CA-1P/1PD
ACOUSTIC
PREAMPLIFIER
OWNER’S
GUIDE
D
esigned for the performing artist as
well as the studio musician, Crate’s
CA-1P/1PD Acoustic Preamplifier
gives you more of what you want: micro-
phone-quality sound, without feedback. And
without being “chained” to a mic stand!
The CA-1P/1PD features two independ-
ent channels, each with its own gain, eq
and reverb/ effects controls, contained in
an easily interpreted single rack space pack-
age. Channel one features an “Active /
Piezo” switch to properly match the pick-
ups of your instrument, a “Shape” control
for a richer sound and a 3-band rotary EQ.
An easy-to-use feedback elimination circuit
with frequency select and cut controls lets
you kill feedback without sacrificing sound
quality. Plus a foot-switchable chorus with
depth and rate controls.
Channel Two offers both low and high
impedance inputs and allows the use of a
rhythm machine, background tape, a high
or low-Z mic, or another instrument.
On the rear panel, a footswitch jack is pro-
vided for the reverb and chorus. Level-con-
trollable XLR and 1/4” balanced line out-
puts allow you to patch into house sound
boards or recording consoles, plus an
effects loop line-in/line-out setup allows
connection of external effects. In addition,
there’s a stereo Headphone jack, direct
Channel Output jacks, and a Stereo Input
jack.
Our optional On-Board Digital Sound
Processing (DSP) offers a variety of digital
reverbs, effects and delays specifically
designed for acoustic instruments, and
available on Crate’s CA-1P/PD.
The CA-1P/1PD was designed by musi-
cians and music-loving engineers. Highly
sophisticated computer-driven assembly
machines and highly skilled assemblers use
only the finest components to produce each
preamp. The final assembled product is test-
ed – and played – by skilled musician/tech-
nicians. It is only after the preamp has passed
this barrage of testing by very particular peo-
ple that it gets packed up and shipped out.
The CA-1P/1PD Acoustic Preamplifier.
Designed to be its best, so you can sound
your best!
About the
CA-1P/1PD:
Crate products are
Made With Pride
in the U.S.A.
To get this preamp to sound its best,
read this owner’s guide prior to its use.
To keep this preamp looking its best,
avoid abrasive cleansers. Wipe the unit
clean using a slightly dampened cloth.
THIS EQUIPMENT HAS BEEN DESIGNED AND ENGINEERED TO PROVIDE SAFE AND
RELIABLE OPERATION. IN ORDER TO PROLONG THE LIFE OF THE UNITAND PREVENT
ACCIDENTAL DAMAGES OR INJURY, PLEASE FOLLOW THESE PRECAUTIONARY
GUIDELINES:
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT OPEN CHASSIS; DO
NOT DEFEAT OR REMOVE THE GROUND PIN OF THE POWER CORD; CONNECT ONLY
TO A PROPERLY GROUNDED AC POWER OUTLET.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE
THIS EQUIPMENT TO RAIN OR MOISTURE.
CAUTION: NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.
CAUTION: OUR AMPLIFIERS ARE CAPABLE OF PRODUCING HIGH SOUND PRESSURE
LEVELS. CONTINUED EXPOSURE TO HIGH SOUND PRESSURE LEVELS CAN CAUSE
PERMANENT HEARING IMPAIRMENT OR LOSS. USER CAUTION IS ADVISED AND EAR
PROTECTION IS RECOMMENDED IF UNIT IS OPERATED AT HIGH VOLUME.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER.
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
"IT IS NECESSARY FOR THE USER TO REFER TO THE INSTRUCTION MANUAL"
“ES NECESARIO QUE EL USUARIO SE REFIERAAL MANUAL DE INSTRUCCIONES.”
