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Engineering Department
Welcome
to the Engineering Department...
So you'd like to restore some of your old vinyl albums and maybe burn custom CDs for yourself. Join others who have found new fun and enjoyment re-engineering the music they like best, done as a labor of love because our kind of music can't be purchased anymore...
This section is not meant to be a textbook on the subject but, rather, an introduction that will possibly save you some headaches and money. It's our goal to help you get up and running with minimum hassle and aggravation, and to help you produce something for yourself that you'll be pleased with once you're done.
Where To Buy -- There are many fine dealers on and off the Internet that offer the audio products you'll need to obtain professional results. Three that we've worked with are listed below:
Broadcasters General Store -- Don't be fooled by their name! Broadcasters General Store can fulfill your audio equipment, audio software and supplies needs at very competitive prices. Knowledgeable sales staff and excellent customer service.
Tracer Technologies offers a selection of sound cards, companion equipment and software. Their companion site, EnhancedAudio.com, provides restoration tips. Both sites offer free demo downloads.
audioXpress.com has an interesting collection of test CDs, including the Golden Ears Audio Eartraining Program, books, kits and other items.
AudioSold, Audiophile Auction Site -- Here's an auction website devoted only to audio equipment and associated items. If you're in the market to buy--or even sell--that "one of a kind" item, this could be a dream come true for you.
Audio
References -- Is TOSLINK the same as S/PDIF? What exactly is 5.1?
Not sure what dither means? Fortunately, there are a couple of excellent
references online that describe these and other elusive terms...
Pro Audio Reference, Dennis A. Bohn, Rane Corp. (a pro audio equipment manufacturer), updated semiannually
Dilettante's Dictionary, Sandy Lerner, Sono Luminus
Have you ever wondered about how analog audio becomes digital audio? Or the differences between sampling rate and bit depth? There's a great multimedia presentation that can be downloaded for free that explains these and other audio basics...
Short Course in Digital Audio, Syntrillium Software Corp. (makers of Cool Edit software products)
Curious about how to build a high-quality analog audio system? Although the guide below is written for pro audio engineers, it still offers a wealth of great information for the home recordist.
A Clean Audio Installation Guide, Allen H. Burdick, Benchmark Media Systems, Inc. (a pro audio equipment manufacturer)
Curing that Buzz -- Do you hear a buzz when you connect your computer or your cable TV box to your hi-fi system? We've found a guide that explains exactly what causes that annoying noise (it also describes how one of their products can safely fix the problem).
ISO-MAX® Troubleshooting Guide, Bill Whitlock, Jensen Transformers, Inc. (a manufacturer of audio transformers and audio/video isolators)
Sound Cards
--
For the best results, get a pro or a semi-pro sound card. There's an excellent site that discusses sound cards, their specifications and performance, and includes links to other sites. We recommend spending time reading before spending your money: PC AV Tech
If you decide to buy, be very careful about input and output levels. A standard level for home (consumer) equipment is often -10 dBV (0.316 Volts), whereas "pro" is +4 dBu (1.23 Volts) --
pro levels are 14 dB, or 0.91 Volts, higher than consumer levels. Consequently, you need to find a sound card that operates at -10 dBV, otherwise your recorded signal will be too low in level, and properly recorded material will be too loud and may cause distortion in your equipment. Many of the semi-pro cards operate at -10 dBV, and some of the pro cards are switchable between -10 dBV and +4 dBu.Getting the Most from Your LPs -- No doubt you want the very best for and from your treasured LP collection. Well, there’s help readily available: The LP Is Back!, by Audio Amateur Corporation, is now in its second printing. "From the pages of Audio Amateur magazine and other sources, absolutely everything the serious LP music collector needs to get the most out of both vintage records or the highest quality new pressings."
"Articles cover: cleaning discs; how to build a cleaning machine; calibrating and maintaining your tonearm and cartridge; and equipment that will improve the quality of long-play record listening."
You’ll find it on the audioXpress website at www.audioxpress.com.
Also available is the MJ Technical Disc No. 3, from MJ Magazine, Japan. "This two-LP set contains test signals, harp music, and instructions for checking and optimizing an LP system to get the most out of this analog technology. The extensive instructions include a discussion of the many issues involved in making the best of LP components--from stylus to cartridge to tonearm to turntable."
