SuperCapacitor Bluetooth Speaker Testing
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- เผยแพร่เมื่อ 13 มิ.ย. 2017
- Testing the amplifier module and 8 ohm speaker. Applying a modification to enable the Aux socket. Testing the module on a super capacitor bank.
www.st.com/content/ccc/resourc... - วิทยาศาสตร์และเทคโนโลยี
You fixed the mute problem! Now I am actually able to use it, thanks.
I’m just getting into these boards and your guys are brilliant learning a lot
I always enjoy your videos. Satiates my desire to build things without burning my fingers with a soldering iron.
Animal Facts
He was practicing his bigclive style
Jens Jensen lol
Sweet video Julian :)
Lots of great information and good explanations!
I recommend trying a capacitor between Mute and ground. Maybe 100uF or so. That would hold the Mute pin low for a moment after applying the power.
Great video and interesting project.
Hello, im getting a POP sound after putting a power supply in, would that solve that POP at startup?
I think yes ! but the pop when connecting bluetooth will continue (if your board have)
i already solved it. i could get rid of a HISS sound while pausing music like this: www.diyaudio.com/forums/class-d/293475-sanwu-tpa3116-csr8635-bluetooth-4-0-noise-fix-15.html#post5310492 and to get rid of the pop sound i needed to change the resistor R21with a 1 MegaOhm resistor and the startup sound is a bit delayed, so no POP sound.
On a day like this, when I did not have time to tinker myself (for a long period!)... it's plain satisfying to see the flux smoke rise while you are tinning :) I don't know why it is so relaxing.
Thanks again for the great tip with the resistance, I have two of these amplifiers and I was looking for this solution.
Thanks again
Greetings from Munich
Brilliant! Thanks so much for the mute mod. Just what i needed for my casevolume project creations.
that's a really nice little speaker! I need to pick a few up
I suggest adding a series cap to filter the sub bass out from the speakers if you are using ones that small, will save wasted power and reduce distortion at higher volume levels.
This is one of the best value for money amplifiers I have bought and tested. When you have this as your sound processor and a set of decent drivers, you have a set on the same or almost the same level as a Marshall Bluetooth speaker at a fraction of the price.
isn't the mute added in if your phone rings, and the speaker polarity markings are located under the green connectors, you have to pull the connectors over slightly to peek under the edge.
Hi Julian I've run into the exact same problem with a similar board and I did a similar mod but using a cap and resistor to prevent really nasty click and thump I was getting on power up. Silly design on the bluetooth muting if you ask me.
very cool project! i kinda want to build a decent Bluetooth speaker myself for the bedside
My Kitsound Manhatten headphones have the same BT chipset in them, if you have the BT turned on and also Aux playing, it muffles both sources, but if you only have one connected or the other, works fine.
It seems like that speaker is designed to be in an enclosure. If you put it in a sealed box or one with small band pass ports that high volume distortion will probably get a lot better.
Which version of John Cage’s “4′33″” were you playing? My personal favorite is the 2004 version by the BBC Symphony Orchestra.
Is it bridgable? meaning you connect the neg on the other audio out. it would be nice to know for subwoofer usages. also any high temp area's? That's gonna need a heatsink perhaps extend life of module
I couldn't help notice, the 2 dip switches next to the caps are labeled SW1 like in the schematic, seems like you could just flip those switches like the schematic indicates for mute and standby?
very nice setup should play for a long time with the cap bank let us know how it works out
Hi ! Thanks a lot for your vidéo !
Do you know how i could plug a manual switch in order to switch between aux and Bluetooth manually ? Thank you for your advices
Really like to see the completed product.
Do all these boards have the same 3.5 input issue? I have a TDA7492 CSR8635
on the way for a wireless speaker set up for a party. I really like your channel. I have taken my soldering iron out again.
