS switch
cause click noise)

0

0

0

: If used during perform-

0

may

.

If the BYPASS switch0is to be used

during performance, it will be necessary

to set the INPUT LEVEL0and OUT-

PUT LEVEL

gain through the flanger circuits is

unity

: INPUT at H and OUTPUT at L

or INPUT at L and OUTPUT at H

4

m

switches so that the

;

.

FEEDBACK LEVEL Control
Controls the amount of feedback used

in the FLANGER modes
control clockwise strengthens the feed-

back and increases the flanging effect

(Does not operate in the OFF or CHO­RUS modes)

.

0

. Turning the

.

FEEDBACK INDICATOR
Lights whenever the EFFECT MODE

switchmis in one of the FLANGER
positions to indicate that the FEED-

BACK LEVEL control0is in effect

0

.

MODULATION

SECTION

The flanging effect is produced by com­bining the output of an audio delay line

with the original audio signal
sult of this combination is a cancellation
of certain frequencies

control @ determines the amount of
initial time delay which occurs

"motion" associated with flanging ef­fects is created by slowly increasing
and decreasing the amount of time
delay by means of an internal low fre-

quency oscillator (LFO)
control

0

thus it controls the rate of change in
the delay time
determines the amount or depth of

change which will occur in the delay
time set by the MANUAL controlO

With the DEPTH control
change in delay time occurs
the change will be maximum
with the DEPTH control0at
the MANUAL controlOno longer has
any effect
TORSmgive visual indication of the
LFO rate

comes bright for the positive LFO

determines the LFO rate,

; the DEPTH control

. The LFO RATE INDICA-

. The indicator on the right be-

. The re-

. The MANUAL

. The

. The RATE

at "0",

0

; at "10"

. Also,

"10",

0

no

peaks, and the indicator on the left be­comes bright for the negative peaks

The EXT CV IN jack
is desired to control the delay time by

means of an external LFO or control

voltage

internal LFO is off and the indicators

0

will light for positive and negative
peaks of the external input
UAL controlOand DEPTH control

will affect the sound as before

The CH-B MOD switch ® can be

used for inverting the external or inter­nal modulating signal used to control

the Channel B delay time

.

that the delay time in Channel B will
decrease when the Channel A delay

time increases, and vis-a-vis

.

0

is used when it

. When this jack is in use, the

. The MAN-

m

.

. The result is

.

EFFECT MODE SECTION

EFFECT MODE SELECTOR Switch

See page 8 for detailed explanation of

the different modes

EFFECT MODE INDICATORS

EFFECT ON/OFF FOOT SW

(switch) Jack

By using a foot switch such as the
Roland FS-1 effect can be remote con-

trolled

. When ON, the effect will be
what selected by the EFFECT MODE
switch ®

.

.

0

5

~

~

~

~

~

~

PHASE and OUTPUT SECTIONS

CHANNEL A PHASE
CHANNEL B PHASE

At INV, the flanging effect will become
weak for the fundamental of the sound,
but strong for the overtones

OUTPUT LEVEL

Set to match the input level of the
device connected to the OUTPUT
jacks

0 4D

Switch

Switch

Switch

0

m
m

.

CHANNEL A OUTPUT Jack
CHANNEL B OUTPUT Jack

POWER Switch

with indicator

®

REAR PANEL

CHANNEL A INPUT Jack

CHANNEL B INPUT Jack

When connections are made simulta­neously to both front and rear panel
inputs, the front panel jacks have
priority

. This means that in the studio,

the rear panel jacks can be used for the

studio normal connections and the
front panel jacks for temporary patch­ing

.

(A

©

CHANNEL A OUTPUT Jack

CHANNEL

As with the inputs, the front panel
jacks have priority

B OUTPUT Jack

.

©

GND

(ground)
For making common ground connec­tions with other equipment

Terminal

C

.

6

6

The first flanging effects in recording
studios were produced by feeding an

audio signal to two tape recorders and

mixing the outputs from the playback

. If a light finger pressure is ap-

heads
plied to the supply reel on one of the

machines, it will run slightly slower,
thus giving a slight delay to one of the

. When this slightly delayed

outputs
sound is mixed with nondelayed sound,

the result is that certain frequencies
are cancelled

the effect which can be heard when
standing near a runway as a jet plane
takes off
cancelled as the direct sound from the

plane is combined with the delayed
sound reflected from the runway

amount of delay changes as the plane
moves off into the distance

studio, this effect is known as flanging
because it was first produced by finger
pressure applied to the flange of the

tape reel

. The effect is similar to

. Certain frequencies are

. The

. In the

.

Modern digital technology has made it
possible to design solid state audio
delay lines which can be used to imitate
the original tape flanging effect
output of the delay line is combined
with the original signal source
actual frequencies which are cancelled
as a result of this combination will
depend on the amount of the time

used

. In most flangers, the delay time

is controlled by an internal low fre­quency oscillator (LFO) which sweeps
the delay time above and below a pre-

determined center delay time

SBF-325 the MANUAL control Q is

used to set this initial center delay time,

thus it determines the initial frequency

cancellations which will occur

RATE control©controls the frequency

of the internal LFO, thus it controls the

rate of the delay time changes

DEPTH control

away from the center frequency posi-

tion the time delay will vary

BACK control®induces positive feed­back into the circuit which tends to ac­cent the flanging effect

determines how far

m

.

. The

. The

. In the

. The

. The

. The FEED-

7

i nC rLMI

FLANGER

.

Cn vrCnM

I

nvu rowluta

Monaural flanging mode

In this mode, the Channel B delay line
is not used and the Channel A delay
line output is connected to both OUT­PUTjacks

Stereo flanging mode

Produces a wide three-dimensional

effect using two independent delay

lines

duced by putting the CH-B MOD
switch ® in the INV (invert) position

00

FLANGER

. A "seesaw" effect can be pro-

II

.

.

.

Example setting for a strong flanging

effect

. Set

. CENTER FREQ control

as desired

Example settings for stereo flanging

.

*If both INPUTS

.

•

0©

are used when
in the FLANGER I mode, the CHAN­NEL A INPUT jack0will have priority
Also, the CH-B MOD switch ® and
the CHANNEL B PHASE switch
have no effect

Using only one output for monaural
sound produces an effect like that of
the FLANGER I mode

.

.

.

0

FLANGER III

Cross-mixing stereo flanging mode

A stereo flanging effect using the two
delay lines and a panning effect to pro-

duce wide, space filling sound

CHORUS

Chorus mode

This mode produces chorus sounds by
means of the delay lines

.

.

.

.

The effect is a little like phase shifted
sound with the addition of a light
depth giving chorus effect
the FEEDBACK control0will produce
large changes in the sound

MANUAL control@
Set at a relatively low position in re­lation to the fundamental (pitch) of the
input sound

•

When using in the monaural mode,

the effect is similar to that of the

. Changing

.

.

FLANGER II mode sound

~

T

he

FEEDBACK control@ does not

work in the CHORUS mode

.

.

it

RATE control0:
Counterclockwise
lessened
Clockwise
When using CHORUS in stereo, the

CH B MOD switch ® is often set at

H

INV

.

: chorus effect is

: chorus effect with vibrato

.