INPUT

The 9303 and 9505 have input jacks for both balanced and unbalanced input signals. The unbalanced inputs use conventional RCA phono jacks. When using the RCA inputs, the rear panel BALANCED/UNBALANCED switch must be set to the UNBALANCED position. The balanced input jacks are dual function connectors which accept 1/4" TRS (Rip Ring Sleeve) phone or XLR plugs. Set the BALANCED/UNBALANCED switch to the BALANCED Position to use these jacks. The connector pin-out is printed on the rear panel of the amp.

Balanced Input: 1/4" Tip Ring Sleeve

The 1/4" balanced input jack is connected according to conventional usage with the Tip high (+), Ring return (–) and the Sleeve ground shield.

Balanced Input: XLR

The XLR balanced input jack is connected according to the IEC International Standard, with pin 2 high (+), pin 3 return (–) and pin 1 ground shield. When preparing to use the amplifier, check the output configuration of the source unit to maintain the proper signal polarity.

Unbalanced Input

Many popular mixers use unbalanced RCA phono jacks for the monitor outputs. For short cable runs RCA audio patch cable can be used without any system performance penalty. Check the mixer specs for the maximum cable length it will drive. Make sure the BALANCED/UNBALANCED switch is set for UNBALANCED operation.

Unbalanced Source with Balanced Input

Better noise rejection for long cable runs can be achieved by using a twisted pair balanced cable from the unbalanced source. At the source end of the cable, connect an RCA plug with the return (–) wire and shield connected to the ground shell of the plug. Wire the plug at the amplifier end of the cable the same as for the regular balanced input connection.

OUTPUT CONNECTIONS

The speaker output connectors are dual binding posts. These binding posts will directly accept 12 AWG wire or banana plugs and are spaced on 3/4" centers to accept dual banana plugs.

MONOPHONIC USE

For systems with high power requirements, the amplifiers can be configured for single channel bridged mono operation. To bridge the amplifier, set the rear panel STEREO/MONO switch to the Mono position; use only the left channel input, and connect the speaker to the red output binding posts. When the amplifier is bridged, the output is floating. Any speaker which requires a common ground from the amplifier output cannot be used in this application. Since a bridged amplifier shares the load between the two channels, the amplifier will effectively drive half of the load. Therefore, for bridged mono operation we recommend using an eight ohm load as the minimum impedance.

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Hafler 9303, 9505 manual Balanced Input 1/4 Tip Ring Sleeve

9505, 9303 specifications

The Hafler 9303 and 9505 are both high-performance power amplifiers that have garnered a solid reputation among audiophiles and professionals in the audio industry. These amplifiers are designed to deliver high-quality sound reproduction with performance and reliability, making them suitable for various audio applications, from home theater systems to professional studio work.

The Hafler 9303 is a versatile amplifier known for its warm sound and consistent performance. With a power output of 100 watts per channel at 8 ohms and 150 watts at 4 ohms, it provides ample headroom for dynamic peaks in music without distortion. The 9303 features a classic, rugged design and is equipped with an exceptional thermal management system to prevent overheating during extended use. Its circuitry incorporates advanced feedback technology that minimizes distortion and enhances audio clarity. The amplifier also supports both balanced and unbalanced inputs, allowing for flexible integration into various audio systems.

On the other hand, the Hafler 9505 takes the performance up a notch with a powerful 200 watts per channel at 8 ohms, and it can reach 300 watts at 4 ohms. This model is ideal for driving larger speakers and can handle demanding audio setups. The 9505 incorporates Hafler's proprietary active feedback design, which maximizes damping factor and ensures accurate transient response. Its robust construction and high-quality components provide longevity and reliability, making it a favorite among professionals who require consistent performance in demanding environments.

Both amplifiers feature dual-mono construction, ensuring independent power supply for each channel, which helps in maintaining channel separation and reducing crosstalk. This design contributes to a wider soundstage and clearer audio reproduction, crucial for critical listening and professional applications. Furthermore, the amplifiers are equipped with comprehensive protection circuitry, safeguarding the components against speaker short circuits and thermal overloads.

In summary, the Hafler 9303 and 9505 power amplifiers represent an excellent choice for anyone seeking reliable and high-fidelity audio performance. With their impressive power outputs, advanced technologies, and robust designs, these amplifiers are versatile enough to cater to both home audio enthusiasts and professional sound engineers, ensuring that they deliver exceptional sonic experiences across various settings.