<p>Hey guys</p>
<p> </p>
<p>As per my intro thread, I recently acquired the Hitachi 3D Super Woofer I'd wanted for a couple of decades or so, and finally got round to getting.</p>
<p> </p>
<p>I love it, but as with most things, I struggle to leave them as they came out of the factory, and this will be the same.</p>
<p> </p>
<p>First thing on the agenda was bluetooth, since obviously we pretty much all carry tons of music on our phones these days and it removes the need to have an Aux in cable plugged into the back of it.</p>
<p> </p>
<p>So I set about opening it up after first taking it for a camping trip last night just to christen its new ownership.</p>
<p> </p>
<p>It was easy enough to solder up the audio connections to the bluetooth module I had (taken from a very low power home made bluetooth only boombox I made last year for camping), so the main issue here was to find suitable power for it. </p>
<p>The bluetooth module I've got here is one that is originally powered by a USB socket, so 5v.</p>
<p>I got my multimeter and started probing around to find some power (since I couldn't see where the main power reaches the boards without completely stripping it (I only removed the top cover to expose the main circuits).<br />
Found several points showing 8.4 volts, a few at 11.4, a couple around 7v, and one that was bang on 5v. Bingo!<br />
<br />
Or not as it turned out. I tried to power the BT dongle from this but found that with a load on it, there was basically no real voltage there after all. Shame. <br />
I tried one of the 8.4v connections (while wondering if it would fry the dongle!), and found they provided suitable power but each time I could hear slight electronic interference when it was powered. Seems to be almost like having a cellphone near a speaker, as it sounds like a data signal from the dongle coming through as audio of sorts. Not sure if that makes sense but almost like you'd hear from a dial up modem or something.<br />
<br />
Couldn't get away from this annoying noise no matter what power feed I use, albeit it's pretty quiet and as soon as you actually play music you cannot hear it. However, I figured that it could just be the power feed so to also protect the dongle and give it the correct 5v supply I'd add in an LM2596 step down voltage regulator.<br />
So I have added one of these to convert the 8.4v down to 5v (these regulators are adjustable and very cheap, about £2), but found it still has the annoying 'data' sound.<br />
<br />
I have wired it in and it all works ok except for this noise you can quietly hear until you play music.<br />
As per just about every bluetooth streaming device I've ever used, it is less loud than the other sources, and I'm not sure if it's worth trying to cater for that with a tiny pre-amp or something. Has anyone done this on here?<br />
But in general it sounds fine, so that's mission 1 accomplished. <br />
<br />
If anyone has any bright ideas how I can stop that noise, or increase the level a little bit on the Aux to make up for BT being less loud then it'd be great to know, thanks!<br />
<br />
This is the guts of the BT dongle I have used:</p>
<p><img alt="BT2_zps4sqtrpik.jpg" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/BT2_zps4sqtrpik.jpg" /></p>
<p> </p>
<p> </p>
<p>Here's the step down regulator I wired in - very handy little things:<br />
<img alt="75e36f67-b098-49f3-bfe0-2f921e36ee24_zps" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/75e36f67-b098-49f3-bfe0-2f921e36ee24_zpsz8omkxxt.jpg" /></p>
<p> </p>
<p> </p>
<p>The two bits wired in together. I have then put some tape around them to prevent any shorts against any existing parts, reassembled, and tested. Works great aside from those 2 minor points I mentioned.<br />
<br />
<img alt="cc5af501-6676-463b-b4fe-fa00c3f0eb00_zps" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/cc5af501-6676-463b-b4fe-fa00c3f0eb00_zpsfgdk68r8.jpg" /></p>
<p> </p>
<p> </p>
<p>So things I want to look at next include stuff like:</p>
<p> </p>
<p>1) Replacing the 8x D cells with a better battery pack alternative (ie that doesn't cost a lot to keep using!).</p>
<p>I am thinking either a Lithium Ion battery pack made of some 18650 cells maybe. I know they can output a lot of grunt so probably more than capable compared to D cells, and can also store quite a lot of amp hours. <br />
