Camden EC1 - Preamp and Headphone Mixer

Discrete mic/line/hi-z preamp featuring the award-winning ‘Camden’ topology from the Camden 500 Preamp and Signal Processor for 500 series
Audio performance at the near-theoretical limits of noise, distortion, and phase/frequency linearity at all gain settings
- EIN: <-129.5dBu, 150 Ohm source, unweighted, <-135.5dBu, Inputs common, unweighted
- THD+N: <0.00025% (1kHz, 35dB gain, +24dBu out)
- Intermodulation Distortion: <0.0006% (50Hz and 7kHz, 35dB gain, +20dBu out)
- Phase Shift: <2.75° (20Hz to 20kHz, 40dB gain), <6° (20Hz to 20kHz, Max Gain)
- Freq. Response: ±0.7dB (<1 Hz to >1000 kHz, 35dB gain), ±1dB (<5 Hz to >200 kHz, Max Gain)
Unique 48v status LED
- 48v LED Lights Orange to indicate voltage charging or dissipating to prevent damage to ribbon microphones and to ensure voltage is fully charged before use
- 48v LED lights RED when voltage is fully charged and ready to use
‘Mojo’ analogue saturation circuits with variable control, true bypass, and 2 discrete styles - Thump and Cream

Thump excites low-end content by boosting lower odd/even harmonics from a range of 160Hz to 20Hz and below
Cream boosts odd/even harmonics whilst also reducing the amplitude of the fundamental frequencies and applying typical transformer-style transient taming

Discrete headphone mixers with independant CH 1, Ext Input, and Aux Input level controls

Monitor the Camden preamp directly with headphones during mic placement to find the sweet spot of the instrument/source
Create zero-latency artist mixes by combining the Camden preamp with external playback from Aux Input 1/4” jacks on Camden EC1’s rear panel
Use the reference grade headphone amplifier for critical listening by sending stereo mixes from the interface into the Aux input and monitoring directly using Camden EC1’s headphone output

Reference-quality, high-powered headphone amplifier

Freq. Response: <±1dB, <1 Hz to >100 kHz
Output Impedance: 0.33 Ohms
THD: 0.0003%, 1kHz
Output Wattage: 2x250mW @ 600 Ohm, 2x450mW @ 220 Ohm, 2x250mW @ 100 Ohm

Balanced XLR output and impedance balanced 1/4” jack outputs for maximum connectivity into audio interfaces and other downstream equipment

-10dB PAD to attenuate preamp output for lowheadroom audio interfaces

Dedicated Impedance balanced 1/4" jack Link output for true instrument DI functionality and splitting instrument inputs to balanced or unbalanced amplifiers and effects

C.A.S.T. OUT port for connecting into 500R8/500ADAT

Transmit Camden EC1’s preamp and Ext Input directly into 500R8 and 500ADAT’s 500 series modules inputs for recording/processing
Receive a stereo mix generated from 500R8/500ADAT and monitor using Camden EC1’s headphone mixer
All managed and distributed via a single shielded Cat 5e, Cat 6, or Cat 7 cable

External high-current 24v, 1.25a power supply with latching connector

All specifications are typical performance unless otherwise noted. All specifications are subject to change at any time. Tested with Audio Precision APx555.
Preamp
Test Signal Path	APx555 (Line Out) - Input 1 - Line Output - APx555 (Line In)
Input Impedance	Mic= 8.9 kOhms 48v Off, 5.4 kOhms 48v ON, Line = 24.3 kOhms, Hi-Z= 1.5 MOhm Unbalanced, 3 MOhm Balanced
Max Input Level	Mic = +17.6dBu (<0.003% THD), Line = +26.5dBu (<0.02% THD), Hi-Z = +24dBu (<0.02% THD)
Minimum Gain	Mic= 8dB, Line = 0dB, Hi-Z = 3dB
Maximum Gain	Mic = 68dB, Line = 60dB, Hi-Z = 63dB
Equivalent Input Noise (EIN)	<-129.5dBu (150 Ohm source, unweighted), <-131dBu (150 Ohm source, A-weighted), <-135.5dBu (Inputs common, unweighted)
Frequency Response	±0.7dB (<1 Hz to >1000 kHz, Min Gain), ±0.7dB (<1 Hz to >1000 kHz, 35dB Gain), ±1dB (<1.5 Hz to 900 kHz, 63dB Gain), ±1dB (<5 Hz to >200 kHz, Max Gain)
Phase Shift	<2.75° (20Hz to 20kHz, 40dB Gain), <4° (20Hz to 20kHz, 63dB Gain), <6° (20Hz to 20kHz, Max Gain)
THD+N	<0.00025% (1kHz, 35dB Gain, +24dBu out)
Intermodulation Distortion	<0.0006% (50Hz and 7kHz, 35dB gain, +20dBu out), <0.0005% (50Hz and 7kHz, 35dB gain, +15dBu out)
Hi-Pass Filter (HPF)	80Hz, -3dB, 12dB/Oct
CMRR	>70dB, typ >85dB, 35dB gain, 10-20kHz, 100mV Common mode
Slew Rate	20V/uS, 35dB gain, +25dBu out
48v LED Thresholds	Off = 48v Off, voltage fully discharged Amber = 48v voltage charging/discharging Red = 48v fully charged
Signal LED Meter Thresholds	Blue = -20dBu Green = -12dBu Amber = +21dBu Red = +24dBu
Max Output Level	Balanced XLR = +27.5dBu (<0.002% THD, 30dB Gain) Impedance Balanced ¼” Jack = +21.5dBu (<0.002% THD, 30dB Gain)
Output Impedance	Balanced XLR = 150 Ohm Impedance Balanced 1/4” Jack = 150Ohm Balanced, 75 Ohm Unbalanced
Link Max Output Level	Impedance Balanced 1/4” Jack = +21.8dBu (<0.006% THD)
Link Output Impedance	Impedance Balanced 1/4” Jack = 75 Ohm Unbalanced, 150 Ohm Balanced (Buffered Output)
Headphone Amplifier
Test Signal Path	APx555 (Line Out) - AUX Input - Headphone Output - APx555 (Line In)
Frequency Response	-1dB, <1Hz to >70kHz
THD	<0.0006% (-104.4dB) @ +20dBu, 1kHz, A-weighted, 300 Ohm load
THD+N	<0.00085% (-101.4dB) @ +20dBu, 1kHz, A-weighted, 300 Ohm load
Output Impedance	0.33 Ohms
Output Wattage	250mW x 2 @ 600 Ohms, 1kHz
	650mW x 2 @ 220 Ohms, 1kHz
	1.21W x 2 @ 100 Ohms, 1kHz
	500mW x 2 @ 32 Ohms, 1kHz
Dynamic Range	114.5dB A-weighted, AES17 method, 20Hz - 20kHz, 300 Ohm load
Noise Floor	-93.5dBu A-weighted, 20Hz - 20kHz, 300 Ohm load
Power
AC Requirements	100V – 240V AC, 50 – 60 Hz
Total Power Consumption	24v, 1.25A DC, 30W
Environmental
Operating Temperature	+1 to 35 degrees Celsius
Storage Conditions	-20 to 50 degrees Celsius
Dims/Weights
Unit
Width	220mm (8.6") (Rackmount Kit Available)
Height	44.45mm (1.75") (1u)
Depth	240mm (9.5")
Unit Weight	1.8kg (3.9lb)
Shipping Carton
Width	360mm (14.2")
Height	120mm (4.7")
Depth	340mm (13.4")
Carton Weight	2.6kg (5.7lb)