Home Recording (Part 3)
Reel To Reel - Your First Move?
More hints for your demos
What constitutes a home recording set-up is open to debate. If you are a singer/song-writer with a publisher already working for you, and you simply want to give him an idea of your new songs on tape, a basic portable cassette deck placed in front of you and your guitar or piano might just cover it. Of course you will have virtually no control over the quality of the sound, and no possibility of altering or adding to it after the initial recording. The time comes when you'll want something better, and that's when stereo reel to reel machines, with 'sound on sound' facilities, which will allow you to build up a more complete musical arrangement on tape, line by line, become interesting.
Let's take for an example, a simple arrangement of a song with a piano, vocals with a harmony and guitar on the choruses, and let's also assume that you are going to have to play and sing everything yourself. As the piano is to form the basic backing this will be recorded first, for the sake of argument on the left channel of the stereo tape recorder. In this situation you can give your full attention to the piano, and will probably find that you can extend yourself to include all the fiddly bits that having to concentrate on the vocal might usually preclude. Having got that right, you may want to put down the guitar next.
The sound-on-sound facility of the tape recorder allows you to use it as a simple mixer, to mix together the signal from the left channel (the piano) with the signal entering it from the guitar, in order that they can both be recorded in their mixed state onto the right channel. Monitoring of the relative levels can be simply done with a pair of headphones, by listening to the composite signal being sent to the right channel. If you get the guitar part wrong the first time through, you still have the original piano track on the left channel intact, and so you can simply go back and try again until you get it right.
The same procedure is repeated in the opposite direction for recording the main vocal, mixing the signal from the right channel (piano and guitar) with the vocal, to be recorded as a whole back onto the left channel. Here again, if you get dyslexic halfway through the last chorus, you still have the piano/guitar track left unaffected on the right channel and so you can keep on going through the vocal until you get it right. The harmony is added by bouncing the left channel (piano, guitar and vocal) together with the second vocal onto the right channel.
There are several machines on the new and second-hand markets that have these sound-on-sound facilities, from a second-hand Akai 4000D at around £80.00 to a new Revox B77 at around £700.00. Pretty well all of the lower price machines are quarter-track, meaning that the tape width is divided into four, with two tracks going in one direction and two in the other, thus allowing the tape to be used in both directions giving twice the playing time. Compared to the more expensive half-track machines, (where the tape is divided into two and only runs in one direction) the quality is inferior. The narrower track width results in a lower signal to noise ratio, that is the ratio between the programme on tape and the residual tape hiss, and makes such machines more prone to the effects of drop outs and head/transport misalignments. All professional stereo machines are half-track, and so owning one gives you the added advantage of being able to playback studio recorded tapes at home.
Regardless of which you buy, it is very important to make sure that you are using the tape for which the machine is aligned. Different types of tape require different bias level and equalisation adjustments to ensure optimum results, and in the professional situation these settings are checked daily. More expensive machines allow fairly easy adjustment, assuming the engineer has the correct test equipment, whereas less expensive models tend to have fixed parameters, in which case you are best advised to use the tape for which the machine was originally aligned, and hope that it hasn't drifted to far from its optimum setting.
"The drawbacks with this sound-on-sound method are that the final recording is in mono..."
Alignment of the heads relative to the tape path is also very important and should also be a fairly simple task for the properly equipped engineer, depending on the construction of the specific model. The importance of keeping the heads and transport clean can not be over-emphasised. The record head is like a ring shaped magnet with a minute gap in its circumference which is filled with a non-magnetic material. As the tape is moved by the tape transport, across the heads, it is made to bridge the gap in the ring with its magnetic coating. As with most things in nature, the magnetic flux takes the easier route through the tape rather than through the non-magnetic material in the gap, and thus the tape is magnetised. You can see then that unless the tape to head contact is good, the transfer of magnetic energy will be impeded, and the quality of the recording will drop dramatically.
