CD 100 Crackles , Clicking and Distortion , Updated
This CD 100 is bought on eBay and still has some trouble ,Can I help?
“The reader had been completely revised with news capacitors and converted to 14 bits instead of 16 , When I received it, the reader had small problems: led tracks that flash, difficulty reading some original ed and often audible crackling during listening (or not). The seller encouraged me to return the drive to him in order to fix these problems. The drive returned a few months later, most of the problems seemed to be sorted out, he had also made a modification so that it heated less. But unfortunately, the crackling noises sometimes recurred with also some distortion during the playback on both channels. So the repair was not perfect, but the seller didn’t want to take care of it much anymore.”
Claims
“Perfect working condition.
- The unit was recently professionally serviced and audiophile modified (total efforts: about 30 man-hours)…
- The operational amplifiers in the output stages were replaced by highly acclaimed OPA2134 by Burr & Brown,
- The experts have put the TDA1540 D/A converter in the non-oversampling mode.”
Aha a NOS modification
Always curious
okay..!?
NOS module 14/16 bit trick..?
470 Ohm resistor, 5 volt from pin 24 to pin 5 , to switch SAA7000 in 14 bit mode.
Super glue
Removed NOS module
Disc height was not correct
Testing
UPDATE 2026-03-08 ,The player came Back , still problems ,
“Audio on right channel is muteed when the players just switch on after a few minutes it start working ..?”
On my workbench i can not reproductie the problem,..! One thing i notice , when touching the decoder board the UNEC is becoming HIGH and met both Channels
Finally i could reproduce de problem, humming sound and trouble with the relay on 1 channel, Causes is Voltage drop due to the modified rectifier, Diodes in Serie ?!
5 volt has a ripple off 700 mVolt
Then still trouble with reading Table Of Content ( TOC )
I added the Service-Manual Changes A03 to A05 on Servo and Decoderboard, A05 has a fault.
Replacing R3501 with a 1 Ohm Resistor , Short almost Capacitor C2501 , and leaves one side floating
Zenerdiode D6541 , must by replace with the 1 Ohm resistor, R3501 must be removed.
Reading TOC fast CD 100 Reading TOC after A03 to A05 changes
More trouble, some weird low frequent rumble , 99% fake BB OPA 2604
Youtube :Counterfeit Burr Brown OpAmps OPA2604
Update 2 : After playing many CD’s there is still something weird happening once in a while in the audio
Found 2 more hidden diodes, i missed ;-(
2 diodes in serie to input LM317 for 5 volt
And BAW64 + 1N4735 Zenerdiode to -18volt LM337
Update 2026 03 26 🙁 “Player has still problems” , this is very strange, it played several days more than 10 albums without problems..
Update 2026 03 30 🙂 “The CD 100has been working properly and there have been no further faults. So far, everything seems normal, and I hope it stays that way. I also wanted to let you know that I think the sound from the player is much better than before – it’s probably down to the changes you’ve made. ”