16-04-2023, 03:58 PM
No, can't be right.
If that were the case, why on earth did they bother to fit the XTAL?
Indeed, the PD1003 also has provision for an RC oscillator, which is not used in this deck.
I'm pretty sure the presets are to set the loop conditions for each speed. Sadly, the adjustment of these are not explained in the service manual. It references another document (ART-467), which I haven't turned up yet.
However, this gives a lot of extra detail about the chipset. Jump to page 13.
http://www.cieri.net/Documenti/Altri%20m...~1980).pdf
On page 30 they give some general information about adjusting the pre-sets when in using the chipset in an XTAL setup.
I've also included a copy of the service manual from Elekrotanya which gives a better quality copy of the schematic.
To make it run at 78 RPM, I think you'd need to use the RC oscillator in PD1003, and ground pin 11 (probably). At the same time, you'd probably need to switch in another resistor in place of the two pre-sets. And that's assuming the power IC is happy working at the higher speeds. Or, assuming you want to digitise the record rather than just play it for fun, speed correction software. Audacity lets you do it:
https://manual.audacityteam.org/man/reco...cords.html
If that were the case, why on earth did they bother to fit the XTAL?
Indeed, the PD1003 also has provision for an RC oscillator, which is not used in this deck.
I'm pretty sure the presets are to set the loop conditions for each speed. Sadly, the adjustment of these are not explained in the service manual. It references another document (ART-467), which I haven't turned up yet.
However, this gives a lot of extra detail about the chipset. Jump to page 13.
http://www.cieri.net/Documenti/Altri%20m...~1980).pdf
On page 30 they give some general information about adjusting the pre-sets when in using the chipset in an XTAL setup.
I've also included a copy of the service manual from Elekrotanya which gives a better quality copy of the schematic.
To make it run at 78 RPM, I think you'd need to use the RC oscillator in PD1003, and ground pin 11 (probably). At the same time, you'd probably need to switch in another resistor in place of the two pre-sets. And that's assuming the power IC is happy working at the higher speeds. Or, assuming you want to digitise the record rather than just play it for fun, speed correction software. Audacity lets you do it:
https://manual.audacityteam.org/man/reco...cords.html