Production/Restoration Software -- Some really innovative people with too much time on their hands have written some really nifty software that is easy to use and which will produce knockout results in restoring audio. It need not be expensive, either.
Users of various brands have their favorites, and are passionate about
the software they like best. In short, most will allow you to effectively
remove record pops, decrease or completely remove hiss, filter hum and
noise at specific frequencies, adjust level, add equalization, decrease
distortion, and, well, pretty much make a nasty old recording into
something quite acceptable! Like anything else, using these products
effectively takes skill, which you will acquire as you "play"
with and learn the software and its capabilities. It's fun!
Some of the most popular seem to be Cool Edit, DC-Art, and DartPro. Results do seem to vary, and can depend on what you're trying to restore. Fortunately, most offer working demo versions so you can experiment with your songs before you buy. We've noted which are for the PC and Mac, and if it is a "plug-in" that requires a "host" program.
from the manufacturer "quickly removes hissing, crackling and scratches from old recordings and makes it easy to add custom effects, record Internet radio or burn CDs")
- Syntrillium Software -- Cool Edit 2000 (PC), Cool Edit Pro (PC)
ClickFix -- Click and pop filter plug-in for Cool Edit 2000 and Cool Edit Pro (PC)
MAGIX -- Audio Cleaning Lab 2004 (
Ponnuchamy -- FlexiMusic Wave Editor is described by the manufacturer as an "Easy to use MP3 audio wave editor. It is inexpensive but has all the features of the others."
Algorithmix -- Sound Laundry (from the manufacturer "a set of high-end, easy-to-use software modules intended for cleaning and mastering noisy, scratchy recordings, especially old vinyl and 78's records, as well as tapes or cassettes")
Steinberg -- Clean! (PC), Clean! plus (v3.0 includes a USB phono preamp) (PC), DeClicker (plug-in) (PC), DeNoiser (plug-in) (PC)
Diamond Cut Productions -- DC-Art Millennium (PC), DC-Art Live (PC)
Dartech -- DART Pro 98 (PC), DART Pro 32 (PC)
Arboretum Systems -- Ray Gun (PC & Mac), Restoration-NR (PC plug-in), Ionizer (Mac)
SEK'D -- Red Roaster (PC), Declicker (plug-in for Red Roaster & Samplitude) (PC)
Digidesign -- Pro Tools (PC & Mac). Be sure to check out Pro Tools FREE at the Digi Store (PC & Mac), which is free.
MTU -- DNoise (plug-in) (PC)
GoldWave -- GoldWave (PC)
CEDAR --
We've discovered that you must use a high quality phono cartridge and preamp, and the preamp must be properly matched to your phono cartridge (technically speaking, the preamp must present the proper resistive and capacitive load to the phono cartridge). This may sound a little complicated, but it's worth investigating. You won't get optimum results from your tick/pop removal software without a precise image being captured from the record (and that can't be done with poor equipment).
Like production/restoration software, users quickly become attached to their "favorite" program. These are some of the popular ones:
DART CD-Recorder (PC)
Roxio -- Easy CD Creator (PC), Soundstream (PC), Toast (Mac), Jam (Mac)
Intimidated by the Restoration Process? --
Are you confused about which software to use and how to do it? Well, don’t be intimidated! You can have hours of fun and produce some spectacular results with a little practice. Preserving
the Music: Recording Your Vinyl LP Albums onto CDs,
by Bob
Cherry
LP
to CD conversion: Music to your ears,
by Matthew Moore
Blaze Audio offers easy, step-by-step instructions that includes connecting the equipment, setting levels, recording and editing, and burning the CD. In a short tutorial, they show just how simple the process can be.
The Audio-Restoration website, operated by respected recording engineer Graham Newton, describes the processes he uses to restore analog recordings. He also provides tips and links to important resources.
Allen Reny from France has put together an excellent website that deals with the subject of vinyl restoration and CD burning. He goes through the steps one by one with detailed instructions, using Cool Edit 2000 software. He even includes sound files with before and after comparisons of audio quality. Whatever method you ultimately choose, you owe it to yourself to read through this excellent site and learn Allen’s techniques.
(We've had a few intermittent problems connecting with this site, but it's worth the effort. If you don't reach it using the link above, try his mirror site.)
