Wednesday Apr 25

USB Phono Preamp

SAN FRANCISCO (8/18/11) – Parasound has introduced the Zphono•USB, a compact preamplifier for magnetic phonograph cartridges and line-level analog sources. Zphono•USB also adds an analog-to-digital converter with a USB port to transfer audio from vinyl LPs to digital media files.

You love your LPs, right? I sure love mine, not to mention a lot of 45s and 78s. I also love the convenience and portability of digitized music files. There are a lot of us who feel that way, but storing music from analog discs in digital form is considerably more of a challenge than ripping CD tracks to computer files.

With CDs, the music has already been encoded into bits and computer software excels at manipulating bits. In fact, at its most basic level that's all that any computer program does. It may look like it's helping balance your checkbook or send an email to Aunt Minnie or draw a picture or make a phone call, but it's really just messing around with memory bits, ones and zeros if you like.

LPs and other analog discs have grooves that emulate sounds waves, not bits. So to get them into digital form, you need some sort of electronic processing gear to help you out.

This is not a new concept. Records generally require special electronic treatment to play well with other sound sources. Magnetic phono cartridges, the only ones that caring listeners will use with their precious recordings, put out minuscule voltages compared to tuners, tape players, CD players, and other devices.

Those voltages need to be preamplified to bring them up to what's called line-level before they can coexist with their peers. A separate preamplifier or preamp circuitry in a receiver is needed to accomplish this. These days very few receivers have such circuitry so stand-along phono preamps are the rule for vinyl listeners. They take in that weak sister phono signal, boost it, apply some necessary equalization, and send it along to some inputs on a receiver.

Now, if you want to be able to send a phono signal to a computer in digital form, what better place to put the music digitizing stuff than into a phono preamplification component? And that's what Parasound did.

The company re-engineered its very capable and neatly compact Zphono preamplifier into a superbly flexible analog-to-digital command center. It has back panel inputs for not only magnetic phono cartridges, switchable for moving magnet and moving coil, the latter with two impedance settings. It also has inputs for two line level analog sources, let's say to dub cassette tapes or record from an FM tuner.

Slightly more arcane are an AC polarity reversing switch to combat possible hum pickup from the power line and a defeat switch for the RIAA equalization. That RIAA defeat affects only the signals at the USB port. Its expressed purpose is to allow users to choose to let their recording software provide that equalization. A more likely use would be to let the software provide non-RIAA equalization for early LPs and for 78s.

The front panel controls include a rumble-filter on/off button, the very important mono switch (more about mono a bit below), and a USB gain control. There's also a headphone jack and a power switch.

To get the digital data stream into your computer, the Zphono•USB uses (obviously) a USB port. There are also standard analog line outputs so you can listen to your records directly whether you're digitizing the music or not.

First of all, the Parasound Zphono•USB is a high-quality analog phono preamplifier engineered for the optimum in playback quality for vinyl LPs. Like its predecessor, the Zphono analog phono preamplifier, which continues in the line, Zphono•USB uses high quality parts and precision RIAA equalization to achieve extremely low levels of noise and distortion, and accurate frequency response.

Regarding mono, I have read that Windows Vista and 7 default to one-channel recording from external USB devices. Wikipedia says "if you are recording a stereo LP into a stereo Audacity track, only one channel of the LP will be transferred, and this will be duplicated in both channels of the track." I doubt that's the way it actually works. It's more likely that the two stereo channels are blended together for both Right and Left. In any case, you will need to change that default to get stereo recordings from stereo sources.

The Zphono•USB is not the first phono preamp with USB capabilities, but this one comes from an audio company with serious high-end, high-definition audio bonafides. I'd give it serious consideration.

Here's wrap-up from the Parasound press release:

The Parasound Zphono•USB is the newest of many Z-Series components, each of which is one rack-space high and only one half rack-space wide. These Z-Series products are popular as stand-alone components and they can be easily rack-mounted using optional inexpensive adaptors.

The Parasound Zphono•USB will be available in the first week of September with a manufacturer's suggested retail price of $350.