https://agateau.com/tags/bluetooth/feedPosts tagged bluetooth2020-03-08T17:41:40+01:00Aurélien Gâteaupython-feedgenhttps://agateau.com/2019/bluetooth-speaker-part-1-introductionBluetooth speaker - Part 1 - Introduction2019-12-25T11:55:18+01:00<p>This article is the first of a series on creating a Bluetooth speaker from an old vacuum tube radio and spare parts I had lying around in the house.</p>
<ul>
<li>Part 1: Introduction</li>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">Part 2: Attempting to update the audio hardware</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">Part 3: Using an existing Bluetooth speaker</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work">Part 4: Frontend work</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3">Part 5: Electronics, take 3</a></li>
</ul>
<p>At the time I am writing this, the speaker is not done yet, so there is still a chance that I never finish it... As you will see, the journey so far as not been straight, I hit a few roadblocks and changed my mind while working on this project.</p>
<p>Let's start with the reason I started this project. When we moved in our house, more than a decade ago, I found this old vacuum tube radio left around by the previous owner:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/the-radio.jpg" title="The radio"><img width="200" height="200" alt="The radio" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_the-radio.jpg"/></a></li>
</ul>
<p>I have always wanted to make something out of it, but never took the time to do so, until last month.</p>
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<p>I initially wanted to restore the existing electronics but after a quick inspection of the internals, learning a lot about the necessary skills to achieve such a restoration and the dangers of working with vacuum tube radio, I decided I would only keep the beautiful wood case. I felt a bit bad about it, so I carefully removed all the parts I would not use and stored it in a box, in case I decide to revisit this later or to donate it to someone with the knowledge to bring this radio back to life. For this reason I am also going to try to avoid drilling any holes in the case, to keep it in its original state.</p>
<h2>Disassembly</h2>
<p>Here are some pictures of the disassembly:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/back-side.jpg" title="Back side, without the back plate"><img width="200" height="200" alt="Back side, without the back plate" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_back-side.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/case-electronics.jpg" title="The case and the electronics, side by side"><img width="200" height="200" alt="The case and the electronics, side by side" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_case-electronics.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/electronics.jpg" title="The electronics"><img width="200" height="200" alt="The electronics" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_electronics.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/front-side-ready-to-sand.jpg" title="The front side, without any decoration, ready to sand"><img width="200" height="200" alt="The front side, without any decoration, ready to sand" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_front-side-ready-to-sand.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/inside-view.jpg" title="The empty inside"><img width="200" height="200" alt="The empty inside" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_inside-view.jpg"/></a></li>
</ul>
<p>Note the three holes in the bottom of the case. I don't know if they were there originally, but I am going to make use of them to fix my home made chassis without drilling new holes.</p>
<h2>Sanding</h2>
<p>Once I had a naked case, I sanded it, and used glue to repair some parts of the top which were going away:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/sanded-case.jpg" title="The sanded case, with some weight on the top to hold the glue in place"><img width="200" height="200" alt="The sanded case, with some weight on the top to hold the glue in place" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_sanded-case.jpg"/></a></li>
</ul>
<h2>Staining and varnishing</h2>
<p>After one coat of staining and one coat of varnishing, it started to look nicer:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/varnished-case.jpg" title="Varnished case"><img width="200" height="200" alt="Varnished case" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_varnished-case.jpg"/></a></li>
</ul>
<p>But then, while I was sanding again the case before applying a second coat of varnish, I noticed there were some varnish runs, so I sanded stronger in that area, but that removed the stain :(. Back to square one: sand again the varnish, stain again, apply a first coat of varnish being extra careful not to produce new runs, lightly sand and apply a second coat of varnish.</p>
<p>After these two coats it looked like this:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/varnished-case-2.jpg" title="Varnished case, take 2"><img width="200" height="200" alt="Varnished case, take 2" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_varnished-case-2.jpg"/></a></li>
</ul>
<p>Looks good enough for now. I might apply a third coat, to make it shiner. We'll see.</p>
<p>That's it for this first article, continue to <a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">part 2</a>.</p>2019-12-25T11:55:18+01:00https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardwareBluetooth Speaker - Part 2 - Attempting to update the audio hardware2019-12-30T12:02:04+01:00<p>This article is part of a series on creating a Bluetooth speaker from an old vacuum tube radio and spare parts I had lying around in the house.</p>
