Retro-fitting MP3 input to 1970s record player?

June 5, 2013 1:27 PM

I have a record player from the 1970s (a Garrard 2025 TC to be exact). How difficult (or risky) would it be to replace the sound input from the tape deck with a mini-jack input so that I can play MP3s (such as from an iPod) through the speakers? Is it just a matter of taking the back off, cutting wires and splicing them together?
posted by Grinder to Technology (4 answers total)

It really depends on the system. In my experience, however, things are very modular -- internally, you might even find things plugged into each other with RCA connectors, no cutting required. If it were me, I'd mess around with it like you're planning, but I'd prepare myself for the possibility of irreprarably breaking things.

Also, if you're talking about the sort of all-in-one stereo system that has a turntable, a tape player, a radio, etc., be aware that those '70s electronics probably have some large capacitors inside -- they can hold a charge a while, so don't zap yourself.

(btw: the model number you showed is just the drop-in turntable, not the system)
posted by AzraelBrown at 1:38 PM on June 5, 2013

Best answer: does this help?
posted by edgeways at 1:40 PM on June 5, 2013

Best answer: The tutorial that edgeways links above is really good. It's basically what I was going to recommend. Rather than looking from the signal coming from the tape deck and trying to insert the auxillary somewhere into the tapedeck, instead you just find the final amplifier section and wire your aux in there. It should be easy enough to find because both the photograph and tapedeck sections will have wires running to the amp.

You'll just need some way of adjusting the incoming level so you don't overdrive the amp. If you had an oscilloscope you could play something on the tapedeck and take a look at the signal and get an idea of the level that the amp section expects ... if you don't have that you can use a pot and adjust it carefully later.

Just keep in mind that somewhere in the device there will be a mechanism for adding RIAA equalization to the signal coming from the phono pickup, and you don't really want to inject your aux signal upstream of that. (The tapedeck shouldn't get the equalization applied to it though, so by looking at where that that is fed to, you should be safe.)

While you have the hood open, so to speak, you might want to put a couple of external RCA preamp outputs from the phonograph and tapedeck sections as well, just in case you ever want to use the machine to dub tapes or records to MP3. (Unless you have that capability in another machine already.) It's pretty trivial to do while you have it open and with all the tools available.
posted by Kadin2048 at 1:49 PM on June 5, 2013

I'd done this many times back in the old days, to convert boomboxes/console stereos into amps/pa systems. In the pre-digital era, it's often as easy as adding a switch to the wires going to the volume control pot(s) such that it cuts the connection from the internal sources (turntable/tape deck/radio) to retrofitted input jack(s). The volume pot/control usually feeds into the power amp portion of the circuit. This setup is surprisingly common with the old all analog stuff. However, there are exceptions that might keep you on your toes. Usual cautions about AC apply. Also possible concerns about impedance and level mismatching.
posted by 2N2222 at 2:28 PM on June 5, 2013