CPX ® CPX 3800 Power Amplifier Owner’s Manual TM
Intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. Intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product. CAUTION: Risk of electrical shock — DO NOT OPEN! CAUTION:To reduce the risk of electric shock, do not remove cover. No user serviceable parts inside.
IMPORTANT SAFETY INSTRUCTIONS WARNING: When using electrical products, basic cautions should always be followed, including the following: 1. Read these instructions. 2. Keep these instructions. 3. Heed all warnings. 4. Follow all instructions. 5. Do not use this apparatus near water. 6. Clean only with a dry cloth. 7. Do not block any of the ventilation openings. Install in accordance with manufacturer’s instructions. 8.
WICHTIGE SICHERHEITSHINWEISE ACHTUNG: Beim Einsatz von Elektrogeräten müssen u.a. grundlegende Vorsichtsmaßnahmen befolgt werden: 1. Lesen Sie sich diese Anweisungen durch. 2. Bewahren Sie diese Anweisungen auf. 3. Beachten Sie alle Warnungen. 4. Befolgen Sie alle Anweisungen. 5. Setzen Sie dieses Gerät nicht in der Nähe von Wasser ein. 6. Reinigen Sie es nur mit einem trockenen Tuch. 7. Blockieren Sie keine der Lüftungsöffnungen. Führen Sie die Installation gemäß den Anweisungen des Herstellers durch. 8.
INSTRUCTIONS IMPORTANTES DE SECURITE ATTENTION: L’utilisation de tout appareil électrique doit être soumise aux precautions d’usage incluant: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Lire ces instructions. Gardez ce manuel pour de futures références. Prétez attention aux messages de précautions de ce manuel. Suivez ces instructions. N’utilisez pas cette unité proche de plans d’eau. N’utilisez qu’un tissu sec pour le nettoyage de votre unité.
INSTRUCCIONES IMPORTANTES PARA SU SEGURIDAD CUIDADO: Cuando use productos electrónicos, debe tomar precauciones básicas, incluyendo las siguientes: 1. Lea estas instrucciones. 2. Guarde estas instrucciones. 3. Haga caso de todos los consejos. 4. Siga todas las instrucciones. 5. No usar este aparato cerca del agua. 6. Limpiar solamente con una tela seca. 7. No bloquear ninguna de las salidas de ventilación. Instalar de acuerdo a las instrucciones del fabricante. 8.
important precautions 1 Save the carton and packing materials! Should you ever need to ship the unit, use only the original factory packing. ¡ Do not parallel- or series-connect an amplifier output with any other amplifier output. For replacement packaging, call Crest Performance’s Customer Service Department directly. 2 3 4 5 6 7 8 Read all documentation before operating your equipment. Retain all documentation for future reference.
table of contents 1 2 TM how to use this manual introduction p.10 installation p.9 p.11 unpacking mounting connecting power cooling requirements operating precautions connecting inputs connecting outputs 3 features overview 4 operation modes 5 CPX owner’s manual p.15 front panel rear panel p.22 stereo parallel bridged mono contents protection features p.
how to use this manual 1 conventions terms official Crest Performance features and each indicator or control on the amplifier will appear as: terms actions specific actions or selections the user can execute will appear as: actions tasks are broken down into steps 1 2 3 warnings Procedures not to attempt. Issues or hazards to keep in mind when operating the equipment. indicators ® What to look for on the equipment display. Alerts, indicators or prompts that may appear. tips Preferred methods.
2 introduction welcome Congratulations on your purchase of the CPX 3800 Series, a power amplifier designed for years of reliable, flawless operation under rigorous use. This amplifier offers the sonic superiority and unsurpassed reliability for which Crest Performance is famous while remaining surprisingly compact. Advanced technology and extensive protection circuitry allow operation with greater efficiency into difficult loads and power conditions.
installation / what to do with the shipping carton unpacking / proper rack-mounting technique mounting / required AC line voltages connecting power / keeping the amplifier cooled cooling requirements / preventing amplifier damage operating precautions 2 connecting inputs connecting outputs p.
2 installation CPX owner’s manual TM unpacking Upon unpacking, inspect the amplifier. If you find any damage, notify your supplier immediately. Only the consignee may institute a claim with the carrier for damage incurred during shipping. Be sure to save the carton and all packing materials. Should you ever need to ship the unit back to Crest Performance, one of its offices, service centers or the supplier, use only the original factory packing.
2 installation cooling requirements The CPX™ Series amplifiers use a forced-air cooling system to maintain a low, consistent operating temperature. Air is drawn into the amplifier by fan(s) on the rear panel, courses through the cooling fins of the tunnel-configured channel heat sink(s), and then exhausts through the front panel grille. If either heat sink gets too hot, its sensing circuit will open the output relay, disconnecting the load from that particular channel.
2 installation CPX owner’s manual TM connecting inputs Input connections are made via the three-pin XLR (pin 2+) or 6.3 mm plug “Combi” connectors on the rear panel of the amplifier. The inputs are actively balanced. The input overload point is high enough to accept the maximum output level of virtually any signal source. inputs outputs connecting outputs All models have two output (speaker) connections per channel.
features overview / location of connectors and controls front panel / legend of panel symbols rear panel 3 p.
features overview CPX owner’s manual 5 4 3 2 TM 1 front panel switches and controls 1 AC Power Switch/Circuit Breaker The CPX Series amplifiers have a combination AC switch/circuit breaker on the front panel. If the switch shuts off during normal use, push it back to the ON position once. If it will not stay on, the amplifier needs servicing. The power only breaks one side of the AC mains. Hazardous energy may be present in the enclosure when the power switch is in the OFF position.
indicators features overview 3 CPX™ Series amplifiers feature three front panel LED indicators per channel: GCL™, SIGNAL and POWER. These LED indicators inform the user of each channel’s operating status and warn of possible abnormal conditions. 3GCL (Gain Comparator Limting) LED A channel’s GCL LED will light at the onset of clipping. If the LEDs are flashing quickly and intermittently, the channel is just at the clip threshold.
