Phoenix Gold pt1800 - Manual (Page 22)

Distortion
Distortion is usually caused by excessive loss in the input controls (the mixer/equalizer/crossover can’t produce enough
output), overdriving resulting in output clipping, or current limiting caused by excessively low load impedances.
1. Check the setting of the Input Level controls. If set too low, the preceding piece of equipment may not have sufficien
output to overcome the loss.
2. Check the speaker connections and verify that all screw connections are tight and that there are no stray strands of
wire to cause short circuits.
3. Verify that the total load impedance presented to the amplifier is within the limits described in this manual for the
mode of operation selected.
Care and Service
Assistance
C a re: Wipe off the pt1250/1800/2400 front panel and chassis from time to time with a soft, dry cloth. If you have something stubborn
to remove, use a mild dish soap or detergent sparingly applied to a soft cloth. Don’t use alcohol, ammonia, or other strong solvents.
Service Assistance: We suggest that you read the Limited Warranty completely to fully understand your warranty/service coverage.
Please promptly complete and return the Warranty Registration Card. Also be sure to save the sales receipt in a safe place. It will be
necessary for warranty service. If your CARVER Professional product should require service, you may contact the CARV E R
Professional Technical Service Department by calling (503) 978-3363 or by writing to us at the Factory address shown below. We will
then direct you to the nearest in our national network of Authorized Warranty Service Centers or give you detailed instructions on how
to return the product to us for prompt action. If you should have questions or comments, please write to the Factory address given below.
Please include the model and serial number of your Carver Professional product, your complete address and a daytime phone number.
I/M pt1250
(Replacement input board for PM 2.0t and pt1250)
● Improved CMRR >80dB @ 1kHz
The “NEW” I/M pt1250 resolves some of the common complaints of the pt1250. Redesigned using the SSM2141
op-amp to provide greatly increased CMRR, the I/M pt1250 now attains common mode rejection >80dB @ 1kHz or
>70dB @ 20kHz. This allows the use of long input lines in electrically noisy environments without annoying noises
becoming part of your program.
● Flatter broadband frequency response
The frequency response of the new input board is flat from 20Hz to beyond 200kHz +0, -0.2dB.
● New grounding scheme eliminates ground loops
An improved grounding scheme shortens the chassis ground path to millimeters eliminating ground loop problems.
● New user selectable (pin2) or (pin3) hot
A jumper on the input board allows the user to select (pin2) or (pin3) as the hot leg of the XLR connector.
20
2T
1R 3S
J4
J1
2 3
4
1
6 3
2 3
4
1
6 3
J2
J3
2T
1R 3S
RIGHT
CHANNEL
LEFT
CHANNEL
PIN3+ PIN2+ 4 1 PIN3+ 4 1 PIN2+
BLK
YEL
ORN
WHT/BRN
WHT/YEL
RED
WHITE
BLK/WHT
GND
11
12
-12V
+12V
RIGHT
LEFT
GND
J100