by Flip Michaels
Can digital be cloned? Most definitely! Digital audio can be copied from one machine to another without ever losing sound quality. It's just numbers being recorded. You can record copies of these numbers without affecting the voltages those numbers represent. The only reason too many generations could cause problems would be if the data got screwed up (somehow). But, most digital recorders have sophisticated error correction schemes to solve this problem.
How is it done? You make digital-to-digital transfers through a separate hole -- you wouldn't use the analog ins/outs for this purpose. Instead, there are two common digital audio standard formats:
S/PDIF (Sony/Philips Digital Interface Format) is the "consumer" digital interface, with both hardware and software specifications. The digital audio is transmitted serially, alternating between the left and right channels, with each sample fitting into a 32-bit "sub-frame" (which is similar to a big word). It includes: synchronization information, the audio itself, some housekeeping and identifying data, and spare bits that can carry data like format info (pro, consumer, stereo, mono). This format uses RCA plugs.
AES/EBU, the "professional" digital interface also has both hardware and software specs. AES/EBU requires balanced lines, a much higher voltage level, and professional cables (XLR or coaxial). Unfortunately, although the language of AES/EBU is similar to S/PDIF, there are enough differences to render them incompatible. (But, they do both sound identical. That is, so the receiving device doesn't get confused. Moreover, digital recorders will generally have a switch to select analog or digital input.)
Should I pay high dollar for a "studio quality" digital recorder when there are lots of truly inexpensive cards you can just plug into an IBM compatible computer? You get what you pay for. Those "inexpensive" cards don't necessarily sound all that great, nor do they all have the extensive features and editing capabilities you'll need. Also, be aware of the MIDI claim. The cards might have MIDI out but not MIDI in, or they might be compatible with standard sequencing software only. Basically, if you're gonna go cheap, just do your homework first. More on DIG IT AL next month!
"They won't take the tape!" Tommy Noles, Production Director, KBMX-FM, Osage Beach, MO.
After researching and writing January's Cheat Sheet, I received a call from fellow RAP member Tommy Noles regarding a donation to ACT! (Alternative Community Training, Inc.): "We have 168 5-inch reels of tape! I'm sad to say that it's not the highest quality of tape, but there are no splices, and each has its own box. (Isn't that special!)"
As it turns out, KBMX-FM converted to CD in October. Tommy contacted ACT! only to find out that they now will only accept metal reels (not 1/4-inch tape). "I hope someone will take the stuff. I'd hate to just toss them in the dumpster."
In need of some work tape? Save some budget dollars and give Tommy a call...
Going to new lengths: Two major tape manufacturers have just expanded their DAT offerings. Sony will offer a 15-minute tape (for the first time) complementing their Pro DAT Plus line (now 15, 34, 48, 94, and 124 minute versions). BASF will also now offer a 15-minute length, rounding out their DAT Master line of 30, 60, 90 and 120 minute tapes. So whattaya think of DAT?!