Klaas Robers wrote:Harry, the cutter may cut a sharp V-shaped groove, while the play back stylus has a rounded top (bottom) and should touch the groove at both sides half way the bottom of the groove and the surface of the disc. That is the reason that both sides of the groove should be well shaped. The shape of as well the cutter, as well as the play back stylus is very well defined. You should find more about that on the web.
Yes i will have to do some more reading ,i would rather try and make the cutter but i might double my chances if i can find a cutting stylus i like on line ..
I can see from the below drawing the cutter should be smooth ruff cut will cause noise from the sides ..i have seen some good and bad results on the net but in both cases its possible to knock something together that works this may have to be a bit of trial and error evolution learning from any mistakes .
Something we know the play back Stylus will scratch the tracks if you by mistake bump the play back arm on a record ..and i have noticed it will scratch a track on a blank cd if used via the cutting arm something i am wondering if its possible to play back ..or stay in that scratched track ...not the correct way of doing things but never know we are talking a different type of cutting surface here a cd not a record which seems harder . pretty much the edison idea he scratched the sound on foil and used the same stylus needle to play back .
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For play back 33 and 45 rpm records a small (artificial) diamond is used. For 78 rpm discs a saphire is used. The saphire has a more blunt shape as it should touch the grove much higher from the bottom. If you play a 78 rpm disc with the diamond it sinks deeper into the grove and you will hear distortion due to the fact that the bottom of the groove is less precisely shaped. On the other hand, if you try to play a 33 rpm disc with the saphire, it will not sink deep enough into the mini-groove and it will loose the groove and starts skating over the surface of the disc.
Its a large learning curve about records and record play back seems simple at first but is pretty complex to do it correctly over 100 years or so years of development .
I don't know anymore why you cannot make a saphire for playing 33 rpm discs and why you cannot make a diamond to play 78 rpm discs, but there is some reason for it. May be that saphire is somewhat flexible and will damage the bakelite groove less, while vinyl is more flexible of its own and the hard diamond will not damage it during play back.
I think i have a double sided stylus if i find it i will have a look under the mircoscope ...i suppose the recording speed via the tracking recording arm with those speed differences of 45 33 78 rpm ..i would think the tracks have to be narrower or wider with the speed change ...as with you mentioning the depth for the stylus for 78 and less for 33rpm...to keep recording time to maximum...makes my head hurt thinking about it ..i will stick with 78 and see how that gos !
My grammophone player, a Philips 202 electronic, was the last Philips grammophone that supported 78 rmp. It came with one play-back element GP400 with a diamond "needle" for 33 and 45. After some time I got a second GP400 element and a friend of mine at Philips, who did these things in his past, exchanged the diamond tip for a saphire tip for 78 rpm. Now I can again play back those old bakelite 78 rpm records.
I have a broken one that could play 16 rpm i have not seen any record in that format...its good you can still get stylus for your player older they are i suppose it harder these days to get spares or it becomes costly if they are rare .
When I came living in Valkenswaard, we had here a delicate factory: Philips Diamond tools. It was no more than a few 100 metres from my home. They made draw stones for the production of the very thin tungsten filaments for incandescent lamps, but also diamonds and saphires for grammophone stylussus. At a certain moment the factory stopped and they built there private homes.
That would of been handy if you could buy them there buy a few in bulk ...like every thing nothing lasts for ever sad as it is .
I can by the way the difference between the edison way and modern way for a record stylus image below
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.