Studio Story Book


I received a call from a studio engineer who had a client that claimed that the multitrack was wowing, making it impossible for the singer to stay in tune with the track.  The engineer was not convinced that there was a problem but wanted me to go in anyway to appease the client.  He failed to mention who this client was, because if he knew that if I knew who it was, I probably would have refused to go in.  (Thanks, buddy!)  During the course of my business, I have had three dealings with this man - all of them highly unpleasant to say the least.

I walked into the control room and immediately realised there was nothing wrong with the machine.  I went through the motions of checking a few things to ensure everything really was OK.  All capstan driven tape machines suffer from slight slippage across the capstan.  The amount of slippage is affected by any tension difference across the capstan.  In this case, the machine was an MCI JH-24 which is fitted with a switch to disengage the pinch roller whilst the machine is running.  This is a useful test to check that the tension servo system is working and adjusted correctly.  I pressed this button and the machine was so well adjusted that the reel servo system was able to maintain almost perfect speed without the capstan system.  The other thing that can happen on an MCI machine is that the capstan servo system can lose control, producing violent flutter (which in this case was not the complaint).  After checking these two things I said "I'm sorry, I cannot find anything wrong with it."

The producer then accused me of doing something to the machine to cover up the problem.  Fortunately there were witnesses in the room who saw that I had not adjusted anything.  So he returned to being adamant that there was still speed fluctuations in the machine and that the singer could not possibly sing in tune to the track.  ("Wouldn't be the singer would it?" I thought to myself.)  For the next half our I went through the exercise of recording three minutes of 1KHz tone onto one track and then playing it back and comparing the playback with the original 1KHz tone from the oscillator through a phase meter.  It took nearly 60 seconds for the speed to drift enough to cause the tone to go out of phase by 180 degrees.  This was an excellent result for any tape machine and the drift we measured could have been caused by drift in the audio oscillator frequency rather than the tape machine, which is crystal controlled.  To put this into musical terms, a musician tunes the strings on a guitar by listening to the beats between two strings.  Any two instruments which could produce beats slower than one second would be considered to be very in tune.  In this case we are talking about a beat period of two minutes - something which I would defy any human being on the face of the planet to pick!

The studio bill was never paid.