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WHY DO YOU USE VACUUM TUBES? AREN'T THEY OBSOLETE? HASN'T MANKIND ADVANCED BEYOND THIS? 

 

Despite advances in many other fields, the truth is that since the demise of the vacuum tube industry mankind has taken a bit of a step backwards. Tubes are not obsolete for the purpose of high end studio condenser microphones, but they are for large scale production of TV sets and radios. We are not aware of any FET mic which sounds similar to a tube mic, so once a device is invented that behaves in a similar manner to a good tube microphone we will be early adapters of that technology.

 

 

IF TUBE MICS ARE SO GREAT, WHY DO YOU MAKE FET MICS?

 

Sometimes FET mics have higher SPL capabilities than tube mics, or a desirable sonic signature, they may be more portable or convenient without their need for an external psu, or simply cost less than a similar tube model.

 

 

WHY DON'T YOU MAKE TRANSFORMERLESS MICS?

 

While we currently do not manufacture any of these mics, they might appear in the future, as transformerless mics can not only reduce cost though elimination of the transformer, they can provide ideal performance for certain music and other recording situations. Some of the measurement mics we use in our anechoic chamber, for example, are transformerless.

 

 

SOME OTHER MANUFACTURERS SAY TRANSFORMLESS MICS ARE VASTLY SUPERIOR TO TRANSFORMER MICS. IS THAT TRUE?

 

Generally this is a ploy to sell a microphone with the same image as a classic transformered mic with the reduced manufacturing cost of the transformerless mic. But this does not mean that there are NO applications for a trnsformerless mic, some musics and instruments (and combinations thereof), as well as extreme remote recording may benefit from a mic idealized without a transformer. This is generally NOT true for the most common studio condenser mic application, vocals. As there is no such thing as an ideal microphone which meets all requirements for all conditions at the same time, the claim that either transformerless or transformered being superior is simply not true, it depends upon the application.

 

 

WHAT IS FIXED BIAS?

 

We refer to this term in reference to use in vacuum tubes, where the most common other option is “self” or “cathode” bias. We make microphones with both systems. Fixed bias fixes the grid or cathode to a fixed voltage to set the operating point of the tube, and requires tube selection at the factory. Self bias allows the tube to find it's own bias point, and self compensates over the life of the tube. Each system contributes to the sound of a microphone. Fixed bias was found in the vintage U47/48, M49/50 (rarely found unmodified to self bias these days), U67 and C12 mics, while self bias was found in vintage M269's, M49b, M49/50c, and ela M251 mics.

 

 

WHAT IS THE DIFFERENCE BETWEEN CLASSIC TUBE MIC CIRCUITS AND MODERN HYBRID CIRCUITS?

 

Most modern hybrid (tube/solid state combinations) use excessive amounts of negative feedback on the tube circuit coupled with harsh sounding solid state transformer substitutes which often have excessive gain and no optimization of system frequency response. Vintage mics have become the standard in high level studios and recordings as they provide a balanced sound which is easier and more flattering to work with.

 

 

WHY DON'T YOU USE MODERN, REGULATED POWER SUPPLY UNITS?

 

Most classic mics were made with unregulated supplies and using a modern regulated supply changes the sound of the mic away from the original vintage sound. In simple circuits like the ones we use, and as used in ALL vintage mics, the mic is really a power supply modulator and as such the psu is part of the audio circuit, not separate from it. Thus any changes to psu topology report themselves as changes tin the sound of the mic. We do have some custom applications were regulated supplies are used, but there is no expectation of vintage sound from these mics.

 

 

SOME OTHER MANUFACTURERS SAY DISTORTION IS THE PRIMARY REASON TUBE MICS SOUND DIFFERENT, AND THAT DISTORTION IS (THANKFULLY) ELIMINATED IN THEIR TRANSPARENT MICS; IS THAT TRUE?

 

No, it is not true, for if it were, the human ability to perceive a difference between 0.05% and 0.005% THD at normal spoken word volume would exist.

 

 

WHY DON'T YOU USE THE TERM "TRANSPARENT"?

 

Once the motion of air molecules (ie: music or sound) has been converted to electrons, there is no such thing as “transparent”, as everything that will be, or can be used in the transmission process from recording to playback has an effect on the resultant sound, therefore “transparency” is either an illusion or effective marketing buzzword. Omni measurement mics, which are great at their intended purpose, are often touted as “transparent”, when in fact they simply provide a snapshot of one point in space at one time, which is not necessarily related to artistic or other informational communication.

 

 

CAN YOU RECOMMEND SOME OTHER RESOURCES TO LEARN ABOUT MICROPHONES?

 

Audio Cyclopedia by Howard Tremaine 1969

Microphones Technology and Technique by John Borwick 1990

AES Microphones an Anthology vol 1-27 1979

 

 

WHAT SIZE CAPSULES DO YOU USE?

 

All of our large diaphragm capsules are 1” OAD (34mm), the thickness of which varies by model. Our custom model 50 uses a 1/2” capsule.

 

 

WHAT KIND OF CAPSULES DO YOU USE?

 

We use our versions of classic CK-12's, kk47's, kk67's, KHE's, and our own Bock/Cardas elliptical capsule.

 

 

WHY DO YOU USE 6 MICRON DIAPHRAGMS?

 

Six micron has proved to be the best compromise between reliability and frequency response for large diameter capsules.

 

 

WHY DON'T YOU USE 3 MICRON OR LESS DIAPHRAGMS?

 

Three micron and less has proven to be unreliable in large diaphragm capsules, and have an unnatural high frequency response, even when the backplate is compensated with additional damping holes. This is not to say thinner membranes have no use at all, as they have been successfully used in smaller diaphragm mics.

 

 

      

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