still work.) The theory there is that the tube is used as a sort of processor to “warm” up the sound. The reality is that these are still solid state mics masquerading as tube mics as cheaply as possible.

Because of the physics behind tube operation, tube mics have classically been subject to certain physical restriction on the length of the cable between the microphone and power supply. As a result, tube mics are normally restricted to cable lengths of about 15 feet. This has sometimes required the use of solid state mics in scenarios such as drum overheads, remote recording or orchestral recording.

Solid state electronics

Solid state microphones cost significantly less to manufacture than tube mics. As such, they are found in the less expensive condenser mics on the market. (As stated earlier, some manufacturers put low-quality tubes in their solid state mics like an effects circuit in order to advertise products as being tube mics.)

In most solid state condensers, the key components are a series of op amps. All M-Audio mics employ FETs (field effect transistors) instead. Logic says that op amps should be preferable because they have lower measured amounts of THD. As discussed previously, while that difference in THD specs is measurable it is not audible in well-executed microphone applications. Op amps, however, can have much more dynamic distortion than FETs￿something you can hear. Moreover, many designs use multiple op amps to do the job of one FET. The difference is so profound that many people think that our solid state mics sound like most manufacturers￿ tube mics.

The Myth of Tube Warmth

There is a common myth that tubes are ￿warmer￿ sounding. It certainly can be said that cranking up a tube amp will make an electric guitar sound ￿warm, ￿fat￿ or ￿distorted. That scenario, however, is one in which distortion is desirable. On the other hand, distortion is the enemy of the engineer who is attempting to record a sound source faithfully and realistically. Here, you want accuracy and transparency rather than any coloration that might be described subjectively with a word like ￿warmth.￿ Fortunately, there are many types of tubes and related circuitry that result in comparatively transparent sound.

It has also been said that tubes warm up digital recordings.This implies that there is something inherently deficient in digital recording. While some purists will always make a case for analog over digital, the fact is that a vast number of todays pro recordings are made with digital technology such as M-Audio￿s 24-bit/96k Delta cards, USB and FireWire solutions.

Digital recording significantly increased the dynamic range, allowing us to better hear the dynamics of recorded material. As a result, people were quick to label digital recording as ￿cold,￿ when using solid state mics. When using a tube mic, everything suddenly sounded ￿warmer￿ by comparison. In actuality, digital recording simply gave us the means of hearing differences we didn￿t hear before (such as how tube output is dynamically truer than solid state).

Manufacturing Standards

There are quite a number of condenser microphones to choose from on the market today. Many look professional on the outside and, indeed, most will give you acceptable sound. However, the fact is that most companies engineer for profit. This guide was designed to help you think about what￿s inside those shiny cases￿and much of that comes down to manufacturing standards.

The story behind affordable matched pairs for stereo-miking

One of the factors that make a significant difference between amateur and professional recordings is the use of stereo miking techniques. Pro engineers have long relied on matched pairs of microphones to attain optimal results from stereo recording methods. Why a matched pair? You wouldn￿t consider monitoring with a mismatched pair of speakers, right? Similarly, you want the left and right mics ￿hearing￿ exactly the same way in order to achieve a balanced sound.

Choosing & Using Microphones

10

Page 10
Image 10
M-Audio Microphone manual Manufacturing Standards, Solid state electronics