It's fairly common to record sources with lots of transient content (particularly things inclined to be harsh...i.e. cymbals) like drums, acoustic guitar, and vocals to tape for a number of reasons. Tape acts as a limiter - when things peak above the area that can be written to tape, that portion of the waveform is simply shaved off, without losing the "punch"...even the best of limiters have a hard time doing this. The components in a tape machine generate a lot of "harmonics", particularly 3rd order harmonics, which for a wide variety of reasons, cancel and phase frequencies down the spectrum. In normal, practical, "actually matters" parlance, it mellows harsh things out and makes them sound "rich".
As for the unit itself, it does this far better than any plugins I've used. The transformer selection is typical for the rest of the Portico line, and imparts a very fat "Portico sound", heavy in the 300-500hz range, which can overwhelm certain things quickly, but is great for fattening up thin parts.
The saturation is great - can be driven incredibly hard and still retain punch, and because of the two channels, you can run a single source to both channels (depending on the setup of your patchbay) and treat the same signal in parallel...leaving one nearly untouched and the other smashed to heck (a technique commonly used on vocals, bass, or drum buss). The tape "speed controls" simulate what happens at different tape speeds - namely a more responsive high-end at the faster setting. This can sometimes add "harshness", depending on the source, but is particularly helpful if the Portico 500hz "fatness" is overwhelming.
My biggest gripe with this unit, one that rendered it EXTREMELY tedious, is the lack of a stereo link. For all intents and purposes, this is a dual mono unit. The pots aren't precise enough that similar settings yield similar saturation, so sending stereo sources through it like a mix or drum overheads (two MAJOR USES for analog tape) is incredibly time consuming and tedious. It took ages to get the stereo image balanced, and even then, I wasn't certain if I was achieving identical effects on the L and R channels of my overhead track...resulting in a shifty snare and kick that seemed to dance around my overhead "center". This was even more noticeable on a full mix.
If you need to run this on several mono sources, or run a single source through two different saturation units, this unit is killer. Sometimes this unit is all it took to get something to sit in the mix. If you're looking for something to reliably handle stereo channels though, you should be prepared to spend some time dialing it in. Either way, great to track through-right after the pre, before the interface - to fat sounds, nice limiting (often essential in today's demand for loud mixes/masters), and well worth the money! $43 a weekend, $95 a month, at Rock N Roll Rentals!