After sometimes even relatively short periods of use, depending on the brand of tape being used, oxide from the tape will be deposited on the heads, thereby preventing proper contact. The same oxide will also form deposits on the capstan and pinch roller making them uneven and giving rise to variations in tape speed (wow and flutter) and also on the rest of the tape transport like tape guides and tension arms, where after building up to a heavy ridge, it will break off and be deposited on the tape causing momentary losses of programme or 'drop outs'.
Therefore, invest wisely in some tissues or cotton buds, and a small bottle of isopropyl alcohol, and give everything that comes in contact with the tape a thorough clean, and throughout the recording process ensure that everything stays that way with regular checks. Low cost tape transports can also have a tendency to chew up tape, and it is important that you find an operational method that treats it gently, and get in the habit of using it: for instance crashing from fast wind straight into play on some machines can get you into a kind of origami mode that can wipe out days of recording. Another thing that can seriously affect the quality of the final product, especially with quarter-track machines, is poor, uneven tape packing when you wind the tape off for storage. If the pack is not smooth and there are thin ridges of tape sticking up at odd intervals, the pressure of the spool flanges on these ridges can cause 'edge damage' where the edge of the tape is forced over, giving rise to a loss of oxide and further resultant drop outs. If the fast wind modes on your machine develop an uneven pack, it is advisable, especially if the tape is to be stored for any length of time, to take the trouble to wind it off in the play mode. This will also help to reduce the effect of 'print through'; this is the result of what is effectively magnetic crosstalk between adjacent layers of tape wound on the spool, which gives rise to a pre or post echo effect on the programme. Although winding it off in the forward direction won't actually reduce the level of print through it will make the echo come after the actual programme which is subjectively less obtrusive.
"To avoid problems with acoustics, it is often easier with a small set-up to record in a very dead environment, and add the reverb back with an artificial reverb device."
The drawbacks with this sound-on-sound method are that the final recording is in mono and if you are using a microphone straight into the tape recorder, you still have very little control over the final sound. The use of a small mono mixer has several advantages. Now of course instead of plugging the microphone straight into the tape recorder, you plug the output of the mixer into its line level input and use the inputs of the mixer for your various mikes and instruments. The gain controls and impedance switching on a reasonable mixer will allow a much wider variety of sources to be recorded and will also permit a certain amount of tone equalisation which should make all the difference to the final product. It also makes it possible for you and your associates to record more than one voice or instrument at a time.
To facilitate this you will need a mixing console with foldback; this allows you to create a separate mix of whatever is going through the console, which you can then use to feed a system of headphones, thereby allowing each interested party a clear picture of what has been recorded previously, and/or what the rest of the band are playing.
With a simple set-up such as this the input of the tape recorder can be plugged into one of the inputs on the console, being careful not to create a loop by sending it via the main output, back to the input of the tape recorder, but instead sending it, with the foldback control on that channel, to the headphone system for listening to the programme previously recorded on tape. Of course you will almost certainly have to run to the extra expense of a separate power amplifier to drive the headphones, and a distribution box, probably consisting of a simple die-cast box with half-a-dozen jack sockets wired in parallel. Bear in mind when purchasing the headphones that every time you plug another set in, the overall impedance that the amplifier is driving into will fall considerably according to the equation 1/R1 + 1/R2 + 1/R3... + 1/Rn = 1/RT where R1, R2 etc. are the nominal impedances of the headphones being connected, n being the last pair, and RT is the overall circuit impedance (nominal). With this in mind then, don't start plugging four or five pairs of 8ohm hi-fi headphones into your distribution box which is to be driven by an amplifier designed to drive into a minimum impedance of 4ohms, or you'll be likely to blow the amp up, or at the very least receive distorted sound through the headphones.
"To produce a stereo recording using two-track machines, you will need two of them if you are going to want to build up an arrangement bit by bit."
