Aphex 1100 MKII - Dual Channel, Class A Tube Microphone Preamplifier with Analog to Digital Converter

The 110 MKII from Aphex is a dual channel, high gain Class A tube microphone preamp. The preamp provides a health amount of headroom and combined with an EIN of -135dBu, allows for the use of more gain without overload distortion or noise.

The "Reflected Plate Amplifier" tube circuit is configured as a single-triode differential opamp to further enhance the preamplifier's common-mode rejection. This circuit topology subtly imparts the tube's sonic warmth and character while retaining a long and stable operating life.

The A/D converter receives signal from the soft mute stage just prior to the analog output level control and triode output stage. This means that both the digital and analog outputs can be used independently, with full and proper calibration of both, regardless of the analog output level settings. The analog and digital outputs respond equally to the input gain, low-cut filter, and all front end conditioning effects.

Each channel contains a twenty-segment LED headroom meter, making it easy to optimize the performance of the preamplifier. The headroom meter is calibrated in decibels below clipping, where 0dB is the analog clipping point. This coincides with the A/D converter's maximum input level, so the headroom meter also indicates the digital audio level accurately. Each channel contains its own independent controls over every function.