A customer recently imported a vintage Presto 75A disk recording lathe from the USA, with a view to cutting records in Europe.
He quickly discovered, like many people before him, that it was spinning a bit slower than it should, when operated from 50 Hz mains, via a simple step-down transformer. As with most vintage record cutting machines, the platter is powered by a synchronous AC motor, which “locks” to the line frequency.
We have done 50 Hz conversions (and even some 60 Hz ones!) on many different lathes and turntables, using all of the possible methods of doing so: New rubber rollers, new capstans, new belt pulleys and even electronic frequency conversion (Agnew Analog Type 191 frequency converter) for professional disk mastering systems.
This week, we will have a look at the Presto 75A, a high quality machine, dating from the 1930’s, which was even used by the BBC as a broadcasting turntable!
Over the past few years, we have restored a number of SME 3009 and 3012 tonearms, covering most of their variants made over the impressively long production life span of this model range.
This outstanding tonearm was first introduced in 1959, setting a standard for high performance tonearm design which is still hard to beat, 60 years later.
We have used our restored SME tonearms on a large number of reference reproduction systems, for our own use and for our customers, such as the Thorens TD160 project which was presented here last February. These systems are excellent for Quality Control in vinyl record manufacturing, to ensure that any defects are caught early.
They are of course also capable of offering an intensely enjoyable, accurate listening experience, coupled with an accurate cartridge.
A rather optimistic gentleman arrived with a Presto MRC-16 disk recording lathe, inquiring about the possibility of repairing the broken suspension and making a cutter head bracket from scratch. He then asked about the possibility of figuring out some way in which lead-in, lead-out, and track mark spirals could be cut on this machine, which was originally intended as a very basic machine, with no provision for spirals, not even a hand crank. Then came the really ambitious part: He would ideally like to be able to adjust the pitch and if possible, control the lathe through his computer!
One glance at the steampunk aesthetic of the manufacturer’s name plate and the overall state of this primitive machine would have been enough to deter the average engineer, in fear that there might be something potentially radioactive hiding within…