ATI Audio Inc.
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Tel: 856-626-3480
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Fax: 856-504-0220
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sales@atiaudio.com
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www.
audio.com
DESCRIPTION
The ATI Model DA2008-1 is a Dual 1X4 Analog Audio Distribution Amplifier, ideal
for every application and every budget. In addition to superb performance
specifications, it features output clipping indicators and a front panel headphone
output.
ICs developed primarily for the instrumentation market had many shortcomings
when used in high quality audio applications. The lack of audio related
specifications, crossover distortion, high noise for low source impedances, limited
output capability and limited gain bandwidth product forced many compromises
when used in audio systems. High ratio input transformers, output boost stages
and multiple stage designs were all used to compensate for op amp deficiencies
and in turn added additional response and distortion problems of their own
Walter Jung, in a definitive series of articles, analyzed and defined slew rate
induced distortion mechanisms, tested many commonly available ICs and
correlated various distortion tests with subjective (listening) criteria. A very
significant result of his efforts was the identification of an IC originally developed
for the European professional audio market which has almost ideal
characteristics for audio use and in particular provides a high slew rate capability
of 13 volts/microsecond, virtually eliminating slew induced Transient
Intermodulation Distortion. By contrast the old standard 741op amp has a slew
rate of only .6V/microsecond
This op amp is now available from several U.S. manufacturers in single and dual
versions and forms the basis for our Model DA2008-1 design. This chip
incorporates an input stage designed for excellent noise performance with a wide
range of source impedances thus eliminating the necessity for input step-up
transformers. An output stage capable of driving 600 ohm loads directly to
+22dBm with total freedom from crossover distortion, high inherent linearity,
100dB open loop gain and 50MHz gain bandwidth product make this an ideal
device for highest quality audio. The absence of Transient Intermodulation
Distortion may be detected by the smooth effortless high frequency output
capability, the absence of the harsh, raspy sound typical of IC amplifiers driven to
full output at high frequencies and the freedom from increasing harmonic
distortion vs. frequency. As used in the DA2008-1, a minimum of 40dB of loop
gain is available for 100:1 distortion reduction even at 20kHz. All program audio
stages in the Distribution Amplifiers use this unique device in its dual version
(NE5533)
INPUT
Input audio feeds a unity gain balanced differential high slew rate Bi-FET input
buffer stage, which presents a 30,000 ohm bridging impedance to the source.
