Groove Tubes MD1a Tube Mic Pair - Price drop!
Posted: Tue Nov 11, 2014 7:08 pm
Mics are in great physical and working condition.
Here's what SOS had to say:
Groove Tubes are a company best known to guitar players for their matched sets of valves, but they also produce valve amplifiers, outboard processors and microphones. Their MD1, 2 and 3 mics have enjoyed success for a number of years, but now they've been given new amplifier circuitry to further reduce noise, increase headroom and lower total harmonic distortion. Though the same capsules are used as in the original models, a new suspension system has been added to reduce handling noise -- some performers are actually taking these mics out on the road.
Because these are valve mics, you can't run them from regular phantom power sources, so Groove Tubes produce the mains-powered PS2A power supply, which can power any two mics (and some other Groove Tubes products) simultaneously. The mic connects to the power supply via a locking 9-way D connector, and while I have to agree with those people who find these a trifle ugly, they do have the advantage of being inexpensive and easy to obtain, so if you do need to repair or replace a cable the bits aren't hard to come by.
MD1a
Physically identical to the original MD1, the MD1a is a fixed cardioid pattern mic featuring a fairly large diameter capsule with a 10-micron diaphragm; it can handle SPLs up to 137dB without recourse to cissy pads -- and there's no LF roll-off switch either. The revised valve preamp circuitry, based on a 12AT7 dual triode, is designed for lower noise and lower distortion, but it also extends the high-frequency response of the microphone. Unlike most cardioid mics, it doesn't seem to have a deliberate LF roll-off built in, so you have to use a pop shield when recording vocals to prevent popping. There are no presence peaks in the response, and though it has its share of bumps and dips, the nominal response is flat from 40Hz-18kHz within 4dB. The equivalent input noise is 20dB SPL and the sensitivity is 50.1mV/Pa. A transformer output stage provides a low 30(omega) output impedance, with a maximum output level of 1.7V RMS at 1% distortion.
Cosmetically, the MD1a is seriously chunky, with its heavy plated brass case and 'bullet-hole' ventilation. The tube shines out through a cut-out GT logo, and the singer performs into the side with the cardioid symbol. An optional heavy-duty shock mount is available, but otherwise the mic can be screwed directly to the top of a conventional mic stand by means of a threaded insert in the base. An equally tough metal grille protects the capsule.
Subjectively, the mic sounds very similar to its predecessor, though there may be just a hint more air around the top end. I never experienced problems with noise with the older model, not because these were particularly quiet mics, but because microphones of this type are invariably used at close range. This newer version is a little quieter than its predecessors, but on paper the biggest difference is the reduction in distortion. Fortunately, this doesn't seem to have compromised the mic's warm, punchy sound and, like the original, the MD1a seems to combine the detail of a capacitor mic with the sort of mid-range punch normally associated with a good dynamic model. The low end is also nicely wide and warm, and when the mic is used close up the sound takes on a very rich, intimate character.
Sale includes two Model 1a mics, one PS2A power supply (that will power both mics), two nine-pin cables and one power cable.
$1000
Please let me know if you have any questions.
Here's what SOS had to say:
Groove Tubes are a company best known to guitar players for their matched sets of valves, but they also produce valve amplifiers, outboard processors and microphones. Their MD1, 2 and 3 mics have enjoyed success for a number of years, but now they've been given new amplifier circuitry to further reduce noise, increase headroom and lower total harmonic distortion. Though the same capsules are used as in the original models, a new suspension system has been added to reduce handling noise -- some performers are actually taking these mics out on the road.
Because these are valve mics, you can't run them from regular phantom power sources, so Groove Tubes produce the mains-powered PS2A power supply, which can power any two mics (and some other Groove Tubes products) simultaneously. The mic connects to the power supply via a locking 9-way D connector, and while I have to agree with those people who find these a trifle ugly, they do have the advantage of being inexpensive and easy to obtain, so if you do need to repair or replace a cable the bits aren't hard to come by.
MD1a
Physically identical to the original MD1, the MD1a is a fixed cardioid pattern mic featuring a fairly large diameter capsule with a 10-micron diaphragm; it can handle SPLs up to 137dB without recourse to cissy pads -- and there's no LF roll-off switch either. The revised valve preamp circuitry, based on a 12AT7 dual triode, is designed for lower noise and lower distortion, but it also extends the high-frequency response of the microphone. Unlike most cardioid mics, it doesn't seem to have a deliberate LF roll-off built in, so you have to use a pop shield when recording vocals to prevent popping. There are no presence peaks in the response, and though it has its share of bumps and dips, the nominal response is flat from 40Hz-18kHz within 4dB. The equivalent input noise is 20dB SPL and the sensitivity is 50.1mV/Pa. A transformer output stage provides a low 30(omega) output impedance, with a maximum output level of 1.7V RMS at 1% distortion.
Cosmetically, the MD1a is seriously chunky, with its heavy plated brass case and 'bullet-hole' ventilation. The tube shines out through a cut-out GT logo, and the singer performs into the side with the cardioid symbol. An optional heavy-duty shock mount is available, but otherwise the mic can be screwed directly to the top of a conventional mic stand by means of a threaded insert in the base. An equally tough metal grille protects the capsule.
Subjectively, the mic sounds very similar to its predecessor, though there may be just a hint more air around the top end. I never experienced problems with noise with the older model, not because these were particularly quiet mics, but because microphones of this type are invariably used at close range. This newer version is a little quieter than its predecessors, but on paper the biggest difference is the reduction in distortion. Fortunately, this doesn't seem to have compromised the mic's warm, punchy sound and, like the original, the MD1a seems to combine the detail of a capacitor mic with the sort of mid-range punch normally associated with a good dynamic model. The low end is also nicely wide and warm, and when the mic is used close up the sound takes on a very rich, intimate character.
Sale includes two Model 1a mics, one PS2A power supply (that will power both mics), two nine-pin cables and one power cable.
$1000
Please let me know if you have any questions.
