High Voltage Audio HVA-NEQ User manual

HVA-NEQ
PARAMETRIC EQUALIZER
USER GUIDE
HIGHgVOLTAGE
A U D I O
WWW.HIGHVOLTAGEAUDIO.NET

FCAUTION: HIGHgVOLTAGE !
RISK OF ELECTRIC SHOCK
!! WARNING !!
HEALTH AND SAFETY
- Always read these complete instructions before operating the equipment.
- Always use a properly grounded IEC cable with this equipment and never
defeat the grounding pin as this provides not only a safety ground but is
required for low noise operation.
- Avoid using this equipment around stray magnetic fields. The enclosure is
designed to shield the circuits from magnetic fields and radio interference and
so during racking of the equipment it’s important to ensure typical grounding
procedures are followed.
- Avoid the use of the equipment in high temperature environments as this can
degrade the performance and reduce the lifetime of the internal components.
- There are some internally accessible adjustments in this equipment. If there is
a requirement to perform internal adjustments, please ensure one is
comfortable with opening the equipment and performing said adjustments.
Please seek qualified assistance if unsure.
- If adjustments are to be made to this equipment, please disconnect the
equipment from mains power prior to opening the equipment and performing
the adjustment. While we understand that some adjustments are to be made
with the equipment live, any damage to the equipment as a result of dropped
metal objects or liquid damage will not be covered by the warranty.
HIGH VOLTAGE AUDIO reserves the right to change the specifications or modify the
designs of its equipment. Company contact information is on the last page of this
manual.
VOLTAGE AND FUSE SELECTION
This equipment is capable of operating over a range of mains voltages to cater for all
regions.
To avoid the risk of fire, replace the mains fuse only with a T500mAL (M205 SLO-BLO
only).

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THANK YOU FOR CHOOSING
HIGHgVOLTAGE
A U D I O
Thank you for choosing products from HIGH VOLTAGE AUDIO. We expect you will
be satisfied with the quality, performance and value of our products, which are made
possible through careful design and construction choices.
ABOUT HIGH VOLTAGE AUDIO
HIGH VOLTAGE AUDIO is a manufacturer of boutique audio electronics based in
Australia. We go to every effort to accurately create the tone, feel and functionality of
great outboard gear. Our work is the culmination of years of experience in sound
production and electronics. Our products are built here in Australia, so our customers
can have the confidence that they will purchase a product that not only sounds great,
but is dependable, reliable and easy to use.
Our products are staples in the racks of renowned mix and mastering studios all over
the world. We design products that are accessible for professionals and enthusiasts
alike.

OVERVIEW
The High Voltage Audio HVA-NEQ parametric equalizer is a powerful, dual-channel
mastering EQ designed with the professional mastering engineer in mind. Each
channel features four precise fully parametric bands, each with a variable Q/shelf,
frequency and cut/boost controls with gain multipliers, low and high pass filters, and
a switchable mid/side matrix to allow for greater flexibility with program material. All
controls are stepped, allowing for precision recall and stereo tracking.
All four bands and low/high pass filters can be independently switched in or out,
allowing for the efficient auditioning of each band or filter. Each band is equipped
with an adjustable Q control which adjusts the bandwidth of each band. The low and
high frequency bands are equipped with a switchable shelf, perfect for adding low
end energy or high frequency sheen.
The gain multiplier toggle switches allow for the fine tuning the amplitude of the
cut/boost switches. This allows for minute corrections to be performed with the x½
multiplier or larger cut/boosts with either the x1 or x2 multiplier selected. The
powerful gain multiplier feature allows for the HVA-NEQ to be easily adapted to
mixing applications where a greater cut/boost range is desired. Each gain switch can
be instantly toggled between cut, boost, or band-bypass.
The HVA-NEQ features a high efficiency, EMI filtered switch mode power supply with
additional filtering added to ensure clean, interference-free performance with a
universal input voltage range to cater for all regions.

