Groove Tubes GT66
Cardioid Tube Condenser Microphone
The GT66 is a large-diaphragm tube condenser, with a fixed Cardioid polar pattern.
It used a subminiature GT6205M tube, which we believe was a pentode, wired as a triode in a Class A circuit. The capsule is Groove Tubes’ exclusive 32mm disk resonator design, in a single-sided implementation (the rear diaphragm was not sputtered). The output circuit uses a custom-wound, nickel core transformer.
Like most of Groove Tubes’ mics, the GT66 has high sensitivity (25 mV/Pa), and relatively high self-noise (23dBA).
The GT66 was reintroduced by Sterling Audio as the ST66. Most specifications are identical, although the ST66 has a list price 1/3 lower than the GT66.
GT66 photos courtesy Archie Anderson
Permalink: Groove Tubes GT66
|Pickup Patterns||Pads & Filters|
(25 mV/Pa; 20 - 20,000 Hz)
| Diaphragm diameter: 25mm
Capsule diameter: 32mm
Diaphragm gauge: 3 microns
|200 Ohms (Low)||Max SPL: 140 dB
Self-noise: 23.0 dB(A)
|680g (23.99oz)||190mm (7.48'')||64mm (2.52'')||
Did we get anything wrong on this page? Please let us know!