Carvin dcm 151 service manual

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OPERATING/SERVICING MANUAL

Carvin

DCM301 DCM151

Pro Line Professional Amplifiers

Please Read Before Operating Your Carvin Power Amplifier

UNPACKING
Carefully remove the amplifier by opening the carton and holding the carton flaps out. Turn the amp upside down
and lift the carton off. Now turn the amp right-side up. In the event the amp is moved or re-shipped ALWAYS" use the
original carton and packing material. If not, structural damage could deface the unit where Carvin orthe Shipping
Co. will not be liable. A replacement carton is available for $12 freight prevpaid. SAVE ALL PACKING MATERIALS!

INSPECTION
Inspect the unit for damage that may have occured in transit. If damage is found, notify the transportation com-
pany immediately, and file a damage claim. The claim must be instituted by yourself,the consignee. Save all car-
tons for proof of damage. Please notify Carvin of any damage done.

AMP SET-UP - Do Not Turn On Yet!
The Garvin Power Amp is designed for table top" or rack mounting". The Four rubber feet may be removed if
amps are to be stacked in a rack.
Sufficient airflow must be provided, since airis drawn through the rear and exhausted through the side vents. The
rack must have an open back. Do Not Operate the amplifier with the cover off (this will defeat the cooling system).

AMP POWER-UP
Connect the required input and speaker cables. Use the Input Mode Switch chart on the next pages to determine
the proper mode switch to select forthe amps desired function. Turn the A & B GAlN Controls down. Turn the amp
ON and listen for the speaker relay to click on. Now turn the Gain Controls up and you should be running.

A. Do Not use Shielded or Coax cables for speakers.
IMPORTANT B. Read paragraph 11 about Speaker Output Fusing.
C. Use youramplifierwith common sense. This amp delivers enough powerto harm any speaker.

AMP CIRCUIT DESCRIPTION
The Carvin Professional Series Amplifier is one the most advanced designs currently on the market.

The output stages use the most advanced D.C. circuitry along with a darlington Op-Amp input, featuring a 50
volt] per micro-second slew rate, for a sound second-to-none leaving no coloration of its own. Also, this Op-Amp in-
put holds the D.C. offset voltage with-in several micro-volts at all times to prevent small amounts of DC. at the out-
put which could affect the operation of your speakers.

The large geometry power base output transistor stage will drive Electrostatic speakers or other highly reactive
speakers with no difficulties. An A.C. capacitor on the front end blocks any DC. voltage that could cause damage to
speakers.

The mechanical design of your new amplifier is unlike ordinary amplifiers. The anodized heat-sinks and power
transistors are modular designed to facilitate easy removal for servicing or exchange. Carefully thought-out wiring
design incorporates military-type wire harnesses with Heavy-Duty pin connectors..All P.C. boards are ridged G10
fiberglass. The reinforced 16 guage steel chassis and anodized aluminum front panel offer exceptional structural
reinforcement.

Your Carvin amp is designed to give years of trouble-free service. If you have further questions about your amp or
need hookup assistance, please call or write us.

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Amplifier Operation

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1. POWER SWITCH Push for ON,

2. The TEMPERATURE INDICATOR, when lighted, indicates overheating. The thermostatic sensor will turn the amp off. In about 30 sec. to
3 min. the sensors Will automatically reset. and the amp is ready to use again. If the sensors trip again, this may indicate A) Speaker loads
below rated speaker Impedance of amp. 8) Shielded or incorrect size speaker cables being used. 0) Inadequate ventilation around the amp.
Note: On hot day, do not use the amp in direct sunlight. Always place in the shade.

3. THE GAIN CONTROL allows the operator to adjust the sensitivity of the power amp to match the mixer output levels. This Gain control
does not limit the amps output. Maximum output can be easily obtained at settings less than Full On. To properly adjust the Gain control: set
amplifier Gain to zero. set mixer or pre-amp master volume at mid position and raise amplifier Gain for maximum volume desired. After
adjustment. use mixer or pre-amp master volume control to control the power amplifier. Note: This usually gives the best signal-to-noise ratio.

