Pyrite

Some time ago a friend of mine bought a Golden Age Pre-73 DLX Mk II and let me probe it with some test signals. So I went home and started modelling it as a fun exercise. It turned out not to be fun, and also that the unit is incredibly linear within a normal operating range (the transformer barely saturated at inaudible frequencies, at least at the impedance I was able to test, and the amp saturated at very high levels), so my model turned out to be quite useless, except for the low cut and air filters.

I decided to put together a plugin with some additional features to make it vaguely useful, in particular I added a compressor (a very weird one, not modelling anything specific), a bass-lift EQ, and I turned the step controls into continuous controls.

The result is Pyrite, a preamp emulation with some EQ and compression capabilities. It really shines on drum sounds, but can also be used on other types of tracks.

To use it properly, you need to be aware of the topology of the processors included (which is different from what you might assume from the interface):

 Transformer -> Saturation -> Compression -> EQing -> Output trimming

The transformer can be used to saturate the very low end, and also as a hi-pass filter on the input stage. The saturation can be set to a soft or hard knee, with two screws to tune the modelling of the original device. There is also a "blend" control that allows you to mix the unsaturated signal back in. The dynamics processor is a soft-ish-knee compressor that focuses more on bringing out the quiet parts than on taming the peaks (at least at moderate values of the Amount knob); it sounds a bit like a parallel compression algorithm. The EQs are a faithful reproduction of the original unit's low-cut and air filters, but with a wider and more continuous range, plus a low-end lift filter modelled on the (linear) behaviour of an EMI REDD console bass lift function.