<ul>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction">Part 1: Introduction</a></li>
<li>Part 2: Attempting to update the audio hardware</li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">Part 3: Using an existing Bluetooth speaker</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work">Part 4: Frontend work</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3">Part 5: Electronics, take 3</a></li>
</ul>
<p>As I explained in part 1, the electronics looked too old so I decided to replace it with a small Bluetooth audio amplifier board and two loud speakers.</p>
<p>I ordered a TPA3116D2-based Bluetooth amplifier from Nobsound and a pair of MTX TX450C, 4 Ohms loud speakers.</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/audio-amplifier.png" title="The Bluetooth amplifier"><img width="200" height="200" alt="The Bluetooth amplifier" src="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/thumb_audio-amplifier.png"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/loudspeakers.png" title="The loud speakers"><img width="200" height="200" alt="The loud speakers" src="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/thumb_loudspeakers.png"/></a></li>
</ul>
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<p>Once the part were there, I quickly tested them using a spare power adapter I had lying around and started to build a chassis using MDF wood.</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/chassis-1.jpg" title="Checking the loudspeaker fits"><img width="200" height="200" alt="Checking the loudspeaker fits" src="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/thumb_chassis-1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/chassis-2.jpg" title="The completed chassis"><img width="200" height="200" alt="The completed chassis" src="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware/thumb_chassis-2.jpg"/></a></li>
</ul>
<p>This chassis was not the finest wood work ever, but it did the job, so it was time to fit the speakers in, connect the amplifier board and give it a more thorough test.</p>
<p>That's when it went all wrong :(</p>
<p>First: the setup was really loud. The amplifier is 50W RMS, turning the volume knob to one tenth of its course was already too much for the room I was testing it in.</p>
<p>Second: when not playing any sound, one of the speakers would often pop at a regular rate. I suspect something was wrong with the board, but maybe it was some interference caused by the power supply. I tried another power supply but the result was the same. I don't think it was caused by the speaker because swapping the left and right speakers led to the same result.</p>
<p>Third: audio playback would cut randomly from time to time. That really made the thing unusable.</p>
<p>Because of all of that, I decided to return the parts I ordered and try a different approach. Some people on Youtube had success buying a cheap Bluetooth speaker, tearing it down and fitting it in an existing case. Since I am not really that good at electronics, this sounded like a safer solution.</p>
<p><a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">Next article</a> will be about this new approach.</p>2019-12-30T12:02:04+01:00https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speakerBluetooth Speaker - Part 3 - Using an existing Bluetooth speaker2020-01-13T08:43:46+01:00<p>This article is part of a series on creating a Bluetooth speaker from an old vacuum tube radio and spare parts I had lying around in the house.</p>
<ul>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction">Part 1: Introduction</a></li>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">Part 2: Attempting to update the audio hardware</a></li>
<li>Part 3: Using an existing Bluetooth speaker</li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work">Part 4: Frontend work</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3">Part 5: Electronics, take 3</a></li>
</ul>
<p>So after the failure of <a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">part 2</a>, I decided to try a seemingly safer approach: buy a small Bluetooth speaker, tear it down and use its guts to power my radio.</p>
<p>I bought a small portable Grundig GSB 710 Bluetooth speaker. It's a mono speaker, but since the radio I am working was also mono, as was common by the time it was created, it felt like a good fit. I checked it worked and started to tear it down:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/teardown1.jpg" title="Opening the box"><img width="200" height="200" alt="Opening the box" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_teardown1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/teardown2.jpg" title="Main circuit is out, unplugged from its speaker"><img width="200" height="200" alt="Main circuit is out, unplugged from its speaker" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_teardown2.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/teardown3.jpg" title="Control board removed"><img width="200" height="200" alt="Control board removed" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_teardown3.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/teardown4.jpg" title="Soldering wires to the ribbon cable, ghetto-style, because I didn't have any connector handy"><img width="200" height="200" alt="Soldering wires to the ribbon cable, ghetto-style, because I didn't have any connector handy" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_teardown4.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/teardown5.jpg" title="Covering the mess with thermoretractable tube"><img width="200" height="200" alt="Covering the mess with thermoretractable tube" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_teardown5.jpg"/></a></li>
