L-21: Extended bottom and clear highs
Release date: October 2008
The API™ 512 microphone pre-amp is an elegant and simple design: Runs on 16 volts +/- power, input Transformer, op amp, and output transformer. The MX-1 respects the heritage of the classic API™ 512 by using the same basic elements; a proprietary input transformers, discrete amplifier blocks, and proprietary UI output transformers.
The L-21 provides stepped control over (post input transformer-pre discrete block) input attenuation and has a true output level control.
As a fully functioning microphone preamplifier, the L-21 has two Hi-Pass Filter settings; 70Hz, 40Hz. Middle position on the switch is for 'off'. The 70 Hz setting is excellent for tracking vocals and drums overheads, with a gently sloped roll off. The 40 Hz is more of a general use to remove excess rumble and bandwidth that would be discarded in the mix process anyway, allowing one to capture more of the fundamental audio frequencies from the source.
The L-21 also provides 48v Phantom Power, a phase reversal switch, selectable (pre input transformer) -10db or -20db pad. The L-21 also includes a high gain switch for more output level.
The L21 can handle +12 db of input, making it useful for inserts or as a live audio line driver between the mixer and amps. The ability to switch the meter between input and output was considered for just such an application.
The design of the L-21 includes onboard regulated power at crucial junctions, insuring repeatable performance from unit to unit, from use to use.
* The L-21 is fully API™ 500 compatible. The L-23 requires an additional voltage. Your rack can be modified, or VSI makes a 10 space rack and a 6 space lunchbox to accommodate the additional power requirements.
