Preserving Transcription Discs
by Doug Hopkinson
Just before the turn of the century, thousands of big round records called electrical transcription discs, began to secretly congregate in a house in Spokane. The rest is history……
Radio Archives will soon be celebrating their 24th anniversary of being in business. Their mainstay product from the start was restored audio but they were also wearing the hats of archivists, preservationists, and role model to the hobby, by default. For 24 years they only sold restored audio of old time radio programs. This January, they launched a once-in-a-lifetime opportunity for collectors to own their entire library of raw, unprocessed, digital audio files. There are an estimated 36,000 files in the collection. This is the raw audio taken directly from their transcription disc collection. These are the base files that were used to produce their ‘sparkling audio’. The files are being released on a subscription basis at the rate of 600 files per month. This author is fortunate enough to be a subscriber and I can say that their raw audio products are top notch quality overall. In retrospect of the 20 plus years of hearing their various restored releases, it’s now quite apparent that starting off with great quality raw audio will result in a superior processed end product. This is really the secret Radio Archives harbored these past 2 decades. Great quality raw audio is the key ingredient.
Radio Archives is an archive because they digitized everything they had regardless of genre, popularity, or completeness. Radio Archives are preservationists because they have saved all their raw audio files and label scans, and continue to take measures to protect the files from disappearing. Radio Archives are mentors and role models to collectors and hobbyists alike but especially so for those a bit more enthusiastic, who look to emulate what Radio Archives does so well by making their own transfers and restorations.
The single primary reason to preserve RAW audio is because of the constant technology advances in audio software. Every year we are closer to an AI audio repair program that can analyze and perfect the audio until it’s like you are standing in the studio; all with the click of a mouse. It’s going to happen, I asked chatGPT the other day and she confirmed it.
Having identified quality raw audio as being the key to the kingdom, so to speak, how does one best go about coaxing it from a transcription disc? In order to answer that, let’s first get familiar with transcription discs.
CHAPTER 1: The electrical transcription disc.
“The act of playing a transcription disc and simultaneously recording it and then saving it to a hard drive or flash drive as a digital audio file is commonly referred to in the hobby as ‘transferring’.”
In the beginning there were transcription discs. Radio stations were supplied with these records that had pre-recorded radio programs on them. Amos and Andy was the first radio program to ever be syndicated and distributed on these electrical transcription discs in the late 1920’s. This practice of syndication was soon to evolve into a lucrative business.
Electrical transcription discs are commonly 16” in diameter. They can also be found in other non-standard sizes up to 22” in diameter! A 16” diameter is by far and away the most common size. Transcription discs can be made from many different materials. One type of early transcription discs were heavy records referred to as shellacs. These beauties can weigh up to 3lbs in a 16” diameter.
Shellac discs (pictured above) are very thick, very heavy, and very brittle. Sometimes these shellac discs were laminated.
Other early transcription discs were made using a black nitrocellulose lacquer coating over an aluminum core (picture above). This type of disc is commonly referred to as an ‘acetate’ or ‘lacquer’. ‘Acetate’ is a misnomer as there is no acetate involved in the manufacturing process of these discs. ‘Lacquer’ is the more appropriate name. Acetate is a nylon based plastic and there were records made of this material as well, before vinyl became the standard.
During WWII, glass was used as a substitute substrate, replacing the aluminum core, which was needed for the war effort. The photo has the sun shining brightly behind the glass disc.
Another early substrate was very thick cardboard or fiberboard that was coated with cellulose acetate, a very flexible, plastic-like material.
This type of disc should never be exposed to water (see above picture). The cardboard core absorbs the water and expands, popping and separating the coating from the core. The coating curled and raised around the outer edge of the disc which affected the audio at the end of the program, as this was an inside start disc. A lesson learned.
Still other early discs were just raw aluminum embossed affairs.
In 1932, RCA Victor developed a thermoplastic resin they called Victrolac. It was supposed to be, and was, more flexible than shellac but it was still a fairly brittle material.
Vinyl was used for records as early as 1930 by RCA Victor but timing is everything and people were not interested in technology when they had no food or money enough to buy the equipment to play a record. Finally, in 1948, Columbia made vinyl a standard substrate for its pressings because of its overall economy, performance, strength and flexibility. It proved to be the most resilient of all substrates.
Radio Archives’ transcription disc collection included thousands of radio programs from every genre and year imaginable. Their disc collection contained every type and size of disc shown above and more! The great selection of transcription discs assured them of a solid base of material from which to create digital audio.
Chapter 2: The Beginning of Radio Archives
Radio Archives was born out of necessity. A hobby, converted into business. The day Radio Archives began releasing their restored audio on compact disc, was the day that all the old school analog vendors can mark down as the beginning of their end. Radio Archives changed the hobby forever.
