See my review of the Fosi Audio BT20A Pro here: ua-cam.com/video/b1zFuLK655g/v-deo.html *SHOP* Fosi Audio BT20A Pro: amzn.to/43g4JT6 *EXCLUSIVE 20% off Discount Code: 20APROWAL20* Discount Valid April 10-30, 2023 Fosi Audio BT20A standard model: amzn.to/43lwTfp Fosi Audio 48V 5A Power Supply: (Coming Soon) 0-48V 10A Variable Voltage Power Supply: amzn.to/3mkJv5P AIYIMA A07 Amp with 32V adapter: amzn.to/3Xu0jEA AIYIMA 48V 5.2A Adapter: amzn.to/3H1CHSh Elac Bookshelf Speakers: amzn.to/3nVrhbJ Speaker Banana Plugs: amzn.to/3zLGrTv Anti-Static IC Puller: amzn.to/3miE8nE 3.5mm to RCA Adapter: amzn.to/4082DC9 Polk Audio PSW10 Powered Subwoofer: amzn.to/3nVXWOa *Related Videos* Fosi Audio BT20A Pro FULL REVIEW here: ua-cam.com/video/b1zFuLK655g/v-deo.html Fosi Audio M0-3 Mini Amp: ua-cam.com/video/wrBPAP3nol0/v-deo.html Aiyima A07 Mini Amp (TPA3255) : ua-cam.com/video/kBim2j7Gm5o/v-deo.html Douk Audio M1 Pro Mini Amp: ua-cam.com/video/WROm7jJbb2M/v-deo.html Mini Amp Video Playlist: bit.ly/3IMdtbN Amp Dyno Modes Explained: ua-cam.com/video/Q0m6NsB-HHc/v-deo.html More Power Output than Power Supply?: ua-cam.com/video/c7QELbpKMuI/v-deo.html *VIDEO INDEX* 0:00 Intro 0:55 48V Tests with 480W Supply 2:42 24V Tests with 480W Supply 3:32 12V Tests with 480W Supply 4:14 48V Tests with 240W Brick 5:28 Final Thoughts *CAMERAS AND AUDIO GEAR Camera - iPhone 13pro 1TB - amzn.to/3nCjGvc RODE Wireless Go II Microphones: amzn.to/3Q6NVHl Shure MV7 Microphone: amzn.to/3A4OICK Zoom H4n Audio Recorder: amzn.to/3BXjVsS 960 LED Panel: amzn.to/2Sxoq3S *TEST BENCH EQUIPMENT* SMD / D'Amore Engineering Amp Dyno: goo.gl/sJTcf7 XS Power D1400 Batteries - amzn.to/2BPFCKW XS Power PSC60 Charger - amzn.to/2CHGcfs Fluke 1000A AC/DC Clamp Meter: amzn.to/2Rw5WDA Handheld Dyno: amzn.to/2u2EgKV My Favorite Screwdriver Kit: amzn.to/2x0VzcE _DISCLAIMER: This video and description contains affiliate links, which means that if you purchase from one of the product links, I may receive a small commission. As an Amazon Associate I earn from qualifying purchases_
This is a fantastic review and power brick comparison! Now I have a question for you, Fosi has a GaN 48V power brick, almost cost as much as the amp itself. Any chance you can test the GaN version also?😊
I'm know others have said this, but- -Would be interesting to see the performance on battery- say 3 and 4 car batteries. Clean DC with ample capacity. This would be the best-case benchmark to reference. -Does the voltage sag during the test? Is the display on the PS the actual output voltage or the set-point (the actual voltage being lower)? -might be interesting to have a scope on the power? See if noise is coming in as the load goes up?
I have always used meanwell , delta , morrnsun , fsp , bel. if you are powering something really important then there is cosel & tdk these are like 10 times more expensive than regular units but the cosel ones are made in japan and way over engeenereed to be as good as possible. For regular use like powering audio amps. Meanwell mornsun and fsp PSUs are all good. I have a meanwell powering a headunit that i use as home radio. And it has never been turned off for once for more than 7 years. It gets power from ups when that occasional power outage happens. I keep it running cus i need to retain the realtime clock and other settings in the headunit.
Are you sure the psu is not making distortion high enough to trigger the test to end? It would be interesting to see on a scope or at least a set of voltage leads to determine what is going on? Keep up the good work I for one love this stuff !
