Iron Age Audioworks V2 User manual

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User’s Manual
V2 Equalizer 

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Thank you for your purchase of an Iron Age V2 Equalizer. Iron Age Audioworks is a small team
of engineers and designers and we truly appreciate your business. We hope you enjoy using
this as much as we enjoyed making it.
Safety
Safety with audio equipment is normally a matter of common sense, but we want to make sure
you get the best use out of your equipment. So please, use common sense including...
●Use typical practices for using electrical and audio equipment.
●Don’t clean this with water or use it around water.
●Any ventilation openings in the case need to remain open.
●Don’t use this around anything that’s hot (such as a radiator or space heater).
●Don’t defeat the ground pin on the plug or use a ground-lift device that does.
●Don’t use a cut or damaged power cord, and keep the cord from getting pinched or
stepped on.
●Don’t service the box unless you’re a qualified technician.
Power
The unit is powered by an internal linear power supply and will accept standard 110 VAC
power. A user-accessible fuse is located on the IEC connector at the rear of the case. It will
come set at +/-22V. Please contact us if you would like to change the supply voltage for use
with other op amps.
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© 2020 by IronAgeAudioworks 1

Overview
The Iron Age V2 is a go-to tracking, mixing, or mastering equalizer featuring two channels of
versatile, musical EQ in a one rack unit space. It features a proportional Q, bridged-T circuit
topology with fully symmetrical active boost and passive cut, true bypass, and an all-discrete
signal path. The output amplifier drives a custom wound Cinemag transformer.
Block Diagram
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Each equalizer channel is a three-band, selectable frequency design using two hand-built
discrete op amps for gain. There are 18 center frequencies divided into three bands (Low, Mid,
and High) as shown below:
Low
Mid
High
33 Hz
400 Hz
5k Hz
50
600
6k
110
750
7.5k
200
1.6k
9.1k
300
3k
11k
400
5k
16k
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Each band features up to 12 dB of reciprocal boost or cut in stepped increments of 2, 4, 6, 8
and 12 dB using a bridged-T filter design. The same filter bank is switched between the
feedback loop of the amplifier in boost and a passive circuit in cut, which ensures that the
boost and cut points are completely identical.
Passive circuits are separated by discrete transistor buffers, which contribute a unique
character to the tone of the unit.
© 2020 by IronAgeAudioworks 2

The bridged-T circuit implementation also features a proportional Q: as the amount of boost or
cut is increased, the bandwidth of the filter is adjusted by a switched resistor to become more
narrow. This allows for a wide range of use from broad-brush shaping to careful tone carving,
but ensures that the filtering is never harsh and always musical.
The Low and High bands can be switched between peaking and shelving behavior. In shelving
mode, the frequency response hits the indicated boost or cut level at the selected frequency
and stays elevated or reduced through the extent of the audible range. This allows for musical
shaping of the high and low extremes of the audio spectrum.
Additionally, the EQ features a switchable band-pass filter with -3 dB points at 60 and 16k Hz.
The module has a balanced transformerless input stage using a third discrete operational
amplifier.
As with all Iron Age products, the V2 uses the M2 discrete operational amplifier, designed and
built in-house by us.
Through the IAA Custom Shop, we also offer a variety of output transformers, op amps, and
even customized center frequencies or features to give you the sound you want. Reach out to
us to whiteboard your idea! [email protected] 
© 2020 by IronAgeAudioworks 3

Controls
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The POWER switch turns the unit on and off. An LED is illuminated when the unit is powered
on.
The IN/OUT button switches the EQ in when depressed. When the unit is not in, a true bypass
circuit is engaged, connecting the channel input directly to the output with no other
components in the signal path. When the EQ is engaged, the LED over the switch is
illuminated.
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Each of the three EQ bands have identical controls. The amount of boost or cut is selected by
the 11 position gain switch. When the gain switch is set to cut, the filters are inserted for
passive attenuation at the selected frequency. When the gain switch is at 12 o’clock no filters
are in the signal path, ensuring a flat frequency response. When the switch is set to boost, the
same filters are inserted to the feedback loop. This ensures equalization moves are reciprocal
and reversibel.
The center frequency for each band is selected by the six-position frequency switch to the right
of the gain switch.
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The PEAK / SHELF switch is a two position toggle which changes the shape of the filter curve
for the Low and High EQ bands at the selected frequency.
The FILTER switch is a two position toggle which engages the band-pass filter.
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© 2020 by IronAgeAudioworks 4

Inputs and Outputs
The input is a nominal +4 dBu amplifier balanced line input via a TRS jack on the rear panel.
The output is a +4 dBu transformer balanced line output via a TRS jack on the rear panel.
Chassis
The Iron Age V2 uses a standard 19” 1RU. The unit is powered by an IEC power cord and an
internal bipolar power supply.
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© 2020 by IronAgeAudioworks 5

Technical Specifications
Gain Range +/-12 dB, per band
Maximum Input Level +20 dBu
Maximum Output Level +26 dBu
Input Impedance >10 kOhms, balanced
Output Impedance <75 Ohms, transformer balanced
Frequency Response +0, -0.6 dB 20Hz-20kHz
Actual Measured Noise -110 dBA
THD @ +15 dBu output 0.014% typical
Power Consumption 150 mA max
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© 2020 by IronAgeAudioworks 6

Frequency Response
Low Frequency 
<<to be updated>>
Mid Frequency 
<<to be updated>>
High Frequency 
<<to be updated>>
Band Pass Filter
<<to be updated>>
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© 2020 by IronAgeAudioworks 7

Warranty
We warrant this product to be free from defects of materials and workmanship for a period of
one (1) year from the date of purchase. We will remedy any defect identified within this period
by repairing or replacing the product at our option. It will be your responsibility to pay for
shipping the product to us, and if the product is determined to be defective, our responsibility
to pay for shipping the product back to you.
LIMITATIONS AND EXCLUSIONS. This warranty, and any other express or implied warranty,
does not apply to any product which has been improperly installed, subjected to usage for
which the product was not designed, misused or abused, damaged during shipping, or which
has been altered or modified in any way. This warranty is extended to the original purchaser
only. THIS EXPRESS, LIMITED WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED, TO THE EXTENT ALLOWED UNDER APPLICABLE STATE LAW. IN NO
EVENT SHALL IRON AGE AUDIOWORKS BE LIABLE FOR ANY SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES RESULTING FROM THE USE OF THIS PRODUCT.
If you suspect a defect in this product, please contact us to discuss the problem (it is possible
that a suspected defect could be quickly remedied or due to improper usage).
Call or email us with any issues, to say hi, or share the music you’ve made. We love this gear
and want you to love it too.
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© 2020 by IronAgeAudioworks 8