Overview of Disc Transfers
Our disc transfer capabilities are truly unmatched in quality. If you seek audophile quality LP transfers, look no further. If you have home recorded discs, 78s, dictation discs, or other obsolete grooved media, we can extract more and better quality sound. The sound from your disc grooves will have traveled through a $60,000 signal path. When master tapes are lost or damaged, and all that is left is a mint LP, The Audio Archive can save the day.
When we say "state-of-the-art", we mean it.
It all starts with a Simon Yorke S7 disc transcription system - one of the top ranked turntables in the world by audiophile reviewers, and also the turntable used at major archives like the Library of Congress National Audio-Visual Conservation Center (NAVCC Packard Campus) for their preservation work.
Our Simon Yorke S7 rests on a Minus K vibration isolation platform that is normally used for an atomic force microscope (AFM). An AFM is used to image and measure atoms (fractions of a nanometer). A nanometer is one-billionth of a meter. A typical atom is 0.1 to 0.5 nanometers in size.
What do atoms and nanometers have to do with playing records? The sound waveforms are captured in the disc grooves with microscopic undulations. Like the AFM, the cartridge and stylus are extremely sensitive to movement and vibration, which is how they reproduce the sound captured in the record grooves. Any external vibration, no matter how slight (someone walking by the turntable, vibration from speakers, etc.), is sensed by the stylus and affects the sound being played back from the record.
The use of an AFM vibration isolation platform for turntable support is an innovation pioneered by The Audio Archive. We combined our experience in nanotechnology manufacturing (automated optical fiber alignment, if you must ask) with our mechanical engineering know-how - along with measurement and testing - to identify an industrial vibration isolator that far outperforms any "audiophile" turntable isolator. Even the popular Vibraplane cannot match the performance of the Minus K isolator.
Stylus Selection the Scientific Way
We use a 150x magnification microscope (a Nikon SMZ-2B) with a 10-micron resolution reticle. We light the grooves with a high-powered fiber optic light that illuminates the grooves extremely well, but with no heat at all.
The 150x microscope allows us to inspect the quality of the pressing, the wear in the groove walls, and closely examine any damage or stubborn contamination.
With a 10-micron resolution reticle, we can accurately measure the dimensions of the groove and using mathematical algorithms developed at The Audio Archive, we can compute the correct stylus geometry and size. Most grooves fall in the range of 70 to 200 microns as measured at the disc surface.
The benefits to using a precision microscope and measuring reticle to stylus selection are:
- Less wear on the grooves, as we can usually identify the correct stylus for playback immediately
- We know what to expect for noise, pressing distortion, and wear before even playing the disc.
- We spend less time testing styli (and less time putting wear on your grooves), thus saving you money
We still ultimately rely upon our ears and listening to the recording to know if we indeed have the right stylus.
This is yet another example of what we mean by "state-of-the-art audio transfers". We leave nothing to chance, and ensure that your recordings are handled carefully and as little as possible.
Disc Cleaning
As the old adage goes, "an ounce of prevention is worth a pound of cure", and this holds especially true of disc cleaning. Attempting to remove noise later using digital processing requires far more time and skill than having simply removed the source of the noise before digitizing the disc in the first place.
We use the Keith Monks Record Cleaning Machine (RCM) for all of our disc cleaning needs. There is no better tool for thoroughly cleaning a record. We use the Keith Monks RCM in conjunction with a variety of cleaning brushes from Disc Doctor together with Disc Doctor cleaning solution, as well as several cleaning solutions which we mix in-house for special purpose work.
Disc Flattening - Removing Warp
The Audio Archive can flatten warped discs (LPs, 45s, 78 shellacs, and dictation discs) when necessary.
When discs are warped, this influences the sound of the recording. The primary affect of warping is that the disc does not lay flat against the turntable platter, and is unsupported where it does not contact the platter. The result is that the disc resonates, coloring the sound. The coloration will also be periodic (the sound will be uncolored where the disc touches the platter, and colored where it is not in contact with the platter).
In addition to sound coloration from disc resonance, warpage will also result in some tracking distortion as the VTF (Vertical Tracking Force) - and hence the SRA (Stylus Rake Angle) - varies with the vertical undulations of the disc.
We use a precise disc flattening tool, the Air Tight Disc Flatter. It can take up to 6 hours to flatten one disc. The flattening is done at low temperatures using very accurately controlled (semiconductor) heating elements. The disc is placed between two extremely flat and parallel plates which very slowly remove the warping.
We have successfully removed warps from LPs, 45s, vinyl dictation discs, and even 78 RPM shellacs. Many of these discs would otherwise be unplayable.
LP Albums and 45 Singles
We use the Lyra Helikon SL cartridge for all of our LP and 45 playback. This is a low-output moving coil cartridge with a very neutral uncolored sound and very wide bandwidth.
The RIAA phono preamplifier from the Boulder 1010 feeds the analog-to-digital converter (ADC). Some audiophile reviewers rank the Boulder 2008 as the best RIAA phono preamp ever made, and at $30,000, one would hope so. The Boulder 1010 is a smaller sibling of the Boulder 2008, and bears a strong family resemblance to its big brother, particularly in its timbre accuracy and stereo imaging.