@Douglas Blake That just does not make sense for the 8 ohm test vs 4 ohm test. The 8 ohm would have been close to 4 ohms in watts if what you are saying is true.
@Douglas Blake sure the psu maybe able to output 10amps but the dyno test is for less then 1% distortion and as you can see the amp uses 7.5 amps at one point but the power reading is not going up on the dyno as it is to dirty and not a clean enough reading for the dyno if you were to put a scope on the psu or the amp you would see it
I don't think that I would pick either one of the power supplies but I would pick a brand name power supply. You could even go with a cheaper Mean Well or anything would be better than Amazons "found somewhere in China brand".
Fosi Audio have a 240W 48V/5A GaN power supply now, for $30 more. Would love to see you test its power claims and put it up against the non-GaN 240W version.
During testing you should also monitor the output voltage on those industrial supplies. It is possible that either a) the amplifier went into protection or b) the power supply went into current limiting.
Just note that you connected the negative power cable to the amp to the earth/grounding connection of the power supply. The grounding/earth is meant for the 220v or 110v supply. You should connect it to the -V connections. I connected mine to the Ground initially and it lost a lot of out put because the earth/ground was not clean. I changed to the -V connectors and it worked way better.
There are three plots for V+, V- and one for earth, neutral and line. Red and Black wires to the V+ and V-, Green on earth, White on neutral and an tiny black on line.
That low quality variable will be the issue. A decent Meanwell brand (industrial) 48V unit will have overload capacity to deal with the tests. When the switchmodes are made for a single voltage they seem far stronger. Thanks for these in depth videos!!
Don't even need meanwell. A 12amp morunsun would do that perfectly fine. Meanwell is good to have if you are gonna use it regularly. Fsp , bel are good aswell. Don't need cosel or tdk unless you want to overspend..
Apparently they are soon to release a new version. I returned my BT30D because it was not compatible with 48 volt 10 amp power supply needed to take advantage of the TI 3255 chip and to get max performance, not achieved with the 32v power supply.
I use those marine/automotive full enclosed grade "step up" boosters (12v - 36v or 12v - 48v) with either 8 or 10 amps. No issues, unless you wire them backwards...then they go "poof". Most of them can accept 8-24v input, too.
Given the lackluster performance of that power supply, I'm slightly surprised that Dick Riculous didn't make an appearance (though this is the "extras" channel.)
Hello Big D! Have you tried the AIYIMA Audio A07 Pro with this power supply? I have a MeanWell 48V 500W PSU, I want to buy a TPA3255 amplifier, but I want to make sure that it will work with it. I want to use it for 12" subs, so power is needed. There is another alternative called Wondom/Sure BRU5. It also has DSP! And you can buy them at half the price of the Fosi and Ayima amplifiers.
Beware of power bricks -- they provide the specified current, but they are frequently not well filtered and can inject audible squealing when used to power chip amps. The 24 volt 10 amp power brick I bought a couple of years ago would probably be OK to power an LED string, but it's not usable for audio gear because of that squealing. Btw, I have what looks to be that adjustable SMPS you used and it worked fine powering my 9 volt guitar pedals -- in fact, it worked better that the purpose-built wall wart I subsequently bought, which resulted in a loud pop when I switched on the power strip that I didn't have with the SMPS.
You´re right, EMI filtering at the output (or a cap multiplier) costs money (40USD!)! But I´m not sure if the other one is filtered. Another point, are the components safe (X, Y capacitors and so on)?
Thanks for sharing. Wondering if the noise or DC jack cable affect the test result?? Cuz, you set to 1% THD. I have the same 480W PSU, it can output 48V 10A...
Did you monitor the voltage on the power supply during the 48v tests? I wonder what kind of voltage went to the amp - if it had voltage drop... at 7.9amps at 48v it should have bested the 5amp power brick... only thing that would drop the overall wattage (in my mind at least) is if the voltage dropped dramatically. very interesting!
Odd, I have that same Drok power supply, connected it up to a heater element with a Kill-A-Watt on the receptacle and dialed it to 42 volts. The Kill-A-Watt showed 439 watts. I chickened out on going any higher because it was kind of a sketchy setup. I wonder if yours was defective?
i bought the BT30 Pro and ended up returning it after discovering that it wasnt compatible with a 48v 10amp power supply, which is needed to get the full performance from the upgraded 3255 chip. A rep from Fosi Audio said this was being corrected in the yet to be released new version....
