DUET 350 OWNER'S MANUAL Serial Number
Table of Contents Page Product Concept and Description .....................................................................................1 Packaging and Features .................................................................................................1, 2 The Rationale for High Power Amplification .................................................................3 Compatibility ......................................................................................................................
1 INTRODUCTION... Congratulations on choosing the Duet 350 Amplifier. Your unit has been individually handmade from the finest parts and materials. The Duet 350 utilizes proprietary Cello circuitry that represents true state-of-the-art in audio electronics and is designed to perform to "as-new" specifications for decades of musical enjoyment. We want your Duet 350 to provide you with complete satisfaction.
2 Packaging and Features (Cont.) To achieve a more affordable price, Cello engineers developed new circuitry which offers outstanding performance without dual choke power supplies. The Duet 350 will drive speakers of any impedance, but it is optimized for loads in the 4 to 8 Ohms range. Some speakers have a low impedance in part of their range. For example, electrostatic speakers may have a dip in the range between 10 to 20 kHz. The Duet 350 handles such anomalies with complete grace.
3 The Rationale for High Power Amplification Real music fills a room. Even a soft instrument such as flute, harpsichord, or guitar is much larger in life than most music systems can easily reproduce. Part of the problem, until now, has been the limitations in power amplifiers. Some amps sound sweet but have no power. Others play loud but lack natural sonic quality. At the same time many speaker systems are not very efficient and require fairly high voltage to reproduce musical peaks.
4 INSTRUCTIONS Unpacking The packing box for the Duet 350 Amplifier should arrive in good condition. Please inspect for damage to the carton, although this is most unlikely due to the strength of the carton construction. Open packing carefully and save all foam pieces and boxes for reuse in the event that the unit must be shipped in the future. Should the boxes become lost, please contact the factory for replacement cartons. The carton should contain: - Duet 350 Amplifier - 1 heavy duty A.C.
5 Custom Made Cables (Non-Cello) Three-conductor shield cables should be used to keep audio(+), audio(-), audio ground and chassis earth separate. If single-ended adapters are made, pins one and three should be jumped and used as ground and pin two should be used as the audio(+). Connecting audio ground and chassis ground may cause or solve grounding problems depending on the system as a whole. Electrical Connections 1) Make sure the circuit breaker is "off'.
6 When you are through, switch the amplifiers off first before turning off the peripheral equipment. Leaving the amplifiers on will not harm them, but be advised that each unit draws approximately 200 watts at idle. If physical damage has occurred to the unit, or it is exposed to water or other liquids, do not use this device until proper repairs and/or unit integrity tests have been effected by authorized personnel. Bridged Operation 1) Use the right channel input.
8 CELLO LIMITED WARRANTY Parts Cello warranties all mechanical parts for five years and electronic parts for life. Labor Labor is the responsibility of the distributor except for the following: Any defective product during the first year shall be repaired by the distributor with labor paid by Cello according to factory rates for a given repair. At Cello's discretion, or if the distributor is unable to perform the repair, the unit may be returned to the factory for service using agreed-upon air freight.
9 Tampering/Abuse/Misuse: Any unauthorized modifications, repairs or tampering, and/or any indications of obvious owner abuse, negligence or improper usage, as determined by Cello Limited shall be grounds to void the warranty. Service If you believe your Cello equipment is not functioning properly, please call the Customer Service department at the factory. If you need to return your component, you will be given an R/A (return authorization) number.
10 ELECTRICAL SPECIFICATIONS Duet 350 Amplifier Power Output Rated Watts (AVG.) 8 Ohms........................................................................350 4 Ohms........................................................................600 8 Ohms bridged mono mode operation ................. 1,200 IMD SMPTE 60Hz & 7kHz 8 Ohms 350W output.....................................................>0.1% THD 20Hz-20kHz 8 Ohms 350W output.....................................................>0.
Cello, Ltd. 315 Peck St., Bldg. 23, New Haven, CT 06513 USA Tel.