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front PANEL CONTROLS
POWER
A single illuminated pushbutton, when latched, will power the unit ready for use with a
white LED indicator within the switch.
M-S / BYP / L-R
Toggles the selections of either MID-SIDE or LEFT-RIGHT processing of the signal.
The centre position completely removes the unit from the signal path for a true bypass.
In M-S mode, the signal is encoded to Mid (M=L+R) and Side (S=L-R) before the EQ
circuit. After the EQ circuit, the signal is decoded back to Land Ragain.
NOTE: M-S mode requires both channels to be engaged.
HPF – HIGH PASS FILTER
A 6 position rotary control to select the roll off frequency of the high pass filter (HPF).
The associated toggle switch engages the filter when IN is selected.
LPF – LOW PASS FILTER
A 6 position rotary control to select the roll off frequency of the low pass filter (LPF).
The associated toggle switch engages the filter when IN is selected.
Hz - FREQUENCY
Each band has a 12 position rotary control to select the centre frequency of the filter.
dB - GAIN
Each band has a 12 position rotary control to adjust the amount of equalization
applied to the signal of the filter. Each GAIN control has an associated BOOST /
OUT / CUT toggle which controls the desired amplitude of the signal, or bypassed.
OUT is a hardwire bypass for that band. To use a band, you must select to boost or
cut prior to equalization. GAIN controls also have an associated x2 / x1 / x½
multiplier toggle. With this selected in x1 mode, the dB gain scale on the front panel
is adhered, providing 0.5dB increments in the GAIN control. By selecting x2, the
gain scale numbers are multiplied to allow for large 1.0dB increments in the GAIN
control. Selecting x½halves the indicated gain scale, providing 0.25dB increments.
NOTE: Although accurate stereo tracking is always maintained between channels at
every gain/multiplier setting, there may be some minor variance in actual dB vs front
PARAMETRIC
EQUALIZER
HVA-NEQ
HIGH
g
VOLTAGE
1.3
1.6
1.0
30
25
20
38
47
57
131
162
200
106
86
70
1.0
0.5
± 0
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
Q
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
Q
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
Q
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
Q
156
126
102
193
236
288
689
856
1k
558
448
362
610
497
405
752
926
1k1
2k6
3k2
4k
2k1
1k7
1k4
3k
2k4
2k
3k7
4k6
5k7
13k1
16k2
20k
10k6
8k6
7k0
L/M
CHANNEL
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
1.0
0.5
1.5
2.0
2.5
4.5
5.0
5.5
4.0
3.5
3.0
dB
Hz
POWER
Hz
5k7
8k4
4k1
10k5
15k3
Hz Hz
R/S
CHANNEL
± 0 ± 0 ± 0 ± 0 ± 0 ± 0 ± 0
Hz
2.2
3.0
LF
LMF HMF
HF LF
LMF HMF
HF
L-R
M-S
BYP
L-R
M-S
BOOST
CUT
OUT
x½
x2
x1
BOOST
CUT
x½
x2
BOOST
CUT
x½
x2
BOOST
CUT
x½
x2
BYP
30
25
20
38
47
57
131
162
200
106
86
70
156
126
102
193
236
288
689
856
1k
558
448
362
610
497
405
752
926
1k1
2k6
3k2
4k
2k1
1k7
1k4
3k
2k4
2k
3k7
4k6
5k7
13k1
16k2
20k
10k6
8k6
7k0
LPF
HPF
34
44
26
20
58
78
34
44
26
20
58
78
23k
5k7 8k4
4k1
10k5
15k3
23k
IN
OUT
IN
OUT
OUT
x1
OUT
x1
OUT
x1
BOOST
CUT
OUT
x½
x2
x1
BOOST
CUT
x½
x2
BOOST
CUT
x½
x2
BOOST
CUT
x½
x2
IN
OUT
IN
OUT
OUT
x1
OUT
x1
OUT
x1
1.3
1.6
1.0
2.2
3.0
1.3 1.6
1.0
2.2
3.0
1.3
1.6
1.0
2.2
3.0
1.3 1.6
1.0
Q Q Q Q
2.2
3.0
1.3 1.6
1.0
2.2
3.0
1.3 1.6
1.0
2.2
3.0
1.3 1.6
1.0
2.2
3.0

panel dB figures due to parts tolerances. The multiplier toggle will effectively provide
36 step gain controls per band!
Q – BANDWIDTH
Each band has a rotary control to adjust the desired bandwidth of the ‘bell’ filter,
ranging between and indicated 1.0 and 3.0 (calculated). Due to parts tolerances, the
Q factor may vary and typical real world measurements of the bands are more within
0.7 and 2.2.
NOTE: Despite the aforementioned variance in Q figures, precise channel tracking is
still maintained.
The LF and HF bands have an additional step to enable shelf mode.

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REAR PANEL CONNECTIONS
The rear panel features XLR INPUT and OUTPUT connectors for the LEFT and
RIGHT channels. These connections have been wired PIN 2 HOT to conform with
AES standards.
NOTE: To run in unbalanced mode, ensure your unbalanced cable ties pin 3 to pin 1
at the cable.
The AC INPUT connection is a typical 3 pin IEC power cable. This equipment is
capable of operating between 100V-250VAC to cater for all regions.
PLEASE REFER TO THE VOLTAGE AND FUSE SELECTION SECTION ON PAGE
2 PRIOR TO POWERING YOUR UNIT.
F CAUTION: HIGH g VOLTAGE !
RISK OF ELECTRIC SHOCK
!! WARNING !!
~100 - 250VAC
50 Hz/60 Hz
RIGHT CHANNEL LEFT CHANNEL
HIGH g VOLTAGE
HVA-NEQ
PARAMETRIC EQUALIZER
OUTPUT OUTPUT INPUTINPUT
AC INPUT

frequency GRAPHS (L-R mode)
LF band @ 20 Hz -Conditions: Gain Max, Multiplier x1, Q: 1.6 (centered)
LMF band @ 102 Hz -Conditions: Gain Max, Multiplier x1, Q: 1.6 (centered)
HMF band @ 405 Hz -Conditions: Gain Max, Multiplier x1, Q: 1.6 (centered)