I have one of those "power banks" for charging USB devices, and I'm sure it's full of those cells. I think it has something like 26ah capacity, so I'm sure some of these might be suitable to make up a rechargeable 12v (ish) pack. Has anyone else done this? Interested to know more if you have!<br />
I think with those they are 3.7v each so a pack would either be 14.8v or 11.1v. I'm not sure if the first would be too much voltage over 12v and the second not enough to directly replace, or if I would have to use a voltage regulator to get it right on 12v maybe??</p>
<p> </p>
<p>2) I'd like a power meter to show what charge is left.</p>
<p> </p>
<p>3) Probably a USB socket so that things can be charged/powered from it if necessary</p>
<p> </p>
<p>4) I have had an idea about using a raspberry pi with a touchscreen and SD card slot for media to also pipe through the Aux in. I had thought about this being in place of the left hand tape deck (since the right one has auto-reverse and that's a nice feature to keep). Not sure about this as it would mean some savagery on this beast and I'm a bit reluctant to do that.</p>
<p> </p>
<p>5) I ordered one of these MP3 player things, which has a screen, SD slot, USB socket, control buttons, and a remote control. Again, I was hoping this would fit in the space of the first tape deck if I can fit it by removing the door, and making a replacement panel. I don't think it could sit flush, but if it's able to revert back to original without wrecking the deck then I don't mind it sticking up. <br />
Also, since it appears to have a spectrum analyser display then that deserves to be seen, so I'd probably angle it up a bit anyway.<br />
<a href="http://www.ebay.co.uk/itm/331617734176?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT">http://www.ebay.co.uk/itm/331617734176?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT</a></p>
<p> </p>
<p><br />
Not sure how far any/all of this will get but we'll see! All fun & games.<br />
<br />
If you guys have thoughts on any of this and good ways of doing any of these bits then I'm all ears, but I will update this topic with any bits as I go along.<br />
<br />
Cheers</p>
<p>Jim</p>
<p> </p>
<p>As per my intro thread, I recently acquired the Hitachi 3D Super Woofer I'd wanted for a couple of decades or so, and finally got round to getting.</p>
<p> </p>
<p>I love it, but as with most things, I struggle to leave them as they came out of the factory, and this will be the same.</p>
<p> </p>
<p>First thing on the agenda was bluetooth, since obviously we pretty much all carry tons of music on our phones these days and it removes the need to have an Aux in cable plugged into the back of it.</p>
<p> </p>
<p>So I set about opening it up after first taking it for a camping trip last night just to christen its new ownership.</p>
<p> </p>
<p>It was easy enough to solder up the audio connections to the bluetooth module I had (taken from a very low power home made bluetooth only boombox I made last year for camping), so the main issue here was to find suitable power for it. </p>
<p>The bluetooth module I've got here is one that is originally powered by a USB socket, so 5v.</p>
<p>I got my multimeter and started probing around to find some power (since I couldn't see where the main power reaches the boards without completely stripping it (I only removed the top cover to expose the main circuits).<br />
Found several points showing 8.4 volts, a few at 11.4, a couple around 7v, and one that was bang on 5v. Bingo!<br />
<br />
Or not as it turned out. I tried to power the BT dongle from this but found that with a load on it, there was basically no real voltage there after all. Shame. <br />
I tried one of the 8.4v connections (while wondering if it would fry the dongle!), and found they provided suitable power but each time I could hear slight electronic interference when it was powered. Seems to be almost like having a cellphone near a speaker, as it sounds like a data signal from the dongle coming through as audio of sorts. Not sure if that makes sense but almost like you'd hear from a dial up modem or something.<br />
<br />
Couldn't get away from this annoying noise no matter what power feed I use, albeit it's pretty quiet and as soon as you actually play music you cannot hear it. However, I figured that it could just be the power feed so to also protect the dongle and give it the correct 5v supply I'd add in an LM2596 step down voltage regulator.<br />
