Based on the MP 1A tube microphone preamp from Tube Tech, the PM 1A is a modular version that fits into their RM8 desktop power supply. The preamp also features a DI input and features extremely controlled and transparent sound.
The amplifier consists of a microphone input transformer with a step-up of +10dB, a dual tube preamplifier with 10dB/step coarse gain over a 20dB to 60dB range, augmented by a fine 2dB stepped attenuation of +/- 10dB, providing a total gain range of +10db to 70dB.
The output amplifier features 2 dual tubes in a push-pull configuration and an output transformer. The microphone input is provided with a switchable -20dB pad, selectable input impedance, switchable phase reverse and switchable +48V phantom power.
A Hi-Z direct inject input is unbalanced and placed in the circuit directly after the input transformer. The gain range for the DI input is 0dB to +60dB, with the microphone input disabled when in use. A high pass filter for the microphone and the DI input is switchable between off, 20Hz and 40Hz.
All tube-based push-pull microphone preamplifier in a modular format
Microphone gain available in 2dB (fine) and 10dB (coarse) steps
600/1200/2400Ω selectable microphone impedance
Includes +48V phantom power, phase reversal and 20dB pad
High impedance direct input
Low-cut filter switchable as Off, 20Hz or 40Hz
Utilizing the pad allows the unit to function as a unity gain line amplifier
Overloading the input stage is not possible, while a red LED shows when output clipping is approaching
In the Box
TUBE-TECH PM 1A - Microphone Preamp Module
One (1) Year Warranty
Table of Contents
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Number of Channels
1 x XLR Microphone (on power supply) 1 x 1/4" TS phone Instrument (on module front panel)
Microphone input available via parallel DB25 connector on power supply
1 x XLR (on power supply)
Output also available via parallel DB25 connector on power supply
+10dB to 70dB
Maximum Output Level
5Hz to 60kHz, -3.0dB
-80dBu, unweighted @ +20dB gain -60dBu, unweighted @ +60dB gain