Ashly SC-63 User Manual

ASHLY

SC-63/SC"66A PARAMETRIC EQUALIZERS

OPERATING INSTRUCTIONS

ASHLY AUDIO INC.

TABLE OF CONTENTS

1. INTRODUCTION / UNPACKING 2

2. FRONT PANEL LAYOUT 3

3. BACK PANEL LAYOUT 4

4. INPUT, OUTPUT, AND POWER CONNECTIONS 4

5. EXPLANATION OF PARAMETRIC EQ AND OUR CONTROLS 5

6. FEEDBACK STEP BY STEP SETUP INSTRUCTIONS 7

7. NARROW BAND STEP BY STEP SETUP INSTRUCTIONS 8

8. MEDIUM TO WIDE BAND STEP BY STEP SETUP INSTRUCTIONS 9

9. APPLICATION AND OPERATION FOR SOUND REINFORCEMENT 9

10. OPERATION FOR USE AS AN INSTRUMENT TONE CONTROL 11

11. APPLICATION AND OPERATION FOR RECORDING 11

12. APPLICATION AND OPERATION FOR BROADCASTING 12

Page

13. APPLICATION AND OPERATION FOR DISCOTHEQUES 12

14. APPLICATION AND OPERATION FOR MOTION PICTURE SOUND & TV 13

15. BLOCK DIAGRAMS 14

16. CIRCUIT DESCRIPTION 14

17. DEFINITION OF TERMS 15

18. TROUBLE SHOOTING TIPS 18

19. SPECIFICATIONS 19

20. GRAPH OF KEYBOARD / MUSIC STAFF FREQUENCY NUMBERS 20

We thank you for your expression of confidence in Ashly products. The unit
you have purchased is protected by a two year warranty. To establish the
warranty, be sure to fill out and mail the warranty card attached to your
product.

Fill out the information below for your records.

Model Number Serial Number

Dealer Date of Purchase

Phone

Salesman

Other Information:

INTRODUCTION

As soon as reproduced audio appeared on the scene, the need for tone controls

was apparent; a common problem has always been loss of frequency extremes.

Early equalizers were simple bass and treble controls which were used to
extend frequency response a bit. This type of tone control is powerless when
dealing with specialized acoustical problems. Movie people of the thirties
designed equalizers to deal with mid-range frequencies and used them for
specific problems of intelligibility. These "dialogue equalizers" along with

other special effects devices such as sound effects filters are examples of

equalizers designed to solve specific problems.

Graphic Equalizers were the first universal tone controls, providing a piece-

wise approximation of total frequency response. All of these equalizers have

a common limitation, some of the characteristics of equalization are fixed.
For example, the center frequency and sharpness for each band of a graphic are

pre-determined. This leads to an immediate frustration because these

characteristics are never exactly appropriate. (What do you do when you need
a fader right between two sliders on a graphic?)

In the late sixtys, the first parametric equalizers were developed by George

Massenburg at ITI. Parametrics provide independent and continuous adjustment
of all three possible characteristics: amplitude, center frequency, and
bandwidth. As a result, virtually any desired frequency response may be
obtained with no restrictions imposed by the equalizer itself.

The Ashly Audio SC-63 and SC-66A parametric equalizers are the result of years
of research and development. They are the most flexible and powerful tool yet
developed for modifying audio frequency response. As such, they can solve
audio problems previously considered insurmountable, and can provide tone
control action to exactly suit particular needs. Of course, they also require
a greater understanding of the equalization process than simpler tone
controls,

We ask that you please read this instruction manual thoroughly before
operation so that you may realize all the features and benefits that the SC-53
and SC-66A parametric equalizers have to offer.

UNPACKING

As a part of our system of quality control every Ashly product is carefully

inspected before leaving the factory to ensure flawless appearance. After
unpacking, please inspect for any physical damage. Save the shipping carton
and all packing materials, as they were carefully designed to reduce to a
minimum the possibility of transportation damage should the unit again require
packing and shipping. In the event that damage has occurred, immediately
notify your dealer so that a written claim to cover the damages can be
initiated.

THE RIGHT TO ANY CLAIM AGAINST A PUBLIC CARRIER CAN BE FORFEITED IF THE
CARRIER IS NOT NOTIFIED PROMPTLY AND IF THE SHIPPING CARTON AND PACKING
MATERIALS ARE NOT AVAILABLE FOR INSPECTION BY THE CARRIER. SAVE ALL PACKING
MATERIALS UNTIL THE CLAIM HAS BEEN SETTLED.

MODEL SC-63

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INPUT, OUTPUT, AND POWER CONNECTIONS

This equalizer should be connected to a 3 wire grounded outlet supplying 120

Volts, 50-60 Hz. Power consumption is 12 watts.

The INPUT is a 10K ohm active balanced type on a standard stereo phone plug.

The (+) or in-phase connection is on the tip and the (-) or out-of-phase

connection is on the ring. When feeding the equalizer from unbalanced

sources, connect the signal hot to the tip ( + ) and the signal ground to the

ring (-). To use the input as a common unbalanced type, simply use a mono

phone plug in the usual way. (See Definition Of Terms, "Wiring", page 17.)

The OUTPUT connections are standard 1/4" phone jacks and mate with a standard
phone plug such as a switchcraft 280. For rack mounted unbalanced audio
systems the output ground may be separated from the case ground by using a

stereo phone plug for the output connection. The output ground is then wired
to the ring of the stereo phone plug for the output connection. The output
ground is then wired to the ring of the stereo plugs rather than the sleeve.

In this manner, ground loops in the rack may be eliminated. This output can
be fed to a balanced input by wiring the ( + ) input to the tip, the (-) input
to the ring, and the shield to ground.

If this equalizer is used in a monaural system, channels 1 and 2 of the SC-66A
may be cascaded to utilize all eight bands of equalization. Connect the input
signal to channel 1 input, connect channel 1 output to channel 2 input, and
take the output signal from channel 2 output. If the audio ground plug
isolation is needed for rack mounting, use a stereo phone plug jumper to
connect channels 1 and 2.

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EXPLANATION OF PARAMETRIC EQ AND OUR CONTROLS

A Parametric Equalizer consists of several filter sections connected together
each capable of continuous and independent adjustment of: (1) AMPLITUDE,

(2) CENTER FREQUENCY, and (3) BANDWIDTH.

On the SC-66A, these controls are mounted vertically below individual in/out
switches, see figure A.

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On the SC-63t these controls are mounted horizontally with center frequency
and bandwidth controls grouped together and amplitude controls for three bands