akai ap-306C; is it any good?

It's a pretty average 1970s Japanese deck. Akai were really tape specialists then so not really known for their turntables.

Basically it's nothing special by the standards of that time but better made than your average plasticky entry level deck today so well worth a spin. Put a Denon DL-110 on it and make sure it's on a steady platform of it's own.

The main shortcomings will be the so-so '70s arm and wiring and the usually poor isolation afforded by the plinth design. Usually these kind of decks have a decent enough Matsu****a direct drive motor mounted in a rudimentary plastic or composite plinth with little thought given to isolating the thing properly.

So on paper the standard measurements for speed stability etc will far outshine a more modern audiophile beltdrive like the Rega or Pro-Ject, but this will be completely negated by the lack of attention given to effectively isolating the motor noise and vibration from the record.

You can usually improve matters greatly by fitting a modern platter mat made of materials like sorbothane or acrylic which were either not invented or else very expensive back then and only found on top of the line decks

This will damp the platter which is usually thin ring-prone pressed steel and prevent a lot of the motor vibration getting to the record.

Also sorbothane feet will help isolate it from it's own vibration and that coming from it's surroundings, another big problem. Adding mass to the plinth if you are handy a DIY is a good idea as the heavier it is the less it will be affected. A good trick is a marble chopping board with sorbothane feet making a support for it.

If you have concrete or stone floors then it will work well enough placed on any heavy furniture. If you have springy suspended wooden floorboards then a wall shelf is the way to go.