The Pendulum Audio Quartet is a Tube Recording Channel Strip. The All-In-One Tracking Tool for High Resolution Recording.
The Quartet is an all-purpose recording tool designed with the ultimate in sound quality and flexibility in mind. We have combined four elements - Mic/DI preamp, Opto-compressor, EQ, and De-esser -into a fully integrated package that it makes it easy to track any source. In addition, the Mic/DI preamp, EQ and Compressor/De-esser are completely independent entities that can be patched out and used separately - a hand feature that makes it a valuable tool for mixing as well as tracking.
The Mic/DI preamp, borrowed from our acclaimed MDP-1, can handle mics, pickups, keyboards, or line-level signals. It features phantom power, input pad, phase reversal, and a switchable lo-cut filter. Independent gain and output controls permit overdrive of the tube stage to vary the harmonic content of the preamp.
The Opto-Compressor, derived from the popular OCL-2, uses our proprietary optoelectronic cell, and has a sound all its own. It can be used in one of four modes: Fast (for 'invisible' compression), Average (rms responding), a new Vintage mode (with program-dependent response), or full manual operation.
Our new 3 band tube EQ, a modifed Baxandall design, is simple but very effective. The HI and LO bands have up to ±10dB of shelving at 15, 10 and 7 kHz, and 50, 100 and 200 Hz respectively. The MID band has a broad ±10dB peaking response centered at 0.7, 1.6, 2.2, 3.3, 5.0 and 6.5 kHz. The EQ can be placed before or after the compressor with the flip of a switch.
The new De-esser, which is implemented within the opto-compressor, uses an entirely new approach. A highly selective inductor-based detector triggers a very fast opto-inductive notch filter. The user can control the depth of the notch, which in turn controls amount of sibilance to be removed. When not triggered, the de-esser is out of the signal path entirely.
Circuit Type: Class A vacuum tube topology with transformerless or transformer-balanced output
Vacuum Tubes: (3) ECC83/12AX7A, (3) 6922/6DJ8
Power: 120V or 240Vac, 45W
Power Supplies: +300Vdc, +6.3Vdc,+12.6Vdc, ± 18Vdc, and +12vdc, fully regulated with soft-start warm-up and output muting
Dimensions: 2U enclosure, 19" x 3.5" x 12.5" (48.2 x 8.8 x 31.8 cm)
Weight:14lbs (6.4kg)
Note: Operating level is +4dBu = 0VU = 1.228v
Unless otherwise stated, all measurements are referenced to +4dBu, 0-80 kHz bandwidth.
All specifications are subject to change without notice.
As with all tube circuits, specifications will vary with tube brand, age or differences in internal structure.
Mic Preamp
Input Gain:+33 to +63dB in 3dB steps
Input Impedance:1500 transformer balanced and floating
Frequency Response:-1.0dB 15Hz and 65kHz with 10K load, +45dB gain, unbalanced or transformer-balanced
-1.0dB 22Hz and 60kHz with 600 load, +45dB gain, unbalanced or transformer-balanced
Noise: EIN less than -125dBu with 150 input load (> 83dB below +4dBu)
Distortion: THD+N less than 0.025%, +45dB gain, unbalanced output;
less than 0.06% from 200Hz-20kHz (< 0.6% at 20Hz), transformer-balanced output
DI Preamp
Input Gain: +20 to +50dB (Instrument), 0 to +20dB (Line) in 3dB steps
Input Impedance: 10M or 1M (Instrument), 100k with 20dB pad (Line)
Frequency Response: -1.0dB 10Hz and 85kHz, with 10K load, + 20dB gain, unbalanced or transformer-balanced
-1.0dB 22Hz and 75kHz, with 600 load, + 20dB gain, unbalanced or transformer-balanced
Noise: EIN less than -113dBu with input shorted (> 83dB below +4dBu)
Distortion: THD+N less than 0.015%, 20Hz-20kHz, +20dB gain, unbalanced output;
less than 0.05% from 200Hz-20kHz (< 0.6% at 20Hz), transformer-balanced output
Max. Output Level: +32dBu into 10k load, Output control at maximum, unbalanced or transformer-balanced
+24dBu into 600 load, Output control at maximum, unbalanced or transformer-balanced
Phantom Power: +48Vdc applied to pins 2 and 3
Mic Pad: -20dB pad at the primary of the mic input transformer
Mic Phase: inverts the phase at the secondary of the mic input transformer
Mic Lo Cut: 12dB/octave rolloff at 75 or 150Hz
Polarity: input and output XLR connectors are pin 2 hot
Equalizer
Circuit Type: modified Baxandall-style feedback equalizer
Input Sensitivity:+4dBu
Input Impedance:10k
Frequency Bands
Hi: ±10dB shelving at 7, 10, or 15 kHz
Mid: ±10dB peaking at 0.7, 1.6, 2.2, 3.3, 5.0 and 6.5 kHz, Q=1.0
Lo: ±10dB shelving at 50, 100, or 200 Hz
Freq. Response: -1.0dB 16Hz and 45kHz with 10K output load, unbalanced or transformer-balanced
-1.0dB 20Hz and 45kHz with 600 output load, unbalanced or transformer-balanced
Noise: > 79dB below +4dBu
Distortion: THD+N less than 0.015% from 20Hz-20kHz, +20dB gain, unbalanced output;
less than 0.06% from 200Hz-20kHz (< 0.6% at 20Hz), transformer-balanced output
Max. Output Level: +32dBu into 10k load, Output control at maximum, unbalanced or transformer-balanced
+24dBu into 600 load, Output control at maximum, unbalanced or transformer-balanced
Opto-Compressor
Circuit Type: optical input attenuator and class A vacuum tube gain stage
Input Sensitivity: +4dBu
Input Impedance: 10k
Freq. Response: -1.0dB 8Hz and 100kHz with 10K output load, unbalanced or transformer-balanced
-1.0dB 20Hz and 100kHz with 600 output load, unbalanced or transformer-balanced
Noise: > 76dB below +4dBu , output control at unity gain
> 76dB below +4dBu , output control at +15dB
Distortion: THD+N less than 0.016% from 20Hz-20kHz, +20dB gain, unbalanced output;
less than 0.06% from 200Hz-20kHz (< 0.6% at 20Hz), transformer-balanced output
Max. Output Level: +32dBu into 10k load, Output control at maximum, unbalanced or transformer-balanced
+24dBu into 600 load, Output control at maximum, unbalanced or transformer-balanced
Max. Gain Reduction: > 30dB
Threshold: off to -20dB
Ratio: 1.5:1 to 15:1
Output:-5 to +15dB
Modes: fast (peak-averaged), average (rms), vintage (program-dependent) or manual operation;
attack time varaible from 1.0ms to 100ms
release time varaible from 0.1s to 2s
