Does anyone know what would cause a hum through speakers when CD player turned off? When it is on, dead silence. As soon as I turn it off, hum starts. Hum changes volume when volume is adjusted.
Either AC mains transmitting through dead power supply and transistors, or it doesn't know the words.
Doctor recommends not turning it off while it's selected on the preamp.
Doctor recommends not turning it off while it's selected on the preamp.
Your suggestion applies only to countries with reversible outlets...
As the O/P has not indicated their country of origin your advice is too localised to be of help.
As the O/P has not indicated their country of origin your advice is too localised to be of help.
The CD player when on probably presents as a very low impedance across the outputs. Perhaps when off the outputs are floating and picking up hum via the RCA leads.
You need to look at the player and see what the muting arrangement is to confirm this although ultimately it probably isn't the cause in the sense of being faulty.
You need to look at the player and see what the muting arrangement is to confirm this although ultimately it probably isn't the cause in the sense of being faulty.
I am actually planning to replace the built in RCA leads with jacks, I will have a look then. Who knows, maybe even this change will fix it ... if I am lucky!
Dare we ask what player it is with captive RCA leads 🙂 Sony used to do that trick on some of their older tuners.
It is my 37 year old Philips CD-202. It is one of 2 I have, 1 original (this one) and 1 modified. I am trying to keep this one as original as I can. So far I have only had to recap the servo board as it stopped reading discs, and change the LED display (segments burn out, common issue). Aside from that it is mint, and works flawlessly.
So that is an oldie 😉
Those use a relay that just opens the audio path at the final output although it does leave a 100k in circuit to ground. They might even be reed relays going that far back.
One possible mod would be to link the relay out and to add a relay instead that shorts to ground when off and opens when on. You would use the same relay drive signal as used now to operate it.
Those use a relay that just opens the audio path at the final output although it does leave a 100k in circuit to ground. They might even be reed relays going that far back.
One possible mod would be to link the relay out and to add a relay instead that shorts to ground when off and opens when on. You would use the same relay drive signal as used now to operate it.
I am pretty sure it does use reed relays, and I happen to have some extras left over from when I replaced them in my CDX (Philips CD104) .... they do tend to stick.
So just an update, I replaced the standard RCA cable that these have soldered directly to them with a set of RCA jacks, and the issue is now gone.
and thanks for the update.