Hi Fidelity: Flat pre-amps change vinyl-to-digital equation

By Joyce Greenholdt

The debate over the relative merits of sound reproduced from a CD vs. a vinyl record hasn’t let up since the new medium was introduced in the ’80s. Because many music-lovers prefer the sound they get from vinyl, the older form has made a comeback. Still, CDs offer some advantages, such as portability, but those with large vinyl collections may balk at buying those albums all over again in CD format.

In response, any number of companies have developed hardware units or computer software aimed at allowing music collectors to transfer their vinyl or taped recordings to CDs or MP3s. One such company is Tracer Technologies, based in Pennsylvania, which offers software for audio restoration, noise reduction, enhancement and even audio forensics. The company also sells audio equipment and supplies and a line of instructional DVDs.

Among the more unusual pieces of hardware offered on the company’s website, www.tracertek.com, are flat phono preamps designed specifically for transferring music from vinyl to a computer. These preamps differ from the normal stereo component in that they do not impose the standard RIAA equalization curve to the audio coming from a vinyl record. Why would this matter when transferring vinyl audio to a digital format?

You can get the answer on Tracer’s Web site, in “excruciating detail,” at http://www.tracertek.com/ccp0-display/newway.html. The short form, according to the Tracer staff, is that the company believes this is part of a new way of transferring the sound from vinyl to get the best possible results. Their reasoning is based on several assumptions:

• Individual components of stereo equipment all produce varying levels of noise, and even two examples of the same component may differ slightly because of manufacturing tolerances.

• For that matter, different copies of the same record may sound different.

• The area in which the stereo equipment is set up will also effect the sound that the listener hears.

• Personal tastes will also influence the final result. As the site points out, “Most of us lose some of our high-frequency hearing as we age. We may no longer get the full impact of a sizzling cymbal hit even if our stereos are playing it just the way it was intended — which is highly unlikely. Also, all of us have personal preferences as to what sounds good. You can tell when someone likes a lot of bass when they share it with you from their cars when you are six lanes away.”

Taking all these factors into account, the company concluded that the best way to transfer music was to make the audio signal that’s sent to a computer’s sound card duplicate, as exactly as possible, the sound that is recorded on the original vinyl.

When music is transferred from a master recording tape to a vinyl pressing, the sound is laid down in spiral grooves on the disk. Loud bass tones require wider grooves, which take up more space on the record, which means less music can be recorded on an album size. To get around this, the record companies reduce the bass that’s laid down on the vinyl — a normal stereo preamp restores that end of the spectrum when the record is played back.

On the high end, the enemy is noise. A record mastering machine uses a cutting element connected to an amplifier to translate the music into the grooves on a record. This amplifier generates noise, which sounds like hiss, due to the intrinsic nature of electronics. It can be reduced but not eliminated. Tiny imperfections in the master record and the final vinyl pressing also generate noise.

However, this electronic noise doesn’t vary much — so to compensate, the record companies pump up the high frequencies in the music to get a better signal-to-noise ratio — and when the record is played back, the stereo preamp decreases the high levels to undo the changes in the recording process.

A normal preamp, whether a separate component or integrated with the turntable, has a preset equalization curve set to the RIAA standard. But there can be variations in how that curve is applied between different preamps, due to manufacturing tolerances and other variables.

Running the audio signal from a vinyl LP through a flat preamp to a computer sound card allows someone using Tracer’s Audio Mentor or DC Seven restoration software to add the RIAA compensation curve via the more precise digital tools in the software. Then the listener can adjust the audio to get playback that sounds best on their equipment and to their ears.

Tracer’s Vice President of Marketing Jeff Klinedinst said that while audio transfers don’t require a top-of-the-line computer, the company does recommend the use of a 24-bit sound card, “but not for the reason you probably think. CD quality is just pretty darn good, and most humans will be very pleased with that level of quality. We ask for 24 bit because it gives the computer more bits of information from which to set the filters and clean the audio. True, they do require more hard disk space, but in a world where you can buy a terabyte of hard disk for less than 100 bucks … does that really matter anymore? A large portion of your readers have sound cards that came bundled with their computers. These are by no means perfect, but they provide adequate quality. Audiophile customers may want to upgrade to better choices.”

Tracer’s Audio Mentor software is designed for people with smaller collections and for beginners. Many of the noise filters and enhancement tools are more automated, and the program can walk beginners through the process of transferring their audio step-by-step, starting with hooking up their stereo equipment into their computer, through the transfer and enhancement process, down to turning out a finished CD or MP3 file at the end.

The DC Seven software is more advanced and more customizable. “Think of it like a toolbox,” Klinedinst said. “With Mentor, you have all of the basic tools you need — easy to use, but powerful in their own right. DC Seven is the big toolbox you keep in the basement that has a tool for any eventuality and can fix just about anything.”

Tracer does offer a special upgrade price on DC Seven for customers who start out with Audio Mentor and then want to move on to the more powerful package, Kline-dinst added. He also emphasized Tracer’s emphasis on customer service. “Generally, our customers have record collections … which makes them a certain age. This was a generation that didn’t grow up with computers in their right hands. We take that into account. Unlike many Internet companies, we answer our phone and e-mails and provide free technical support to our customers. We encourage both customers and interested people to call us. We’re happy to answer their questions and put their minds at ease — prior to ever selling them anything.

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