"REFERREZ-VOUS AU MANUAL D'UTILISATION"
"UNBEDINGT IN DER BEDIENUNGSANLEITUNG NACHSCHLAGEN"
EXPLANATION OF
GRAPHICAL SYMBOLS:
"DANGEROUS VOLTAGE"
“VOLTAJE PELIGROSO”
"DANGER HAUTE TENSION"
"GEFAHLICHE SPANNUNG"
=
=
ATTENTION
RISQUE D'ELECTROCUTION
NE PAS OUVRIR
VORSICHT
ELEKTRISCHE SCHLAGGEFAHR
NICHT OFFENEN
ATTENTION: POUR REDUIRE D'ELECTROCUTION NE PAS
ENLEVER LE COUVERCLE. AUCUNE PIECE INTERNE N'EST REPRABLE
PAR L'UTILISATEUR. POUR TOUTE REPARATION, S'ADRESSER A UN
TECHNICIEN QUALIFIE.
VORSICHT: ZUR MINIMIERUNG ELEKTRISCHER SCHLAGGEFAHR NICHT
DEN DECKEL ABENHMEN. INTERNE TEILE KONNEN NICHT VOM
BENUTZER GEWARTET WERDEN. DIE WARTUNG IS QUALIFIZIERTEM
WARTUNGSPERSONAL ZU UBERLASSEN.
The DSP Section (CA-1PD only):
SAR
LAR
SPR
DLY
MULTI
Crate’s On-Board Digital Sound Processing (DSP)
offers a wide range of different digital reverbs, effects
and delays designed specifically for use with acoustic
instruments and vocals. Select the type of effect desired
by rotating the Rev Mode control (#23). This control is
divided into five sections: Small Area Reverbs (SAR),
Large Area Reverbs (LAR), Special Reverbs (SPR),
Delays (DLY) and Multiple Effects (MULTI).
The following chart provides a list of the DSP settings
along with a brief description of each effect.
SAR: Small Room 8’ x 8’ empty room w/hardwood floor
Small Rehearsal Hall 20’ x 40’ hall, wood floors, hard walls
LAR:
Large Hall 50’ x 100’ hall, about 50 persons
Concert Hall 5000-seat hall, full crowd
SPR:
Gated Reverb Reverb tail “cut off”
Reverb/Predelay Reverb with a 130ms predelay
DL
Y: Slapback, short 125ms delay + reverb
Slapback, Med-short 240ms delay + reverb
Slapback, Medium 350ms delay + reverb
Slapback, Long 530ms delay - 600’ travel time
MUL
TI: Chor-Delay 400ms delay w/modulation
Chorus Modulation
Flange Short chorus
Delay 1 125ms delay + reverb w/20% regen
Delay 2 125ms delay + reverb w/25% regen
Instrument Doubler Sim. second track slightly out-of-sync
On the Front Panel:
INPUT
GAIN
ACTIVE
PIEZO
SHAPE
PEAK
010
LOW
-15
0
+15
MID
-15
0
+15
HIGH
-15
0
+15 0
-15dB
-30dB
FREQ
80Hz
500Hz
4kHz
1. 2k
Hz
175
Hz
CUT
CA-1P ACOUSTIC GUITAR PREAMP
CHORUS REVERB
REV/EFF
SEND
010
DEPTH
010
RATE
LOW-Z
HI-Z
010
GAIN
010
PHANTOM
CHORUS
LOW
-15
0
+15
HIGH
-15
0
+15
REV/EFF
SEND
010
RETURN
MODE
010010
SAR
LAR
SPR
DLY
MULTI
INPUT
GAIN
ACTIVE
PIEZO
SHAPE
PEAK
010
LOW
-15
0
+15
MID
-15
0
+15
HIGH
-15
0
+15 0
-15dB
-30dB
FREQ
80Hz
500Hz
4kHz
1. 2k
Hz
175
Hz
CUT
CHORUS
EFFECTS
SEND
010
DEPTH
010
RATE
LOW-Z
HI-Z
010
GAIN
010
PHANTOM
CHORUS
LOW
-15
0
+15
HIGH
-15
0
+15
EFFECTS
SEND
010
010
CHORUS
CHORUS
CA-1P
ACOUSTIC GUITAR
PREAMP
CHANNEL ONE CHANNEL TWO
MASTER
LEVEL
CHANNEL ONE CHANNEL TWO
MASTER
LEVEL
1 32 18174 5 6 7 8 9 10 11 12 13 14 15 16 19 20 21 22 23 24 25
Channel One:
1: Input. Plug a patch cord from your instrument’s output jack here.