Finally, if you'd just rather not do it yourself, there are many services that will transfer your vinyl to CD for you. We have not used any of these firms ourselves and therefore cannot specifically recommend any particular service to you. (This list will be expanded as we learn of other companies).
CD Recorders
-- "Consumer"
audio CD recorders--like those from Philips, Pioneer and Harmon
Kardon--are similar to cassette recorders. You connect them to your stereo system and record
CDs. If you are thinking about buying one, consider a few facts...
- Since you must use special Audio CD-Rs that cost more--because of a built-in licensing fee--you'll miss all of those great computer CD-R sales.
- You can't edit the song. If you're trying to remove a song from a live recording, you'll find it difficult to do "on the fly," and you only have one chance to get it right.
- If you start recording at the wrong time, you can wind up with either a big gap before the song, or missing its beginning. Again, you have one chance to get it right or you've just made a dandy coaster.
Still, CD Recorders are great devices. But if you have a PC, you can often add what you need for about the same cost--or maybe even less--and have a lot more flexibility.
CD-R "Sound" -- Many people believe that different brands of CD-Rs sound "different," and that a replicated (manufactured) CD sounds "different" when compared to the CD-R master from which it was created. Just how "different" CD-Rs sound--or what that elusive "difference" is--hasn't been precisely described or quantified.
Certainly CD-R quality plays a role. Using a Digital Recordings DEDpro Digital Error Detector, we "informally" tested a few CD-R brands using the same burner and player. Several Verbatim (dark blue and light green) and Taiyo Yuden CD-Rs tested error free; one EMTEC CD-R Master Ceramic Plated was error free, another had two errors; while a few "budget" brands exhibited hundreds of errors on each disc. The few replicated discs we tested were either free of errors, or only a few errors were detected.
Friend and frequent contributor Derek Au pointed us to some software that will perform basic CD-R media integrity tests and identify who actually manufactured the disc: Nero CD Speed.
"Nero CD Speed is a benchmark which can test the performance of CD-ROM drives, DVD-ROM drives and recorders." However, the three functions we're excited about are: CD Quality Test, ScanDisc and CD-R Info.
According to CD Speed’s documentation:
"The CD Quality Test scans the disc for errors and shows the read speed.
"- Compare the recovery strategy of different drives when a low quality or damaged CD is used.
"- Check the quality of the CD(-R/W) media
"- If you have a CD recorder, you can check if the data on the CD-R(W) is written correctly but for this purpose the ScanDisc function is better suited.""ScanDisc is a function which will show you the quality of a disc. The test consists of two parts, the File Test which simply reads all files on the disc and reports all errors. This test can also be used for benchmarking to give you an idea on how well the drive performs with for example software installing. The Surface Scan checks the quality of each sector and shows the results in a graph."
"CD-R Info shows important information of a CD-R or CD-RW disc.
Company name of the disc manufacturer. This is not the brand name.
"Manufacturer:
"Code: Each company has a different code.
"Disc Type: CD-R or CD-RW.
"Usage: General or Audio. Only Audio CD-R(W)'s can be used in stand-alone cd recorders.
"Recording Layer: Type of recording layer.
"Recording Speed: Minimum and maximum speed at which the disc can be written. This information is only available with CD-RW's.
"Capacity: Blank capacity in MSF (Minutes:Seconds.Frames) and MB (MegaByte).
"Additional Capacity: This field shows whether the disc has a capacity higher than 80 minutes. This information is not available with all high capacity discs.
"Overburn Capacity: Shows the maximum available capacity. This information is retrieved from the database of the Overburning Test."
Several leading archivists favor Mitsui Gold CD-Rs. And even though each manufacturer has their own story to tell, Mitsui does offer some compelling reasons why their discs are ideal for audio...
-- Why Mitsui CD-R for Music?)Excerpts from Why Mitsui CD-R for Music?
When you "burn" a CD-R, your writer creates "pits" in the dye layer that make up the 0's and 1's for digital recording. Mitsui's Phthalocyanine dye reacts more quickly to the writing laser than other dyes. Because our dye reacts in a "burst" mode instead of a "melt" mode as with other dyes, sharper pit edges are created... These sharper edges are easier for CD players to read, so more faithful sound reproduction is possible.
