The Model 7602 Microphone Preamplifier/Equalizer is based on a classic and revered design utilizing pure Class ‘A’ circuitry. This unit is made with 100% discrete components, hand wound transformers and was fabricated to precisely match vintage counterparts manufactured in the early to mid 70’s. The Model 7602 represents a dramatic breakthrough in delivering vintage audio performance at an affordable price.
Equalizer Section (Selectable 3 band design with a flexible filter section)
Filter - This is a high pass filter with 3db loss at 300Hz, 160Hz, 80Hz, and 50Hz with an 18db cut per octave slope.
Low Equalization - This section has a shelving slope with four frequency selections: 220Hz, 110Hz, 60Hz, and 35Hz. This equalizer affects the selected frequency and all others below it. The gain control provides 20db of boost or cut.
Mid Equalization - This section has a peaking characteristic with six frequency selections: 360Hz, 700Hz, 1.6k, 3.2k, 4.8k, and 7.2k. The gain control provides 20db of boost or cut.
High Equalization - This section has a shelving characteristic with five frequency selections: 16k, 12k, 7k, 4.9k and 3.4k. This section adjusts the selected frequency and all others above it. The gain control provides 20db of boost or cut.
Model 7602 Features
- Fully balanced transformer mic and line inputs
- Balanced XLR output
- Hi-Z direct input for instruments on the front panel
- 48VDC phantom power switch
- 180 degree phase reversal switch
- 20 position gold contact ELMA rotary gain switch for both Mic and Line sections
- Output level control functions as a fader when going straight to tape
- Oversize power supply provides many times the current needed for optimum sound quality and will power two units
- One-year warranty
By employing classic circuit design, polystyrene capacitors, a gold contact ELMA gain selector and custom wound transformers, Chameleon Labs ensures that the Model 7602 will exhibit classic audio sound.
The Model 7602 has a transformer balanced input with a range between 20dB and 80 dB of gain. The separate line input is transformer balanced and accepts input levels from -20 to +10dB.
The CPS-1 (sold separately) is a 1U rack mountable regulated, toroidal power supply for the 7602 and is required for operation of the unit. The CPS-1 features the ability to supply power to two 7602 units for dual channel operation.
Model 7602 Specifications
Input impedance: Microphone – 1,200 ohms
Line – 10,000 ohms
D.I. – 100,000 ohms
Sensitivity: Microphone – -80dBm to -20 dBm in 5dB steps for 0 dBm output.
Line – -20 dBm to +10 dBm in 5 dB steps for 0 dBm output.
Noise: Measured at 80 db of gain with 200 ohm input termination, without 20Hz to 20kHz to assist in filtering out noise.
-49dbu with final output stage at 50% EIN -129 dbu;
-46dbu with final output stage at unity EIN -126 dbu;
-56dbu without final output stage EIN -136 dbu.
Controls either “flat” or switched out.
Output: Balanced and floating to feed a 600 ohm load.
Maximum output +26 dBm into 600 ohms, or +20dBm into 150 ohms.
Output impedance: 600 ohms, balanced (source impedance 75 ohms).
Frequency Response: 11 Hz – 77.65 kHz – 3 dB.
Level variation is less than 0.2%.
Distortion: 1k Hz = 0.0245%