I've got the same power supply, using it to charge large Lifepo4 batteries, l run it at a consisten 380w...14A at 27v from the charger, but its fed 230v ac...it can indeed deliver 480W when pushed to max.I think the problem with yours is the 110v input.
The Dyno is measuring with clipping and distortion tracked. It's probably the brick designed for audio amplifier usage has some filtering optimized for that usage. Versus the general purpose power supply has such a wide range for it's filtering. The optimal filter capacitor is based on the current draw of your load, the voltage, the inductance of the load, the reactance of the load. Even just looking at a load of 0-10 amps and 0-48volts, that's a very wide range to filter for.
Did you see voltage drop on the variable power supply? Based on the math something is completely wrong. Fluke showed 8amps with 48V it gives 384W of power consumption and SMD showed 2 x 70 which is 140, so efficiency of the amp went down (when 140W dissipates on such small chip is insane) or voltage dropped?
he does this on so many of the videos i notice, you are the first one to say something, basically he doesn't know how to calculate efficiency or is reading them incorrectly on purpose so that they sell on amazon, idk either way it's freakin annoying, to the point where i kinda stopped watching him.
This is class D, it has an efficiency of 90%, that is, 90% goes to power and 10% goes to consumption and heat;.at 140 W, 14 W are dissipated there!))) so everything is normal!)) even if the efficiency is not 90%, that radiator will withstand 30 W in the test. and in real music where impulses are even more so...
Really strange how the amp meter shows a current draw of over 7.9a, that's around 380 watts yet you only got around 76w per channel?? Something is wrong here haha, doesn't add up.
You will really need to use your brain on this one but number one amplifier loses power because it's users power itself number to the current the current clamp is likely in average maximum mode and showing the highest peak number of the current not to the continuous Reading
@David Knight Audio might be but generally class D amps are not that inefficient if it was class A/B it would make sense but it obviously isn't, something is wrong here.
its simple. the power brick is outputting dirty power the dyno is looking for clean power and only shows clean power so the amp maybe trying to output more and more power but its to dirty for the dyno
Can you measure the voltage coming out of the power supply? If your fluke measured 7 amps of current then if it was truly putting out 48 volts then yeah, it should have been better than the brick. Also the negative voltage is odd. So if you wired something from the positive voltage to the negative you’d have 96v potential. I’m wondering if you’re really only seeing half the voltage you think you are.
Hello, I am curious to know how the Fosi amp would perform if it was connected to a 48V bank of Lithium batteries. Have you done any tests using batteries? I would imagine that there may be an improvement in sound as there is no noise. Thanks
Did you make sure the switch on the side is 110v and not 220v? Mine came from Amazon switched to 220v. With it switched to 110v I am getting much higher readings from this power supply.
Never push a product past its limits, especially when it comes to fire hazards like powered amplifiers! From what I read, Fosi says they are coming out with a better version because even though the chipset works best at 48V 10 amp (and puts out closer to advertised power output), the power handling of the unit is not good enough currently. I think there is a good reason 48V 10 amp supplies are not yet available from them directly, they know it cannot handle that in the current form.
What do you think if an Ifi Zen One Signature is connected as an auxiliary and used as a Dac, connect a CD, by USB to a PC or streamer and digital to a TV to watch movies and Bluetooth? With a Spektor 2 or Sony CSS5 speakers. To start audiophilia in a 10 M2 living room? Greetings from Argentina!!!
Well something it's wrong! And I say that because, you pulled 7.9A times 48v out of that power supply! That means you pulled around 380watt! But your device shows a total of 150watt both channels together! How it's that possible? Have you had I voltage dropping?
Can you comment on the quiescent power draw for this Amp? My BT20A Pro sits at 35C (room ambient about 18C) which seems to indicate there might be a problem, my BT20A was cool at idle.
@Douglas Blake Well I let mine get nice and warm and pulled it out of the chassis and started poking around and the only thing I could find that's getting hot is the heat sink, and it was HOT. The voltage regulator is an XLSEMI XL7015E1 which is rated to 80V and was just warm when I poked it.