Thanks for the mute fix - that was such an annoying design error. I wish I'd thought of trying an extended mix of the John Cage piece :D
I'm amazed I actually managed to do the soldering using much magnification. :)
Interesting mod. You should include the model of the bluetooth receiver in the description and/or title, so that people can find it when they search about the aux problem.
i have the same amp. my broblem is that the swhitching on and connecting to bluetooth sound (''the bluetooth device is ready to pair'' ''the bluetooth speaker is ready to use'') sound is so loud that it hurts my ears... can that sound be turned off anyhow ? thanks you all for help! :)
If I were to desolder the volume up and volume down buttons, I'd like to replace with one rocker switch. What type would i use... SPDT? DPDT? Other?
why don't you route the mute pullup resistor through the jack detect switch on the 1/8th inch phono jack connector? that way you'd only unmute it when there was a possibility for input.
I have an amplifier like that, earlier revision and it gets wonky at maxed volume as well. I did have fun testing voltages from 9V-19V based on what I had around. Give it more voltage and you'll get more volume out of it and not have to use max and get the distortion anymore.
You need to build a nice Walnut case for the speaker mounts now, Julian!
Thank you, I gonna try it to. Just what I need, about the mute mod
The mute function on the data sheet was likely supposed to be connected to an aux input jack that had a built in switch. My guess is that either the jack they used doesn't have the internal switch that senses when you plug in an input or they simply didn't connect it up. In situations where this amp board may be driving a higher amplification stage, you would likely want to mute the aux input when not in use to reduce noise. When you finalize your project it would likely be a good idea to have a switch for the aux input just to eliminate possible noise.
I have a problem with the amp. On the left channel it sends 10V to the speaker and on the right channel 1.4V. So the left speaker gets to much volts and makes a loud pop when going in stand-by and makes big movements while playing music.
Hi Julian, old follower here, love the content. I have the same board minus the jack. Can you please tell me what is the role of the R24 resistor (marked with 101, right beside the dip-switches)? Mine gets very hot (burning hot) and I don't know why. Also the board shuts-down randomly
Can you, please, connect the speaker voltage (loaded by a speaker, of course) to your scope so we can see output? Inject in the input a sinusoid?
You should try the board on your hifi speakers, this little class D amplifiers usually sound amazing.
I had one before, It worked fine! They didnt recode the CSR Bluetooth chip for allowing the AUX audio, as ive been told. Mine had working Volume buttons with i think play and pause working. I guess it varys seen as how cheap they are.
My amplifier board giving aux output,looking everything ok but no sound coming from both speakers channel when i am using blutooth no input working neither bluetooth nor aux input.i am using 19v laptop charger for power.two speaker using 8ohm 40watt.but overall no sound.what could be the reason?also playing on full volume both board and mobile but no sound.
You got quite the speaker thump at 15:49 when you plugged power in. Is that since bypassing the mute? Could you add a simple timer circuit to only bypass the mute after a second or so of receiving power?
+Azayles Yes, I think the mute also works as an anti-thump. I'll investigate a simple timer circuit.
HI that would be nice. i dont have an aux socket on my TDA7492 with 50w and this start pop is annoying...
My amplifier looks all good my bluetooth also working, I am using 19v laptop charger but still no sound from speakers on both channels.what could be the reason?
Hi Julian, great videoI´d like to hide the board inside a cabinet.Do you know a trick that will start the board up at full volume without pressing the volume button?
Can I ask you 2 questionsthe first question would it be possible to have the volume buttons be off the circuit board and elsewhere but within the same unit
Alternatively if I wire say a 10K potentiometer between the speaker and the board could that act as a volume adjustment knob
They mute it to conserve power - don’t know about the tda chip but the Yamaha YDA138 uses about 220 mA idle ... and about 220 mA at reasonable volumes, so, yeah, quite a point in muting it
That mute pin is to stop the power surge going to the speakers when the power turns on as well as to prevent bluetooth and aux both playing at once. If you dont want it to mute, disconnect it from bluetooth.
The schematic seems to show switch contacts on the mute circuit. Maybe your aux cable isn't inserting far enough to break these contacts?
