CONNECTING THE GFA-7805/7807 TO YOUR SPEAKERS

When connecting the amplifier to the loudspeaker, it is vital to maintain proper polarity (positive to positive, negative to negative). On the GFA-7805/7807, the positive terminal is color coded RED and labeled “+,” and the negative is color coded BLACK and labeled “-”. The positive terminal on the speaker will be color coded RED, or will be labeled “+,” “pos,” “positive,” “8 ohms” or “4 ohms.” The negative terminal on the speaker will be color coded BLACK, or will be labeled “-,” “neg,” “negative,” “C,” “Common,” “G,” or “ground.”

We recommend that your speaker cables be terminated with “U” type spade connectors. These will give the most contact area insuring long-term reliability. The spade connector should have a maximum width of 0.57 inches and an opening width of no less than 0.25".

To properly connect the speaker cable to the binding posts, turn the insulated head of the binding post clockwise until the wire or connector is firmly secured. Finger pressure is sufficient and you should not use pliers or other tools which could damage or over-tighten the binding-post assembly. The binding posts have been designed in such a way that finger pressure is all that is required to cause a “pinching” action among the different metal surfaces to ensure proper connection.

It is very important to use the correct size of wire in order to avoid unnecessary loss of amplifier power in the cable, reduction of amplifier damping factor and other undesirable conditions. Sound audio engineering practice suggests the use of at least AWG16, stranded, copper cable. Recommended capacitance of the speaker wire should not exceed 5OpF per foot. This insures high frequencies will not be rolled off.

All loudspeakers having a nominal impedance down to 4 ohms can be connected to and driven by the GFA-7805/7807. The amplifier can drive these low-impedance speakers at more than adequate power levels with no difficulty. It should be noted that many loudspeaker systems which are nominally rated at 4 ohms drop in impedance, in some parts of their frequency range, to as low as 2 ohms (and sometimes less). You will not experience difficulties even with these very low impedance loads unless you demand excessively high volumes levels from your system.

We do not recommend that you run additional sets of speakers to the GFA-7805/7807. If you choose to add remote speakers in another room, we strongly suggest that a switching system to disconnect the non-home-theater speakers be incorporated when the surround sound (home theater) mode is in operation. A device such as the ADCOM GFS-3 or GFS-6 speaker selector is recommended. A Speaker Selector enables you to maintain good sonic integrity while giving you the flexibility to add speakers throughout your house.

We suggest that you follow this chart below for maximum speaker lengths and minimum wire gauges. If longer runs are needed, we recomend that you consult with your ADCOM Dealer to maximize the performance of your system for your exact conditions.

up to 24 feet

AWGI6

up to 36 feet

AWGI4

up to 58 feet

AWGI2

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Adcom GFA7807 owner manual Connecting the GFA-7805/7807 to Your Speakers
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GFA7807 specifications

The Adcom GFA-7807 is a high-performance power amplifier known for its exceptional sound quality and engineering. As part of Adcom's renowned lineup of audio equipment, the GFA-7807 is celebrated for its ability to deliver powerful and accurate audio reproduction, appealing to audiophiles and casual listeners alike.

One of the standout features of the GFA-7807 is its impressive power output. It provides 200 watts per channel at 8 ohms and can deliver up to 350 watts per channel at 4 ohms. This robust power handling allows it to drive even the most demanding speakers with ease, ensuring that the music remains dynamic and detailed, regardless of the volume level. This amplifier's ability to maintain its performance under high loads is a crucial attribute for high-end audio setups.

The GFA-7807 employs a Class AB amplification design, which balances the benefits of both Class A and Class B amplifiers. This design helps minimize distortion and crossover issues, ensuring that the output remains clean and precise, particularly in the midrange frequencies. The amplifier's low total harmonic distortion (THD) rating further enhances its audio fidelity, making it an excellent choice for critical listening.

In terms of build quality, the Adcom GFA-7807 is constructed with rugged components designed to withstand the rigors of prolonged use. The sturdy chassis and high-quality connectors contribute to its durability, while also minimizing interference and maintaining signal integrity. The amplifier is also equipped with extensive protection circuits, which guard against short circuits, thermal overload, and other potential damage conditions.

Another noteworthy characteristic of the GFA-7807 is its versatility. It features multiple input options, including balanced XLR and unbalanced RCA connectors, allowing for seamless integration into various audio systems. Additionally, its rack-mountable design makes it an ideal choice for professional setups and home theaters alike.

Overall, the Adcom GFA-7807 power amplifier stands out in the audio landscape due to its impressive power handling, low distortion, rugged construction, and versatility. Whether used in a high-fidelity music system or a home theater, it delivers a remarkable listening experience that captures the essence of the original recording, making it a must-consider option for enthusiasts looking to elevate their audio setups.
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