Frequently Asked Questions
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Knowledge Base > Discontinued Products > 303 Interface Amplifier (Bi-directional)
What is the pinout for the PS-3 power supply?
There are two separate AC supplies coming out of the PS-3: 8.5 VAC @ 1A and 34.5 VAC CT @ 250mA. Pinout is as follows: 8.5 VAC on pins 6 and 1, 17 VAC on pins 7 and 3, center tap @ pins 4 and 5 are connected to earth ground. This is when viewed at the end of the PS-3 7-pin DIN plug.
Where can I find a Data Sheet for the 303 Interface Amplifier (Bi-directional) or 305 Distribution Amplifier (1x4)?
How long can the cables be connecting the 303 to my computer or CD player?
The unbalanced cables (those connected to the -10dBV equipment or RCA connectors) should be kept at 6 feet or less to minimize the noise and hum that may be induced. The balanced (+4dBu) cables can be ran hundreds of feet with very little induced hum and noise.
Where can I find Schematics for the 303 Interface Amplifier (Bi-directional)?
Why is the signal from my 303 Interface Amplifier (Bi-directional) noisy?
Check the input signal. The 303’s unbalanced inputs are designed to run at -10dBV nominal, and the 303’s balanced inputs are designed to run at +4dBu nominal. Make sure that you are feeding a line level (not mic level) signal to the 303 at the appropriate nominal level. Check gain settings on downstream equipment. The system gain structure should be such that the 303 operates at or near unity gain. Is the input signal already noisy?
Where can I find a User's Guide for the 303 Interface Amplifier (Bi-directional)?
Where can I find a Flow Chart for the 303 Interface Amplifier (Bi-directional)?
Can my Symetrix-manufactured unit normally powered by the PS-3 be battery powered for remote use?
No, the only option would be to use a 12VDC to 117VAC inverter with the supplied PS-3 inline power supply.
Why is the signal from my 303 Interface Amplifier (Bi-directional) distorted?
Check the input signal. Is it too hot, or is it already distorted? Check the output loading. It should be above or equal to 600 ohms. Is the input of the device following the 303 clipping? Is something else clipping?