Strange occurrence, i bought a similar power supply but not as adjustable it's only 48v 12.5a 600w but you can fine tune the voltage to like 40 or up to about 55 it works very well with the subwoofer version of the aiyima a07 (bridged TPA3255 single 600w mono output) have 2 10" 500w subs connected in parallel al 2 ohms and it powers them very well, (they are still underpowered but i am planning to upgrade the amp to a different one soon) i did try to measure the current draw with a clamp meter but it's limited by the amp at about 9-10a at the power supply before the amp starts to clip badly so sadly i cannot test it's full "48v 12.5a 600w" rating but i can confirm it is at least 10A the voltage doesn't drop at all so i guess you just got a bad or fake one, moral of the story is to be careful because it looks like there are some fakes out there.
Its been a while since this video but you should do a video on the rockville bluamp 21 if its worth it to you. I have mine powering 2 rockville 8s at 4 ohms pretty nicely. Its actually funny as hell lol
Looking at the variable power supply output wiring. You had the output connected incorrectly. The positive + connection wire was correctly fitted to the + terminal. However you had the negative - wire made to the chassis earth terminal, and not the negative terminal of the output. This would massively limit the output voltage.
Hey buddy! I know you from the car audio channels! Hey I have some interesting questions . How do I join the group and all that so I can pay to send sensible questions? God bless and merry Christmas
hello, I have a possibly naive question. I have a smart plug that measures power consumption. I noticed that the power consumption of fosi bt20a pro (32V) at 50% volume is usually 4-10watt maximum. Is this normal or I have a defective device?
This is class D, it has an efficiency of 90%, that is, 90% goes to power and 10% goes to consumption and heat;. that is, when consuming 4-10W, it will deliver many times more power to the acoustics in fact! if it consumes little, you can turn on the fan heater in that outlet!)))
Loving the extras big D hey I know Amazon sells a version of this power supply that has adjustable voltage AND adjustable current. Did you pop the case apart to see if there was another pot in there somewhere limiting the current? Also I'd ring out each terminal on that strip to confirm that each screw is actually what it says it is. Great video as always and that is a dope amp regardless of the power output!! :)
Kinda of in strange I wondering if that factory power supply is actually put out 48v it probably rated at that but that not what it's putting out it probably higher voltage. I'm only wondering this because you can get the adjustable in high voltage for no extra charge really IV seen up to 72 v that iv seen at that amp range. usually the price increase by the amount of amp supplyed by the power supplys. Example 48v 15amp 29$ but for a 12v only 100 amp power supply range your talking 250$ even a 12v at 50amp is around 75$ 🤔💯🤯👍✌️🎵🎶
YES. I was going to say this but looked through the comments first. It would be slightly over-voltage, but I expect not to the point of damage. ALSO test at 36V. The point is to see what the best this amp can do with truly clean power. Then other power supplies can be judged against this optimum situation. YES.
REALITY CHECK! Thank you very much for this! I am from the late 70s when THE GOLD INDUSTRY STANDARD was the watts per channel at 8 ohm at a frequency response of 20hz to 20,000 hz with the other rating being at 1khz which was always highe. At least I can relate to your tests instead of all the marketing BS....."1,000,000 watts per channel!", "I can drive my Klipsch 96 inch woofer with this tiny amp", "The whole band was playing through this amp at Madison Square Garden, it was so loud people were wearing ear plugs!!!" I am totally baffled by the 48V/10A PS...(Piece of S???) Could it be that there is a limiting factor in the amp itself? Is there a way to test the PS by itself connected to some electronic measuring equipment? In the meantime I appreciate the 48V 5A Power Supply you tested. Is there an in-between 48V 7.5A version out there, preferably in a power brick mode? Thanks for the clearing all the marketing hype!
Hi, I recently read somewhere that the ayima power bricks make an audibly mid range hum when used with fosi amps. Has anyone else here has that experience?
I just received a BT20A and they skimped out even further on the PSU, it's now a 24v 4.5a power supply. To answer your question, I do not hear audible noise out of the amplifier. I can put it out on an oscilloscope if you'd like to see what that looks like but by ear, I don't have noise.
