Riff Raff Makes

Bluetooth Restomod of a McMichaels Vintage Radio

I bought this radio from Ebay in a sorry state, it had been a parts bin for longer than I've been alive judging by the vintage of the parts lying around inside it. That didn't stop me from having a go at making it work first - it did power up, didn't have any output and components started pouring their fluids out pretty quick. It might have been revivable, in the sense that I could have a wee tube radio nobody wants. Instead I shelved it and picked up a bluetooth amp to mess with.

The parts

These parts are pretty optional, there are plenty of bluetooth amp combos as well as your inputs to consider, tuner knobs will work with my control scheme but a wheel would require a different approach, basically this'll get you this style of radio working or, if you just like the notion of an enclosure with a set of knobs for controlling your bluetooth amp/boombox.

The Amplifier US UK
I chose this one because it has momentary buttons for control, which are easily replaced with different switches
The switches US UK
I used this 4 pole 3 way rotary switches after failing to get momentary ones, I'd still swap to them but these do give a nice action, the power switch is the original one
The Speakers US UK
Obviously the speakers I got from my Kenwood centre speaker aren't an option but the idea's not bad, old centres are cheap, generally contain two full range speakers, if you look for something that didn't come with a sub they'll be better suited. Otherwise, I've linked some reasonably cheap speakers that should be a fair start for little outlay
The Knobs US UK
The knobs on my radio were missing so I picked up some cream chicken head knobs to replace them.

Gutting it out

This was really easy on this radio, after I pulled the tuner knob off I could remove the 3 feet that screwed the chassis in to place and remove all the components that were in my way, if you're committed to gutting something like this, you're best just to get some nippers out and start clipping components out, since it's all deadbugged in there.

Once I had this done I put all the bits I'd need to keep in the radio and stuck it at the back of a shelf for a while, I did reuse the original power switch, since it was fine and already fit nicely.

Rewiring the amplifier buttons

This is pretty easy with this particular board, the buttons all have a common rail, so you can take one lead to sort all your switch poles and just bring selector wires. I just popped off the tactile buttons and stripped a USB cable for Back, Forward and Volume Up/Down, the story's the same for each of these, basically the rotary switch just contacts the switch when it's moved in the right direction, if you're not tied to rotary switches by your enclosure any push button or even momentary on/off/on toggles would work in place of these.

Speakers

These are easy, just solder some leads on to the speaker terminals and use the screw terminals on the board, if you're not sure about polarity just make sure it's the same on each one, that'll generally keep you right.

I'm sure a lot of people would question my speaker placement, since it's pretty weird - it doesn't work right up against a wall but a few inches away from it and you'd be hard pressed to tell what was going on, I did have some notion of making a clever enclosure that allowed two front facing speakers through the front grill. (I wanted to keep the original grill cloth, with is glued to a plywood backing with the holes in it for the single original speaker.) Ultimately it's a pretty quick way to resolve the issue of having a less than ideal enclosure.

The speaker choice I made was based on having something to rob speakers from, it's not a terrible way to do it either. There's a lot of cheap kit with decent speakers that isn't sought after because it wasn't made by the right company at the right time, or more likely, it's got that less than desirable 90's styling.

How well it all works

Overall this works really well - it pairs in a second or two from switch on, the controls are responsive and it looks great. The sound is pretty decent, at some volumes it can get a little peaky on the highs and bass reproduction isn't stellar, to be expected with two full range speakers in an essentially open case. Despite that it's a good enough listening experience that it's worth it.

Making one portable

I toyed with the notion of making this portable, I'd sort of settled on the idea of doing it for around the house use, using a sealed lead acid battery and solar charge controller to deal with recharging, in the end this would be a fight to get in to the case. This amp presents an interesting option though - Dewalt have a beautifully overpriced bluetooth speaker available, not really worth it compared to any £20-30 speaker from china, however this amp will happily run at the range of voltages available from your power tool batteries - so a cheap knock off battery contains everything you'd need to make this work as far as protection circuitry goes.