Miad audio Lcpq 4040 User manual

LCPQ 4040

Discrete 4-band EQ

Operator’s Manual

Version 1.2

MIAD Audio

Aleje Jerozolimskie 137/55

Warsaw, 02-304, Poland

Email: [email protected]

Phone: +48 882 153 350

Table of Contents

1.0 LCPQ 4040

1.1 Overview

1.2 Features

1.3 Front Panel

1.4 Rear Panel

2.0 PS 230

2.1 Overview

2.2 Features

2.3 Front Panel

2.4 Rear Panel

3.0 Troubleshooting

4.0 Specifications

4.1 LCPQ 4040 Technical Specifications

4.2 LCPQ 4040 Dimensions

4.3 PS 230 Technical Specifications

4.4 PS 230 Dimensions

5.0 Appendix

5.1 Warranty Registration

5.2 Product Warranty

5.3 Block Diagram

5.4 Frequency Response

5.5 EQ Response Curves

5.6 Recall Sheet

Important Safety Instructions

•Please read these instructions.

•Keep these instructions in a safe place.

•Do not operate this unit in the presence of rain, liquids, or condensing

moisture. Liquid entering the product enclosure presents the risk of fire or

electric shock injury.

•Clean only with a dry cloth.

•Do not install near any heat sources such as radiators, heat registers, stoves, or

other devices that produce heat.

•Do not defeat the safety purpose of the polarized or grounding type AC plug.

•Protect both the AC power cord to the power supply and the DC cable

between the power supply and the EQ unit from being walked on or pinched.

•Use only attachments/accessories specified by the manufacturer.

•Unplug this device during lightning storms or when unused for long periods of

time.

•Refer all service to qualified personnel.

WARNING

TO REDUCE THE RISK OF FIRE OR ELECTRIC

SHOCK, DO NOT EXPOSE THIS APPARATUS

TO RAIN OR MOISTURE

DO NOT USE A DAMAGED OR EXCESSIVELY

WORN IEC CABLE TO CONNECT THIS UNIT

TO AC POWER

TO DISCONNECT THE UNIT COMPLETELY

FROM THE MAINS, UNPLUG THE UNIT. !

ATTENTION

Exposure to extremely high noise levels may cause

permanent hearing loss or damage.

1.0 LCPQ!4040!

1.1!Overview!

! !

The LCPQ 4040 is a transformer balanced, high performance all-discrete equalizer

with four passive RLC sections in cascade configuration.

Each band has a variable level control ranging from -12dB to +12dB. The four bands

of equalization offer selectable Shelving/ Bell on the first and fourth band and

selectable HiQ/ LowQ on the second and third band.

Each band can be independently bypassed. When an EQ band is not engaged, the

audio signal still travels through the transformers and the discrete circuit but not

through the RLC circuit and thus the unit can be used as a high quality unity gain line

amp. In addition to the individual bypass, the unit employs a true bypass relay system,

where the input signal is connected directly to the output. When the unit is not

powered (or in situations where the power accidentally goes down), the bypass relay

system is automatically activated and therefore the signal will not disappear.

The LCPQ 4040 features Carnhill high-level audio signal input and output

transformers and a combination of four Carnhill and custom made tapped inductors

(5% tolerance) that were chosen after extended listening tests and measurements.

The unit consists of Grayhill rotary stepped switches for frequency selection, plastic

conductive potentiometers (10% tolerance) for boosting/cutting, Wima polypropylene

(low tolerance) film capacitors in the RLC path, Panasonic audio grade electrolytic

capacitors in the active circuit and Neutrik connectors for the audio and power

connections.

Each unit is hand-built and hand-wired. All the components are chosen and tested

thoroughly for best performance, musicality and long-term reliability.

1.2!Features!

! !

