Buying the Right Preamp


So, up to this point we’ve learned that your microphone takes sound waves (your voice) and converts them into an electrical signal. But unfortunately, the signal coming from your mic is too weak to be recorded. We need a device to amplify the signal first. This is where the preamplifier, or preamp, comes in. You’ve got a number of options, from stand-alone mic preamp to mixing board to full-blown audio interface, and we’ll talk about each of these.

Caution 

No matter what kind of preamp you choose, there’s one particular feature that’s an absolute must if you’re using a condenser microphone. Since condenser mics require external power in order to function, your preamp is going to need an option called phantom power. Basically, all this means is that the preamp is equipped to deliver power to the microphone so that it can work. If you’ve got no phantom power, then that $500 condenser mic you just bought will give you $0 of actual use, except maybe as a paperweight.

Analog Preamps

A stand-alone preamp, also known as an analog preamp, has but one job: to take an XLR input from your microphone, amplify the signal up to what is known as line level, and then pass it on as cleanly as possible. It’s called an analog preamp because it doesn’t digitize the sound - it leaves that task up to your PC’s sound card. Simply attach a cable from the preamp’s output port to the microphone jack of your card.

Like anything else, analog preamps come in all price ranges ($50 to $2,000). Here are a few solid choices for your perusal:

  • At a mere $50, the ART Tube MP preamp is an excellent choice. Rather than using a solid-state amplifier, it makes use of vacuum tubes to amplify the sound, which many professionals claim gives the mic a “warmer” sound. Another good example of a vacuum tube preamp is the PreSonus BlueTube DP Stereo Tube preamp, which provides both solid-state and tube amplifiers, letting you set the level of tube amplification (and hence the warmth). It can be had for about $200.

  • One of the cleanest preamps you can get for under five hundred bucks is the AudioBuddy by M-Audio. At just $80, this little workhorse provides excellent low-noise amplification. I used one for a couple of years when first starting out, and it’s the starter preamp I typically recommend to my Camtasia Studio training clients.

  • On the higher end, the Focusrite Platinum Voicemaster Pro ($650) throws in a lot of bells and whistles like no-latency monitoring, vintage harmonics, and voice-optimized EQ. It’s an excellent choice, but may be overkill for most users.

If you’re working with a lot of other audio inputs (such as musical instruments), then a full-fledged mixing board might suit your needs better. These boards include a boatload of microphone and instrument inputs, and most can provide phantom power to your condenser mic. All those knobs and buttons are also really impressive looking, so if you’ve got a lot of customers or clients swinging by your office, it can make a nice trophy piece. Be wary, though. I’ve found that the actual microphone preamps in most mixers can’t compare to stand-alone units unless you go really high-end.

Audio Interface Devices

Analog preamps can be had rather inexpensively while still providing clean sound, but there is still a small problem, friends. No matter how nice the signal coming from your preamp may be, once it leaves the preamp, that beautiful signal is now at the mercy of your (probably) factory-installed, OEM, cheaporific sound card. By relying on your sound card to digitize the signal for recording, you’re introducing a new link in the chain of your audio quality, and probably the weakest one. Fortunately, there’s a wonderful invention created just for computer-based recording, specifically the digital preamp, or audio interface.

An audio interface acts like a preamp and sound card in one. It comes in two styles: internal and external. Internal interfaces plug into one of your computer’s free PCI slots, and generally come equipped with a series of cables, and sometimes even some sort of external box, for connecting your XLR cables and other inputs. Be sure to read the fine print prior to buying an internal card, though. Many do not include phantom power as part of the package. Additionally, these cards take up one of your precious PCI slots (thus requiring you to open your PC for installation, which is something to think about if you’re squeamish about that stuff), and if your main computer goes on the fritz, so does your ability to record.

A much handier way of amplifying and digitizing your sound lies in external audio interfaces. These little miracle boxes have all the XLR and instrument inputs you need to take your content, amplify it, digitize it, and then pass it on via Firewire or USB to your computer, where Camtasia Studio can then record it. No sound card is required for digitization, because technically speaking, the audio interface is a sound card, and it’s one that typically comes with an infinitely more advanced ADC (that’s analog-to-digital converter for the acronym-challenged among you). The average sound card can only handle 16-bit, 44.1 kHz, whereas many external audio interfaces can record with 24-bit, 96 kHz fidelity. To take advantage of this, you’ll need a more advanced software solution for your audio than the Camtasia Audio Editor (Adobe Audition and Sony Vegas are two such choices).