Microgroove
Microgroove discs are best played with a slightly larger stylus than LPs. For microgroove discs we use an Ortofon SPU Classic N moving coil cartridge with a custom stylus for microgrooves, which plays with less noise than an LP stylus. This cartridge and stylus, along with all of our cartridges and styli for non-LP discs were made to our specification by Expert Stylus in the UK.
78 RPM Shellac Discs
Sometimes referred to as the cockroach of recording formats, it is the most durable format (as in "hard"). Along with that durability comes brittleness - they need to be treated like fine china, otherwise you will either chip or shatter the disc, or develop a hair-line fracture.
This commercial format is most susceptible to being:
- Used as landfill. They are large and heavy, and consumers and archives alike will quietly dispose of these to make room for other things.
- Used as clay pigeons or discus throwing (we're not kidding). Edison Diamond Discs are best for this, so they say.
We certainly do not recommend disposing of shellacs in landfill or using them as clay pigeons. The point we are making is that shellac discs were so ubiquitous that people often didn't think twice about disposing of them. The cultural risk that we run is that shellacs could disappear without anyone noticing until it is too late, thinking that someone else must have a copy.
You might ask, "Don't the record labels have master copies?" You may be surprised to learn that the masters were disposed of long ago. Some record labels continue to hold some of their most valuable masters, but the majority do not. The commercial shellacs are often the only copies we have left. Keep in mind that there have been many decades of consolidation of the record labels - one record label buying another - and in the process materials are lost and disposed of.
The period of 78 RPM shellac production spans nearly 60 years, with many changes in recording technology from acoustic recording to electric recording, improved cutting methods, and a huge range of equalizations. The commercial shellac is a recording format with few, if any standards, other than it has grooves and it rotates.
This lack of standards makes restoring shellacs a labor intensive effort, ranging from stylus selection to determining the proper speed of rotation and equalization. The shellac media itself is fundamentally noisy, adding to any restoration effort.
16-inch Electcric Transcription Discs
Transcription discs are one of the most fragile disc formats, and are high on the list of formats that should be preserved sooner than later. We've devoted an entire resource page to transcription discs to educate people on identification, handling, cleaning, stylus selection, playback and storage.
Home Recordings
These are essentially the same as 16-inch transcription discs. They use the same technology, and only differ in that they are essentially
Why didn't consumers use professional blanks with their consumer recorders? After all, professional blanks sound better because they are easier to cut and have less noise. But, because the professional blanks were softer, they were also more easily damaged and worn, could not be played as often, and had to handled more carefully. A soft substrate was acceptable for the professional blanks because they were often shipped to radio stations for broadcast or to a studio for mastering or duplication, and only played a few times by professionals on professional equipment. On the other hand, the consumer blanks had to strike a balance between soft (better audio quality) and hard (can be played many times and handled easily). When striking that balance, consumer blanks generally erred on the hard side (sacrificing fidelity for durability).
In general, the consumer blanks had less plasticizer than professional
blanks, making them a bit tougher to cut, and the resulting grooves shallower and with more limited frequency range than the professional blanks. Some consumer blanks are on a fiber cardboard-like substrate. The fiber substrate tends to amplify any noise in the recording and imparts its own sound to the recording as the fiber almost acts like a drum head in its sonic character. We constrain the substrate when playing discs to minimize this amplification, nonetheless it is still present.
The consumer record cutting machines were also primitive compared to the professional machines. Add to this the inexperience of the operator (consumer) and the poor quality of consumer microphones, and it seems you would be lucky to have any recording at all!
Home recordings are usually in the worst condition (ie. damaged and worn) from careless handling (dirt, scratches, gouges, bends and warps) and being played incorrectly (wrong styli, wrong tracking force) . Compared to all the other work we do, the home recordings are by far the most labor intensive, and the sound quality most compromised.
Anecdote: When presented with a large pile of home recordings and asked, "Do we have to transfer and play all the discs to figure out which ones are most worth digitizing?", we reply, "Officially, yes - it's the only way to know for sure, but unofficially - almost without fail - the most damaged and worn discs will also be the most interesting." There is a reason they were played most frequently. Naturally, these discs will also be the most difficult to play and restore, and afterwards the transfers will still sound relatively poor because of all the wear and damage.
We advise people that it is best to set your expectations low when it comes to sound quality. Expect a lot of noise, difficult to understand speech (due to wear, low-performance microphones, too much or not enough gain, poorly cut grooves), and limited high frequency response (the recording may sound muffled). Nonetheless, you will be able to hear the sounds of the past.
Dictation Discs
We can transfer both CAV (Constant Angular Velocity) and CLV (Constant Linear Velocity) dictation discs. Formats include:
- Edison Voicewriter (CAV)
- Gray Audograph (CLV)
- Soundscriber (CAV)
We have yet to encounter a disc format that we cannot play. In a few cases, we purchased an original dictation machine, carefully disassembled it, and then reverse engineered the format (speed and equalization).
Aluminum Discs
Aluminum is a relatively hard material in which to cut a groove. High frequencies, in particular, suffer the most from the aluminum groove cutting process.
You will find discs with labels like Kodisk, Remsen, Repeat-A-Voice, Speak-O-Phone, and Stearns Brothers.