•Fully discrete (transistor) circuit

•Transformer (Carnhill) balanced input and output

•Carnhill and custom made tapped inductors

•Thirty four selectable frequencies

•12dB of Gain/ Attenuation per band

•Selectable Shelving/ Bell on Band1 and Band4

•Selectable HiQ/ LowQ on Band2 and Band3

•Individual bypass on each band

•True bypass relay system

•High quality Neutrik XLR connectors

•Low components tolerance for stereo configuration

•Hand-built and hand-wired

•3-year limited warranty

1.3!Front!Panel!

! !

A. SHELVING/ BELL SWITCH – This switch toggles between Shelving and

Bell shape. When the switch is pressed, the Bell shape is active.

B. OFF – When the FREQ.rotary switch is in the OFF position, the band is

not engaged (i.e. the filter circuit and the LEVEL control are inactive).

However, the audio signal still travels through the discrete circuit and the

audio transformers.

C. FREQ. – This rotary stepped switch determines the frequency point for

each band. The frequency points for each band are as follows:

Band 1: OFF, 45Hz, 65Hz, 100Hz, 180Hz, 330Hz, 470Hz

Band 2: OFF, 180Hz, 220Hz, 270Hz, 330Hz, 390Hz, 470Hz, 560Hz,

680Hz, 820Hz, 1kHz, 1.3kHz

Band 3: OFF, 1.2kHz, 1.5kHz, 1.8kHz, 2.2kHz, 2.7kHz, 3.3kHz, 3.9kHz,

4.7kHz, 5.6kHz, 6.8kHz, 8.2kHz

Band 4: OFF, 3.3kHz, 4.7kHz, 6.8kHz, 10kHz, 15kHz, 23kHz

D. LEVEL – Each band has a high quality continuously variable

potentiometer that controls the amount of gain or attenuation (+/- 12dB).

E. HI-Q/ LOW-Q SWITCH – This switch controls the sharpness of the peak

or dip and it toggles between High Q and Low Q. When the switch is

pressed, the High Q is active.

F. IN – This switch toggles between the active (LED ON) and bypassed

(LED OFF) modes. Since the unit employs a bypass relay system, no

audio signal passes through this switch. Instead, the IN switch is a DC

voltage switch that controls the relays’ state.

1.4!Rear!Panel!

A. 6-PIN DC POWER SUPPLY INPUT – This input allows interconnection

of the external supply (PS 230) required for the unit to operate. A 2-meter

power supply cable is supplied with every unit.

Pin out is as follows:

Pin 1= Chassis Ground

Pin 2= -28V (audio circuit)

Pin 3= +28V (audio circuit)

Pin 4= +24V (relay bypass system and bypass indicator)

Pin 5= 0V (reference for +24V)

Pin 6= 0V (reference for ±28V)

B. 3-PIN AUDIO OUTPUT – This is a transformer balanced XLR output

with the following pin configuration:

Pin 1 = Ground

Pin 2 = Hot (+)

Pin 3 = Cold (-)

C. 3-PIN AUDIO INPUT – This is a transformer balanced XLR input with

the following pin configuration:

Pin 1 = Ground

Pin 2 = Hot (+)

Pin 3 = Cold (-)

D. PRINT – Contains information regarding the model, the serial number and

the origin of the unit.

2.0 PS!230!

2.1!Overview!

! !

The PS 230 is a 3-rail linear power supply capable of powering two LCPQ 4040 units,

housed in a robust enclosure.

The unit provides ±28V DC for the audio circuit and +24V DC for the relay bypass

system and the bypass indicator (LED). In order to cut the cost (and for the shake of

simplicity), a lot of audio euquipment use a common power rail for the audio circuit

and for other functions such as relays, LEDs, lamps, etc. However, it is a better

practice to use a dedicated power rail for all non-audio circuits. Therefore, the PS 230

has an additional +24V DC rail, which ensures that no unwanted noise (caused by the

relays and the bypass indicator) is added to the audio signal.

The PS 230 can be switched for 115V AC or 230V AC operation and the mains fuse

is accessible to the user from the rear side of the unit (in the IEC inlet).

