This is way off the cuff but we can't understand what's going on. In his tv room, my son has an older Sony CD player hooked up to an amplifier (used both an old Onkyo integrated and presently a newer Marantz). He is an opera lover so he plays opera on the CD player and if he listens in a long session, the next time he turns on his amplifier not always but often, the opera music starts to play where he left off and the CD Player has yet to be turned on and even if he removes the CD from the player that isn't turned on. Can anyone explain this phenomenon. When he told me that I laughed at him so when I visited him he demonstrated and sure enough it happens. The CD player is only hooked to the amplifier through the rca plugs and are powered from the same power strip but separate plugs. If anyone can make a semblance of sense out of this I would appreciate it.
A guess: does the amplifier digitally process the signal somehow? In that case it could have some of the previously played disk stored in a buffer.
I doubt either of these amplifiers, especially the old Onkyo (ca late 80s), have any digital buffer. Obviously he hasn't done all possible tests but it was just bizarre for him and likewise myself. For example he has never seen how long it will play more than a minute or so, nor unplugged the CD player, etc. Just though some electronic guru might explain it or someone else has ever had the same experience. Thanks for the guess. I guess I couldn't say you're not correct.
Don't know if it helps, but the CD player is a Sony CDP203ES never modified. The first amp was an Onkyo Integra A8015 and the second amp a Marantz PM5004.
If it plays for a second or two , it's the antiskip buffer. The power would have to be either ON or Standby for this to happen as well.as a battery backup on the board.
I suppose that's a possibility but it plays much longer than a few seconds and both the CD player and amplifier have been off for some time, i.e. 1 day. Not sure if either of the amps have battery backup, but the CD player is out of the 80s and unlikely to have any battery still working. I suppose a capacitor might store enough juice to run a buffer.
I observed it with my car audio. It continues playing the CD from the point where I had stopped previously. Provided the same CD is loaded in. But my home CD player doesn't do it.
It'll be a firmware bug - probably a soft on/off switch so the firmware's always active if plugged into the mains. The on-off switch on the front panel provides a signal to the microcontroller/microprocessor, it doesn't switch anything off really.
Switch off at the mains and you'll probably save a measurable amount of electricity as well as avoid ghost CD playing!
Switch off at the mains and you'll probably save a measurable amount of electricity as well as avoid ghost CD playing!
It all sounds very odd to me. The Sony player is only 2nd or 3rd generation technology (from the mid 1980's) and very little different in the audio stages to the original CDP101. This player has a proper mains on/off switch 😉 no standby supplies or backup supplies here.
The Marantz amp looks pretty conventional to me.
The Marantz amp looks pretty conventional to me.
In support of what Mooly is saying, the CD player is very old and the Onkyo Amp it was originally hooked up to was of similar age, out of the 80s. I would be shocked if there was a significant buffer in either piece and remember that this happens when the amp is turned on but no the CD player and even if the CD in the player is removed. I will have him see how long it would play under those conditions when it happens next. There has to be an explanation as I am reluctant to call Ghost Busters as I am a retired scientist.