Like most bluetooth speakers from china, you might find that you have to hold the play pause button for a few seconds for the AUX to work
I just bought the new tpa3118 amp from aliexpress and ive seen vids on youtube that theres a voice once its powered on. Do you have any idea how to stop it on powering up
Hey just a question regarding this board is is possible to set the vol to max when using bluetooth. I am planningto use in the ceiling to drive a speaker using the room lighting power so I will have no access to the button but as you know when you turn on the vol is set at half if you soilder the button on it will beep at the max setting. have you any ideas.
Regards
Greg
is there a cable detect switch in the phono you could use to pull the mute up to 3.3v?
+Tom That's worth looking at
I think the sound in your device is turned off due to the fact that the AUX input passes a sufficiently strong signal and triggers the protection of the chip of the amplifier. Try to lower a volum in AUX. I had a similar problem when on this board I put the capacitors on the speakers as a filter and when I increased the volume on the board of the amplifier, I was protected and I had to reconnect the power supply.
Hey julian! It would be great to see how long this amp lasts when you fully charge your supercap bank and let it blast with 50% and then 100% volume. Just for the info :)
Julian, consider adding a boost regulator with an enable pin, set it up to turn on around 8.25V and off at whatever the minimum is for the regulator, this would allow you to run much longer.
Of course it matters how you connect the speakers!
If right, the speakers are in phase. If not, they are out of phase. Something you don't want.
Yes the polarity matters if your using two speakers.
If they are out of phase they can cancel each other out to some degree.
Interesting project. The voltage change will make that tda7492p start to sound quieter as the voltage comes down. At 20v it might make 20wpc and at 8v it might make 5wpc. So depending on the volume level you might notice the difference every 20 minutes or so while listening.
What happens if you disconnect the Bluetooth entirely? Will that allow for the Jack to except and play through that method?
I have the same module but I have very disturbing noises when switching on and also from the bluetooth module. Did you have that with your board?
for the wire strippers, you have to bring the wires on the donwner part so the insulation doesn't get stuck.
Put a buck/boost module between the caps and the amp?
is 4'33" copyrighted? would it be possible to get a copyright strike for playing it?
Probably, when you say that you're playing it...
can a rotary encoder be added for volume control?
Hello. I recently bought one of this amps, but when i plug a laptop charger to it (its a 19v 4A) already connected to AC, the amp gives a lot of sparks o.O Do you know whats the problem? Also i tried to measure the amperage of the amp in use but it simply got sparks in the multimeter terminals... is something wrong there?
i think you need to add a little support behind the buttons to prevent the board flexing, or move the buttons maybe. Looking good so far
I have that same amp and love it
the mute circuit seems like par for the course from One Hung Lo Electronics
if the speaker connectors have a common ground, then the easiest way to find "-ve" connection is to see which 2 screw connections had continuity? or am I missing something?
I think the -ve of the two channels are not common as both +ve and -ve can swing between 0 and vcc in this amp. Connecting both the -ve together will short the amp.
Check the bottom of the board. Labels are sometimes put on the bottom of a circuit board.
The movement of the speaker at 15:44 is a bit strange when you plug in your caps.
Looks like it moves from maximum to minimum movement.
Maybe because the mute pin is not functional anymore.
You are correct...
Meiestrix No, thats just because of the Bluetooth Module booting up. My Speakers do the same without cutted mute pin.
Member Berry well it probably is because of that. Dc is being put out on the output. The output should have been muted.
Meiestrix that's very bad for ur speaker or amp... especially when it has more oomph... wanted to say the same... beat me to it
I put an RC time delay circuit on the mute pin to allow some time to mute upon startup to avoid click and thump. Works great.
Could you continue the ESP videos, they are great.
I cannot seem to locate the video where he posts a link for that speaker.
You shouldn't tin the ends of cables going into screw terminals. Solder is soft so it gives you a larger contact surface at first, but because it's so soft it will also slowly yield to the clamping pressure exerted by the screw, "creeping" out and increasing the impedance of the connection over time, until the wire eventually comes loose. For a speaker cable it's perhaps not a big deal, but for mains stuff it's a serious fire hazard. If you don't want to go to the trouble of crimping on a ferrule, you should just twist the strands and screw them in directly.