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HF band @ 2 kHz -Conditions: Gain Max, Multiplier x1, Q: 1.6 (centered)
Q @ 2 kHz – Conditions: (HF band, including shelf)
HPF – HIGH PASS FILTER

LPF – LOW PASS FILTER

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CALIBRATION
INPUT GAIN ADJUSTMENT
The HVA-NEQ has internal INPUT GAIN adjustment trimmers for both channels and
is calibrated before shipment. If further adjustment is required, unity gain calibration
can be performed as follows:
1. Ensure the equipment is powered OFF and the IEC power cable is unplugged,
but the XLR input and output cables are connected. ALL BANDS SHOULD BE
BYPASSED BEFORE PROCEEDING.
2. Viewing from the top of the enclosure, unscrew the four (4) Philips head screws
that are located toward the rear of the case and carefully pry the lid upward; a
suction cup is handy for this task.
3. Carefully plug the IEC power cable and push both POWER button to be
illuminated. Ensure the MS / BYP / LR controls for both channels are in BYP.
4. Feed a -12 dBFS, 1kHz sine wave tone using a signal generator from your DAW
into each channel and take a note of the signal on each channel of your DAW
software where the generator is feeding the HVA-NEQ channels (e.g. -10.5
dBFS).
5. Now toggle the MS / BYP / LR control to be in LR mode and take a note of the
DAW master output signal, reset this signal by clicking the indicated dB signal
of the channel (e.g. -11.2 dBFS).
6. Adjust the BLUE trimmer for each channel (marked R_TRIM and L_TRIM)
separately and ensure that the master output measures the same as the the
measurement taken in step 4 (e.g. -10.5 dBFS).
7. Once both channels have the same signal measure when both LR and BYP,
calibration is complete.

8. Carefully POWER OFF the unit and re-assemble the lid by sliding the lid firstly
toward the front of the unit at an angle, then dropping the rear of the lid into the
enclosure. Screw the four (4) Philips head screws back into the enclosure.

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SPECIFICATIONS
INPUTS
Balanced XLR (accepts unbalanced)
OUTPUTS
Balanced XLR (accepts unbalanced)
DIMENSIONS
19” 3RU, 295mm deep
LEVEL
+4 dBu nominal
FREQUENCY
CONTROLS
12 step rotary switches
GAIN CONTROLS
12 step rotary switches
3-way toggle – BOOST / BYP / CUT
3-way toggle – x2 / x1 / x½
Q CONTROLS
5 step rotary switches with additional shelf step on LF/HF
bands
HPF CONTROLS
6 step rotary switches with 2-way toggle (IN / OUT)
LPF CONTROLS
6 step rotary switches with 2-way toggle (IN / OUT)
POWER CONTROL
Single illuminated pushbutton
FREQUENCY
RESPONSE
20 Hz – 23 kHz
FILTER GAIN RANGE
x2 - 11.0 dB, x1 - 5.5 dB, x½- 2.75 dB
NOISE LEVEL, dB (A)
~-108 dB
THD, %
~0.00108%
THD + NOISE, dB (A)
~-95 dB
MAX INPUT LEVEL
~+21.5dBu
MAX OUTPUT LEVEL
~+21.5dBu (balanced operation)
Power supply
All regions (100-250VAC) T500mAL SLO-BLO
Replacement fuse (M205)
*Specifications subject to change without notice.
BLOCK DIAGRAM SHOWING SIGNAL FLOW
XLR
INPUT
M/S
ENCODER
HVA-NEQ MAIN CIRCUIT
XLR
OUTPUT
M/S
DECODER
L/R L/R
BYPASS
HPF EQ
BANDS
LPF
OUT OUT

REPAIR & WARRANTY
High Voltage Audio warrant the HVA-NEQ with a warranty period of two (2) years from
the date of purchase for parts and labour, subject to inspection. Products will be free
of manufacturing defects. This warranty does not include damage incurred through
shipment, rough user operation of the product or modifications or attempted repair by
unauthorized personnel. This warranty is offered solely to the original purchaser of the
product, directly from High Voltage Audio and is not transferrable. This warranty does
not include shipping charges to and from High Voltage Audio.
In the event you require repair or warranty assistance with your unit, you should first
initiate contact through our contact page, outlining any issues in detail. The information
provided will be assessed to determine the best outcome for repair.
Any unit failures within a period of 7 days are liable for a direct replacement upon
receipt and assessment of the defective unit. The customer is responsible for
immediately notifying High Voltage Audio of defective units within this period.
Any unit failures outside of a period of 7 days will be covered under a full two (2) year
warranty period from the date of purchase, including parts and labour. The customer
will be responsible for return freight to High Voltage Audio. High Voltage Audio will
cover freight back to the customer for repaired or replaced units. No other
shipping/taxes are included.
Exceptions to the above cases will be assessed on an individual basis with the
customer to determine a mutual agreement.
Warranty service communication must be conducted directly through High Voltage
Audio.
High Voltage Audio reserves the right to alter the design of their products and
specifications without notice.
CONTACT
web: http://www.highvoltageaudio.net
facebook: http://www.facebook.com/hvaudio
instagram: http://www.instagram.com/hvaau
email: [email protected]

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A U D I O

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