Something that makes a surprisingly huge difference to the apparent quality of a recording is the controlled use of reverberation. To avoid problems with acoustics, it is often easier with a small set-up to record in very dead environment, and add the reverb back with an artificial reverb device. The three main types available are digital, plate and the one most likely to be applicable here, the spring reverb. Some quite small mixers will have a spring built in, notably on the secondhand market, the old WEM five channel, mono Audiomaster, which has foldback, reverb and adequate metering and tone equalisation. By modern standards it's rather large for what is does, but you should be able to pick one up for about £100.00, and it also has balanced mic inputs which, at that price, is a bonus.
If you buy a desk without built in reverb, it should have an 'effects send' facility, otherwise known as an 'echo send' or an 'auxiliary send'. This is virtually the same as the fold-back mix, except that this time the separate mix is sent to an external effects device, in this case a spring reverb. The signal coming out of the device, complete with its coating of reverb is then either fed back into a channel on the mixer so that it can be mixed in with the main signal before it goes to tape, or fed back into what amounts to a separate channel provided specifically for the purpose called an effects return or echo return, which similarly allows the effected signal to be mixed with the main signal before it goes to the tape recorder via the main output.
To produce a stereo recording using two-track machines, you will need two of them if you are going to want to build up an arrangement bit by bit. You will also need a stereo mixer, which will give you all the advantages of the monophonic unit, whilst also allowing you to give the recording a stereo image. When using a single stereo machine to do mono sound-on-sound recordings as previously described, the left and right tracks are always in synchronisation with each other, which means with certain better quality machines you can often get away with doing 'drop ins.'
"Most small mixers will only have a mono foldback facility..."
For instance, suppose you had already recorded the piano and guitar backing track and you had just made a mistake in the second verse, putting down the vocal. Under the right circumstances it would be possible to run the tape back to a point a few seconds before the mistake, put the machine into play, and only drop it back into record at the start of the second verse allowing you to recommence your vocalising before the mistake without having to go right back to the beginning of the song. Although this is usually operationally rather tricky with non-professional equipment, it is possible. However when you start to use two machines to do stereo sound on-sound, there is no way within the context of a small home set-up, to lock the machines together so that they run perfectly in sync. This means that should you make an noticeable mistake during the last line of the song, you'll have to go right back to the top and start again.
The method for stereo sound-on-sound is as follows. You record the first part of your arrangement in stereo using the mixer, on both channels of one of the machines. You then connect the outputs of that machine to two of the inputs on the mixer, panning them hard left and right to the two main outputs, ready to be sent to the second machine in stereo. The next group of instruments are now put through the mixer to the main outputs with their relative stereo positions.
The second machine's monitor facility is switched to 'source' so that the signal at its output is the same as that at its input, i.e. the mix of the recorded material on the first machine and the new group of instruments. This is in turn connected to another pair of inputs on the mixer and sent via the fold-back to the headphone system, so that you can adjust all the relative levels and so that the musicians can hear what's going on. Most small mixers will only have a mono foldback facility and so in order to critically adjust the stereo images, you can simply plug a pair of headphones into the headphones socket of the second machine.
Having got the levels and imaging right, you record the composite signal leaving the mixer on the second machine. Subsequent parts can be added in a similar way.
If you can't get hold of a separate foldback amp just now, you may get away with using the headphone output from the tape recorder being used to record, depending on the power of its headphone amp and the number and impedance of the headphones being used. This means though, that you have to listen to the balance of sound that is going to tape, and you don't have the freedom to create a separate balance specifically for foldback, which is sometimes quite necessary to give the players what they need to stay with the track.
A multi-facility hi-fi amp can make monitoring a little easier, but remember that you can't monitor very loudly — if at all, via speakers whilst recording with microphones, as the sound coming through the speakers will be re-recorded on tape.
One last work of advice: Don't completely trust the metering on either the mixer or the machine, but rather experiment and see how much level you can get on tape without distortion. This will make a lot of difference to the quality of the end result.