EQ1-LP

Weiss EQ1 - the reference when it comes to digital mastering EQs. Available in four different models, including linear phase and dynamic versions.

The EQ1 is a two channel digital equalizer with seven parametric bands. It has digital inputs/outputs exclusively. The EQ1 is available in four different configurations. All of them work at up to 24 Bit/96 kHz. The basic model is the EQ1-MK2, the linear phase model is the EQ1-LP, the dynamic model the EQ1-DYN. The EQ1-DYN-LP incorporates both LP and DYN versions in one unit. The mode of operation (LP or DYN) can be chosen after power-up. All models are user-upgradeable to any other version.

EQ1-LP, the EQ1-MK2 with linear phase response The EQ1-LP has the same parameter set and features as the EQ1-MK2. In addition it can be switched between minimum and linear phase behavior. Linear phase means that the delay introduced by processing is constant across the whole spectrum, unconstrained by the EQ settings. The sound, or character, of an equalizer has been said to be influenced by phase response as for example John Watkinson mentioned in Studio Sound magazine 9/97: "... much of the audible difference between EQs comes down to the phase response." The EQ1-LP is therefore the ideal tool for corrective amplitude adjustment, without the unwanted phase distortion added by standard equalizers.

BASIC EQ1 FUNCTIONS:

The basic features are common to all four models, namely the seven identical parametric bands, i.e. all seven bands cover the entire audio frequency range. Each band has Boost/Cut, Frequency and Q/Slope knobs and operates in any of the following modes: High shelving, low shelving, peaking, high cut, low cut, bypass.

CONTROLS, DISPLAY:

There are seven times three knobs in order to have "one knob per parameter" operation. The knobs are touch sensitive to switch the LCD to display the parameters of the touched band. The LCD shows the overall frequency response, the detailed parameter values and various status information.

SNAPSHOTS, MIDI, METERING:

Other basic features are an A/B compare memory, a 128 position snapshot bank with two additional banks for back-up (can also be dumped/recovered via MIDI), a peak meter with over indicators, MIDI control for each parameter, an overall bypass switch and an overall gain control, a channel ganging switch.

SIGNAL PROCESSING, CONNECTIVITY:

The internal processing is done at 88.2 or 96 kHz in a 40 Bit floating-point format. A very low noise filter architecture optimized for audio is used. The digital input/output are in AES/EBU format on XLR connectors. The AES/EBU output can be POW-R dithered to 16, 20 or 24 Bits.

M/S MODE:

The EQ1 can be switched to M/S mode which is especially useful for the

dynamic model of the EQ1. Also see the article: "Stereo Shuffling: New Approach - Old Technique" by Michael Gerzon. Other specialties are variable slope shelving filters and very high Q (up to 650) peaking filters for notching out offending frequencies.

POWER:

Mains voltage: 115 V or 230 V with voltage selector

Fuse rating: 500 mA slow blow

Power consumption: 40 VA max.

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SIZE:

Depth: 30 cm

Width: 43,3 cm (19")

Height: 8,8 cm (2HU)

AES/EBU INPUT:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz

Maximum input word-length: 24 Bits

Channel Status Data: Input accepts professional or consumer format

Channel Status Data Bits forwarded to AES/EBU output: see table below

Connector: XLR female

AES/EBU OUTPUT:

Sampling frequencies: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz (always the same as the input)

Output word-length: 24 Bits

Connector: XLR male

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AES/EBU CHANNEL STATUS DATA:

The EQ1 allows to convert the incoming Channel Status Data as follows:

From Consumer to Professional

From Professional to Consumer

Transparent mode, i.e. Channel Status Data is fed forward to the output without any conversion (one exception, see below)

The following tables describe how the output Channel Status Data Bits are generated in the various conversion modes.

Output selected: Consumer format, Input: Consumer format:

All Bits fed forward (transparent), except for Byte 1:

Bits 0...6: 0000000 (category code general)

Bit 7: 1 (original)

Output selected: Consumer format. Input: Professional format:

Byte 0:

Bit 0: 0 (consumer)

Bit 1: 0 (audio)

Bit 2: 1 (copy allowed)

Bits 3, 4: Pre-emphasis according to input

Bit 5: 0 (two channel mode)

Bits 6, 7: 00 (Mode 0)

Byte 1:

Bits 0...6: 0000000 (category code general)

Bit 7: 1 (original)

Byte 2:

Bits 0, 1, 2, 3: Sampling frequency according to input

Bits 4, 5: 00 (accuracy grade II)

Bits 6, 7: 00

Bytes 3...23: Reserved bytes

Output selected: Professional format. Input: Professional format:

All Bits fed forward (transparent), except for Byte 2:

Bits 0, 1, 2: 001 (max. sample length = 24 Bit)

Bits 3, 4, 5: 101 (24 Bit word-length)

Bits 6, 7: 00

Output selected: Professional format. Input: Consumer format:

Byte 0:

Bit 0: 1 (professional)

Bit 1: 0 (audio)

Bits 2, 3, 4: Pre-emphasis according to input

Bit 5: 0 (source fs locked)

Bits 6, 7: Sampling frequency according to input

Byte 1:

Bits 0, 1, 2, 3: 0001 (two channel mode)

Bits 4, 5, 6, 7: 0000 (no user Bit encoding)

Byte 2:

Bits 0, 1, 2: 001 (max. sample length = 24 Bit)

Bits 3, 4, 5: 101 (24 Bit word-length)

Bits 6, 7: 00

Bytes 3...12: All Bits 0

Byte 23: CRCC byte

Output selected: Transparent. Input: Any format:

All Bits fed forward (transparent), except if EQ not bypassed for Byte 2:

Bits 0, 1, 2: 001 (max. sample length = 24 Bit)

Bits 3, 4, 5: 101 (24 Bit word-length)

Bits 6, 7: 00

OVERLOAD:

Number of consecutive over-samples to cause "over" display: 1...16 selectable

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FILTERS:

The filter topology used in the EQ1 is a very low noise filter structure for a state of the art performance.