2: Active/Piezo switch. Set this switch to match the type of pickup
device on your instrument: for active electronic pickups, set the
switch to “active” (out). For passive/magnetic pickups, set it to
“piezo” (in).
3. Shape. This switch serves as a mid-cut control when pressed in,
adding fullness to the sound of your instrument.
4: Gain. Set this control near its center position for starters, then
adjust to suit your playing style and instrument’s output level. For
the best signal-to-noise ratio, the nearby Peak LED (#5) should
flash occasionally when you play.
5: Peak LED. This indicator LED will light when the input signal is
near the limits of the amp’s input stages. Adjust the Gain control
(#4) so this LED flashes occasionally.
6: Low. Adjust this control to get the best sounding bass response for
your instrument. Excessive boost of the low control can cause an
unnatural howling and should be avoided.
7: Mid. Adjust this control to get the best projection and midrange
tones for your instrument.
8: High. Adjust this control so your high notes and harmonic over-
tones are lively but not overpowering.
9: Freq. Used in conjunction with the Cut control (#10), this control
allows you to eliminate feedback at the most offending frequency.
For proper use, read the section entitled “To Eliminate Feedback”
to the immediate right.
10: Cut. Use this control along with the Freq control (#9) to eliminate
feedback, as described in the section entitled “To Eliminate
Feedback” to the immediate right.
11: Effects Send (CA-1P) / Rev/Eff Send (CA-1PD). Adjust the level of
the signal sent to an external effect (if the rear-panel effects loop is
used) or the amount of internal DSP reverb (CA-1PD) for Channel
One with this control.
12: Chorus On/Off switch. Activate the internal chorus by pushing
this switch into its locked-in position; press the switch again
(switch out) to turn the chorus off. This switch is bypassed when a
footswitch is used (see #36, rear panel).
13: Chorus Depth. Adjust how much chorus effect is applied by rotat-
ing this control – the further you turn to the right the greater the
intensity of the effect, pitch wavering up and down.
14: Chorus Rate. Adjust the speed of the chorus effect by rotating this
control – the further you turn to the right the faster the effect.
Channel T
wo:
15: Low-Z input. Connect a low impedance mic cable here for vocals.
16: Hi-Z input. Connect a high impedance mic cable, a rhythm
machine, the output of your backup tape machine or an instrument
here.
17. Phantom. Some low impedance mics require power to be applied
to their signal pins for proper operation. When using this type of
mic, press this switch in. The phantom switch applies 15V to pins
2 and 3 of the low-Z input jack (#15). (Mics not requiring phantom
power will not be affected by the phantom power switch.)
18: Chorus On/Off switch. When Channel One’s chorus switch (#12)
is pressed in, this switch controls the chorus for Channel Two.
(Chorus is only available for this channel when Channel One’s cho-
rus switch is pressed in.)
19: Gain. Adjust the level of the Channel Two input signal with this
control for the best mix with Channel One’s signal.
20: Low. Adjust this control to get the best sounding bass response for
your instrument. Excessive boost of the low control can cause an
unnatural howling and should be avoided.
21: High. Adjust this control so your high notes and harmonic over-
tones are lively but not overpowering.
22: Effects Send (CA-1P) / Rev/Eff Send (CA-1PD). Adjust the level of
the signal sent to an external effect (if the rear-panel effects loop is
used) or the amount of internal DSP reverb (CA-1PD) for Channel
Two with this control.
23: Reverb Mode (CA-1PD only). Selection of digital effects is made
with this control. A listing of the available effects settings is given
in the section entitled “The DSP Section.”
24: Reverb Return (CA-1PD only). Adjust the amount of the DSP
reverb effect with this control - the further you turn to the right the
deeper the effect.
25: Master Level. Set the overall output of the preamp with this con-
trol.
To Eliminate Instrument Feedback:
One of the most common problems encountered when amplifying
acoustic instruments, especially in small environments, is feedback.