2.2!Features!

! !

•High efficiency, low noise design

•Switchable 115V/ 230V AC

•Capable of powering two LCPQ 4040 units

•Separate power rails for the audio signal and the relay bypass system

•LED indicators for each power rail at the front of the unit

•High quality 6-pin Neutrik connectors

•Hand-built and hand-wired

•3-year limited warranty

2.3!Front!Panel!

A. AC POWER SWITCH – This switch turns the unit ON and OFF. Make

sure you do not plug (or unplug) the 6-pin DC cable between the

power supply and the EQ unit while the unit (PS 230) is ON. Hot-

plugging (i.e connecting the DC cable while the unit is powered on)

may damage your equipment.

B. POWER INDICATION (-28V) – This LED allows visual confirmation of

the presence of -28V.

C. POWER INDICATION (+28V) – This LED allows visual confirmation of

the presence of +28V.

D. POWER INDICATION (+24V) – This LED allows visual confirmation of

the presence of +24V.

2.4!Rear!Panel!

A. 6-PIN DC POWER SUPPLY OUTPUTS – This output allows

interconnection of the LCPQ 4040 unit. Up to two EQs can be connected

to the power supply.

Pin out is as follows:

Pin 1= Chassis Ground

Pin 2= -28V (audio circuit)

Pin 3= +28V (audio circuit)

Pin 4= +24V (relay bypass system and bypass indicator)

Pin 5= 0V (reference for +24V)

Pin 6= 0V (reference for ±28V)

B. PRINT – Contains information regarding the serial number and the

manufacturing date of the unit.

C. IEC MAINS INLET – Including the 115/230V AC switch and fuse. Make

sure that the AC voltage indicated on the IEC inlet is the same as the

mains in your country and that you use the correct fuse. An IEC mains

power cord is supplied with every unit.

! !

10!

3.0 Troubleshooting!

In the event of unit operational failure, contact MIAD Audio at [email protected] or for

more contact information, check our website (www.miad.eu). Before contacting us,

please be prepared to describe in detail the exact problem that the unit is experiencing.

It is highly recommended that customers do not attempt to troubleshoot their own

units or have them repaired at unauthorized repair centers. Please note that any

modification to the existing product will void the warranty.

4.0 Specifications!

4.1!LCPQ!4040!Technical!Specifications!

Frequency Response: 20Hz - 20kHz, +0/ -0.3dB

THD+N: Less than 0.01%, +4dbu, 20Hz -22kHz, unity gain, 22kHz BW

Signal-to-Noise Ratio: <92dB (unweighted), re +4dbu, 22kHz BW, unity gain

Maximum Output Level: +21dbu, 20Hz -22kHz into 600 Ohms

Dynamic Range: 113dB re +21dBu, 22kHz BW

I/O Connectors: Transformer Balanced XLR (1.Chassis, 2.Signal +, 3. Signal -)

4.2!LCPQ!4040!Dimensions!

Unit!!!!!!Shipping!

Width: 482.6mm (19-inch rack) Width: 550mm

Depth: 300mm Depth: 450mm

Height: 43.7mm (1U rack) Height: 180mm

Weight: approx. 3kg Weight: approx. 4kg

4.3!PS!230!Technical!Specifications!

Input Voltage: 115V AC or 230V AC, 50/ 60Hz

Output Voltage: -28V DC, +28V DC, +24V DC

4.4!PS!230!Dimensions!

Unit!!!!!!Shipping!

Width: 230mm Width: 340mm

Depth: 170mm Depth: 240mm

Height: 80mm Height: 180mm

Weight: Unit approx. 2kg Weight: approx. 3k

11!

5.0 Appendix!

5.1!Warranty!Registration!

To be eligible for the three (3) year limited warranty, the original purchaser must

5.2!Product!Warranty!!