So I have added one of these to convert the 8.4v down to 5v (these regulators are adjustable and very cheap, about £2), but found it still has the annoying 'data' sound.<br />
<br />
I have wired it in and it all works ok except for this noise you can quietly hear until you play music.<br />
As per just about every bluetooth streaming device I've ever used, it is less loud than the other sources, and I'm not sure if it's worth trying to cater for that with a tiny pre-amp or something. Has anyone done this on here?<br />
But in general it sounds fine, so that's mission 1 accomplished. <br />
<br />
If anyone has any bright ideas how I can stop that noise, or increase the level a little bit on the Aux to make up for BT being less loud then it'd be great to know, thanks!<br />
<br />
This is the guts of the BT dongle I have used:</p>
<p><img alt="BT2_zps4sqtrpik.jpg" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/BT2_zps4sqtrpik.jpg" /></p>
<p> </p>
<p> </p>
<p>Here's the step down regulator I wired in - very handy little things:<br />
<img alt="75e36f67-b098-49f3-bfe0-2f921e36ee24_zps" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/75e36f67-b098-49f3-bfe0-2f921e36ee24_zpsz8omkxxt.jpg" /></p>
<p> </p>
<p> </p>
<p>The two bits wired in together. I have then put some tape around them to prevent any shorts against any existing parts, reassembled, and tested. Works great aside from those 2 minor points I mentioned.<br />
<br />
<img alt="cc5af501-6676-463b-b4fe-fa00c3f0eb00_zps" src="http://i26.photobucket.com/albums/c113/Cret/Cret015/cc5af501-6676-463b-b4fe-fa00c3f0eb00_zpsfgdk68r8.jpg" /></p>
<p> </p>
<p> </p>
<p>So things I want to look at next include stuff like:</p>
<p> </p>
<p>1) Replacing the 8x D cells with a better battery pack alternative (ie that doesn't cost a lot to keep using!).</p>
<p>I am thinking either a Lithium Ion battery pack made of some 18650 cells maybe. I know they can output a lot of grunt so probably more than capable compared to D cells, and can also store quite a lot of amp hours. <br />
I have one of those "power banks" for charging USB devices, and I'm sure it's full of those cells. I think it has something like 26ah capacity, so I'm sure some of these might be suitable to make up a rechargeable 12v (ish) pack. Has anyone else done this? Interested to know more if you have!<br />
I think with those they are 3.7v each so a pack would either be 14.8v or 11.1v. I'm not sure if the first would be too much voltage over 12v and the second not enough to directly replace, or if I would have to use a voltage regulator to get it right on 12v maybe??</p>
<p> </p>
<p>2) I'd like a power meter to show what charge is left.</p>
<p> </p>
<p>3) Probably a USB socket so that things can be charged/powered from it if necessary</p>
<p> </p>
<p>4) I have had an idea about using a raspberry pi with a touchscreen and SD card slot for media to also pipe through the Aux in. I had thought about this being in place of the left hand tape deck (since the right one has auto-reverse and that's a nice feature to keep). Not sure about this as it would mean some savagery on this beast and I'm a bit reluctant to do that.</p>
<p> </p>
<p>5) I ordered one of these MP3 player things, which has a screen, SD slot, USB socket, control buttons, and a remote control. Again, I was hoping this would fit in the space of the first tape deck if I can fit it by removing the door, and making a replacement panel. I don't think it could sit flush, but if it's able to revert back to original without wrecking the deck then I don't mind it sticking up. <br />
Also, since it appears to have a spectrum analyser display then that deserves to be seen, so I'd probably angle it up a bit anyway.<br />
<a href="http://www.ebay.co.uk/itm/331617734176?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT">http://www.ebay.co.uk/itm/331617734176?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT</a></p>
<p> </p>
<p><br />
Not sure how far any/all of this will get but we'll see! All fun & games.<br />
<br />
If you guys have thoughts on any of this and good ways of doing any of these bits then I'm all ears, but I will update this topic with any bits as I go along.<br />
<br />
Cheers</p>
<p>Jim</p>