Mitsui CD-R exhibits extremely consistent signal performance across the entire CD. Because of Mitsui's attention to detail, our molding process results in discs that are flatter than the competition.
Mitsui CD-R has the highest reflectivity in the industry, which improves the accuracy of the player read-back.
Because our dye formulation has remained unchanged for over 5 years, the drive manufacturers know what to expect when designing CD drives. That's why our media works in any type of drive or player. (Our competitors need to change their dye formulations to accommodate different writing speeds. Other additives are used to improve resistance to UV light and heat).
(Read the entire story
Other technical information is available at Mitsui Advanced Media and Mitsui CDR-Store.com.
Some experts also believe that burn speed is important. Regardless of the drive's capabilities, one theory suggests that no audio CD should be burned faster than 4x.
Considered less often is the CD-RW recorder itself. Yamaha, for example, has developed the Audio Master Quality Enhancement System which is said to improve audio quality. According to Yamaha:
This exclusive new Yamaha feature is designed to guarantee the best possible audio recording quality on conventional 74 or 80-minute CD-R discs. When Audio Master Recording Mode is enabled, the system widens the lands and the pits, significantly reducing jitter created during CD-R recording, improving audio and music recording quality to a level rivaling professionally prepared music CDs.
But there is a penalty: 63 minutes of recorded audio instead of 74 on a 650 MB disc, and 68 minutes instead of 80 on 700 MB. Tom's Hardware Guide discusses Audio Master Quality. Also visit the Yamaha website for information on the CRW3200 series of CD-RW recorders.
Needless to say, this subject remains controversial. And while some scientific data exists, there doesn't appear to be a conclusive answer...yet. In the meantime, Andy McFadden's CD-Recordable FAQ provides some guidance that may help you reach your own decision.
Keep in mind, though, that this debate may not be resolved anytime soon.
Labeling CD-Rs -- Are you potentially damaging your precious CD-R archival media by how you label it? If you're using the wrong marker or an adhesive label, maybe your are.
Some inks, especially those that are solvent-based, can permeate the disc surface and damage either the reflective or dye layer (Media Sciences presents some very interesting test results here). Markers said to be "safe" are available...
Maxell DiscWriter® Permanent Markers are described as "Safe, non-toxic, non-alcohol based, water resistant." Available in four colors.
According to TDK, its "CD Mark pen has been thoroughly tested and approved for safe use on all recordable CDs." Choose from four colors.
Available from Apogee is a "special CD-R Pen [that] makes writing on the disc safer." Black only.
Despite these specially developed markers, some advocates still believe the only safe area for labeling is the clear center ring.
It may also be wise to use
stick-on labels cautiously. The American National Standards Institute
("ANSI," an organization that develops standard practices) IT-9 committee
recommends that stick-on labels not be used for long term storage
because some adhesives "outgas" over time, which can adversely
impact the disc. Further, labels can cause the disc to spin out of
balance, resulting in reading and tracking problems, including increased
jitter. The Optical Storage Technology Association provides a great deal
of information in its paper CD-R
and CD-RW Questions and Answers.
How CDs Are Made
-- Ever wonder how CDs are made? Cinram, a large manufacturer of
CDs, DVDs, and audio and video cassettes, tells
how--step-by-step--in a fascinating White Paper titled Plant
Tour of How Compact Discs are Made.
MP3 Quality -- There is considerable
confusion regarding the difference between MP3 audio files and WAV audio
files. We thought that a short discussion might help you understand the
differences and where each type is applicable. We'll tell you about
streaming audio, too. MP3 is a "lossy" process--it discards parts of the music
that it thinks you can't hear. Its decisions are based on very complicated
algorithms that experts have developed over time. However, what it thinks
you can't hear and what you actually can't hear are sometimes quite different. Encoding songs at 128 Kbps, the most common bitrate especially on the
Web, tends to cause high frequency dulling--some of the high
frequency "sparkle" is permanently lost. It usually isn't
objectionable, but it is noticeable especially when you compare it to the
original. MP3 encoding, though, does allow you to store a large number of songs
in a small amount of space. Instead of 10 MB per minute for true CD-quality
audio recorded as a WAV file, a 128 Kbps MP3 file is about 0.9 MB per
minute because of its 11.0:1 compression. Using the highly respected Fraunhofer IIS and Thomson Multimedia MP3
converter, we converted a WAV file that had been digitally extracted
from a CD. We then analyzed the difference. The WAV file showed audio
frequencies to about 22 kHz, as expected. But the MP3 file was
chopped off at about 16.9 kHz, except for a few rogue high frequency
peaks. Click below to see the difference... Analysis of MP3
Converted File
Probably the most serious drawback is that the information it chooses
to dispose of is lost forever and cannot be recovered. Consequently, if
you're trying to preserve a priceless recording, some of its nuances will simply cease to exist. MP3 definitely has its place and can be a great choice in many
situations. But if you can do it, trust your precious recordings to full,
uncompressed CD quality audio only. MiniDiscs -- The digital MiniDisc format, originally conceived by Sony as a digital
replacement for the cassette, has come a long way since its introduction.