You may be able to enhance the sound quality by adjusting the gain.
That's what the 2 DIP switches are for.
With both in upper position the gain is 21,6 dB
1st down, 2nd up: 27,6 dB
1st up, 2nd down: 31,3 dB
Both down: 33,6 dB
Yes i have a similar thing with a Bluetooth board i have when bluetooth runs it mutes the input socket .
with the supercapacitors and one speaker it takes ~7 to 10 seconds for 0.01 volt to get consumed if we assume that the real charge of your capacitors is 2.5volt each then we are talking about 15 volts so in order to go from 15 to 8 volts at the aforementioned rate there needs roughly one and a half hour to pass... so not that much really (comparing with other BT speakers that last for hours some do more than 8 )
Goodjob! You can see Blueshift hellium in google - it is a bluetooth supercapacitor powered speaker 4 sale :) And a little note for people who have no idea why speakers have + and -, when they work both way, and there is AC going on..... THAT is because the left and the right speaker must have the same phase, otherwise many people complain of headache, and the sound probably is not so good for people with musical ear.
Good day I just wanted to ask what is the lowest impedance it can handle I would like to know because what I have is one sub 100 watts 8 ohms and will add two 90 watts 4 ohms connected in parallel, I hope someone can answer if what I am doing will be just fine. Thanks in advance
Are my calculations wrong or is 16v * 500f (16v * 500a/s = 8000w/s = 8000/3600 = 2.2 ah)thats like a 13sel aa batery pack
Hi, the resistance gave result enabled or auxiliary
Mute feature could be fixed with a 555 timer and maybe a few resistances if you are up to some hard wiring.
plugged my guitar pedalboard supply into one of these (fuel tank classic 9V DC) and the power LED lit briefly but now nothing...anyone have any ideas?
Think you killed it. RIP
Actually there is an marking for the polarity just under the screw terminals.
Julian, tinning the wire ends that go into screw terminals isn't a good idea. I was told so myself but didn't really believe it until I found out myself the hard way.
The problem is that the pressure makes the solder actually flow, just very slowly. The inevitable result is that the connection gets loose, and then you'll get sparks, which are *hot*.
This way I managed to *melt away* the plastic of a lustre terminal with which I had connected two 5W heating foils in series to 24V. That's not even half an Amp.
I should add that the time scale was several months until the actual short, and that there was really NO mechanical stress on the connection - other than of course that of screws pressing onto the tinned wire ends.
What is the polarity of the amplifier power input???
I have the same stripping tool - just ditch the red stopper bit, stuff always gets jammed
Polarity DOES matter. If you have two speakers in reverse polarity, you will have two speakers canceling each other out and practically just have the identical signal muffled and the difference of the two channels louder than usual
You've made a case for matched polarity between channels, not absolute polarity. I doubt if absolute polarity matters.
Julian only had one though, so no destructive interference :P
Absolute polarity doesn't really matter but to say polarity doesn't matter over a speaker can be VERY misleading when the case of mono and stereo differs so much
Speakers are driven with "AC", so polarity doesn't matter as long as ALL speakers are using the same polarity (driven in phase). You will not hear the difference swapping polarity on all speakers. However a phase mismatch by connecting one of the speakers reversed will mostly affect low frequencies, you would find the bass missing or sound strange, especially if they share the speaker housing (for example the trunk of a car). Some home cinema subwoofers (with builtin amplifier) has a phase shifting switch, which I would assume is for people connecting their speakers wrong (or to better fit the room acoustics perhaps). Usually all amplifying transistors invert/phaseshift the signal about 180 degrees (high on the sinus wave = low out and vice versa) but that is usually taken care of by preamp circuitry, so that input is in phase with output.
Don't you think your comment was misleading then?
LOL Julian , use black micro switch near capacitor, turn ON/OFF SW 2MUTE or SW 1STBY, is on circuit diagram too 10:50 :) i think is a solution and u dont need 10k resistor ;)
Those are gain controls, not mute and standby.
The documentation says that when the Bluetooth is active it overrides the aux input.
