Audio Systems: Add audio jack to record player..., old vinyl records, resistor network


Question
My wife wants me to make digital copies of about 100+ old
vinyl records. I recently bought a combination radio/record
player that has no audio output jack. (Detrola,Model KM837)
I'd like to add a jack and then copy the records to my
laptop, then to her Ipod. Can you give me an idea of what
I'll need? I went to Radio Shack today and they looked at
me as though I was from outer space. They didn't have a
clue. I did something similar when I was a teenager (in the
1950's) and while it worked, I recall that the volume for
the earphones was overpowering. I think I added a resister
to that one but there must be a better way. You can tell I
don't have a lot of experience here. Can you get me
started? Thanks, Bob, Augusta, Georgia

Answer
If it does not have an audio output then you are better off purchasing different hardware.  The cost of adding an audio output jack is enormous and requires engineering consultation.

BUT: Wait.  Does this unit have loudspeakers or headphone outputs?  It must have some output somewhere.  What ever that is it is possible to adapt an output from it.  Since I am not familiar with this model can you explain its overall product features to me so I can tell you if there is hope?

FOR EXAMPLE: If there are speakers in the box then you can get output from the amplifier that is feeding the speakers; you must know how to get at the speaker wires and to build a bridging resistor network such that electrical isolation is sufficient and reduction of the level is suitable for line level audio to feed an iPod or recorder.  

Hope this gets you started on the project.

C

PS:  You will find this unit is not really HIgh Fidelity and if you want good results from your LPs you will be better off with a good turntable and preamp to feed a recorder or other device.