@@mitchellroberts7954 Wow! funny I also read somewhere that the 48 volt psu is a must, and also it’s not. I’m surprised Fosi have downgraded the standard PSU as they don’t seem like that kind of company. It’ll encourage people to upgrade tho. PS thanks for the offer I’ll trust your ears!
No, the amp has Bluetooth built in. The amp also has RCA in, so you can get a Aux out to RCA cable if you don't want to use bluetooth but it's not much better than Bluetooth imo. Your phone has a DAC. I would recommend a dedicated DAC if you are listening from other sources such as a laptop or PC that don't have Bluetooth.
Dac on the phone is not powerfull.. the quality also depends on the brand and type. If you want upscale your audiopile experience you should buy a dedicated dac. Donggle dac at least
Very true! Second hand meanwell PSU's off of eBay and whatnot are a staple for hobbyists. Often under $100 for 500-1200w PSU's ranging in voltage from 12v to 48v
Interesting. Measurements aside, I ordered the 48V-5A supply from Fosi directly to replace the 32V-5A that comes in the box. And it doesn't feel like I'm getting a whole lot more power out of it. Whereas I'm at about 65% I needed with the 32V one, I'm now at about 55% with the 48V version. Should the difference in volume output be so small?
See my review of the Fosi Audio BT20A Pro here: ua-cam.com/video/b1zFuLK655g/v-deo.html
*SHOP*
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Fosi Audio 48V 5A Power Supply: (Coming Soon)
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Fosi Audio M0-3 Mini Amp: ua-cam.com/video/wrBPAP3nol0/v-deo.html
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Amp Dyno Modes Explained: ua-cam.com/video/Q0m6NsB-HHc/v-deo.html
More Power Output than Power Supply?: ua-cam.com/video/c7QELbpKMuI/v-deo.html
*VIDEO INDEX*
0:00 Intro
0:55 48V Tests with 480W Supply
2:42 24V Tests with 480W Supply
3:32 12V Tests with 480W Supply
4:14 48V Tests with 240W Brick
5:28 Final Thoughts
*CAMERAS AND AUDIO GEAR
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*TEST BENCH EQUIPMENT*
SMD / D'Amore Engineering Amp Dyno: goo.gl/sJTcf7
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XS Power PSC60 Charger - amzn.to/2CHGcfs
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Handheld Dyno: amzn.to/2u2EgKV
My Favorite Screwdriver Kit: amzn.to/2x0VzcE
_DISCLAIMER: This video and description contains affiliate links, which means that if you purchase from one of the product links, I may receive a small commission. As an Amazon Associate I earn from qualifying purchases_
That power supply says that in order to use the 48v u have to hook it to a 220v look at the paper that came with it
@@charlieknoll1269 it puts out 48V just not 10A with 110V AC
Ya it's time to just get a ajustable power supply that has enough amps to test even the more powerful mini amps they make ones with over 1000 watts
I can't wait for the 48v power supply to be released, I bought the amplifier the other day and wouldn't mind the extra power!
This is a fantastic review and power brick comparison! Now I have a question for you, Fosi has a GaN 48V power brick, almost cost as much as the amp itself. Any chance you can test the GaN version also?😊
Did you check the input voltage selection was on 110? Seen on other forums that amazon US has shipped them set to 230 so the output barely works.
You should test with a quality SMPS such as Mean Well or Mornsun.
I'm know others have said this, but-
-Would be interesting to see the performance on battery- say 3 and 4 car batteries. Clean DC with ample capacity. This would be the best-case benchmark to reference.
-Does the voltage sag during the test? Is the display on the PS the actual output voltage or the set-point (the actual voltage being lower)?
-might be interesting to have a scope on the power? See if noise is coming in as the load goes up?
I am glad that I have ordered the extra 48 V 5 Amp power brick with my amp.
Need CEA rated power supplies now lol
IKR?
I have always used meanwell , delta , morrnsun , fsp , bel.
if you are powering something really important then there is cosel & tdk these are like 10 times more expensive than regular units but the cosel ones are made in japan and way over engeenereed to be as good as possible.
For regular use like powering audio amps. Meanwell mornsun and fsp PSUs are all good.
I have a meanwell powering a headunit that i use as home radio. And it has never been turned off for once for more than 7 years. It gets power from ups when that occasional power outage happens. I keep it running cus i need to retain the realtime clock and other settings in the headunit.
