The Thermionic Culture Swift Balanced is a balanced version of Thermionic Culture's latest stereo valve EQ. The use of balanced input and output provides quieter performance and increased volume.

The Thermionic Culture Swift is a stereo valve five-band EQ with a switchable high-pass filter built to the highest standard. It is equally capable of tuning individual instruments as it is to shape the final mix.

The 19", 3U equalisers use an all-valve signal path with two double-triode valves per channel, combining new-old-stock GE5965 and new production JJ ECC802S valves.

The Best of Vintage Designs

At the core of the Swift is a Baxandall EQ based on the 1950 REDD mixing desks that Vic Keary modified while working at Lansdown Studios. The Low-frequency shelf offers a choice 50 or 100 Hz frequencies via a toggle switch and offers a maximum boost or cut of +/-12dB. The High shelf offers a similar set of controls with a choice of 7 or 12kHz.

The Swift can recreate the famous Pultec resonant shelf with the high-pass filter.

An additional Presence section is based on Vic Keary's 1963 design found on his original console design at Chalk Farm Studios. It adds a broad 4dB lift to the high-mid and high frequencies with a choice of three frequency points.

The Midrange section takes its cue from the classic Pultec EQ with separate boost and cuts sections, each with dedicated frequency points. The Mid cut section offers a choice of frequencies ranging between 350Hz, 700Hz, 2kHz or 7kHz three Q settings. The maximum attenuation levels vary between 5, 10 and 15dB depending on the bandwidth. 

The Mid lift section operates very similarly with frequencies ranging between 1khz, 2kHz, 3kHz, and 4.5kHz. Maximum boost levels are also dependent on the Q settings and range between 6dB (Low Q), 9dB (Med Q) and 15dB (High Q).

An EQ for the Modern days

The two-channel equaliser also brings major improvements, including a modern, specially-designed Sowter transformer and valves (tubes) never used in this type of circuit.

An additional Air control is also included, reminiscent of a Pultec 16kHz boost and the NTI Night pro-EQ3. It allows opening up a mix or any instrument without harshness.

Tonally, the Swift offers a surprisingly neutral sound for a valve EQ with a hint of analogue character, subtle richness in the low frequency and a smooth top end providing a slightly larger-than-life sound.