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Topic: Technics SL-XP 300 (Read 4374 times) previous topic - next topic
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Technics SL-XP 300

Hi Guys!

I just thought I´d share a little story with you: my first CD-player was a Technics SL-XP 300 which was a little portable player. I bought it back in 1991 for 300,- Deutschmarks. It came with a cable remote control built into the headphone cable but was used most of the time at home. It was replaced in 1995 by a Pioneer PD-S 802. Anyway, shortly after purchasing the Pioneer the Technics fell to the ground by accident and the shaft on which the tracking mechanism slided was dislocated. I couldn´t repair it and so I put the player into the garbage. The more the years passed I grew more and more melancholic towards the Technics. I wanted to have back, checking every now and then into eBay to maybe win another one. One week ago I was lucky and yesterday the player arrived - for just 9.10 Euros incl. shipping costs.



There are some scratches on the players' surface but it apparently was in good condition - since it played the first CD I tested it with rightaway. But the sound coming out of the headphone output was horribly distorted on transients. I thought "Well, some parts have aged in the 20 years - at least it´s only a portable player probably not designed to live that long". I dissambled it anyway only to find that some sugary liquid had been spilled into the player some time ago, most of this sticky, dried liquid was underneath the little mainboard and obviously created leakage. With the dried liquid this thick I was wondering that the player was even running properly! So I cleaned the mainboard from underneath with isopropylic alcohol using a toothbrush and approximately 50 Q-Tips. Some solder points even had some surface rust which thankfully could be removed. The worst point was the place where the headphone amp had been soldered on: there the liquid had turned to the colour of intransparent caramel, probably because of some heat from the amp. Thankfully the top of the mainboard and the drive were not "stickyfied".

Guess what, now the distortions are completely gone. I also was interested in how good a 20 year old little portable player would measure. See here:



Pretty good, eh? Actually I´m a bit surprised that it still measures this good, I didn´t expect this. On closer inspection of the graphs though it appears that it jitters relatively much and has relatively high distortions at higher frequencies, especially with signals coming close to 0 dBfs. I also measured my Pioneer DVD-player some time ago which does not have a problem with those signals. Is that normal for older CD-players? What part has aged?

I also recorded the testsignal in 88.200 kHz to see the aliasing artifacts (from a test I´ve read in 1991 I knew that it has them), here they are in iZotope with music:



With the RMAA created testsignal it could be seen that they also reach down into the audible frequency band. It also inverts the polarity of the outputted signal.

If I wanted to find out how it sounds against a, say, digital rip how I´d do it? I did a recording with my E-MU in 88.200 of some songs and compared them to their (upsampled to 88.200 in order to avoid some resampling inside windows) counterparts ripped from the same CD with the pc drive. I assumed that the E-MU is good enough to do measurments and a comparison but I don´t really know if that assumption is correct. Anyone interested in audio signals?
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