Corey Bailey
           Audio Engineering
USEFUL INFORMATION
                  PLAYING A WIRE RECORDING Playing a wire recording can be a daunting task but, if done carefully, one can extract the contents. The wire is made of stainless steel and is very fine, averaging approximately 0.005 inches, (about 0.12mm) or, approximately the diameter of a strand of human hair. The average speed was quite fast, about 24 inches per second (approximately, 61cm/s). Wire recorders were used for various tasks and popular with consumers as well until audio tape came along and replaced the technology. There two basic types of wire recorders: those that used a spool having a small hole (about ¼”) to be used on a corresponding shaft and those that used a spool with a much wider diameter center hole (about 1-3/8”). The later being the consumer model which is more common. Both types use a record-play head. Most wire recorders use separate heads (one for each function) that are built into one head assembly. Because the wire is so thin, tangles and breakage are a real problem. When the wire broke (and it will), I used to splice it by soldering about a 1/4” overlap which would be hardly noticed because of the play speed, even if I had to trim some to make a clean splice. However, the method is very tedious and time consuming so, I defaulted to the standard method of tying a square knot, which is still tedious. Knots and other anomalies seem to pass through the head just fine. I have yet to come up for a good method of cleaning the record-play head because the slot is so narrow. The method that I currently use is a dedicated reel of thick sewing thread that I will soak with denatured alcohol and play for about 30 seconds. Before playing a wire, it’s best to advance the mechanism by hand in order to line up the head with the spool of wire. Observe how the wire spool will unwind so that the head travel will match the way the wire unspools. You can do this by rotating the take-up spool on most machines. The available user manuals recommend starting the head at the top of the travel. However, in practice, I’ve found that matching the position of the wire to be best. Fidelity is poor by today’s standards, averaging from about 50Hz to 5kHz. You may notice an unusual amount of hum that is baked into many wire recordings. This is mainly due to the drive motor being poorly isolated, mechanical operation of the machine while recording and playing and the electronic technology of the time.   I learned right away to take the play head direct into a modern microphone preamp which produces much better fidelity. You will need a microphone preamp with plenty of gain (about 70+ dB). Equalization should not be a problem. As far as I can tell, wire recordings didn’t use any EQ. However, use your ears and get the best sound. I generally transfer flat, then do any EQ, editing, etc. on a copy of the file. Many of the consumer recordings that I transferred were recorded by holding a microphone up to a speaker which, is not the best method. Most wire recorders used a crystal microphone which has it’s own fidelity issues. Plus, the average person doing the recording was unaware of good microphone techniques. That said, I have transferred some wire recordings that were very well done so, it’s possible to get good results. I have both types of wire recorders so that I can play the most used formats. Both types use mechanical switching for play and rewind. Rewind is generally scary fast and the tension is often slack. This is where most of the tangles happen. I have found that applying very light pressure to the supply reel during rewinding (which was the take-up reel during playback) will vastly reduce tangles. You can do this by gently laying a finger on the supply reel. The weight of your finger is usually enough. Some machines have a turned up edge on the take-up reel to facilitate threading so you have to watch out. The wire needs to take the same path during rewind as it did during playback because the head assembly moves up and down or in and out to provide an even wind. One would think that head wear would be a problem but I haven’t noticed a decrease in fidelity over time. At first, I tried a number of things to avoid the possibility of wearing the play head during rewind but they usually ended up in disaster. So now, I just ‘let it rip’ and try to avoid tangles. Return to TOP of page © Corey Bailey Audio Engineering
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