Spectra 1964 STX 100 D rebuilds the microphone channel from the Spectra Sonics consoles made between 1964 and 1971 and fits it into a single 500 series slot. Instead of one gain stage it runs two 101 amplifier modules together with US-made input and output transformers.
Old console tone without owning the console
Original Spectra Sonics desks survive in a handful of rooms worldwide and cannot realistically be kept in service. The STX 100 D repeats the same circuit in a package over 75% smaller and drops into any 500 series rack, so the same character is available on a pair of snare channels without maintaining vintage hardware.
Transformers on both ends of the path
An input transformer and an output transformer together produce a midrange density that a preamp with iron on one side only does not reach. A three-position pad plus continuously variable input and output controls let you place the operating point deliberately: back off for clarity, drive harder when a vocal should thicken on the louder phrases. With 64 dB of gain on tap, low-output ribbons and dynamics are not an issue.
KEY FEATURES
- Microphone channel from the 1964-1971 Spectra Sonics consoles
- Two 101 amplifier modules in a fully discrete topology
- US-made input and output transformers
- Single 500 series slot, original circuit reduced by over 75%
- Three-position pad with continuously variable input and output
- 48 V phantom power and polarity reverse
TECHNICAL SPECIFICATIONS
- Gain: 64 dB
- THD: less than 0.03% at 20 Hz - 20 kHz
- Signal to noise: better than 120 dB, unweighted
- Maximum output: +18 dBm, 20 Hz - 20 kHz
- Power requirement: less than 50 mA at +18 dBm
- Input impedance: 600 Ohm nominal
- Output impedance: less than 50 Ohm
- Frequency response: 10 Hz - 50 kHz
- Phantom power: 48 V
- Polarity: 180 degree reverse, mic or line input
- Input/output control: continuously variable, three-position pad
