There are four stereo compressor types in the TFPRO range, although they are all stereo compressors, they have individual characteristics and facilities that make them ideal for certain uses.
Optical compressors work when the audio signal reaches a ‘threshold’, a light shines on photo-resistors and they momentarily pull down the volume creating ‘volume compression’. The reason that opto compressors can sound so good is a combination of the management of the time constants in the compression and the natural time constants of the photo-resistors.
The P38
The original P38 was designed in 2001 and was the descendent of compressors designed by Ted in the 1960s after working with Joe Meek and running his own studio at No 21 Denmark Street, London.
Original design work done in 1965 – 1970 showed how optical compression could be superior to other methods, but technology for controlling attack and release was limited at the time.
The P38 made full use of the early development work but incorporated modern technology, with radical design innovations in variable ratio control, automatic transient release and ‘sum and difference’ compression which eliminated the image shift problems that had always plagued stereo compressors of the past.
With its switched compressor ‘models’ the P38 became a brilliant mastering tool with the ability to apply the subtlest compression to any type of music.
The P38EX
Mastering engineers fed back a lot of praise for the P38, but also a couple of requests….. ‘wouldn’t it be nice if we could access the compression sidechain so that we can introduce EQ to the compression for different effects?’ And ‘we would like to use parallel paths of compressed and non-compressed material’.
Ted took the original P38 design and added the EXtra facilities…. Hence P38EX. The main compression performance of the P38EX is the same as the P38 exactly.
The P38V7
In 2007 after many requests from studios and engineers, Ted re-visited the original designs of the P38 to produce a compressor that had more of the original ‘earthy’ quality of his early Joemeek® compressors, particularly the original SC2 1.05. While retaining the new variable ratio, he re-arranged the circuitry to incorporate a relay operated ‘hard-wire by-pass’ and introduced a 2-step compression release system to give finer control. This compressor is particularly suitable for heavy rock and roll recording as well as adding depth and realism to 21st century music.
The P38V8 ‘LEGACY’
Late in 2011 Ted decided to introduce what is the most ‘retro’ of all the compressors…. The ‘Legacy’. This is a blatant return to the roots of compression, it uses the original photo-resistors that were used in the 1960s and in the early Joemeek® compressors, and has the simplest of controls so that it can be set up instantly and will sound good immediately. Although it has some ‘up to the minute’ technology in the variable ratio control, it breaks with TFPRO tradition by using old-fashioned bakelite control knobs and a single meter! (In the heat of a recording session the single meter works just fine…. And it’s big!).
The ‘Legacy’ is a delight to use and produces that power and weight that characterises the best opto compression.
Joemeek® is a registered trademark of PMI Audio Group.