Broadcasters and consumers alike have embraced the format because it is
small and extremely easy to use--and because the quality rivals that of
CDs. But, like MP3, it uses a "lossy" process called ATRAC--pronounced AT-rack, not
A-track (Sony didn't want it to sound like
"eight-track")--to
reduce the amount of information it has to record (the compression ratio
is about 5:1). The process has matured
and is far less noticeable than when it was introduced. However, our MP3
comments about preserving the full-fidelity of treasured recordings
apply here too. To learn more about MD's,
take a look at the premier site that tells all: The
MiniDisc Community Page. Streaming Audio -- Many years ago, brave souls would listen to distant stations on
shortwave radio. But the Internet has certainly changed what's available
to us in the comfort of our own home.
About all you need to listen to radio stations that are streaming
audio on the Internet (see the Now Playing page) is a
computer equipped with sound and an Internet connection. Multimedia computers usually fit the
requirement nicely.
Two of the most common "players"--software that's used to
"decode" or play the stream--are Real Player and Windows Media
Player.
MiniDiscs are
smaller and a little thicker than a 3-1/2" diskette and allow immediate random access to individual tracks,
capability of erasing and re-recording, low price, digital quality, mono
option for speech applications--and, they fit neatly into a shirt or
blouse pocket! ‘Nuff said, by us, anyway.
Windows Media should be preinstalled on PCs that use Windows as an operating system, or you can find it at Windows Media.
The free basic Real Player can be found at Real Player. Be sure to scroll down to the bottom of the page. That's usually where you'll find the "free" version.
Even though a 28.8 Kbps modem connection is supposed to be sufficient, generally faster is better. Otherwise you may hear frequent interruptions in the audio as the player "buffers" (stores) data because it is playing it faster than the data is being received.
-- Over time, analog reel-to-reel technology has been a surprisingly good medium for archiving precious recordings. But a chemical flaw in the oxide's binder formulation years ago has rendered some tapes largely unplayable today. Not all brands and tape types are affected--according to an article in the June 5, 1999, edition of Billboard, Ampex 406/407 and 456/457 are "usually found in unstable sticky-shed condition." Those tapes occasionally found in unstable condition include 3M Scotch 306/307, R600, 20X series, 206/207, and Agfa PEM 468/469.
The symptom is obvious: tape guides and heads become contaminated by binder/oxide within seconds or minutes after the tape begins to play. In particular, you will hear the high frequencies disappear as buildup increases on the reproduce head and the tape may begin to squeal. During rewind or fast forward, the tape will slow to a crawl as the guides and lifters become contaminated.
The
most widely supported method to solve this problem is low-temperature,
low-humidity "baking." It’s not a permanent fix, but
it will at least allow you to transfer your cherished recordings to a
different medium. Convection ovens
that are well behaved at low temperatures are recommended (such as the
Farberware T4800 Turbo Oven, which we haven't tested), but
seemingly the best idea of all came from Gary,
We probably shouldn't have been surprised, but not all dehydrators are created equally. For example, the Ronco model does not use a fan, nor does it have a temperature control. Other units may also lack a temperature control or use very small fans. While this may be acceptable for food dehydrating, it isn't for tape baking.