Switching power supply vs old power supply
@@wal2 try with 4 12 volt battery in serie to make 48v
I would like to suggest Meanwell power supply
Great and reliable power supplies
Are you sure the psu is not making distortion high enough to trigger the test to end? It would be interesting to see on a scope or at least a set of voltage leads to determine what is going on? Keep up the good work I for one love this stuff !
@Douglas Blake That just does not make sense for the 8 ohm test vs 4 ohm test. The 8 ohm would have been close to 4 ohms in watts if what you are saying is true.
it's 100% dirty power out of that psu
@Douglas Blake sure the psu maybe able to output 10amps but the dyno test is for less then 1% distortion and as you can see the amp uses 7.5 amps at one point but the power reading is not going up on the dyno as it is to dirty and not a clean enough reading for the dyno
if you were to put a scope on the psu or the amp you would see it
I don't think that I would pick either one of the power supplies but I would pick a brand name power supply. You could even go with a cheaper Mean Well or anything would be better than Amazons "found somewhere in China brand".
Fosi Audio have a 240W 48V/5A GaN power supply now, for $30 more. Would love to see you test its power claims and put it up against the non-GaN 240W version.
During testing you should also monitor the output voltage on those industrial supplies. It is possible that either a) the amplifier went into protection or b) the power supply went into current limiting.
I bought the recommended 48v 12.5 amp power supply at 600 watts.... that's what the amp recommends
Interesting results.
I am curious what the XBox power supply bricks can support.
Great video sir!
I don't think they are 48V? I'll look into it, thanks for the suggestion
@@wal2 12 volt I believe
Just note that you connected the negative power cable to the amp to the earth/grounding connection of the power supply. The grounding/earth is meant for the 220v or 110v supply. You should connect it to the -V connections.
I connected mine to the Ground initially and it lost a lot of out put because the earth/ground was not clean. I changed to the -V connectors and it worked way better.
You're totally right! The test setup was flawed from the beginning. He needs to fix it, redo his test and repost the findings.
There are three plots for V+, V- and one for earth, neutral and line. Red and Black wires to the V+ and V-, Green on earth, White on neutral and an tiny black on line.
Do the same with V3 please
Another great video. Regardless of the outcome, your test of these little amps is entertaining. Appreciate the effort.
You should check the actual voltage output of those supplies, higher voltage will give you way more output of an unregulated amplifier
That low quality variable will be the issue. A decent Meanwell brand (industrial) 48V unit will have overload capacity to deal with the tests. When the switchmodes are made for a single voltage they seem far stronger. Thanks for these in depth videos!!
Don't even need meanwell. A 12amp morunsun would do that perfectly fine.
Meanwell is good to have if you are gonna use it regularly. Fsp , bel are good aswell.
Don't need cosel or tdk unless you want to overspend..
Apparently they are soon to release a new version. I returned my BT30D because it was not compatible with 48 volt 10 amp power supply needed to take advantage of the TI 3255 chip and to get max performance, not achieved with the 32v power supply.
I use those marine/automotive full enclosed grade "step up" boosters (12v - 36v or 12v - 48v) with either 8 or 10 amps. No issues, unless you wire them backwards...then they go "poof". Most of them can accept 8-24v input, too.
Given the lackluster performance of that power supply, I'm slightly surprised that Dick Riculous didn't make an appearance (though this is the "extras" channel.)
Ok. Usually variable ps has 10a max? But that is with the lower voltage,and the higher you go less current ? Isn’t it so .?
I have the 36 volt 10 amp supply and it does great. But I have not tried any the variable voltage power supplies. Interesting results
Time to throw together a simple linear supply for testing....great video thanks
Sometimes the Gods smile upon you. I was just researching these last night. Thank you UA-cam algorithm!
Thank you.
Hello Big D!
Have you tried the AIYIMA Audio A07 Pro with this power supply?
I have a MeanWell 48V 500W PSU, I want to buy a TPA3255 amplifier, but I want to make sure that it will work with it. I want to use it for 12" subs, so power is needed.
There is another alternative called Wondom/Sure BRU5.
It also has DSP! And you can buy them at half the price of the Fosi and Ayima amplifiers.