Acoustic instruments typically have inherent qualities which cause res-
onant feedback at specific frequencies. Instrument tone controls and
sound board eq’s are helpful in getting rid of the problem, but since they
operate around relatively wide frequency bands the musician must sac-
rifice sound quality in his quest to do away with feedback. Since Crate’s
feedback elimination circuit isolates the offending frequency, you can
now eliminate feedback without affecting your overall sound.
Chances are, you may not have a problem with feedback at all. In
that case, leave the CA-1P/1PD’s Freq and Cut controls at the fully-
counter-clockwise position. However, if you do encounter feedback
while playing, set the Cut control to -30dB (fully clockwise) and adjust
the Freq control until the feedback is gone. Reduce the Cut to about the
12:00 position and readjust the Freq control as needed. Continue reduc-
ing the Cut control and readjusting the Freq control until there is no
more feedback with the Cut control as far to the counterclockwise posi-
tion as possible. This way you’ve effectively eliminated instrument
feedback without sacrificing sound quality.
CA-1:
CA-1P:
On the Rear Panel:
WARNING:
TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
AVIS:
RISQUE DE CHOC
ELECTRIQUE. NE PAS OUVRIR.
POWER
AC LINE IN
HEADPHONES/
LINE OUT
MASTER LINE OUTPUT
PIEZO
ACTIVE
010
LOW Z HIGH Z LEVEL
CHANNEL OUTPUT EFFECTS LOOP
RETURN SEND REVERB/
CHORUS
FOOT
SWITCH
STEREO INPUT
CA-1P
2018A
MADE IN THE U.S.A. BY SLM ELECTRONICS
1400 FERGUSON AVE., ST. LOUIS, MO 63133
TIP = ONE, RING = TWO
TIP = TWO, RING =ONE
CHANNEL ASSIGNMENT
CHANNEL TWO CHANNEL ONE
3635343332313029282726 393837
CA-1P/1PD Block Diagram:
channel 1
stereo
input
input
active piezo
freq cut
filter
gain low mid high
peak
shape depth rate
chorus
rev/
effect
send
active
piezo
channel 2
low-z
input
hi-z
input
phantom
power
tones
effects
line out
left right
rev/
effect
send
low high
tones
gain
effects
return
left
master
level
right
reverb
return
reverb mode
effects
send
DSP
low-z
bal.
hi-z
bal.
headphones/
line out
level
line out
ch. 1
out
footswitch
chorus
on on
chorus
on
ch. assign
ch. 2
out
CA-1PD
only
26: Power Switch. Turns the preamp on and off – lights up when the pre-
amp is on.
27: Line In. Connect the female end of the AC line cord here. Connect the
male plug to a suitable source of line voltage. Refer to the voltage
information on the back of the preamp for its voltage and current
requirements.
Note: This is a grounded plug. To avoid the possibility of electric
shock, DO NOT defeat the ground connection in any way!
28: Headphones/Line Out Master. Use this jack to connect a pair of stereo
headphones or to send an high impedance, unbalanced line level
stereo signal to a house sound board, a recording console or an exter-
nal power amplifier by means of an 1/4” stereo plug-terminated cable.
The level at this jack is controlled by the Master Level knob (#25, front
panel).
29: Low Z Bal. Use this jack to connect a low impedance, balanced line
level mono signal to a house sound board, a recording console or an
external power amplifier by means of an XLR-terminated cable. (Pin 1
is ground, pin 2 is signal +, and pin 3 is signal -.) The level at this jack
is controlled by the Line Out Level knob (#31).
30: High Z Bal. Use this jack to connect a high impedance, balanced line
level mono signal to a house sound board, a recording console or an
external power amplifier by means of an 1/4” stereo plug-terminated
cable. (Ring is signal +, tip is signal -, and sleeve is ground.) The level
at this jack is controlled by the Line Out Level knob (#31).
31: Line Out Level. Adjust the level of the line out signal with this control
- the further you turn to the right the stronger the signal. (This control
works independently from the master level control.)
32: Channel Two output. Use this jack to connect an unbalanced, line level
mono “direct out” signal from Channel Two to a house sound board, a
recording console or an external power amplifier by means of an 1/4”
mono plug-terminated cable. This signal is post-EQ and pre-Master
Level.