4. EQUALIZER DEFEAT SWITCH To use the equalizer, push the switch to the "in" position. If the equalizer is not used. set the switch to the
"Out position. Once the switch is selected for the Out" position, the equalizer is removed electrically from the amps circuit to give the amp a
flat response. This swnch also allows for good comparisons between equalized settings and the natural flat response of your program
material.

5. GRAPHIC EQUALIZER A 9 Band Graphic Equalizer has been optimized for sound reinforcement which includes the tuning of all
frequencies from 30HZ to 20K Hz. Precise 1 octave bands are set at 60. 125, 250, 500. 1K, 2K, 4K. 8K, and 16K Hz. Boost and Cut is set at a
maximum of 15dB which is more than enough for average adjustments.

Operation: When all slider knobs are centered along the zero line". the equalizer has no effect. By raising any slider off the zero line, that
portion of the audio spectrum (1 octave wide) is boosted. Likewise. lowering the slider from the zero line reduces the power in that particular
band. The left hand sliders control the lower frequencies (bass) and the right sliders control the high frequencies (treble). The middle sliders
control the mid-frequencies.

REAR PANEL

6. LINE CORD All Garvin equipment is supplied with 3»conductor line cords, ending in grounding type plugs. This arrangement will greatly
reduce the possibility of electrical shock when used with proper S-conductor outlets.

7. The GROUND SWITCH enables the operator to remove the AC. Line ground off the chassis. This totally isolates the amps ground
system. Select this switch for the most quiet hum position.

8. PRIMARY FUSE. All Garvin Professional amplifiers are wired for 120 VAC and are fused at 5 amps.

9. FAN A computer-grade tan is incorporated in your amplifier to allow running at maximum power output in a rack cabinet without thermal
shut-down. Note: After a period of time. the fan bearings may loosen up, yielding slightly more fan noise. This is normal.

10. SPEAKER OUTPUT The amplifier's output has two Phone Jacks (wired in parallel) along with a Dual 25 amp Banana plug. Red denotes
Positive and Black denotes negative speaker outputs.

11. OUTPUT FUSE An output fuse is offered for added speaker protection. However. the 10AGC fuse supplied with your amp is too large to
protect any speaker. This large value is supplied because some speaker systems like Carvin have theirown protection. If you wish protection,
remove the 1OAGC and install the following suggested fuse values.

A. 3A2AGC Fuse for Horn Drivers up to 50 Watts (Bi-Amped).

B. 1AGC Fuse for Horn Drivers up to 50 Watts using a Passive Crossover.

C. 2/2AGC Fuse for Woofer rated between 100 and 150 Watts.

D. 2/2AGC Fuse for 2 or 3 Way speaker system rated at 100 Watts.

These approximate fuse values are for 8 Ohm speakers. Double all fuse values when paralleling speakers together.
CAUTION This amplifier is powerful enough to damage any speaker. The above fuse recommendations can only be used as a gmde. Your
requirements may be different.

PROCEED WITH CAUTION: WE ASSUME NO RESPONSIBILITY FOR ANY DAMAGE DONE T0 SPEAKERS REGARDLESS OF
CIRCUMSTANCE.

12. INPUT Your amplifier will accept either a Balanced Line through the DSF connector or an Unbalanced Line through the Phone Jack. The
DaF Connector Wiring; Pin 1 is Ground. Pin 2 is Negative Bal., Pin 3 is Positive Bal. The Balanced circuit features a transformerless
Differential Amplifier designed for balanced lines down to 150 Ohms. lmpedances as high as 50,000 ohms can also be used but With some
loss of high frequencies. The transfonnerless design incorporated offers superior THD and Frequency Response over conventional inputs.