Johnnyb, thanks for your information regarding the effects of the servo circuit used on the SL1200s and pardon my layman's knowledge of this subject.
I still find it questionable though.
As I understand it a servo circuit reads some method of feedback so many times a second and when there is fluctuation error the circuit makes a correction.
The process of the error, the sensing of the error, and the correction of the error, however quickly its done simply must create some stepping. Almost digital in nature.
Consider, back in the day when these circuits were first developed the reading rate was, say, 100 times second. Today that technology can read thousands of times a second.
I'm not sure how one would measure this but obviously the Panasonic engineers had a method which led them to change and/or improve this function on the SP decks. Using outboard processing and power supply to drive the far more robust SP motor they made two more versions of these functions in the SP controllers. Did any of these updates make it to the drive of the SLs?
That said, I would be skeptical of claims made by anybody marketing products for the SL.
On the broader picture of the SL1200 my experiences are like Zenblaster's. It didn't take a great deal of money to find a deck that takes LP playback to another level altogether. I learned this lesson the hard way with poor speaker choices and expecting better electronics to remedy a fundamental shortcomings of the speakers.
Still, when I brought my brand new SL home, punched that start button for the first time and that platter came up to speed so damn fast, that turntable endeared itself to me and I will not sell it.
After reading your tweaks I think I'm going to give them a shot. Thank you very much.
I still find it questionable though.
As I understand it a servo circuit reads some method of feedback so many times a second and when there is fluctuation error the circuit makes a correction.
The process of the error, the sensing of the error, and the correction of the error, however quickly its done simply must create some stepping. Almost digital in nature.
Consider, back in the day when these circuits were first developed the reading rate was, say, 100 times second. Today that technology can read thousands of times a second.
I'm not sure how one would measure this but obviously the Panasonic engineers had a method which led them to change and/or improve this function on the SP decks. Using outboard processing and power supply to drive the far more robust SP motor they made two more versions of these functions in the SP controllers. Did any of these updates make it to the drive of the SLs?
That said, I would be skeptical of claims made by anybody marketing products for the SL.
On the broader picture of the SL1200 my experiences are like Zenblaster's. It didn't take a great deal of money to find a deck that takes LP playback to another level altogether. I learned this lesson the hard way with poor speaker choices and expecting better electronics to remedy a fundamental shortcomings of the speakers.
Still, when I brought my brand new SL home, punched that start button for the first time and that platter came up to speed so damn fast, that turntable endeared itself to me and I will not sell it.
After reading your tweaks I think I'm going to give them a shot. Thank you very much.