An
upgrade to the model suggested by Eddie Ciletti is the NESCO
American Harvest FD-50T Pro-Timer Classic Food Dehydrator. The
"T" model adds accurate digital temperature and digital time
control, which are very desirable features. Temperature is adjustable
from 95 to 150 degrees (F) in 5 degree increments, and time to 48 hours
in 30 minute increments. It is rated at 500 watts (120 VAC) and has a 4.5" fan powered by a 1200 RPM motor. The inner diameter of the trays
is 12-11/16", thus accommodating 10-1/2" reels with ease.
The FD-50T intakes air from the bottom (make sure it is sitting on a hard surface), heats it and blows it up through a duct in the sidewall of the trays (click on the image above to enlarge). Slots allow the hot air to pass under and over each tray so heating is uniform. Moist air escapes through a center tube and up out the top cover. According to the manufacturer, this method is the "Exclusive, patented Converga-Flow." "Competitive dehydrators," they say, "require tray rotation." Also, "Drying pressure automatically adjusts to the number of trays added."
We mounted four temperature sensors inside the FD-50T, two on the tray below and two on the tray above an aluminum reel of Ampex 456 (1/4") tape. We set the temperature to 115 degrees (F); after 45 minutes of operation, we measured an average maximum temperature of 114 degrees, and the sensors were within 3 degrees of each other, which is well within their accuracy rating (ambient temperature was 75 degrees (F)). We rotated the temperature sensor trays 90 degrees and repeated the test to find similar results. And the top surface of the reel was within 0.1 degree of the bottom surface. From what we can tell, this unit really does heat uniformly. In addition to its accuracy, the digital temperature control also maintains a reasonably constant temperature within 4 degrees (when set to 115 degrees, it cooled to 110 degrees, then heated to 114 degrees). When set to 120 degrees, we measured an average maximum of 119 degrees.
We've successfully baked two 10-1/2" reels of 1/4" tape simultaneously by adding an optional tray (we think it's a good idea to have an empty tray at the bottom, top, and in-between the tapes. We did find that adding the extra tray caused the temperature to fall by about 5 degrees, for which we could easily compensate. We also placed small weights on the cover to provide a better seal with the tray below.
The NESCO American Harvest FD-50T has allowed us to recover audio from some priceless 2-track master tapes. As an added bonus, we received a complimentary packet of Original Beef Jerky Spice and Beef Jerky Cure with our FD-50T. By the way, be sure not to dehydrate food at the same time you're baking tapes.
One final note about ovens: Absolutely avoid toast ovens because their temperature can soar 15 degrees (F) in a mere 10 seconds, and their minimum temperature can be above 140 degrees (F), possibly damaging your tapes beyond repair. Be very, very, very careful, but don’t be afraid--the process does work if done properly.
Before you begin, take a look at the links below for important, detailed information...
"Baking" Magnetic Tape To Overcome The "Sticky-Shed" Syndrome
Tape Restoration Services, Resources, Tips, and Projects
If
I Knew You Were Coming I'd Have Baked A Tape!
(This is an edited/expanded version; the
original can be found HERE.)
A very interesting paper about magnetic tape deterioration was presented by Gerald D. Gibson, U.S. Library of Congress, at the IASA Conference in Perugia, August 26, 1996:
Magnetic tape deterioration: recognition, recovery and prevention
The Archives -- Curious about the history of recording and why things were done the way they were? There's a terrific site that covers: Origins; Cylinder vs. Disc; New Popular Music; Electric Era Replaces Acoustic Era; Music for the Masses; Magnetic Tape Recording Invented; Tape Recording Comes to America; War of the Speeds; Rock and Roll; From Stereo to Cassette; Video Tape Recording; Japanese Introduce Helical Scan; Betamax Battles; and Digital Revolution.
Check out Steve Schoenherr's Recording Technology History.
Extinct Media -- Well, we didn't know whether to include this on the Just For Fun page or as an interesting if not unusual footnote to the Engineering page. But here it is, an eclectic site devoted to media that just didn't make it. You first need to take a look at the Dead Media Manifesto to find out what these folks are all about, then peruse the The Dead Media Working Notes which, quoting from their site, is an "accumulated, archived, (and now collated!) collection of submissions from list members; an ad hoc database of the deceased, the slowly-rotting, the undead, and the never-lived media." Where else are you gonna get the skinny on wax cylinders or Clegg-Selvan pneumatic cash-carrying transportation tubes?