Folks, New guy here. Sorry for the interruption. I've been reading this thread all day. Nice project, but deeper then I want to go. I am seeking a simple answer to a few questions. I am looking at these DYI TPA 3255 BTL configured amps that you see on amazon and ebay. They come in a black box with power switch and volume up front , and connectors in back. BUT no power supply. I need an AMP to support a small studio and I'm looking at around 110 to 125W rms per channel. Based on page 194 of this thread and the RMS calculation that CharlieLaub did, It appears a 42volt external power supply would do the trick. But I can't figure out how many Amps I need with that 42v supply. I think its 12amps, but I'm not a expert with Ohms law. Can you help here. Am I correct or am I missing something? Are there other concern I may need to address using this Black Boxed TPA3255 DYI units?
Many questions about this unit. I found a few of them similar as you have described.
For 2 loud speakers for small studio? TPA3255 sounds like a good choice for many 4 ohm and 8 ohm loud speakers that are rated for power output rating of TPA3255. What loud speakers will you be using? What rated watts and ohms of speakers? I'd start with electrical load of speakers to make sure this amplifier will work out.
Personally I would get a proper made TPA3255 board that has high quality electronic components with appropriate rated electrical components able to support 125% of TPA3255 power output rating with the highest voltage rating possible. 48VDC of high quality voltage input source seems appropriate for TPA3255 from what I have read but every component of the board has to be rated for this voltage. I like thick high quality PCB along with high quality "audiophile" electronics. Balanced XLR input seems best for audio input signal.
I don't think it's a good idea to push electrical load rating to 100% of design.
I would use speakers loads at 50% to 75% of rated load of TPA3255 power output to ensure good cool reliable operation to ensure electrical conductors, electrical components are not overloaded and dissipate heat/resistance to ensure good quality voltage through out circuit.
I also like to see good electrical ground bonding appropriately designed in the amplifier to get rid of ghost voltage that is disruptive to audio quality or damaging to electrical components.
Those Amazon units without power supplies may work out but based on low price and no power supply it seems like they are being rushed out to market and are not well thought out. Power supply is very important for good operation.
For the power supply for those Amazon cheap TPA3255 units that will work with 48VDC I would look for a 600W rated design. I think that would be sufficient for designed specification of TPA3255 but I'm not sure those boards would really perform at that level because of design. Some review testing would be good to see before buying.
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Read this :
Which TPA3255 amp do you recommend? | Page 15 | Audio Science Review (ASR) Forum
Put your choice on any High End TPA3255 Board you won't be disappointed.
Another excellent amplifier I discovered it is this one, really really surprising Class H amplifier !!! :
[Class H Amplifier] BRZhifi quick review amplifier
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Hi Rick.
I just found an interesting power supply that may work out for TPA3255. I have no experience about it and haven't seen any reviews but based on description if true it looks like excellent design for TPA3255.
Keyword
800W DC48V LLC Switching power supply board for amplifier PSU TPA3255
Come in only board or fully built.
Here is fully built for reference on ebay.
https://www.ebay.com/i/122691330794?chn=ps
I would check for best source to get best design build of this power supply board from reputable vendor.
Seems like a viable affordable option for high quality PSU if it is legit.
I respect all other opinions based on observation or experience.
I'm considering it myself at this point if I end up building my own TPA3255 amplifier.
I made an excellent diy Linear PSU for $50
You need a toroïdal PSU
Rectifier board AC>DC
A design wood box
Check my previous topics
This works absolutely great as well
You need a toroïdal PSU
Rectifier board AC>DC
A design wood box
Check my previous topics
This works absolutely great as well
Here goes :
Rectifier board > 4x 10000µF Nover
Toroidal PSU 300VA 28/30V AC
45V DC after conversion
Parlo Italiano anche ) Se hai bisogno di aiuto, ci sono )
Rectifier board > 4x 10000µF Nover
Toroidal PSU 300VA 28/30V AC
45V DC after conversion
Parlo Italiano anche ) Se hai bisogno di aiuto, ci sono )
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Actually the description of the power supply I am referencing too is rated for continuous load o 400W-500W.
MAX load of 800W for 5 minutes before shutting off to protect power supply.
Link to just the Power Supply I have suggest worth investigating more.
800W DC48V LLC Switching Power Supply Board For Amplifier PSU TPA3255 Amp etc | eBay
Full specs from description:
48vdc @600W continuous would probably best choice for proper built TPA3255 PCB amplifier card.
I would feel comfortable using this suggested 48vdc 400W-500W continuous designed power supply if in fact it is built to its stated ratings. Many good lower power required loud speakers would work at 400W-500w power supply rating.
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DrMordor
What VAC input did you test with?
Experience is best. Thank you.
Please share a better same type of power supply closer to 600W continuous rating based on your experience.
Thank you.
What VAC input did you test with?
Experience is best. Thank you.
Please share a better same type of power supply closer to 600W continuous rating based on your experience.
Thank you.
DrMordor I just noticed the PowerSupply you have referenced is not the same one that I have suggested. Look at link I posted.
DrMordor
Chinese watts on half bridge topology?
Chinese standard voltage VAC input? Hong Kong is 200V; Taiwan is 110V @50HZ?
Thanks.
Chinese watts on half bridge topology?
Chinese standard voltage VAC input? Hong Kong is 200V; Taiwan is 110V @50HZ?
Thanks.
Any power supply has a transformer, that has a certain wattage, this unit uses an etd34 which has a power of 350 watts longtime.
Doc,
I am about to buy the PCB for capacitor bank for tpa3255 amp, in below link
HP7 Main filter power supply PCB|pcb|pcb powerpcb power supply - AliExpress
what are the resistor and axial legged capacitor for?
same pcb with capacitors assembled, sold by same seller.
Noted doc, thanks.
If am about to use 10000uf,50v x 4, what will the resistor value?
Also, adding MKP/MKS caps in parallel, will improve sound quality?