During the first three (3) years from the date of the original purchase, this product is

warranted to be free from defects in materials and workmanship under normal use,

service and maintenance. This warranty is limited to failures during normal use,

which are due to defects in material or workmanship. If any defects are found in the

materials or workmanship, or if the product fails to function properly during the

applicable warranty period, MIAD Audio, at its option, will repair or replace the

product.

This warranty applies to the original purchaser and is subject to the following terms

and conditions:

1. The warranty only applies to MIAD Audio products purchased directly from

MIAD Audio or from authorised MIAD Audio dealers. The authorised dealers of

MIAD Audio products are listed online at www.miad.eu/Dealers

2. The warranty does not cover any of the following: damage caused by the user;

spillages or moisture; neglect, abuse or misuse, including but not limited to the

failure to use the MIAD Audio product for its normal purpose in accordance with

the manufacturer's instructions for usage, failure to properly maintain the MIAD

Audio product in accordance with the manufacturer's instructions, and/or the

failure to use the MIAD Audio product in accordance with the manufacturer's

specifications; use of product with incompatible or faulty equipment; unauthorised

modifications; repairs conducted by unauthorised persons or service centres; the

model and/or serial number being altered, removed or made illegible; damage

resulting from improper packing or mishandling by a shipper; accidents; acts of

God; Cosmetic defects, such as paint finish, and general wear and tear or any cause

beyond the control of MIAD Audio.

3. If the equipment requires warranty repair, return authorization must be obtained

from MIAD Audio prior to shipment. Equipment should not be shipped until return

authorization and proper shipping address is obtained from MIAD Audio.

4. Any products returned MIAD Audio for repair should be in their original

packaging and they should include: (1) complete description of the problem; (2)

name, address, phone number and e-mail address; (3) receipt of original purchase;

(4) power supply and all accessories and cables.

12!

5. MIAD Audio will not accept any warranty replacement without the original proof

of purchase of the MIAD Audio, and without the registration of the MIAD Audio

product. It is the original purchaser's responsibility to keep the original proof of

purchase safe at all times, as MIAD Audio is not obliged to provide a replacement

of the original proof of purchase, and to transfer that proof of purchase to any

subsequent owners of the MIAD Audio product.

6. The purchaser is responsible for the shipping costs to and from MIAD Audio.

MIAD Audio is not responsible for damage resulting from improper packing

and/or mishandling by a shipper.

7. MIAD Audio reserves the right to inspect any products that may be the subject of

any warranty claims before repair or replacement is carried out. Final

determination of warranty coverage lies solely with MIAD Audio.

13!

5.3!Block!Diagram!

14!

5.4!Frequency!Response!

Frequency Range: 20Hz to 20kHz / Magnitude Range: -1.0dB to +1.0dB

(All bands ‘ON’ at unity gain)

5.5!EQ!Response!Curves!

The graphs below demonstrate some of the measured response curves for each band.

BAND 1 BAND 2

Top Curve: Shelv. - Max. Boost @ 45Hz (20Hz – 40kHz)Top Curve: Low Q - Max. Boost @ 560Hz (20Hz – 40kHz)

Bottom Curve: Bell - Max. Cut @ 45Hz (20Hz – 40kHz)Bottom Curve: Hi. Q - Max. Cut @ 560Hz (20Hz – 40kHz)

BAND 3 BAND 4

Top Curve: Low Q - Max. Boost @ 3.3kHz (20Hz – 40kHz)Top Curve: Shelv.- Max. Boost @ 6.8kHz (20Hz – 40kHz)

Bottom Curve: Hi. Q - Max. Cut @ 3.3kHz (20Hz – 40kHz)Bottom Curve: Bell - Max.Cut @ 6.8kHz (20Hz – 40kHz)

15!

ARTIST _______________________________ PROJECT _______________________________ DATE __________________

TRACK ________________________ INSTRUMENT __________________________ ENGINEER _______________________

NOTES __________________________________________________________________________________________________________