MINIMIZING NOISE IN THE SYSTEM

Your choice of separate components is the right way to secure the best performance from a music system, but the wide-band characteristics and complexity of the best sys- tems may also not conceal the introduction of ground loops and noise pickup-especially RFI (radio frequency interference). With exceedingly high quality equipment we may become conscious of distractions that would be ig- nored on a lesser level. Careful interwiring practice will greatly reduce the likelihood of such problems.

The DH-110 is a very quiet preformer. There can be oc- casions where even the finest equipment exhibits hum or noise due to irregularities in its interconnection. The sim- ple expedient of reversing line cord plugs will often reduce hum. Listen to the hum level after each change, reversing only one cord at a time.

CAUTION: Do not indiscriminately disconnect and reconnect a power amplifier when other components are turned ON. Use the DH-110 muting circuit for protection against loud noises. With the power amp connected to a switched convenience outlet on the DH-110, turn the preamp OFF, reverse the amplifier line cord, and then turn the preamp ON.

Use connecting cables of high quality, and treat them with care. Unplug cables by grasping the connector-not the cord-to maintain good connections. We have no evi- dence that special connector platings are required, but the surfaces should be free from grease, fingerprints, or any contaminate that may prevent a firm and complete connec- tion. Some audiophiles are convinced that a good contact cleaner is an important adjunct to a high quality music sys- tem.

It does not usually reduce noise to connect each compo- nent to an ‘earth’ ground. This may even aggravate a ground loop problem, for good ‘earth’ grounds are hard to find, and unsatisfactory grounds are likely carriers of RFI.

The previous suggestions may also help reduce RFI. In difficult cases, RFI filters can be purchased for insertion between the line cord plug and the wall outlet, or a device called a ferrite bead may be installed in the phono stage by a competent technician. If you use a pre-preamplifier and find that it is RF1 sensitive, increasing the cartridge com- pensation capacitor may help (moving coil cartridges do not require a specific value), or try connecting a 0.01 mfd capacitor across the phono input jack that feeds the pre- preamplifier. Even for experienced engineers, RFI pre- sents problems which often demand that they simply ‘try and try again’.

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Hafler DH-110 manual Minimizing Noise in the System
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DH-110 specifications

The Hafler DH-110 is a revered preamplifier recognized for its remarkable performance and versatility in the audio industry. First launched in the early 1980s, the DH-110 developed a reputation for delivering high-quality sound reproduction, making it a favorite among audiophiles and home theater enthusiasts alike.

One of the key features of the Hafler DH-110 is its dual-mono design, which ensures that the left and right channels are processed independently. This configuration helps to eliminate crosstalk and maintain clarity, particularly in complex musical passages. The DH-110 employs high-quality components throughout its circuitry, including metal film resistors and film capacitors, which contribute to a clean signal path and minimize distortion.

The preamplifier offers a wide range of inputs, accommodating various sources such as turntables, CD players, and tape decks. The inclusion of a phono stage for both moving magnet and moving coil cartridges is a standout feature, allowing vinyl enthusiasts to achieve optimal sound quality from their records. This versatility is enhanced by selectable input sensitivity, ensuring that each source can be tailored for the best performance.

Additionally, the DH-110 supports tone control, featuring bass and treble adjustments that enable users to dial in their desired sound signature. While some audiophiles prefer a pure, unaltered sound, the option to adjust bass and treble can be appealing for customizing the listening experience.

The design of the DH-110 exudes classic elegance, incorporating a simple yet functional aesthetic with a robust chassis designed to minimize resonance. The front panel includes clearly labeled knobs and buttons, ensuring ease of use during operation.

In terms of connectivity, the Hafler DH-110 includes both tape monitoring loops and multiple outputs, allowing seamless integration into existing audio systems. The preamplifier can be connected to various power amplifiers, delivering a balanced audio experience that meets the demands of both casual listeners and serious audiophiles.

In conclusion, the Hafler DH-110 is a testament to quality engineering, offering superior performance, versatility, and user-friendly operation. Its combination of advanced technologies, including a dual-mono architecture and high-grade components, make it a timeless choice for anyone seeking to enhance their audio experience with a reliable preamplifier. Whether for home theater use or critical listening, the DH-110 continues to be a solid investment for audio enthusiasts.
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