Monday, August 3, 2015

Fixing the SCD-1, SCD-777ES, or other transports

Advice on fixing SCD-1 or similar transport

General advice on fixing CD players from Lampizator, a celebrated audio modder.  Lampizator has spent more time noodling around with old CD players than anyone, and he says he has only once ever seen a bad laser, and that was caused by his boosting the laser drive signal.  Most of the time, CD problems are caused mechanical failures of various kinds, many due to accumulating grunge or hardening lubricants.   Lamizator curses the professional techs who make bucks by unnecessarily replacing lasers, therefore depleting the precious stock of factory parts.  He says that if you can hear the disc spinning at a controlled speed for 2-3 seconds when the disc is loaded, the laser is fine because in most players the disc won't even start spinning unless the laser detects a reflective surface.

It does now seem that the "fixed laser" transport (FPM) was Sony's most intense, and probably best, effort to remove transport vibration and jitter.  Sony had been making these transports back to the beginning of the CD era with the professional CDA-5000 Compact Disc Analyzer, and a series of high end CD-only models in the 90's also used a fixed laser transport, such as the CDP-XA7ES.  The last go around was for the SCD-1 and SCD-777ES models.

The Vintage Knob says:

FPM was intended to suppress vibrations where there are more in the first place (the spinning CD) rather than try to minimize those which have a much lower magnitude - in the laser pickup itself.
So the disc's spinning motor and rotor become the moving parts (one big moving part), and the laser block remains... fixed on its base.
But TVN also says that FPM was less expensive than Sony's other premium mechanism, the all aluminum BU-1 with magnetic rails.  And lower cost was a key motivation to bring it back in the mid 1990's.

The SCD-1 did achieve a lower jitter measurement in Stereophile than I remember for any other player, FWIW, playing CD's.  However I have not tried doing a systematic comparison and the jitter measurement techniques may have changed over the years.

While the original high end SCD players have many SACD loving fans (the consensus emerged almost right away that there were better Redbook players from Esoteric, Krell, Marantz, and others) many have had a love/hate relationship with the transport.  It is apparently somewhat unreliable, and by 2006 or so many owners were stocking up on lasers, sled motors, and spindle motors.  Sony tends not to offer service or even parts after 10 years or less, and they may have already used up all the spare parts before them in earlier repairs (sometimes unnecessary part replacements, according to Lampizator).

The general consensus now is that Esoteric makes the best mechanisms such as the VRDS which itself comes in several versions.  But if I want a "reference" player specifically for SACD, the SCD-1/SCD-777ES still represent a kind of reference benchmark.

Here are the 3 parts that some people were stocking up on:

1. Spindle motor: P# 1-763-254-11
2. Sled motor: P# X-4952-147-1 
3. Laser Pick up: P# A6062396A

Here's a thread with a guy fixing an SCD-1 which originally had pictures.

A friend has a boom box with cassette and CD player.  The CD player is often not working, though I got it to work a few days ago up to track 7 out of 10.  I think there is possibly something making laser movement difficult.  We agree it is worth fixing this because CD/Cassette boom boxes are basically not being made anymore, thanks to the kind of planned "markets" we have (planned by corporations to extract the maximum from us).

It's a CFD-S26.  Here is a similar model being repaired:

And here's a DIYAudio thread about fixing CD transports that starts (near the end) to discuss the adjustment of the sacred pots "track and gain" and "focus gain" that the service manual advises you not to adjust.  Well apparently lots of people with nothing to loose often try and win, for a few months anyway.  I once saw a friend adjusting those pots…and it looked just crazy.  After watching that you wonder how CD's mostly work at all, if just a hairs breadth of a turn of some pot inside is the difference between Perfect Sound Forever and junk.  But then again, I once calibrated a Sound Technology 1700 analyzer…and that's a similar experience.

And here's a more detained DIYAudio thread on CD player restoration and adjustment.

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