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アンプ ATI Audio HDA400のPDF 取扱説明書をオンラインで閲覧またはダウンロードできます。ATI Audio HDA400 3 ページ。 Stereo headphone amplifier

DESCRIPTION

The HDA400 is a rugged, AC powered headphone amplifier, which will provide

excellent performance driving a wide range of typical stereo headphones. It will

drive the usual 32 to 600 ohm high efficiency stereo headphones to teeth rattling

levels near 120dB SPL with a combination of high output voltage swing (16Vp-p)

for high impedance phones and a protected high current capability (.2Ap-p) for

low impedance phones. It will do the above at distortion levels below .10% and

response flat to .25db both measured over the full frequency range of 20Hz to

20kHz.

The HDA400 has balanced, bridging ¼ inch TRS stereo program inputs with front

panel CLIP indicator, MASTER level control and MONO/STEREO switch. Inputs

are electronically balanced but will operate properly when if an unbalanced ¼

inch TS plug is inserted. An internal input stage gain selector plug (P2) optimizes

the input stage gain for either -10dBu or +4dBu nominal inputs or the program

INPUT CLIP indicator shows input overdrive. A MASTER LEVEL control and

MONO/STEREO switch adjust the program signal fed to all output channels

Four high compliance output channels drive paralleled front and rear ¼ inch TRS

output headphone jacks. The high compliance output circuitry comfortably drives

all phones from 32 to 600 ohms. Although designed to drive either the front or the

rear output jack, the HDA400 will drive two sets of headphones plugged into the

same channel with only slightly reduced drive to each. To minimize major

loudness differences use identical headphones. Individual output channels can

be setup for monaural operation by inserting a jumper wire into the WX02

position of the desired channel. Do not use mono headphones with a Tip- Sleeve

plug with the HDA400. The rear jacks can also feed remote headphone

distribution boxes.

The HDA400 includes an internal bi-polar power supply, which will operate at 115

or 230VAC by changing internal jumpers. The power cord is a standard IEC320

type that you can easily swipe from someone else if you lose it.

CONNECTIONS

Balanced inputs are connected with their HI to TRS -TIP and LO to TRS-RING,

Shields go to TRS-SHLD. Unbalanced input lines should be connected with their

center hot wire to TRS-TIP and with the cable shield to TRS-SHLD. Be careful to

observe HI-LO input polarity to avoid monaural or center stage cancellation

effects The HDA400 is shipped setup for -10dBu nominal input level (+12dBu

peak). An internal jumper plug P2 may be moved to accommodate levels at

+4dBu nominal (+22dBu peak). To change P2, remove the top cover by

removing the four upper Phillips head screws (two on each side). P2 is located

on the right side of the PC board directly behind the volume control and has two

positions; for –10dBu inputs move the plug to the left, for +4dBu inputs move the

plug toward the right. Ensure that no internal wiring is caught or pinched, replace

the cover and screws.

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