Alto EQU215 User manual

www.altoproaudio.com
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Version 1.0
MODEL: EQU215- MKII V2
Revised on Jan,2010

CONTENTS
1. Introduction.....................................................................................................................1
2. Specification....................................................................................................................2
3. Block Diagram................................................................................................................3
4. Schematic Diagram........................................................................................................4
5. Wiring Diagram..............................................................................................................9
6. PCB Layout..................................................................................................................10
7. Test Procedure.............................................................................................................14
8. Exploded View & Mechanical Parts List.......................................................................18
9. BOM List..................................................................................................................................20

The EQU215-MKII V2 Graphic Stereo15-Band Equalizer is an extremely musical and
flexible Graphic Equalizer, based on many years of experience and designed to provide a
permanent precise equalization to musician, performer, and studio engineer. It can be used
wherever is requested to modify the frequency “contour” of a sound and can offer a solution
to many common sound problems and allows the user to use the creativity to obtain nice
results in terms of sound characterization.
The EQU215-MKII V2 Graphic Equalizer Features:
Constant Q circuitry with a 3% center frequency accuracy
Control range +/-6dB/+/-12dB selectable
Active balanced and unbalanced input and output connectors
Variable input level control
Signal clop pilot
Ground “LIFT” switch to disconnect signal ground from chassis ground
Power off automatic bypass function
Line voltage selectable robust and compact design
Mountable in a 19’’ rack unit (1U)
Manufactured under QS9000, VDA6.1 certified management system
1. Introduction
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Type EQU215-MKII V2 2*15-Band: 2/3 Octave, ISO spacing(1H series)
Slider Travel 20mm with positive centre detent
Range +/-6dB or +/-12dB selectable
Active balanced XLR and 1/4'' TRS
Unbalanced RCA
20k Ω(bal.)
15k Ω(unbal.)
Maximum input level 14 dBu
Active balanced XLR and 1/4'' TRS
Unbalanced RCA
Output impedance ＜600Ω
High pass filter 40Hz(12dB/Oct)fixed-button type
Low pass filter 16KHz(12db/Oct)fixed-button type
Frequency response 20 Hz to 50kHz at -1.5dBu
THD+N% ＜0.01% (@1kHz, all VR at middle position)
S/N Ratio 110dB
95V -120V AC -60Hz
220V-240VAC -50Hz/60Hz
Consumption 9W
Dimension 483(W)*220(D)*44(H)mm (19''*8.66''*1.7'')
Power supply
Input impedance
Output connections
Input connections
2. Specification
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3. Block Diagram
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
4. Schematic Diagram
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Blue
Black
Red
PT
5. Wiring Diagram
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6. PCB Layout
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EQU215-MKII V2 Finished Product Test
Test Instruments
1. AP (Audio Precision)
2. Dual-track oscilloscope
Instrument setting
1. Set proper AC input voltage
2. Connect the output signal of AP to the input of EQU215-MKII V2
3. Connect the output of EQU215-MKII V2 to the input of AP
Adjustment according to following procedures
1. Set the potentiometer of 15-band EQ in center, set the input level at 0dB, all buttons out
2. Turn input level to maximum, the output level shall be +12dB/-1dB, and the distortion shall be
0.007%/+/-0.001%
3. Set INPUT LEVEL at minimum, the output level shall be -12dB/+/-1dB, and distortion shall be
0.007%+/-0.002%
7. Test Procedure
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4. Adjust the input level so that the AP output is 0dB, the frequency response is as following
5. Adjust the input level so that the AP output is 0dB, press the HI-pass button and the frequency
response is as following
6. Adjust the input level so that the AP output is 0dB, press the low pass button and the frequency
response is as following
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7. Press EQ button down, keep RANGE out and the LED indicates +12, adjust slide buttons to
maximum and minimum, measure the frequency response independently and the curve shall
be as following
8. Turn off the AP input signal and set input level as maximum, the AP setting is as following, now
it shall be no more than -82dB
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9. Turn on the AP input signal, and set the input level at maximum, the AP setting is as following,
the maximum non-distortion level is +28dBu+/-1dB and distortion is 1%
10. Now, the S/N shall be no less than 110dB
11. Connect AP input and output to Channel 2,repeat steps 1~10
12. All slides shall be set in center and all buttons out before shipping
~Test Completed~
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MODEL No: EQU215-MKII V2
8. Exploded View & Mechanical Parts List
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