Polarity makes a hug difference if listening to headphones. With in-phase speakers, a sound that comes from both sides equally will appear to be in the center of your head. If the speakers are out of phase, you will hear them both distinctly on the sides of your head.
Hello Julian what about Adding a make header pin 2 pin to that Resistors bypassing it. With a Jumper on the header pins? are they close enough you can do that?
+joseph chrzempiec I may add a switch, because disabling the mute circuit compromises the anti-thump.
Julian Ilett ahh okay I understand I think I had this problem on another bluetooth speaker I had. that explains a lot
Julian, 'ianstrobe' claims the Play/Pause button doubles as an input
select switch. Holding it down for 3 seconds toggles between AUX and
Bluetooth input. It appears the modification was in vain. Were there any
instructions with the device?
+alanmelb I did try holding the buttons down, but maybe not for 3 seconds. I'll give it a try.
what is the frequency response of the speaker ?
looks quite a good speaker
Probably 70-11000 Hz at BEST.
probably a dumb question but are super capacitors more efficient then batteries?
Hey if you don't get the polarity correct it's only going to be a hundred eighty degrees out of phase but not to worry you can always switch it back cheers.
a few months ago I blew up amp and BT chip on this board while trying to fix this exact aux problem :D, it really throws you down and wrecks your nerves because a month of shipping is not satisfying :D My problem is that I fix things turned on and accidentally touch the wrong pins >:{ bad habit...
You could try bridging the speakers for more volume, and maybe use a boost driver to get all the voltage from the caps :D
Did you measure the current used by the amp, at least with one speaker? It would also be interesting to confirm whether the current increases as the voltage reduces (i.e.: constant power), or reduces or stays the same, and how this changes with volume. All relevant to the runtime on one supercapacitor charge of course.
No, I've not done that yet. Power output should be proportional to the voltage squared, but maybe the chip has some kind of compensation. That bit of fun is still to come :)
Just calculated by measuring the voltage drop rate in the video. It dropped 0.05V in 32sec. The capacitor bank is 6 x 500F in series, which is 83F combined. 0.05V x 83F = 4C, which is 0.13A for 32 secs. That gives a power of 10.5 x 0.13 = 1.4W. The 8 x 700F capacitors that you're planning to use hold 4Wh from 8 to 20V, so if that 1.4W avg stays constant then you'll get a little under 3 hours usage on 1 charge. That's with just one speaker, so guesstimating that the speaker is using 1W then the pair would be 2.4W, giving 1.6 hours runtime, but considerably better with reduced volume. Not bad for capacitors!
Not bad indeed. Hopefully the total cost can be kept under $100 too :)
You can also say, if it's linear:
10.55 to 10.54 Δt = 6.04 slope 0.0017
10.54 to 10.53 Δt = 7.08 slope 0.0014
10.53 to 10.52 Δt = 4.92 slope 0.0020
10.52 to 10.51 Δt = 9.34 slope 0.0011
10.51 to 10.50 Δt = 5.03 slope 0.0020
10.50 to 10.49 Δt = 6.05 slope 0.0017
10.49 to 10.48 Δt = 4.87 slope 0.0021
Give a average slope of 0.0017
u(t) = U(0) - 0.0017t
t = - (u(t)-U(0)) / 0.0017
If I trust the datasheet, 8 to 26 volt for the chip.
And the maximum voltage of the capacitors 16.2 volt (2.7 * 6).
t = - (8 - 16.2) / 0.0017 = 4523.5 s = 80.4 min. = 1.3 hours of playing time.
can you add aux in except bluetooth module
julian D: it mutes cause it connects to your phone via bluetooth. turn off bluetooth and it should work fine via aux
My 100w version once I turn off current Bluetooth source. I push the play button and in about 10 seconds the amp board starts looking for a new source.
Julian, have you considered building a crossover for the speaker, to limit the frequencies it responds to? For example (I don't know the specs for that speaker) limit frequencies below 400Hz and allow the rest through.
www.audioholics.com/diy-audio/building-a-do-it-yourself-loudspeaker-design/crossover-design