3 features overview 6 CPX owner’s manual TM 7 8 9 0 ¡ rear panel 6 IEC Mains Connector This is a standard IEC power connector. An AC mains cord having the appropriate AC plug and ratings for the intended operating voltage is included in the carton. Warning - all apparatus with class 1 construction shall be connected to a mains socket outlet with a protective earthing connection. U.S.
features overview 3 7 Low Cut Switch This switch is used to activate the LOW CUT filter for the corresponding channel. It is a push-type switch that requires a small tool to activate. The IN position routes the input signals through the 40 Hz LOW CUT filter, while the OUT position bypasses the filter. This filter will cut extremely low frequencies, protecting speakers from the possibility of over-excursion. The filter low-frequency rolloff is 12 dB per octave.
3 features overview 0 Conn. Mode Select Switch Depressing the rear panel CONN. MODE select switch connects both input connectors together in parallel. This directs the same input signal to both channels and allows one connector to be used with a patch cable to drive another amplifier. In the OUT position, both input connectors operate independently. Do not operate the CONN. MODE select switch with the amplifier powered on. See the sections on Stereo, Parallel and Bridged Mono Mode for more information.
4 operation modes / choosing the appropriate mode / switching between operation modes / special considerations when using bridged mode CPX owner’s manual TM stereo parallel bridged mono p.
operation modes 4 stereo For stereo (dual channel) operation, turn the amplifier off and set the mode select switches on the back panel to the OUT (extended) position. In this mode, both channels operate independently of each other with their input attenuators controlling their respective levels. For example, a signal at channel A’s input produces an amplified signal at channel A’s output, while a signal at channel B’s input produces an amplified signal at channel B’s output.
5 protection features / description of protection features CPX owner’s manual TM GCL™ gain comparator limiting IGM™ impedance sensing AUTORAMP™ signal control thermal protection short circuit DC voltage protection turn on/off p.
protection features 5 The CPX Series amplifiers incorporate several circuits to protect both themselves and loudspeakers under virtually any situation. Crest Performance has attempted to make the amplifiers as foolproof as possible by making them immune to short and open circuits, mismatched loads, DC voltage and overheating. If a channel goes into the Gain Comparator Limiting or GCL™ gain reduction mode, the speaker load remains connected but clipping percentage or output power are instantly reduced.
5 protection features CPX owner’s manual TM turn-on/turn-off protection At power-up, the amplifier stays in the protect mode with outputs disconnected for approximately six seconds while the power supplies charge and stabilize. While the output relays are open, the GCL™ LEDs light. When power is removed, the speaker loads immediately disconnect so that no thumps or pops are heard.
safety / protecting your speakers / the owner’s role in amplifier safety 6 speaker protection user responsibility p.
6 safety CPX owner’s manual speaker protection All loudspeakers have electrical, thermal and physical limits that must be observed to prevent damage or failure. Too much power, low frequencies applied to high frequency drivers, severely clipped waveforms and DC voltage can all be fatal to cone and compression drivers. The Crest Performance CPX Series amplifiers automatically protect speakers from DC voltages and subsonic signals. For more information, see the section on Protection Features.
service and support / when to get support / ways to contact Crest Performance 7 support contact us p.
7 service and support CPX owner’s manual TM support In the unlikely event that your amplifier develops a problem, it must be returned to an authorized distributor or service center or shipped directly to our factory for service. To obtain service, contact your nearest Crest Performance Service Center, Distributor, Dealer or any of the worldwide Crest Performance offices. For those with Internet access, please visit the Crest Performance web site.
specifications a CPX Series TM CPX 3800 Rated Power Bridged 8 ohms 2650 watts @ 1 kHz at <0.1% T.H.D. Rated Power (2 x 4 ohms) 1300 watts per channel @ 1 kHz at <0.05% T.H.D. both channels driven Rated Power (2 x 8 ohms) 775 watts per channel @ 1 kHz at <0.05% T.H.D. both channels driven Rated Power (1 x 4 ohms) 1500 watts @ 1 kHz at <0.05% T.H.D. Rated Power (1 x 8 ohms) 875 watts @ 1 kHz at <0.05% T.H.D.
b service and support cable length (in feet) feet 5 10 feet 40 feet 80 feet standard wire gauge (AWG) CPX owner’s manual TM power loss into power loss into 8 Ω load (%) 4 Ω load (%) power loss into 2 Ω load (%) 18 .79 1.58 3.16 16 .50 1.00 2.00 14 .31 .62 1.24 12 .20 .40 .80 10 .125 .25 .50 18 1.58 3.16 6.32 16 1.00 2.0 4.00 14 .62 1.25 2.50 12 .40 .80 1.60 10 .25 .50 1.00 18 8.00 12.60 25.20 16 4.00 8.00 1.60 14 2.50 5.00 10.00 12 1.60 3.
setup c glossary of terms (for setup) Stereo Music with two separate channels, usually a left and right channel. Mono Music with only one channel. Crossover An electronic device that separates high and low frequencies and sends them to different outputs. The separate signals are usually sent to a high out and a low out. Bi-amp The separation of high and low frequencies with a crossover, using separate speakers and power amps for each.
NOTES
CREST AUDIO LIMITED WARRANTY Effective Date: November 1, 2000 What This Warranty Covers Your Crest Audio Warranty covers defects in material and workmanship in Crest Audio products purchased and serviced in the U.S.A.
http://www.crest-performance.
