Unusual record player modification
Submitted By Member: Nuvistor
We had a customer who had bought a top of the range CTV then a top of Hackers range of HiFi, he had spent a lot of money with us.
So one day he walks into the shop with a relatively cheap portable record player, I thought nice easy repair but why does he want that with the Hacker he had.
It turns out he wanted to know if we could modify the player to play Pathe records from around the year 1910. This sounded interesting, I knew nothing about these Pathe records but he new enough. They run at 90 RPM and play from the middle out, they also use a Hill and Dale recording method. He knew automatic was not possible but could we help.
So after a bit of thought and talking through the options with him I decided on a course of action. First disable the automatic section, nice and easy, next get a piece of brass turned to be exactly twice the diameter of the 45 RPM step on the pulley that would fit over the stepped pulley. The last action was to get the cartridge to play the hill and dale grooves. I cannot remember the correct way to wire the cartridge but you put the two outputs in series, but cannot remember if its opposing or in phase, I think it was opposing, then get a stylus made with a suitable size for the groove, from memory about 5 thou radius.
The set worked very well, made the customer very happy and I enjoyed the change from Fixing TV’s.
From looking on the web it seems the modern way to do it is to play the records at 45 rpm, set the software to double the speed and record the vertical deflection of stylus, then use the software to clean the file up.
I had nothing like that in around 1975, but customer was very happy with the results.
Hey – Just found this – nice one. Proves if you’ve got it you don’t lose it. Regards.
Hi.
Interesting read. I’ve around a dozen hill and dale discs from 1912 they are not Pathe or the Edison Diamond disc but an obscure make, I’ve forgotten the make offhand and they are securely locked away, they are rare as there were only between 50 & 100 of each pressed, they are unplayed except when I modified a Sonotone 9TA cartridge wiring to record these discs.
For acoustic they are brilliant and the lack of surface noise uncanny, for the correct speed I got a motor spindle turned at a local engineering shop after working out its diameter, the deck is a Garrard AT6.
Hi Mike,
Thanks for the information on wiring the cartridge.
Frank
Regarding cartridge wiring, I once read an interesting thesis about optically scanning a disk (LP) and using software to render the audio.
It wasn’t until the final paragraph he admitted that he had assumed that one channel was vertical and the other horizontal deflection. But it only took a minor code change to fix it.
I Remember Tomorrow’s World demonstrating a turntable which could play records with and array of five lasers to scan the grooves.
It worked well, but I imagine it would be expensive to make & probably only viable for remastering by a record label or an organisation like the BBC who hold a large disk library.