</ul>
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<p>While rummaging through the basement I found another treasure left by the previous house owner: an old mono speaker.</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker1.jpg" title="The speaker"><img width="200" height="200" alt="The speaker" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker2.jpg" title="The box says it's 15 W RMS, 4 Ohms. Sounds good"><img width="200" height="200" alt="The box says it's 15 W RMS, 4 Ohms. Sounds good" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker2.jpg"/></a></li>
</ul>
<p>After checking it worked, I decided to use it for the radio. That meant tearing it down as well and creating a chassis for it:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis1.jpg" title="That front plate is a bit rusty"><img width="200" height="200" alt="That front plate is a bit rusty" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis2.jpg" title="Back view"><img width="200" height="200" alt="Back view" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis2.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis3.jpg" title="I had to break the front plate to get the speakers out without damaging any component"><img width="200" height="200" alt="I had to break the front plate to get the speakers out without damaging any component" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis3.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis4.jpg" title="All parts of the chassis have been cut"><img width="200" height="200" alt="All parts of the chassis have been cut" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis4.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis5.jpg" title="Let the glue dry"><img width="200" height="200" alt="Let the glue dry" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis5.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis6.jpg" title="You never have too many clamps"><img width="200" height="200" alt="You never have too many clamps" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis6.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis7.jpg" title="Installing the speakers in their new home"><img width="200" height="200" alt="Installing the speakers in their new home" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis7.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis8.jpg" title="All connected"><img width="200" height="200" alt="All connected" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis8.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis9.jpg" title="Looks good enough, especially since it will be covered eventually"><img width="200" height="200" alt="Looks good enough, especially since it will be covered eventually" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis9.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis10.jpg" title="Checking the chassis fits correctly in the original case"><img width="200" height="200" alt="Checking the chassis fits correctly in the original case" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis10.jpg"/></a></li>
</ul>
<p>It was time to test... We used the radio to play music during Christmas Eve. It was working well, but after pausing the music during the meal, we were unable to turn it back on. Damn.</p>
<p>The next day it was back to normal. I suspect there is a power-saving feature in the GSB 710. I spent a few hours trying to figure out how to bring the amplifier back from that state, without success...</p>
<p>This meant I am almost back to square 1: the chassis and the speaker I can keep, but I need to find yet another replacement for the Bluetooth amplifier.</p>
<p>After some more research I found this website: <a href="https://www.radio-workshop.co.uk/">the Radio Workshop</a>. Ray, the workshop owner, is clearly a passionate. He prefers bringing back the original electronics to life, but he actually supports <a href="https://www.radio-workshop.co.uk/bluetooth-technology/">adding Bluetooth to beyond repair radios</a>, and even produced an <a href="https://www.radio-workshop.co.uk/turn-a-vintage-radio-into-a-bluetooth-speaker-ebook/">eBook explaining how he does so</a>. I bought the eBook, ordered the components, and now I am waiting for them to all arrive.</p>
<p><a href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work">Next article</a> will be about some work I did on the front-side, waiting for the required components to arrive.</p>2020-01-13T08:43:46+01:00https://agateau.com/2020/bluetooth-speaker-part-4-frontend-workBluetooth Speaker - Part 4 - Frontend work2020-01-26T23:51:06+01:00<p>This article is part of a series on creating a Bluetooth speaker from an old vacuum tube radio and spare parts I had lying around in the house.</p>
<ul>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction">Part 1: Introduction</a></li>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">Part 2: Attempting to update the audio hardware</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">Part 3: Using an existing Bluetooth speaker</a></li>
<li>Part 4: Frontend work</li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3">Part 5: Electronics, take 3</a></li>
</ul>
<p>So, while I was waiting for the components I ordered at the end of <a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">part 3</a> to arrive, I spent some time working on the "frontend": the front panel of the radio.</p>
