Gyraf Audio is an audio electronics manufacturing, research, and development company, based in Aarhus, Denmark. It was originally founded in partnership with Feedback Recording, one of Denmark’s largest recording studios (sadly now defunct). Today the small-scale company continues to meet the steadily rising demand for ‘old-fashioned’ recording equipment, a trend that has hardly slowed, despite the prevalence of affordable DAW-based recording.
Premier products include the magnificently-monikered GRYATEC XXI MAGNETO-DYNAMIC INFUNDIBULUM — or G21 for short, billed by its creator as being the ultimate passive analogue clipper. As such, it is designed to overcome classic multi-banding problems due to filter phase shift spoiling recombined frequencies by dealing with all frequencies in parallel and only opening frequency-selective channels into the clipping circuitry. According to Gyraf Audio, clipping generates harmonics, but, in this case, clipping byproducts are effectively prevented from entering and exiting the audio as they are no longer within the right frequency range since clipping takes place at the remote end of a frequency-selective channel.
More ‘traditional’ is the GYRATEC XIV PARALLEL-PASSIVE EQUALIZER (G14), a true tube, all-passive, stereo EQ, consisting of five bands, each with 11 switchable frequencies, variable Q, and boost/cut selection. The two channels are linked, controlled by one set of controls, while the equaliser itself is an extended version of passive inductor/capacitor-type filters found in the likes of classic Pultec designs. However, it aims to overcome their simplicity by being a truly passive design, based on switching a set of inductors and capacitors in and out of circuit, combined with an E88CC (6DJ8) tube-based makeup gain/output stage. No ICs or semiconductors are present anywhere in the signal path… a true tube unit, indeed!
On a more straightforward naming level — though no less impressive for it — the GYRATEC II TUBE PREAMP (G2) is effectively an all-tube recording channel, combing a mic/line preamp, an equaliser, and an optical compressor. While solid state electronics are used in its power supply and side chain, the audio signal itself never gets touched by anything other than tubes and transformers. It also happens to be the most popular product produced by Gyraf to date. Meanwhile, the GYRATEC IX MIC PREAMP (G9) is a dual true tube mic preamp — simple, yet powerful, based on a variable-gain input tube stage driving a tube SRPP (Shunt Regulate Push-Pull) output stage. Silicon is nowhere to be found, needless to say!
Other notable products include GYRATEC X VARI-MU TUBE COMPRESSOR (G10) — a true tube stereo compressor based on the classic variable-mu principal of controlling the gain by altering current in differential tube pairs which was deployed on early devices due to its inherent speed, yet remains popular today due to the topology’s sonic byproducts — and the GYRATEC III ELECTRO-OPTICAL COMPRESSOR (G3) — a true tube stereo compressor based on the opto VCA principal of controlling the gain by means of a light-dependent resistor a la Universal Audio classics like the LA-2A and LA-3A that, though not as fast as the variable-mu method, is much more subtle, sonically.