Limiter combined with an asymmetric wave modifier
For many years, we made the Model 508 Phase Rotator. This device
didn’t make anything any louder, but it made a limiter more effective by
making waveforms more symmetric and easier to limit. It was a great tool for
asymmetric signal sources like vocals, horns, or close-miked strings.
The rotator is an all-pass filter that alters the phase of each component
the signal differently depending on its frequency. If a 50 Hz signal
is passed through, it will come out with identical polarity on the output.
But, if an 800 Hz signal is passed through it will come out with the polarity
completely reversed. A side effect of this adjustment is to make the
waveform more symmetric.
This is what it does. The top waveform is a typical female vocal recorded
with Neumann U87. It’s asymmetric, with peaks in one direction greater than
in the other, because the human vocal cavity is just that way.
The bottom waveform has been processed by the phase rotator. It’s more
symmetric, with peaks more evenly distributed between the top and bottom of
the waveform. This means when you limit it, the limiting will be more even
between the top and bottom, and you can limit it more aggressively without
distorting it. It is especially useful on severely asymmetric waveforms
like brass instruments and vocals.
After the phase rotator we have included a high speed opto limiter with a simple
threshold control, incredibly fast attack, and controlled decay that depends
on how hard it limiting. This is not your like an old 1176, it lets you
limit harder than that! It uses a modern opto element with a very sharp knee
and very fast operation.
Kludge Audio 509$529
