Neptune Sound Studio
Studer A80VU Simple Electronics Adjustment
In 2005, I thought just for the record, it would be fun to produce a video showing how to align the electronics of the Studer A80VU recorder - reproducer. I soon found out that it was in fact a lot of hard work and expense to do so. My first experience with this type of procedure was with an MCI JH110B I had just bought. It had cost me to the tune of $90.00 per hour to pay the tech to teach me how to adjust the machine correctly, which at the time, the machine needed doing. If I recall correctly, I think it was three hours, $$$ plus tax. The Suder A80VU audio electeronics are fitted with standard volume indicators bearing external manual adjustable reference pots and selector switches for reading bias, record, repro, sync, erase. Since standard volume indicators are a fixed reference bridging the circuit at 7500 ohms, these pots allow the indicator to be adjusted for each of the five signals for correct reading and reference. If one follows the Studer manual for this procedure, it can get confusing even to an experienced engineer. Currently and for many years, advances in tape flux technology have rendered it unnecessary to reduce signal levels for adjusting bias and high frequencies. The demonstration follows the signal reduction method indicated in the manual. In my case I chose to drive a strong signal from the oscillator source and then reduce the signal at the incoming record amplifier for bias frequency adjustments. An external meter adjusted for easier and more accurate reading is used here for bias and high frequency adjustments where the signal has been reduced to - 20 dB. As most of you audio engineers know, this practice stems from years of experience and training where driving a strong signal down a line produces the cleanest, quietest, best sounding tones for reproduction. Of course, it is far easier to just turn down the oscillator volume. The introductory music that you hear, I wrote the music and recorded it with my trio on a 24 track Studer A80 in 1982 on Scotch 250 tape. Unfortunately the 2" reels were stored in a century old (1851) damp cellar for fifteen years where a stream of water ran through it in the spring. I loaded the reel that you hear complete with water stains and without having to bake the tape, it played perfectly, (tones intact 20 hz - 20 khz), though I had to re-tape the splices as the original splice tape had given up from dampness. Would CD's, DVD's, hard drives stand this type of torture ? From experience in both digital and analogue audio recording - reproducing, well recorded magnetic analogue recodings are in my mind, as being something special, both sonically and physically. The video is broken down into three episodes and takes approximately thirty minutes to watch. Some patience is required as each episode takes several minutes to buffer depending on the speed of your computer system. It is not set to auto play, so after the video is finished loading, click the arrow at the left of the status bar to play.
This video is not intended for the experienced audio engineer.
Cheers !
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