<p>In case you forgot, this is what the original front panel looked like at the beginning:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/the-radio.jpg" title="The front panel"><img width="200" height="200" alt="The front panel" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_the-radio.jpg"/></a></li>
</ul>
<p>After some work on the cabinet itself, the wood looked much better:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/varnished-case-2.jpg" title="After tainting and varnishing"><img width="200" height="200" alt="After tainting and varnishing" src="https://agateau.com/2019/bluetooth-speaker-part-1-introduction/thumb_varnished-case-2.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/speaker-chassis10.jpg" title="Speaker mounted in"><img width="200" height="200" alt="Speaker mounted in" src="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker/thumb_speaker-chassis10.jpg"/></a></li>
</ul>
<p>But the original radio had a cloth and a grille to hide the speaker, so there was more work to do on the front side.</p>
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<p>The circular station indicator was too damaged to be used, which is why the internal chassis I built does not include room for it.</p>
<h3>The grille</h3>
<p>I originally thought the metal grille was too damaged as well, and planned to build one with wood, but decided to try to save it nevertheless since I prefer to re-use as much of the original material as possible.</p>
<p>Some thorough sanding and two coats of gray paint gave it a nicer appearance:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/sanding1.jpg" title="Sanding"><img width="200" height="200" alt="Sanding" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_sanding1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/sanding2.jpg" title="More sanding"><img width="200" height="200" alt="More sanding" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_sanding2.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/painting.jpg" title="The painted grille"><img width="200" height="200" alt="The painted grille" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_painting.jpg"/></a></li>
</ul>
<p>I then installed it in the cabinet and inserted behind it the cloth I intended to use to cover the speaker. I wanted to check if it looked OK, as I was not confident the grey would fit well with the wood of the cabinet.</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/testing.jpg" title="Testing the grille with the cloth"><img width="200" height="200" alt="Testing the grille with the cloth" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_testing.jpg"/></a></li>
</ul>
<p>I was pleasantly surprised with the result. No need to build a custom grille!</p>
<h3>The grill cloth</h3>
<p>Now it was time to really install the cloth I tested the grille with. To do so I cut a piece of wood to create a frame on which to glue the cloth:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/cut1.jpg" title="Piece of wood has been cut, drilled some holes"><img width="200" height="200" alt="Piece of wood has been cut, drilled some holes" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_cut1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/cut2.jpg" title="Removed the middle part to crate the frame"><img width="200" height="200" alt="Removed the middle part to crate the frame" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_cut2.jpg"/></a></li>
</ul>
<p>Time to glue the cloth on the frame:</p>
<ul class="thumbnails center" style="clear: both">
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/glue1.jpg" title="Placing the frame on the cloth after ironing it out"><img width="200" height="200" alt="Placing the frame on the cloth after ironing it out" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_glue1.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/glue2.jpg" title="Glueing two opposite corners"><img width="200" height="200" alt="Glueing two opposite corners" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_glue2.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/glue3.jpg" title="Not the nicest job, luckily this side is not visible :)"><img width="200" height="200" alt="Not the nicest job, luckily this side is not visible :)" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_glue3.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/glue4.jpg" title="One never has enough weight to press glue while it's drying"><img width="200" height="200" alt="One never has enough weight to press glue while it's drying" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_glue4.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/glue5.jpg" title="Screwing the frame in front of the speaker"><img width="200" height="200" alt="Screwing the frame in front of the speaker" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_glue5.jpg"/></a></li>
<li><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/final.jpg" title="Placing the chassis inside the cabinet: looks good to me!"><img width="200" height="200" alt="Placing the chassis inside the cabinet: looks good to me!" src="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work/thumb_final.jpg"/></a></li>
</ul>
<p>Overall this went well, and I am happy with the result. Now I need to fill the holes left by the original knobs under the grille. I plan to install a power+volume knob and a play/pause button on the left side, then previous & next buttons on the right side. I "just" need to find the right buttons on the Internet :)</p>
