The 652 is a stereo vacuum tube preamplifier with mic/line-level inputs
Using the GAIN control, the engineer can achieve 5 - 60 dB of gain from the uniquely-biased tube input stage, followed by a MASTER attenuation control in the output buffer stage. Want a clean yet musical replication of the source How about the creamy saturation of an esoteric vintage preamplifier
The 652's gentle drive characteristics allows for a broad tonal palette depending on how hard you hit it with signal. It is designed to interface with all types of microphones (including ribbons), and the line-level input pad allows you to add analogue warmth to any track from a digital audio workstation; making it an indispensable tool for adding colouration and harmonic distortion!
12AX7 input stage with 12-position gain switch, 5 - 60 dB (5 dB steps)High-voltage transistor buffer output stage (4x FJP5200)Discrete Class-A operation, low-noise topologyHermetically-sealed relay switching, with gold-plated contactsVariable input impedance for mic: 300 ohms, 1200 ohmsSource selection switch: Mic and Line-LevelPhase inversion switchSelectable high-pass filter of 10Hz, 80Hz, and 200Hz (first order)Regulated low-noise power supply, with +48V DC phantom powerHigh-quality Beldfoil shielded cabling throughoutCustom Lundahl input and output transformers
Typical Test Parameters: 2mV RMS sine, 1 kHZ, 1200R input impedance, 100K output load impedanceInput Impedance: 300, 1200 (Mic), 15K (Line)Maximum Input Level: +4dBV (XLR, 1200R setting), -2dBV (XLR, 300R setting)Maximum Output Level: +15 dBVXLR Output Impedance: < 65Recommended Minimum Load: 300Frequency Response: 18Hz to > 50kHz (-3 dB)High Pass Filter Characteristics: -3dB @ 80Hz or 200Hz, 20 dB/decade (first-order)Maximum Gain: 60dB (1200R XLR input - XLR output, unweighted)EIN Noise: -128dBV (20Hz ~ 20kHz); -130dBV (A-wtg)Residual Output Noise (Master at Zero): -121dBV (1uV) 20Hz ~ 20kHzNoise Factor: 5dB re 150R source impedance (20Hz ~ 20kHz)THD+N: 0dBV to 15dBV, 0.03% to 2%Tube Per Channel: 1x 12AX7Phantom Power: +48V DCPower Sequencing:- Soft-start for tube filament supply;
- Soft-start for tube high voltage supply;
- 30s turn-on delay for output relays;
- Output relays mute immediately at power-down
Power Requirements: 110-120V / 220-240V, 50/60Hz, 30VA max.Power Consumption: 24 WattsDimensions: 19" W x 3.5" H x 12.25" DWeight: 6 kg