Hi all,
First time boomboxer here so go easy, on a whim picked up a Sharp GF-9494 for what I thought was a good price on eBay, originally bought a bluetooth receiver to go into it and it was absolute garbage, so sent it back and instead decided to go down the Apple Airplay route. I already have a few cheapish all-in-one speakers as well as an Airport Express plugged into my main hi-fi, and it's nice to be able to stream the same music all round the house simultaneously.
Thought it'd make a nice winter project, but we're into spring now and it's been on the kitchen table too long! Wishlist for the project
The unit itself:
It's a wee bit battered but not too bad, adds to it's rustic charm I suppose! Gave it a bit of a clean up inside and out but saving a full strip down for another day. Also sprayed a boat load of contact cleaner everywhere and everything is sounding loads better for it.
The idea was to use one of these cheapo Airplay receivers I picked up from Amazon:
Actually sounds pretty good and wi-fi reception on it seems to be decent enough, it also creates it's own wifi network when out of range of my main network, so that'll be great for streaming to if I ever take it out and about.
I was going to connect that to the phono inputs using this:
That's the only thing I was going to hack about, desolder the inputs and re-attach them directly to RCAs for the input.
Then the last piece of the puzzle (and the bit I'm having trouble with) - power. Got one of these from Amazon thinking it'd do the job:
I was getting all excited, ready to go wild with the glue gun getting everything fixed in place, but thought I'd wire everything up and give it a quick test first.
iPhone connected with RCAs to phono input through line level convertor - sounds great. Did the same with the Airplay box powered externally, streamed like a dream. Then I hooked up the USB board internally to the power supply and plugged in the Airplay box- and I get crazy feedback.
I was a bit unsure of how to hook up the USB board - it's specs say it can take anything from 9V to 40V input and the output is 5V, I measured 33V across the power input (the black and red wires coming from the lower-right board in the picture below). There are 3 pins on the USB board, one input, one ground and one output, since the output is 5V I thought I'd try putting it in parallel, my thinking being the Airplay box wouldn't be drawing that much power - so plugged from the power output board into the input pin on the USB board, then out from there again to the input on main board.
So basically - not sure where to go to overcome this feedback? I thought it might be a ground issue, so connected a wire from the phono ground to the chassis of the line to phono convertor, but that didn't sort it. Perhaps I need to ground it from the power supply ground? Or ground the Airplay box somehow? Or perhaps it's nothing to do with ground and I've inadvertently wired up the power supply in a terrifying and haphazard manner?!
Any thoughts gratefully received...
First time boomboxer here so go easy, on a whim picked up a Sharp GF-9494 for what I thought was a good price on eBay, originally bought a bluetooth receiver to go into it and it was absolute garbage, so sent it back and instead decided to go down the Apple Airplay route. I already have a few cheapish all-in-one speakers as well as an Airport Express plugged into my main hi-fi, and it's nice to be able to stream the same music all round the house simultaneously.
Thought it'd make a nice winter project, but we're into spring now and it's been on the kitchen table too long! Wishlist for the project
- Not die or burn the house down (can't say electronics are my forté, I thought this'd be a nice project to learn a bit more though)
- No external modifications if possible - no holes drilled or pots sticking out or anything like that, keep everything inside and powered internally
- Keep as many existing features as possible working (tape, radio, mic in)
- If possible, have it so it'll run off battery too
The unit itself:
It's a wee bit battered but not too bad, adds to it's rustic charm I suppose! Gave it a bit of a clean up inside and out but saving a full strip down for another day. Also sprayed a boat load of contact cleaner everywhere and everything is sounding loads better for it.
The idea was to use one of these cheapo Airplay receivers I picked up from Amazon:
Actually sounds pretty good and wi-fi reception on it seems to be decent enough, it also creates it's own wifi network when out of range of my main network, so that'll be great for streaming to if I ever take it out and about.
I was going to connect that to the phono inputs using this:
That's the only thing I was going to hack about, desolder the inputs and re-attach them directly to RCAs for the input.
Then the last piece of the puzzle (and the bit I'm having trouble with) - power. Got one of these from Amazon thinking it'd do the job:
I was getting all excited, ready to go wild with the glue gun getting everything fixed in place, but thought I'd wire everything up and give it a quick test first.
iPhone connected with RCAs to phono input through line level convertor - sounds great. Did the same with the Airplay box powered externally, streamed like a dream. Then I hooked up the USB board internally to the power supply and plugged in the Airplay box- and I get crazy feedback.
I was a bit unsure of how to hook up the USB board - it's specs say it can take anything from 9V to 40V input and the output is 5V, I measured 33V across the power input (the black and red wires coming from the lower-right board in the picture below). There are 3 pins on the USB board, one input, one ground and one output, since the output is 5V I thought I'd try putting it in parallel, my thinking being the Airplay box wouldn't be drawing that much power - so plugged from the power output board into the input pin on the USB board, then out from there again to the input on main board.
So basically - not sure where to go to overcome this feedback? I thought it might be a ground issue, so connected a wire from the phono ground to the chassis of the line to phono convertor, but that didn't sort it. Perhaps I need to ground it from the power supply ground? Or ground the Airplay box somehow? Or perhaps it's nothing to do with ground and I've inadvertently wired up the power supply in a terrifying and haphazard manner?!
Any thoughts gratefully received...