<p>Ideally I would like to paint them using the same gray paint I used for the grille, but I have no idea if this is doable, we'll see.</p>
<p><a href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3">Next article</a> will tell another attempt at getting the electronics work as expected, stay tuned :)</p>2020-01-26T23:51:06+01:00https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3Bluetooth Speaker part 5 - Electronics, take 32020-03-08T17:41:40+01:00<p>This article is part of a series on creating a Bluetooth speaker from an old vacuum tube radio and spare parts I had lying around in the house.</p>
<ul>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-1-introduction">Part 1: Introduction</a></li>
<li><a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">Part 2: Attempting to update the audio hardware</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">Part 3: Using an existing Bluetooth speaker</a></li>
<li><a href="https://agateau.com/2020/bluetooth-speaker-part-4-frontend-work">Part 4: Frontend work</a></li>
<li>Part 5: Electronics, take 3</li>
</ul>
<p>If you remember well, my first attempt at electronics for this Bluetooth speaker project was using an <a href="https://agateau.com/2019/bluetooth-speaker-part-2-audio-hardware">all-in-one Bluetooth + amplifier board</a>. It did not go well, so I tried to <a href="https://agateau.com/2020/bluetooth-speaker-part-3-using-an-existing-bluetooth-speaker">use the guts of an existing Bluetooth speaker</a> instead. That almost worked, but I experienced stability issues I was not able to solve :(</p>
<p>This article is about the third attempt: following the instructions from <a href="https://www.radio-workshop.co.uk/">the Radio Workshop</a> (which I mentioned at the end of part 3) to get a working Bluetooth + mono amplifier (hopefully).</p>
<!-- break -->
<h3>Assembling</h3>
<p>The original instructions from the Radio Workshop connected everything using heat-shrinking tubes, but I felt it would be more robust and cleaner to use some prototyping circuit boards to hold all components together.</p>
<p>I made a mistake when I ordered the boards though. The ones I received look like this:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/pcb.jpg"><img alt="The PCB" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_pcb.jpg"/></a></p>
<p>I later discovered these kinds of board are meant to be used with connectors like these to create circuits:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/connector.jpg"><img alt="A PCB connector" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_connector.jpg"/></a></p>
<p>Since my boards did not come with any connectors, I add to resort to connecting my components using loads of solder, the remainings of resistor pins and a good deal of cursing! Live and learn, they say. For sure I am learning a lot with this project...</p>
<p>Here is the circuit, connected to the speaker:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/completed-circuit.jpg"><img alt="The circuit" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_completed-circuit.jpg"/></a></p>
<p>The connecting mess on the back side:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/connecting-mess.jpg"><img alt="Connecting mess" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_connecting-mess.jpg"/></a></p>
<p>And the hackish connection between the Bluetooth receiver and the amplifier:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/hackish-bluetooth-amp-connection.jpg"><img alt="Hackish Bluetooth receiver to amp connection" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_hackish-bluetooth-amp-connection.jpg"/></a></p>
<h3>Testing</h3>
<p>After all this it was time to test it... Does it work?</p>
<p>Short answer: YES, mostly!</p>
<p>Long answer: as you can see on the circuit picture, I powered the circuit using AAA batteries from one of my son toys, but I would prefer to power it using either an USB plug or an USB battery. Unfortunately, when I tested this it caused crackling sound. I suspect either the amplifier or the Bluetooth receiver are a bit sensitive to power variations.</p>
<p>I assume this can be fixed using a capacitor to clean the output of the power supply, but in the worst case I'll just use a set of rechargeable AAA batteries, so at least this is not a blocker. Any suggestion on this topic are very welcome!</p>
<h3>Wood support</h3>
<p>To make the circuit less messy and less prone to breakage, I mounted it on a small piece of wood:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/circuit-on-wood-support.jpg"><img alt="The circuit on its wood support" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_circuit-on-wood-support.jpg"/></a></p>
<p>The volume potentiometer is not on the amplifier board anymore, I desoldered it and inserted wires between it and the PCB to be able to mount it on the front side of the radio.</p>
<p>I had to drill holes in the circuit board since none of my screws would fit the tiny corner holes... I left the Bluetooth receiver hanging as there was no room to drill any hole in its board :)</p>
<p>Since there need to be some room between the boards and the support, I hacked some spacers by cutting the top of 3 ribbed anchors:</p>
<p><a class="reference external image-reference" href="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/diy-spacers.jpg"><img alt="DIY spacers" src="https://agateau.com/2020/bluetooth-speaker-part-5-electronics-take-3/thumb_diy-spacers.jpg"/></a></p>
<h3>What's next?</h3>
<p>Next article is going to be about mounting the buttons to the front side. It's taking way longer than expected, but I am getting there!</p>2020-03-08T17:41:40+01:00