Hi, i recently started a project to renovate an old radio to a bluetooth speaker for my dads birthday. I learned the basic for speaker building by watching videoes and reading in this forum, but when it comes to which power supply to use I cant really get the hang on what to get. And i cant find any source on how to find the rigth power supply.
I need help to know how much Wats/Amps i need. I will be forever gratefull if someone could help me
I use this amp: (which i want to run on 32 Volts)
TDA7498 Dual-Channel Class D Audio Stereo Amplifier Board Component Power 2X100W | eBay
And i use these speakers:
FOCAL 690AC - Bass Brothers
I need help to know how much Wats/Amps i need. I will be forever gratefull if someone could help me
I use this amp: (which i want to run on 32 Volts)
TDA7498 Dual-Channel Class D Audio Stereo Amplifier Board Component Power 2X100W | eBay
And i use these speakers:
FOCAL 690AC - Bass Brothers
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The amp requires a single voltage.
Use one of these... 24V 20A will be fine. You can turn the ADJ pot to get about 30V
AC 110V-220V TO DC 5V 12V 24V Switch Power Supply Driver Adapter LED Strip Light | eBay
Use one of these... 24V 20A will be fine. You can turn the ADJ pot to get about 30V
AC 110V-220V TO DC 5V 12V 24V Switch Power Supply Driver Adapter LED Strip Light | eBay
Thanks alot mates!
No they dont have any costumer service
One more thing, will i have trouble with noise or heat if i put this into a a wook cabinet?
I wouldn't recommend a wooden box unless it is very well vented.
Even a metal one will need vents.
Your first statement is you want to renovate an old radio, do we assume that the old radio is the focus point and that it is working and has some selector that would select between radio and the Bluetooth that you want to add.
Secondly, this old radio does not have an amplifier in it therefore you want to add the 100 + 100 watt class D amp board.
Thirdly do we assume that this old radio does not have speakers at all and that you want to build or have built a pair of speakers for it.
The question would be what is the rating of the speakers do you need 100 watt per channel?
Your choice of voltage is fine for this type of amp and to simplify matter use a laptop power supply of between 27 - 32V and 5 - 6 amps.
As kodabmx mentions above, class D does not have a heating problem since it is switching and highly efficient.
Secondly, this old radio does not have an amplifier in it therefore you want to add the 100 + 100 watt class D amp board.
Thirdly do we assume that this old radio does not have speakers at all and that you want to build or have built a pair of speakers for it.
The question would be what is the rating of the speakers do you need 100 watt per channel?
Your choice of voltage is fine for this type of amp and to simplify matter use a laptop power supply of between 27 - 32V and 5 - 6 amps.
As kodabmx mentions above, class D does not have a heating problem since it is switching and highly efficient.
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The SMPS heat has to go somewhere.
If the wooden box is closed it will just circulate and keep heating up.
I don't know your Dad.
_My_ Dad would be fine with 1 to 5 Watts.
The "100W" on that amp is at very high voltage. It is also more than the speakers you link are rated. And 75W in a 6x9 is absurd, just marketing. 20W is usually all a 6x9 can take without sounding ugly or just melting.
24V 6A will work the speakers up above 50 Watts. 12V-15V 3A will give ~~20Wpc, near the sane limit of those speakers, and a BIG LOUD sound in a home.
Don't over-design. If Dad really wanted a 69,000 Watt stadium rig, he'd already have one.
_My_ Dad would be fine with 1 to 5 Watts.
The "100W" on that amp is at very high voltage. It is also more than the speakers you link are rated. And 75W in a 6x9 is absurd, just marketing. 20W is usually all a 6x9 can take without sounding ugly or just melting.
24V 6A will work the speakers up above 50 Watts. 12V-15V 3A will give ~~20Wpc, near the sane limit of those speakers, and a BIG LOUD sound in a home.
Don't over-design. If Dad really wanted a 69,000 Watt stadium rig, he'd already have one.
The cabinet is about 40 liters, it is vented by a speaker tube and is loosley sealed. I was thinking of having a hole underneath for the fant of the powersupply. should that be ok?
Thanks again for the help!
Yes that should be fine. I've used them in much smaller sealed metal enclosures. If you're willing to settle for less power you can use a laptop brick instead. If you use a Chinese SMPS like I linked it should be rated at twice the power you actually need (they seem overrated, 720W with a 500W transformer inside etc).
The cabinet is about 40 liters, it is vented by a speaker tube and is loosley sealed. I was thinking of having a hole underneath for the fant of the powersupply. should that be ok?
Thanks again for the help!
Ok, I thought you meant just a small box for the amp.
Many powered speakers have amps inside them.
There is usually a metal back plate on the speaker box to radiate heat but then they are usually hundreds of watts.
For the few watts you are using it should be fine inside the box.
Thanks alot for all the help, Been so busy with school lately so i dont got to work with the radio as much as i like.
To cap up i took your advice about my overkill build and setteled on a laptop power brick rated 24 v 5 amp. Now the problem is that i cant fint a panel power Jack plug that is rated for more then 3 amps..
Any idea if that is OK, or do someone know What to search for?
To cap up i took your advice about my overkill build and setteled on a laptop power brick rated 24 v 5 amp. Now the problem is that i cant fint a panel power Jack plug that is rated for more then 3 amps..
Any idea if that is OK, or do someone know What to search for?
the 5A is a maximum continuous rating (or at least that is what it should be).
The amplifier will draw a continuous current very much lower than that.
The problem we all have is that the transient current demand of the speaker/s is MUCH higher than the average current demand.
The capacitors in the decoupling and PSU have to meet that transient demand.
small capacitors can only meet a short term transient demand.
Longer term demands have to come from the PSU.
But SMPS generally don't have big output capacitors. The speaker effectively draw much of it's current from the filters and the secondary of the isolating transformer.
It's the rating of these components that needs to be guessed at to meet the speaker demand. A 160VA transformer can feed around 80W to 160W of maximum amplifier output, an SMPS needs a MUCH HIGHER VA rating
Choosing a lowly rated SMPS may result in the SMPS shutting down, or going into some current limiting protection mode, when it is exposed to high speaker demand.
Your 24Vdc 5A will need to be tested with the working amplifier to find out if the two are compatible.
Now back to your question. Because the average current demand is MUCH lower than the maximum, the heating effect of the average current demand will not stress a 3A connector. Use it.
The amplifier will draw a continuous current very much lower than that.
The problem we all have is that the transient current demand of the speaker/s is MUCH higher than the average current demand.
The capacitors in the decoupling and PSU have to meet that transient demand.
small capacitors can only meet a short term transient demand.
Longer term demands have to come from the PSU.
But SMPS generally don't have big output capacitors. The speaker effectively draw much of it's current from the filters and the secondary of the isolating transformer.
It's the rating of these components that needs to be guessed at to meet the speaker demand. A 160VA transformer can feed around 80W to 160W of maximum amplifier output, an SMPS needs a MUCH HIGHER VA rating
Choosing a lowly rated SMPS may result in the SMPS shutting down, or going into some current limiting protection mode, when it is exposed to high speaker demand.
Your 24Vdc 5A will need to be tested with the working amplifier to find out if the two are compatible.
Now back to your question. Because the average current demand is MUCH lower than the maximum, the heating effect of the average current demand will not stress a 3A connector. Use it.
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