CD Player repair

[Geoff101]

I have a Sugden SDT-1 player and an AU51 transport sat in my cupboard, both not working. Both used to work and were in my system. I had been waiting to send them to Sugden but they haven't been accepting service work for many months now.

The CDT-1 works as far as the digital output but all you get out of the analogue is a constant hum. I have tried the obvious things - replacing the DAC, filter and a big resistor on the bottom of the analogue PCB that had rotted away.

The AU51 Transport won't read. Again - I've tried swapping the laser, the whole mech and the mech with the board it's on but no difference.

Both of these are now beyond my random swapping bits approach and need someone clever to look at them.

Ideally, I'd like someone within reach of Oxfordshire if anyone can recommend someone?

I'd like to keep the transport as I have the matching DAC but the CD player will probably get sold so needs to be economically viable.

Thanks
Geoff

[dowser]

Shame you’re not in Switzerland, I’d happily take a look.

[Geoff101]

No-one??

[StanleyB]

Unfortunately you are just too far for me. But check the following in the CD player.
Take the top cover off.
Switch on the CDP
Put is a disc and see if it spins up.
The last part is important because it will tell you if the laser is seeing the disc or not. Only after the laser detects a disc will the motor start rotating so that the laser can read the CD files list and their location on the disc.

The constant hum on the CDT-1 could be a power supply issue. Check for a dry soldering joint on the voltage regulators and electrolytic capacitors in the power supply.

[ijrussell]

Not too close (Sheffield) but there is a chap on PFM called Mike Pickwell (@Mike P) who repairs TDA1541-based CD players/DACs and Philips CDM transports.

[Geoff101]

Thanks Ian - I'll try to look him up.

[WOStantonCS100]

Can I revive the thread and take it in a different direction while remaining on the same topic?

Here goes...

I am feeling pretty good. I am now 2-0 having just repaired/restored two CD players I had around the house:

1. Sony CDP-CX350

replaced all 3 belts (including the one under the platter)
replaced the laser assembly (lubrication where appropriate)
replaced the felt pads on the loading pinchers

2. Adcom GCD-575

cleaned the microswitch (the drawer would only open for a fraction of a second before closing again)

I have read forum advice that said this problem wasn't worth digging into the machine and better to just replace it. Hmmm, really... It took me all of 45 minutes, some acetone and an old toothbrush. Of note, this machine also makes use of the TDA1541A chip. I became very careful about what forum advice I heed many years ago.

NEXT!!!

[Lawrence001]

I'd never advise not to look inside a decent CDP to see if a problem is relatively easily resolvable. In this case it has a decent Stereophile review and some interesting features including remote controlled polarity (some find this useful to check if it makes a difference without getting up and sitting down again as the difference is subtle, if any!) and even better:

"Another novel feature is AFPC (Analog Frequency/Phase Contour). Switching this gives you a dip in the presence region, boosting frequencies below 1kHz by about 1dB, cutting frequencies above 1kHz by an increasing amount to –3.2db at 20kHz. This is akin to a slight LF boost upward with the Quad 34 preamp's tilt control."

So the Adcom is definitely a keeper!

[WOStantonCS100]

I'd never advise not to look inside a decent CDP to see if a problem is relatively easily resolvable. In this case it has a decent Stereophile review and some interesting features including remote controlled polarity (some find this useful to check if it makes a difference without getting up and sitting down again as the difference is subtle, if any!) and even better:

"Another novel feature is AFPC (Analog Frequency/Phase Contour). Switching this gives you a dip in the presence region, boosting frequencies below 1kHz by about 1dB, cutting frequencies above 1kHz by an increasing amount to –3.2db at 20kHz. This is akin to a slight LF boost upward with the Quad 34 preamp's tilt control."

So the Adcom is definitely a keeper!

Agreed.

First, I should say that the advice to ditch the Adcom was NOT from anyone here on AOS. So, no worries there!

Interestingly enough, the Adcom uses a Sony laser assembly. Everything is about implementation, right...? It's analog output is certainly acceptable. I do not find it irritating. There is also a coax SPDIF if one is so inclined. In stark contrast, through the analog outputs the Sony is just a run of the mill mega cd changer at best, sometimes annoyingly sterile with all the digital nasties one would expect. However, like most of them, this has Toslink optical; so, the possibilities of better sound are endless. Even just running the digital out to the Sony receiver is a notable lift in sound quality, in my opinion.

Most importantly, since the Denon DCD-1600NE is getting the boot (sadly), for very little cash outlay, I have not lost a disc spinner...I have gained two.