Garrard model 3500 turntable made standalone

I’ve been refurbishing a Packard Bell solid state stereo console (probably close to an RPC-720) and I decided to remove the built in turntable and fit my own in its place.  Technically mine is less featureful in that it doesn’t do 78rpm, but it was a gift and is of better quality than the old one. That being said it seems this turntable still works (once I lubed it a bit) and I made it into a standalone box so it could still be of some use. 

It seems to use a U-21.1 829 stylus.  I found some information on this indicating that it’s a ceramic cartridge, but it also is a later model one that has a signal strong enough to use a magnetic cartridge preamplifier.  I cannot confirm that because I had an unused preamp (this one) and could get nothing out of the turntable.  I tried isolating the preamp circuit in the stereo console radio module and was able to use just that portion of the circuit and route it out to a separate amplifier. 

preamp functioning isolated from the rest of the radio unit

Now I needed to trace the circuit and luckily it was standalone and just used the dc power supply in the radio unit to power the preamp.  Here’s the circuit I traced:

This is a mono amp, there are two of these in the console

I decided to remove that from the radio and just route the input signal to the output so I can use my turntable with built in preamp here. 

well labeled board harvested of components and bypassed

Now I need to reassemble the components into a small box, let’s use that preamp I tried earlier and has not been super useful. 

there’s also components on bottom

This works, it’s not ideal from an audio quality standpoint, but right now my priority is making this thing useful, not good. 

4 pin plug, green earth, black switched mains, red hot, black neutral

One thing that I didn’t expect is the turntable being just straight mains powered and having switched mains out.  That switched mains is used to power an external amp, I mounted an interesting set of outlets on the back of the turntable box, you can use it for an amp if you like.  I also used some right angle mounted audio jacks stolen from the original cabinet and a nice switched and breaker-ed mains input jack I found. 

No idea where I got those outlets but I have a bunch and I love them

That’s that.  It works, now.  Some handles and some feet and now it’s at least a moderately servicable turntable which can continue to be useful.

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