As a collector, I remember hearing a cd of theirs with restored material on it and just being in awe of the clarity. This became the new standard of quality that I wanted for all the programs I collected. Their competition was mostly selling cassettes but that soon changed. A few old time radio vendors began to figure out how to do CDs. They saw what was happening and tried to keep up. Radio Archives began influencing the hobby from day one. Challenging collectors to find a better product and hobbyists to step up their game and make their own high quality audio. This new quality was not just a challenge to collectors and hobbyists, other OTR vendors found they needed better audio and digital formats if they were going to be able to compete and remain in business. No other company had or has the same quality of audio as Radio Archives who refer to their restored files as ‘sparkling audio’. It remains a niche market today. It’s no accident that Radio Archives has survived over two decades in business. They are excellent at what they do.
As previously revealed, in order to have the best quality restored audio you need to start out with the best quality unprocessed or ‘raw’ audio files and there are five factors that will determine how good your raw audio files will sound. First, is the physical condition of the transcription disc. A disc can be dirty, warped, scratched up, chipped, cracked, and more. We have no control over the physical condition of a disc until we own it and then we can only improve it so much, depending on the problems it has. We can undo a warp fairly simply. We can overcome some skips. We can glue a broken disc back together. The bottom line is pretty obvious, the better the physical condition of the disc, the better the resultant audio file will be.
The second factor in getting the best quality audio is the equipment you are going to use for playing the discs. The better your equipment, the better sound you will get on your transfer. For many years, collectors had to use the same machines that the radio stations had, the old workhorse, RCA Type 70.
At one time, these machines were state-of-the-art. That time has come and gone. These machines are the size of a small washing machine. There are still hobbyists that use these machines to play their discs. If they use them to make digital transfers, the resultant file will be full of disagreeable things like rumble, wow, and flutter. In addition, the nail-like stylus that sits at the end of the 2 pound tonearm, is constantly wearing down the grooves. This is NOT the type of equipment you want to use even though it is the original equipment. Luckily, there are quite a few intelligent and creative people that have contrived ways to customize modern turntables as to enable them to play 16” diameter discs. Standard household turntables were never designed to play discs larger than a 12” diameter. The majority of transcription discs are 16” diameter. Employing a customized modern turntable, using a modern tonearm and modern styli, a better quality transfer is practically guaranteed.
Rek-O-Kut was a company that manufactured turntables. It went out of business but the name was licensed to Esoteric Sound, who use it to this day on their own customized transcription turntables. These customized turntables are a hobby staple today. Radio Archives owned a couple of brand new, top of the line, Rek-O-Kut restoration turntables like the one pictured below as well as other similar units.
The unit pictured below, also distributed by Esoteric Sound, was one of their secondary machines.
Having the proper turntable is half of the equation. The other half is the stylus. Stylus selection is everything when it comes to quality transfers. Radio Archives was well stocked with assorted sizes of styli.
A stylus is the needle which attaches to the cartridge; which attaches to the headshell; which attaches to the tonearm. Every transcription disc is different. One will have worn grooves, one will have micro grooves, another one has never been played. The grooves are different on every disc. In order to get the best sound, you want the needle to be making good contact with the groove wall where the sound resides. If the stylus is too narrow, it will ride at the bottom of the groove making contact low on the groove wall. If the stylus is too wide it will ride at the top of the groove and may not even stay in the groove at all.
The only way to know which size stylus will yield the best sound from a given disc is to try them all out until you get the best result. Not only are there different widths, there are also different shapes on the tip of the stylus. There are truncated and elliptical tips.
The 2 pictures above illustrate that a stylus needs to ride in the groove correctly both side to side and up and down. They also show how a worn stylus can actually cause damage to the groove walls. This is why it is important to have a good selection of styli to choose from and replacements at hand. It’s all about the needle reading the groove wall. There will always be one stylus that sounds better than the others. The right tool for the job as they say.
The third factor to ensure the best quality audio is to cleaning the disc thoroughly before playing it. Most of these transcription discs are between 70 and 90 years of age. Dirt was around back then, and continues to thrive today. Grooves can be impacted with dirt. Even discs that have never been played can have dirt and dust in the grooves, AND there can be detritus from the manufacturing process left within the groove walls. Cleaning is the number one game changer in the world of transcription discs if you want to improve quality of the audio.
Of all the different types of transcription discs, lacquers are by far the most sensitive to their immediate climate. Ideally, all transcription discs should be stored in a cool, dry place. It is very common for lacquers to become cloudy and begin forming a sticky white substance on the surface known as palmitic acid. This is the result of the nitrocellulose lacquer coating, chemically breaking down.
