TFPro P9 Mastering EQ - parametric EQ with HP and LP, shelves

Created by the genius designer Ted Fletcher (who sadly passed in 2025), he built the P9 to be his definitive mastering equalizer. He based it on the A-Range design, and combined discrete electronics, transformer-balanced outputs with carefully selected transformers, and threw in some extra features like HP/LP and Shelves. And it came out as a beutiful, adictive sound, so pure that deserves a place in any high grade mastering chain. Here is the technical info from his website: /////////////////////////////////////////////////////////////////////////////////////77 //////////////// Description EQ is available everywhere. EQ is on everything we buy in pro audio. EQ is perhaps the most common audio tool in the market. EQ is used in every aspect of the recording process; and any studio engineer has his/her favorites… Ted Fletcher is not new to EQ. From his console designing days, he has produced many designs, and has heard a great many more… His favorite design of all time has now become the TDE; Ted’s Definitive Equaliser! Features: Wide bandwidth High Quality Transformer inputs Uniquely warm glossy sound High capacity output stage NO POTS!! All controls are switched. What Makes the TDE? The TDE is a two channel, four band EQ. 2 bands are high and low shelving, 2 bands are parametric mids. There are high and low pass filters on each channel. The first major difference with the TDE from other EQs from the outside is that none of the controls are potentiometers (pots), they are all switches. This is a major feature of older equipment, that enables precise control over every parameter, and repeatability of results. Over the years, with things like EQ, pots have replaced switches to save on manufacturing costs, however, for the purist, pots can be very inaccurate and failure prone. On the inside, the TDE features a classic design of EG using inductors and vintage amplifiers. This design is an adaptation of Barry Porter’s classic that oozes musicality and richness. The amplifiers are pure class A, discrete that in themselves add a quality that is hard to define, yet unmistakable. Subtle, Extreme The P9’s inductor driven EQ does more than simply cut and boost frequency. Gentle phase transitions make the EQ applied sound completely natural and warm. Even with the most gentle EQ setting, music sounds warmer and more complete. As a mastering tool, the P9 can subtly enhance the mix in ways that you can hardly measure, but are unmistakable to the ear. The P9’s switched settings give the engineer confidence in the basics of what the P9 is doing to the mix, but the subtleties will remain a mystery, leaving plugin EQs sounding brittle and dull in comparison. Because of the P9’s extreme smoothness, you can apply heavy EQ to a sound before losing any musical qualities. That’s not to say that the EQ goes unnoticed though, under heavy EQ, sounds take on a completely new character that is unmistakably the classic design of this EQ working hard. When used to extremes, the P9 is an awesome musical tool, shaping sound to amazing effect. Filter Each P9 channel comes with high and low pass Sallen and Key filters on 4 way switches for 3 frequency settings and an off position. In use, these filters are as smooth as it gets. Useful for tracking and the mix. The P9 is not a cheap equaliser. It is designed to be everything that Ted Fletcher could possibly want from an EQ, and each unit is hand made to his exacting standards in England. It is a product exclusively for people who can hear the difference, and want the best for their sounds and mixes. The P9 features, 2 channels of… 4 bands of Inductor based EQ All switched settings (rotary and toggle) 12 EQ gain stages boost/cut per band (24 gain positions in total) Mid Q shaping (2 bands) 11 input and output gain settings 3 way high pass filter 3 way low pass filter input clip meter post EQ 9 LED meter EQ bypass switch Technical description All rotary controls are multi-position switches with the gain or equalisation set by fixed 1% resistors. It’s a 2-channel unit with a common built-in power supply, separately screened to eliminate any interference between the mains transformer and the sensitive inductors used in the mid frequency circuits. The Input stage The line level Input stage uses a completely new circuit incorporating a precision input transformer (giving 5KV fully floating isolation) followed by a balanced gain-correcting amplifier formed from dual silicon (not J-Fet) operational amplifiers arranged so that gain is shared and kept to a minimum. The op-amps are types with minimal 3rd order distortion and extremely low noise. Operating level is chosen so that from a noise floor of around 118dB below input, and a maximum level within the stage of +26dBu, we can achieve a stage signal/noise ratio of 112dB and at the same time, an overload margin of 32dB. This input stage performance is achieved across a bandwidth of 1OHz to 2SKHz (although these…