Direct mp3 download or play:  Signal Generator Piece

Here is something I made in 1974 using two tape recorders, and either a homemade theremin or an audio generator. I honestly can’t remember some of the details or what instrument I actually used, because I have a habit of not labeling tapes. I do remember having access to recording equipment at Diablo Valley College in Pleasant Hill, California because of a class in electronic music.
Located in a small room, was a recording setup with two tube type Magnecord tape recorders. They were very heavy professional units, which could handle ten and a half inch reels. One was a model 1028 and the other a 1048. They looked identical, except the 1028 had 7 1/2 and 15 ips and the 1048 had 3 3/4 ips and they were both half-track stereo. There was a professional looking Sony mixer with 8 or more channels. I think there were two Ampex amplified speakers with tubes similar to the one pictured. My setup for this recording was to feed the audio generator into a mixer input and have it panned to one side. Then the output of the mixer was connected to the ‘line in’ of one Magnecord recorder. Then I took the ‘line out’ of the recorder monitoring the third (playback) head and fed a stereo line back into the mixer. I made sure the audio signal was on the opposite side with respect to the audio generator input. This would create a ping pong (left/right) echo.  Next I ran the tape from the first recorder to the other recorder setup just to the right of the first machine.  The second tape recorder fed a stereo signal back into the mixer which would feed back the sound recorded on the first recorder a few seconds later.
With everything set up I could now begin recording. I very carefully started both recorders. They were both running at 71/2 ips with the first machine recording and the second machine playing.  Also the tape tension had to be just right to avoid breaking the tape or being too loose. While running this arrangement for a few minutes, I determined how high I could raise the faders on the mixer before the feedback would get out of control and become distorted. I then started fading tones from the audio generator up and down, letting the feedback from the two tape recorders process the sound. I recall being inspired to make this recording after learning about Brian Eno doing a similar and I admit a much nicer recording. I was also influenced by the sound effects of a favorite movie of mine, “Quatermass and The Pit.”  In addition, I’ve always liked the sound effects on “Doctor Who,” particularly the episodes from the late 60s through the middle 70s. I very much admire the work of the BBC Radiophonic Workshop, which made the sound effects and music for a good number of British TV series including Doctor Who.
After making the recording onto a 7-inch reel, the tape could simply be played back on a single tape machine, and what I have here is the result. I know this is a bit goofy, but it did give me goose bumps the fist time I heard it.

Magnecord Model 1028 Professional Tape Recorder

Eico Model 377 Audio Generator

Ampex Model 620 Amplified Speaker