I was once a mastering engineer myself, long before digital audio and CD's were even heard of. It was a totally different world; one that dealt more with physics and mechanical limitations than just keeping the 'ones' and 'zeros' in line. During my 'first run' at Criteria (1966-1972), I was assigned to the disc mastering room when Jack Davis, the resident mastering engineer, took a leave of absence for several months. Most of our mastering business was for for a local distributor's pressing plant that specialized in Latin music. While I did not relish the idea of being trapped in that 8 X 10 room all day, away from the big studio and the live recording, the upside was that I got to learn how to operate the Scully lathe; a gorgeous piece of machinery costing far more than most anything in the studio.

I learned some valuable lessons in that tiny room about phase relationships, stereo matrixing, and the reason for RIAA curves. When cutting a "master laquer", one had to be extremely careful about levels. Too much, and the grooves in the master would "intercut", leaving you with an un-playable record that would skip every time the stylus arrived at the intercut area. Too much high frequencies could easily burn out the cutter head, costing a ton of money to replace, and putting our mastering business behind by days. Too much low end, and the cutting stylus would lift completely off the laquer, creating what we called a "land"....and the record would skip.

Master laquers were actually thin discs of aluminum coated with a thick layer of laquer on each side. We had to be very careful with these 'blanks' as even the tiniest of scratches would ruin them. Every time a master was cut, it had to be visually inspected with a microscope to check for lands and intercuts. Even one of these imperfections meant a "blown" laquer, and you had to start all over again. And God help you if a bad laquer went to the plant. That might mean thousands of defective pressings going out to retailers and buyers.

A mastering engineer's job in the vinyl era was to basically make sure that a proper laquer master could be produced from the specific program material on tape without altering the sound to any great degree. The M.E. would usually listen to all the tracks or songs and make notes of any inconsistent levels or peaks. The total time per side had to be determined to set the LPI control ("lines-per-inch"). During the actual disc cutting, the M.E. would make appropriate adjustments, "on the fly". There were definite time limits when cutting records, usually around 18 to 20 minutes per side. You could only cut those grooves so close before they would begin to touch or "inter-cut". In actuality, there is only one continuous groove, but as it spirals inward on the disc, it runs parallel to itself. The longer the time on a 'side', the shallower we had to make the groove; consequently using less level to keep the groove from wiggling 'out-of-bounds' and intercutting. There was a limit and a set standard as to how far in towards the center of the laquer you could go. The further towards the center you got, the slower the linear speed of the disc past the cutting needle. Subsequently, the 'high end' would begin to drop off rapidly.

About the only similarity in disc cutting then and CD mastering now was the never-ending quest for "hotter" levels. At Criteria, we were always bringing in the latest hit records and measuring their levels in the mastering room to see what the competition was doing. The hottest record I ever saw was the Beatles' "All You Need Is Love" which measured at peak an unbelievable +13 db! Most 45's at the time were peaking at around 8 - 9 db. The only tools we had back then were the compressors and equalizers, and those were used only to keep audio peaks from screwing up the laquers during cutting.

As previously stated, vinyl mastering limitations were of a physical nature. You simply could not make the stylus excursions go beyond a certain limit without frying the cutter head. And even if you could "maximize" or smash the audio signal into what we hear now, you'd burn out the cutter head trying to put that on vinyl.

Unfortunately - like many sound companies - there is a proliferation nowadays of 'mastering houses' owned by people who, by virtue of their financial resources, have become self-appointed ME's with little or no backround in audio engineering. Many of these houses advertise on-line and offer free samples of their 'mastering'. I recently sent a track off my latest album to one such company, just to see what they would do. What came back to me was almost laughable. The dynamics were completely gone, and the distortion was ridiculous.

In an attempt to 'master' my own album, I learned that it takes more than just a couple of plugins to do the job right. No matter how hard I tried, I could not match the levels of some professionally mastered commercial releases I used for a reference. Proper mastering requires thousands of dollars' worth of exotic gear and a very accurate monitoring system. The program to be mastered is most often taken out of the digital domain via very expensive and accurate D/A converters before it is run through several different analogue filters and compressors, all of which have their own 'flavor'.