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musical instrument details
Vintage API 550A-1 Discrete 3-Band Equalizer 500 Series Module
Estimated price for orientation: 799 $
Category: API 550A 500 Series 3band EQ Equ
Class:
Description Brand: API Model: 550A1 Type: Vintage Equalizer UPC: Does not apply
DESCRIPTION - This listing is for an API 550A-1 Discrete 3-Band Equalizer 500 Series Module. Recapped in 2008"API 550A-1
Same features as the 550A but made to be an economical version in the late 70’s. Key differences with the 550A are:a) Electronically balanced input in contrast to the unbalanced input of previous three band eq’s. This alone makes some prefer using it when experiencing the 6 db drop when interfacing electronically balanced output to an unbalanced input.
b) Constant Q instead of the proportional Q of the 550A
c) Use of integrated circuits (IC)
d) Uses one 2520 opamp in the output stage – usually a HuntingtonLooking at the inside, there is one 2520 driving the output transformer with a feed-forward design using a NPN transistor. The other amps are IC’s with an LF356 balancing the input and a TL074CN quad amp powering the bands and filter. The front rotary switches plugged into the circuit board with connectors.
Description
| Brand: | API | Model: | 550A1 |
| Type: | Vintage Equalizer | UPC: | Does not apply |
DESCRIPTION - This listing is for an API 550A-1 Discrete 3-Band Equalizer 500 Series Module. Recapped in 2008"API 550A-1
Same features as the 550A but made to be an economical version in the late 70’s. Key differences with the 550A are:a) Electronically balanced input in contrast to the unbalanced input of previous three band eq’s. This alone makes some prefer using it when experiencing the 6 db drop when interfacing electronically balanced output to an unbalanced input.
b) Constant Q instead of the proportional Q of the 550A
c) Use of integrated circuits (IC)
d) Uses one 2520 opamp in the output stage – usually a HuntingtonLooking at the inside, there is one 2520 driving the output transformer with a feed-forward design using a NPN transistor. The other amps are IC’s with an LF356 balancing the input and a TL074CN quad amp powering the bands and filter. The front rotary switches plugged into the circuit board with connectors.
Same features as the 550A but made to be an economical version in the late 70’s. Key differences with the 550A are:a) Electronically balanced input in contrast to the unbalanced input of previous three band eq’s. This alone makes some prefer using it when experiencing the 6 db drop when interfacing electronically balanced output to an unbalanced input.
b) Constant Q instead of the proportional Q of the 550A
c) Use of integrated circuits (IC)
d) Uses one 2520 opamp in the output stage – usually a HuntingtonLooking at the inside, there is one 2520 driving the output transformer with a feed-forward design using a NPN transistor. The other amps are IC’s with an LF356 balancing the input and a TL074CN quad amp powering the bands and filter. The front rotary switches plugged into the circuit board with connectors.