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10PCS LM13700 LM13700N INTEGRATED CIRCUIT LM13700N IC http://www.ebay.com/itm/-/141988445100
AUX Interface 2 X 25W Bluetooth 4.0 Audio Digital Power Amplifier Board TDA7492P http://www.ebay.com/itm/-/162077346671
10pcs 4.8x13.4cm Stripboard Prototype paper circuit Board Breadboard vero pcb http://www.ebay.com/itm/-/282029963769
5pcs Type A Male USB to DIP 4 Pin 2.54mm Power Supply Adapter Module http://www.ebay.com/itm/-/181924147693
DIY kits Mega328 Transistor Tester LCR Capacitance ESR meter Frequency Signal http://www.ebay.com/itm/-/111990329664
https://www.crowdsupply.com/blueshift
http://www.st.com/content/ccc/resource/technical/document/datasheet/35/01/97/6b/20/ce/40/6f/CD00211320.pdf/files/CD00211320.pdf/jcr:content/translations/en.CD00211320.pdf
10PCS LM13700 LM13700N INTEGRATED CIRCUIT LM13700N IC http://www.ebay.com/itm/-/141988445100
AUX Interface 2 X 25W Bluetooth 4.0 Audio Digital Power Amplifier Board TDA7492P http://www.ebay.com/itm/-/162077346671
10pcs 4.8x13.4cm Stripboard Prototype paper circuit Board Breadboard vero pcb http://www.ebay.com/itm/-/282029963769
5pcs Type A Male USB to DIP 4 Pin 2.54mm Power Supply Adapter Module http://www.ebay.com/itm/-/181924147693
DIY kits Mega328 Transistor Tester LCR Capacitance ESR meter Frequency Signal http://www.ebay.com/itm/-/111990329664
https://www.crowdsupply.com/blueshift
http://www.st.com/content/ccc/resource/technical/document/datasheet/35/01/97/6b/20/ce/40/6f/CD00211320.pdf/files/CD00211320.pdf/jcr:content/translations/en.CD00211320.pdf
Julian please please buy a new better microphone that makes you not sound like you are talking in a tin can!!
Isn't it great when things line up.
Postbag. I love getting things in the mail. Especially Electronics! Carry on, good Man. Fascinating.
I'm not sure I you persuade the project w the speakers, I highly recommend 'mdf' wood plates. They are rather cheap, and have good audio performance. Plus ofc imo get some better speakers, you won't get to far with 2,25". Although price is important to you I'd recommend tang band 3,5" woofers. If you want more information, lmk and I'll give you more details since I build my own class d boombox currently.
I have brought this same pcb but it's not giving sound on audio jack and on bloototh sound is getting cut in middle middle what can be the issue
BTL = bridge tie load.
I'm not a high level expert, just a nominal hobbyist,,, it means that these amp chips are capable of 4 channels, or by bridging 2×2 , you get a stronger 2 channel output.
Also,, I think you would be better off using a lesser power hog of an amp for your project, like the PAM8403. 5 volts , 3 watts per channel. I've messed with these, and they are pretty decent for what they are, that is,, if you don't really need the Bluetooth aspect.
love your videos i am a newby in elctrics so cool to learn
I'm going to build a Bluetooth speaker box using the amp you reviewed. Do you think a rotary encoder could be used to replace the volume buttons?
You could hang the 2nd Vocoder on the big board on the wall as an art piece that works as a Vocoder!
Later, FW.
i found an Audio Receiver Board Wireless Stereo Music Module around 5-6$ i can recommended also get Acrylic case for it too because I don't want to buy chromecast audio
I've run the numbers for the supercapacitor powered speaker project, and they look reasonable. The specs for the TDA7492P show it draws a quiescent power of around 0.6W at 20V. It'll be less than that for lower voltages, but there will be other losses on the board. Let's say 0.5W avg over 8-20V. A couple of reasonably efficient speakers at a typical listening volume in a quiet room would require around 0.2W each on average. Let's say 0.5W for the two, allowing for inefficiency of the amp. Total 1W average, ballpark. With 8 x 700F 2.5V capacitors in series, you get a 700/ 8 = 87.5F 20V combined capacitor. By my calculation the energy released in dropping this from 20V to 8V works out at 87.5 x (20*20 – 8*8) / 7200 = 4Wh. So at an average of 1W that should last around 4 hours. This will vary considerably depending on actual board and speaker efficiency, and particularly on volume, but it sounds usable.
One problem is that the available power drops rapidly as the supply voltage drops. The TDA7492P specs show around 4W per speaker at 8W as compared to 25W at 20V. So at louder volumes the distortion will increase rapidly as the supply voltage drops. It would be tempting to consider a boost converter to maintain the supply voltage to the amp as the battery voltage drops. This would also squeeze a little more out of the capacitors, but not much. Allowing the capacitors to drop down to 2V would yield a total of 4.8Wh – a 20% increase. Unfortunately the boost converter inefficiency would cancel out this benefit, and that's before taking into account that maintaining the amp supply at 20V would result in greater quiescent losses in the amp. I'll be interested to see how this all works out in practice.
The reason to get the 50w amp is if they are claiming 50 you'll end up getting 15 rms.
btl = bridge tied load. dont use -ve on speakers as common.
Hi Julian, I was that impressed with the component tester I ordered one, I have a couple allready, one I blew up with a charged capacitor, and the other looks like this but doesnt have anything like the functionality.
BTL = BRIDGE-TIED LOAD.
Has anyone seen gerbers for similar boards to the ones that julien baught here?