33: Channel One output. Use this jack to connect an unbalanced, line level
mono “direct out” signal from Channel One to a house sound board, a
recording console or an external power amplifier by means of an 1/4”
mono plug-terminated cable. This signal is post-EQ and pre-Master
Level.
34: Effects Loop Return. Patch into an external effects device using this
jack and the Effects Loop Send jack (#35). Connect a shielded cable
from the output jack of the external effects unit to this jack.
35: Effects Loop Send. Connect a shielded cable from this jack into the
input jack of the effects unit.
36: Footswitch - CA-1P: Connect a one-button footswitch (such as the
Crate CFP-1) here for remote on/off control of the chorus. When con-
nected, the footswitch overrides the front panel chorus on/off switch.
The footswitch tip controls the chorus; sleeve is ground.
CA-1PD: Connect a two-button footswitch (such as the Crate CFP-2)
here for remote on/off control of the DSP section and chorus. When
connected, the footswitch overrides the front panel chorus on/off
switch. The footswitch tip controls the chorus, ring controls the DSP;
sleeve is ground.
37: Channel Assignment switch. This switch assigns the tip and ring con-
nection of the Stereo Input jack (#39) as follows:
Switch OUT: Tip = Channel One, Ring = Channel Two
Switch IN: Tip = Channel Two, Ring = Channel One
38: Active/Piezo switch. Set this switch to match the type of pickup device
on your instrument: for active electronic pickups, set the switch to
“active” (out). For passive/magnetic pickups, set it to “piezo” (in).
39: Stereo Input jack. For instruments with stereo outputs (such as
acoustic guitars with pickups in the bridge and a built-in microphone),
connect a stereo 1/4” cable here to send one signal (for example, the
bridge pickups) to Channel One and the other to Channel Two. The
Channel Assignment switch (#37) determines which channel receives
which signal.
Crate continually develops new products, as well as improves
existing ones. For this reason, the specifications and information
in this manual are subject to change without notice.
CA-1P/1PD
Technical Specifications:
©1997 SLM Electronics • A Division of St. Louis Music Co.
1400 Ferguson Avenue • St. Louis, MO 63133
P/N 47-434-02
05/97
Channel One: Low: +/-15dB @ 80Hz
Mid: +/-15dB @ 650Hz
High: +/-15dB @ 10kHz
Input Impedance: 25k ohm (Active), 2.2M ohm (Piezo)
Input Sensitivity: 22mV RMS (Actv), 9mV RMS (Pzo)
Sens. to Eff Send/Line out: 70mV
Max Input Signal: 6v RMS (17v peak to peak)
Feedback Elimination: Freq: variable from 80Hz to 4kHz
Cut: variable from -0 to -30dB
Channel T
wo: Low: +/-15dB @ 80Hz
High: +/-15dB @ 10kHz
Input Impedance: 3k ohm (Lo-Z), 20k ohm (Hi-Z)
Input Sensitivity: 3mV RMS (LZ), 15mV RMS (HZ)
Sens. to Eff Send/Line out: 9mV (LZ), 50mV (HZ)
Max Input Signal: 10v RMS (28v peak to peak)
Effects Loop: Line Out 1v RMS, Line In 1v RMS
Stereo Input:
Input Impedance: 20k ohm to Ch. 2
25k ohm Active to Ch. 1
2.2M ohm Piezo to Ch. 1
Input Sensitivity: 15mV to Ch. 2
22mV Active to Ch. 1
9mV Piezo to Ch. 1
Eff Return to Line Out Sens:
50mV
Eff Return In. Impedance: 11k ohm
Eff Send Out. Impedance: 2.2k ohm
Line Out Out.Impedance: 220 ohm (Lo-Z), 2.2k ohm (Hi-Z)
Ch. 1 Out. Impedance: 10k ohm
Ch. 2 Out. Impedance: 10k ohm
Power Requirements: 120VAC, 60Hz, 14VA;
100/110VAC, 50/60Hz, 14VA;
230VAC, 50/60Hz, 14VA
Size and Weight: 1-3/4”H x 19”W x 7-5/8”D,
9 lbs.
/
