Alpha Channel

Analogue Hit Maker
It's time to show your DAW who's boss

• SSL analogue channel processing for your audio workstation
• Pro mic preamp with line and instrument level switching
• Studio class EQ, Filter and Limiter sections
• Variable Harmonic Drive circuit - a time machine of distortion characteristics
• Analogue or digital outputs direct to your DAW

All great sounding recordings have to start somewhere...

With the classic combination of a mic preamp, filter, EQ and dynamics, the XLogic Alpha Channel brings SSL’s sonic legacy bang up to date in an analogue channel strip designed to provide the perfect front end to your digital audio workstation.
With all the features needed to record great vocal or instrument tracks, the Alpha Channel offers a studio class mic pre and processing based on SSL’s years of experience in designing the world’s leading analogue recording consoles. A huge proportion of the music you know and love was recorded on SSL, renowned for the superior audio qualities you’ve heard on countless hit records. That elusive sonic ingredient is here in the Alpha Channel.

Features

• Professional ultra clean mic preamp with line level & Hi Z instrument input switches
• ‘Variable Harmonic Drive’ circuit; a Time Machine of distortion characteristics
• High Pass Filter with selectable 40Hz, 80Hz or 120Hz cutoff frequency
• Built in professional quality Analogue to Digital conversion - as standard
• Auto sample rate sensing and self adjustment
• Three band SSL parametric EQ with mid freq Q control and dual LF curves
• Intelligent auto compression that maximises recording headroom and avoids DAC clipping

Physical *

• Depth: 230mm / 9" casing only
• Height: 44.5mm / 1.75" (1 RU)
• Width: 438mm / 17.25" casing only     482mm / 19" inc’ rack ears
• Weight: 3.0kg / 7 pounds
• Power: < 20 Watts
• Boxed size: 320mm x 550mm x 80mm       12.75" x 21.75" x 3.25"
• Boxed weight: 3.5kg / 8 pounds

*All values are approximate


Connections

• Power: IEC320 3-pin connector, 100 – 240 Vac, 50 – 60 Hz
• Analogue I/O
• Microphone: Balanced, 3-pin XLR-F, Zin = 1kΩ (10kΩ for Hi Z)
• Instrument: Un-balanced, ¼" Mono Jack, Zin = 1MΩ
• Output: Balanced, ¼" Stereo Jack, Zo = 40Ω
• Insert Send: Balanced, ¼" Stereo Jack, Zo = 40Ω
• Insert Return: Balanced, ¼" Stereo Jack, Zin = 10kΩ
• Link (2 of): RCA phono, limiter sidechain control voltage (dc.)
• Digital I/O
• SPDIF In: RCA phono, 1V pk-pk, Zin = 75Ω, SPDIF format.         The ADC will lock to this signal if present.
• SPDIF Out: RCA phono, 1V pk-pk, Zo = 75Ω, SPDIF 24bit format.         Synchronised to SPDIF In, else free-runs at 44.1kHz.

Measured Performance

• Mic Gain To Output:: 20dB min, 76 dB max
• Instrument Gain To Output:
• 26dB min, 82 dB max
• Pad Attenuation:: 20 dB
• Input Impedance (Ω):

 Mic:1K / 10K
 Instrument: 1 MEG

• Noise Figure

         Mic, Zin = 10R: -130.5 dBU
         Mic, Zin =150R: -127.5 dBU

• Dynamic Range:

    Mic Gain Min: 105 dB unweighted
    Mic Gain Max: 76 dB unweighted

• Common Mode Rejection: 70 dB from 50Hz to 10KHz with 1Vp-p Common Mode

• Max Common Mode In: 5V p-p

• Frequency Response

• Mic To Out: +/- 0.2 dB from 10Hz to 70KHz

-3dB (HF) : 250 KHz

• Mic Amp Distortion - A Typical Specification

Output Level:	Output Level:	THD Knob CW
+5 dBU	0.03 %	0.1 %
+10 dBU	0.05 %	0.3 %
+15 dBU	0.06 %	0.5 %
+20 dBU	0.09 %	2 %
+24 dBU	0.15 %	5 %

• Maximum Analog Output: +24.3 dBU (10K)

EQ

• LF Section:

LF Shelf Gain Range: +/- 19 dB
LF Bell Gain Range: +/- 15 dB
Shelf Freq Range: 40 - 600 Hz
Bell Freq Range: 35 - 500 Hz
Bell Q:1.4

• Mid Section:

Gain Range: +/- 17 dB
Freq Range: 300 - 5200 Hz
Q Range: 0.7 - 1.9

• HF Section:

Shelf Gain Range:+/- 19 dB
Shelf Freq Range:1.5KHz - 22 KHz

• EQ Dynamic Range: 100 dBU

Limiter

• Limiter Threshold: - 3 dBFS
• Limiter Ratio: 6, over-easy
• Limiter Headroom: 12 dB min, 14 dB typ
• Attack Time: 50 uSec
• Release Time: 200 mSec
• Limiting Distortion: 0.5 % max
• Non-Limiting Distortion: 0.001 %

Insert Point
Operating Level
Limiter Switch Out:24 dBU, unity gain to output
Limiter Switch In:12 dBU, +12 dB gain to output

• Output Impedance (SEND): 150 Ω
• Input Impedance (RETURN): 10 KΩ

ADC

• ADC Type: 24 bit, 192 KHz CS5361 ADC

Sampling Rate: locks to user supplied SPDIF IN Range: 32 KHz to 108 KHz

• No SPDIF In: Defaults to 44.100 KHz
• SPDIF In: 200 mV p-p IN min 5V p-p IN max
• SPDIF Out

(Level): 1V p-p
(Impedance): 60 Ω

• ADC Performance Measured From Insert Return:

Dynamic Range, 20KHz measurement bandwidth
 
Fs= 32K: 110.5 dB, A-wgt
Fs= 48K: 110 dB, A-wgt
Fs= 96K: 109 dB, A-wgt

• ADC Distortion, 1KHz test tone
• Level Distortion in 20K meas bw

-0.5 dBFS   0.0006 %
-10 dBFS    0.0015 %
-20 dBFS    0.004 %
-30 dBFS    0.013 %
-40 dBFS    0.04 %

• ADC Freq Response

Fs = 48 K: +/- 0.1 dB, 20Hz - 20KHz
Fs = 96 K: +/- 0.1 dB, 20Hz - 40KHz

• Miscellaneous

Phantom Power: 47.5V typical
Output Gain Range: +/- 19.5 dB