This breakdown process will continue until the lacquer flakes away leaving only a bare aluminum disc. Palmitic acid can easily be washed off and that will halt the process temporarily; but normally, once a disc begins to form palmitic acid, it only leads to a slow death and an unplayable transcription disc in the end. Delamination is not always caused by palmitic acid. Damage to the disc can cause chipping of the coating, letting air get underneath, and time works its magic. This is why careful handling and proper storage is important; it can mean the difference between hearing a show from nearly a century ago, or having it crumble away, never to be heard again.
Other types of discs have their own flaws. All these different types of discs have one thing in common with each other, grooves. I said cleaning is important. I don’t think I can stress that point enough. Less dirt means more groove. More groove means more sound.
Dirt is not easy to remove from narrow crevices like record grooves. Dirt that has settled for 70 to 90 years is practically permanent. The image above is magnified about 1000 times. So, what is the best way to clean your transcription discs? Most collectors that clean their discs before playing them, clean them manually, with a microfiber washcloth, a little water and some elbow grease. I have witnessed transcription discs being washed in the kitchen sink with dish soap and a dish brush. Some hobbyists swear by the Disc Doctor and his products. Using any of these methods is a better idea than to not clean a disc before transferring it.
If you owned thousands of discs like Radio Archives did, how would you go about cleaning them? At the time they initially purchased the discs, the only professional record cleaning machine around was the Keith Monks Machine (pictured below). It was very expensive and relatively slow.
The process of cleaning a disc requires water, some type of cleaning agent and a cloth or brush. Depending on the type of brush used, there is always a real possibility of groove damage which will affect the audio to some extent (especially if you are using a dish brush). Radio Archives removed the risk entirely by opting to go with ‘touchless’ technology. They invested in two ultrasonic cleaning tanks. One was for the chemical wash, one was for the rinse. The water they used was reverse osmosis water. The cleaning agent they used was the same used by the Library of Congress for their preservation work of records. The main ingredient is a powerful surfactant. Surfactants are chemicals that reduce the surface tension of any liquid they are added to, enhancing the liquid’s ability to spread and wet. This helps water get down into the grooves and lift out any dirt within. The term ‘touchless’ means there will be no damage to the grooves from scrubbing with an inappropriate brush.
These ultrasonic tanks were not originally designed for use with records in mind, especially 16” diameter records. These tanks are regularly used for cleaning in the medical field, the automotive industry, and by fine jewelers, just to name a few.
One cannot simply stand a stack of discs in the tank and let them shake. It was perhaps possible, but the labels would get wet and smear, or fall off, or both! Here is human ingenuity at its best. Threaded rod, nylon spacers, wingnuts, and a couple pieces of 1x1 pine board, allowed Radio Archives to clean 15 discs at a time and keep the labels out of the water.
The discs were all ultrasonically cleaned, then ultrasonically rinsed, and then received a final reverse osmosis water bath to make sure all dirt and chemicals were off of the discs before they go to the next staging area.
The final step in cleaning is letting the discs fully dry before transferring them.
The fourth factor to great transfers, and one that Radio Archives considers to be just as important as cleaning a disc, is applying an equalization curve to the audio. They did it by using a KAB Souvenir EQS MK12 chronologic equalizer.
‘Equalization is the act of manipulating the volumes of any number of frequencies when recording or reproducing audio.’
Radio Archives had two of the units pictured above, using one for each turntable whenever they transferred their discs. A preamp is required because the input levels are too low coming from the cartridge. The KAB EQS is just a fancy preamp that gives you 12 equalization curves rather than the standard one curve (RIAA), which happens to be the wrong curve for transcription discs.
Equalization curves are built into preamplifiers. Modern preamplifiers have the RIAA curve (started in 1954). Using modern equipment with RIAA curve built in, to record a disc that was recorded using an NAB curve is not going to accurately reproduce the audio on the disc. Every record company also had their own curves, and their curves would change from year to year. There are all sorts of equalization charts to be found if you consult the Google. For the purposes of our hobby, old time radio, there are 12 basic curves. If you are transferring a disc from 1930 for instance, you might need to use the AES curve or the NAB curve. KAB has integrated all 12 curves into their unit. You push a button and get an instant setting. You can then manually adjust if necessary until the sound is just right. By using this piece of equipment Radio Archives has accurately reproduced and preserved the original sound as it was meant to be heard, from thousands of transcription discs.
The fifth and final factor to creating quality transfers is a love for and dedication to the hobby itself. A person that really loves old radio programs, who loves preserving audio, is going to take extra care to get things right, more than someone just going through the motions will. Radio Archives sounds like they love what they do. Their preservation library of 36000 raw audio files is a lifetime’s labor of love. They did everything right. Over the years their methods have been noted and copied by collectors, hobbyists, and their competition. Radio Archives deserves accolades for being true pioneers in the modern method of transferring transcription discs. Hooray and thanks Radio Archives! We appreciate you.
Be sure and listen to the Audio Clip on the Preservation Library Product Page at the top of this page, for a sample of many of the Radio Shows that Radio Archives has transferred.