Now, audio interfaces don’t merely consist of a box - there’s a software component as well. Each manufacturer has its own proprietary solution, and some are better than others. Before making your purchase, be sure to check reviews of both the hardware and software as well as read the company’s fine print to determine if all of it is compatible with your PC. No reason to fret, though - most companies do a pretty respectable job of keeping their basic audio drivers updated, and some even throw in some audio recording and mixing software to round things out. For those looking for a heftier software package than Camtasia Studio for recording their audio, this can be a pretty compelling value-add. Or it can be junk. It all depends on the capabilities of the software and your own needs, so do your homework.

Of course, I am prepared to help point you in the right direction. Here are a few recommended audio interface devices you might want to check out:

  • PreSonus Firebox. I’ve been using this little $300 audio interface as my main preamp for about a year now, and I can’t say enough good things about it. It sports a built-in software-based mixer, and is also bundled with Cubase LE recorder/mixer software. Additionally, it includes a headphone jack for low-latency monitoring. The Firebox comes with all needed cables and even a power supply, though technically you don’t need it - it can draw power right from your Firewire card.

  • M-Audio Firewire 410. This is another audio interface in the $300 range. It offers two headphone out jacks with independent level controls, can crank 192 kHz output, and includes the Maximum Audio Tools software package.

  • For the USB side of things, the M-Audio MobilePre USB Interface offers 16-bit/48 kHz output, two balanced XLR inputs, and is powered by a USB 1.1 connection, all for about $150.

  • For about $100 more, the Edirol UA-25 offers full 24-bit/96 kHz recording. Also completely USB-powered.

All the above units offer phantom power, so owners of condenser mics can relax with the knowledge that their microphones will work with any of these.

USB Microphones

If your head is swimming right now with all the cost and complexity of having to pick up a good mic, preamp, and analog-to-digital converter (not to mention all the cables you’ll need to connect them together), there is a simpler option I should let you know about. I speak of the USB microphone. Imagine, if you will, a preamp and digitizer built right into the mic. All you have to do is jack it right into a standard USB port, and that’s about as complicated as it gets on the hardware side. On the software end of things, the same caveats apply here as with the audio interface. Prior to purchase, make sure that the included software is compatible with your operating system, and always make sure you have the latest update to get the best stability and functionality. Voilà. You have a complete recording solution in one unit.

These microphones represent the ultimate in portability and convenience, and from the few units I’ve been able to test, they don’t sound too bad, either. Best of all, the cost is pretty palatable, especially considering that everything you need is built in. This is a relatively new product type, and as such, the playing field doesn’t yet have many contenders. But there are a few standouts. Here are five units you might want to consider:

  • Samson C01U. This was one of the first available USB mics, and at $70, probably the least expensive. TechSmith actually sells these from its web site as a Camtasia Studio accessory. Sound quality is decent, but its comparatively high noise floor and lack of ability to monitor input in real time makes it a difficult unit to heartily recommend.

  • While not yet available at the time of this writing, Samson did just announce a new USB mic, the G-Track, that offers the unique ability to mix tracks directly from the mic. It sports both an instrument jack and (praises be…) a headphone jack for low-latency monitoring of your input. It is scheduled to ship May 2007 with an estimated retail cost of around $400.

  • Marshall Electronics MXL.006. Pricing in at the $130 mark, this cardioid mic sports a three-position attenuator switch to adjust the gain directly from the mic.

  • Blue Snowball. This mic’s spherical shape is more reminiscent of a webcam than a microphone. Available for around $100, it features two cardioid (one for voice, one for instrument) and one omnidirectional pickup pattern. A desktop tripod and shock mount are available separately.

  • RØDE Podcaster. A newly available addition to Aussie manufacturer RØDE’s already excellent product line famous for low self-noise. This is the only mic available right now that offers a headphone jack for low-latency monitoring. As a special value-add, RØDE created a special podcast hosting service just for Podcaster owners. This mic can be had for only $150, which seals it as my top recommendation as an outstanding bargain.

All of the above mics support various flavors of Windows and Macintosh. Be sure to read the fine print carefully to make sure that your OS is supported.




Camtasia Studio 4. The Definitive Guide
Camtasia Studio 4: The Definitive Guide (Wordware Applications Library)
ISBN: 1598220373
EAN: 2147483647
Year: 2007
Pages: 146
Authors: Daniel Park

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