Spectra 1964 STX 100 D

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