Newbie Question

Hello all,

I've been on these boards just a few hours, so please forgive my ignorance on all things related to my new toy, a Magnavox PD6709FE91 Console. I bought this from an individual who refinishes and updates stereo cabinets locally, and was as excited about its use as a piece of furniture as I was about the radio/phonograph itself.

I am most interested in using the working components of the unit, and if something is FUBAR, I will simply place more modern electronics into the unit to get the job done (note: I don't mean I will hack the circuitry, I mean I would probably get a small receiver or home theater PC and use it to drive the existing speakers using the console's stereo out ports). The phonograph is working, the 8-track is working, and the AM radio is working. The FM radio does not work and I'm encountering a couple of issues with the stereo line-in (which I planned to use to hook up iPod, etc). I can deal with the lack of FM radio, but I would really like to salvage the line-in functionality if I can.

I can get sound out of the line-in (actually, the 8-track hooks into the same line-in and sounds fine) but when I connect an iPod or other device through an adapter, I get muted sound and tons of distortion if I turn the iPod device output beyond 50% or so. At this level of input to the unit, I have to turn the volume up to max to fill the room. When the AM radio is turned on, max volume will blow my eardrums... so it doesn't appear that there is any problem with the speakers themselves.

Again, I apologize for my ignorance. Is there something I can/should do to correct this issue (and/or should I bother to see a service technician)? Or, should I just move on and enjoy the piece of furniture and my ability to finally play my Dad's LPs?

Ipod devices sometimes are simply not compatable with vintage gear, unless substantial modifications are done.
Line input/outputs are based on "line level" voltages and a particular loading, depending on the type of equipment involved.
Solid State = usually low impedence. (10K-47K)
Tubes = high impendance. (250K-2Meg)
The voltage level required is usually .707v, roughly half a volt.

Not familier with that particular console, I'd say it's loading the Ipod down.
Perhaps if the 8 track was dis-connected, it might make a difference - only IF the tape player is in circuit at the same time.

Over the internet it's difficult or impossible to determine things farther.

MattTech wrote:Ipod devices sometimes are simply not compatable with vintage gear, unless substantial modifications are done.
Line input/outputs are based on "line level" voltages and a particular loading, depending on the type of equipment involved.
Solid State = usually low impedence. (10K-47K)
Tubes = high impendance. (250K-2Meg)
The voltage level required is usually .707v, roughly half a volt.

Not familier with that particular console, I'd say it's loading the Ipod down.
Perhaps if the 8 track was dis-connected, it might make a difference - only IF the tape player is in circuit at the same time.

Over the internet it's difficult or impossible to determine things farther.

Many thanks for the quick reply. It's truly remarkable to be able to have access to skilled insight from you and the members of the forum. I am reasonably electronics-savvy (I run a research lab that studies neurophysiology) and have a multimeter at home (and an oscilloscope and electronics shop in my lab) that I could use in a pinch. I imagine that if indeed the line in is underpowered, I will need to figure out what the solid state input is expecting. I wonder if there is a way to do this "non-surgically" (i.e. without probing the guts of the SS components in fear of disrupting the currently-working parts)? ...perhaps starting by measuring the impedance of the 8-track outputs (that seem to work fine when loading the same input circuit)?

The logical way to go about this is determining from a service schematic what the line inputs are all about - and only then can a proper "fix" be implimented.
Without a schematic, and knowledge of impedences involved, plus poking around blindly, will only be a waste of time, guessing, and endless frustration.

MattTech wrote:The logical way to go about this is determining from a service schematic what the line inputs are all about - and only then can a proper "fix" be implimented.
Without a schematic, and knowledge of impedences involved, plus poking around blindly, will only be a waste of time, guessing, and endless frustration.

Thanks for the advice. I will let you know what (if anything) I am able to figure out.