Beware of power bricks -- they provide the specified current, but they are frequently not well filtered and can inject audible squealing when used to power chip amps. The 24 volt 10 amp power brick I bought a couple of years ago would probably be OK to power an LED string, but it's not usable for audio gear because of that squealing. Btw, I have what looks to be that adjustable SMPS you used and it worked fine powering my 9 volt guitar pedals -- in fact, it worked better that the purpose-built wall wart I subsequently bought, which resulted in a loud pop when I switched on the power strip that I didn't have with the SMPS.
You´re right, EMI filtering at the output (or a cap multiplier) costs money (40USD!)! But I´m not sure if the other one is filtered. Another point, are the components safe (X, Y capacitors and so on)?
Thanks for sharing.
Wondering if the noise or DC jack cable affect the test result?? Cuz, you set to 1% THD.
I have the same 480W PSU, it can output 48V 10A...
Did you monitor the voltage on the power supply during the 48v tests? I wonder what kind of voltage went to the amp - if it had voltage drop... at 7.9amps at 48v it should have bested the 5amp power brick... only thing that would drop the overall wattage (in my mind at least) is if the voltage dropped dramatically. very interesting!
Odd, I have that same Drok power supply, connected it up to a heater element with a Kill-A-Watt on the receptacle and dialed it to 42 volts. The Kill-A-Watt showed 439 watts. I chickened out on going any higher because it was kind of a sketchy setup. I wonder if yours was defective?
Next toroidal vs r core transformer
i bought the BT30 Pro and ended up returning it after discovering that it wasnt compatible with a 48v 10amp power supply, which is needed to get the full performance from the upgraded 3255 chip. A rep from Fosi Audio said this was being corrected in the yet to be released new version....
I've got the same power supply, using it to charge large Lifepo4 batteries, l run it at a consisten 380w...14A at 27v from the charger, but its fed 230v ac...it can indeed deliver 480W when pushed to max.I think the problem with yours is the 110v input.
input voltage means nothing for a switching psu
The Dyno is measuring with clipping and distortion tracked. It's probably the brick designed for audio amplifier usage has some filtering optimized for that usage. Versus the general purpose power supply has such a wide range for it's filtering. The optimal filter capacitor is based on the current draw of your load, the voltage, the inductance of the load, the reactance of the load. Even just looking at a load of 0-10 amps and 0-48volts, that's a very wide range to filter for.
Did you see voltage drop on the variable power supply? Based on the math something is completely wrong. Fluke showed 8amps with 48V it gives 384W of power consumption and SMD showed 2 x 70 which is 140, so efficiency of the amp went down (when 140W dissipates on such small chip is insane) or voltage dropped?
@Douglas Blake no, amp meter showed 8A of consumption during test, psu should be able to give 10amps.
@Douglas Blake hey, Im still talking just about the test test from the yt not about the real life.
he does this on so many of the videos i notice, you are the first one to say something, basically he doesn't know how to calculate efficiency or is reading them incorrectly on purpose so that they sell on amazon, idk either way it's freakin annoying, to the point where i kinda stopped watching him.
This is class D, it has an efficiency of 90%, that is, 90% goes to power and 10% goes to consumption and heat;.at 140 W, 14 W are dissipated there!))) so everything is normal!)) even if the efficiency is not 90%, that radiator will withstand 30 W in the test. and in real music where impulses are even more so...
Really strange how the amp meter shows a current draw of over 7.9a, that's around 380 watts yet you only got around 76w per channel??
Something is wrong here haha, doesn't add up.
You will really need to use your brain on this one but number one amplifier loses power because it's users power itself number to the current the current clamp is likely in average maximum mode and showing the highest peak number of the current not to the continuous Reading
@David Knight Audio might be but generally class D amps are not that inefficient if it was class A/B it would make sense but it obviously isn't, something is wrong here.
its simple. the power brick is outputting dirty power
the dyno is looking for clean power and only shows clean power
so the amp maybe trying to output more and more power but its to dirty for the dyno
Is the ground wire out connected the isolated chassis ground and not the V-?
But yah Meanwell is the trusted brand.
Can you measure the voltage coming out of the power supply? If your fluke measured 7 amps of current then if it was truly putting out 48 volts then yeah, it should have been better than the brick. Also the negative voltage is odd. So if you wired something from the positive voltage to the negative you’d have 96v potential. I’m wondering if you’re really only seeing half the voltage you think you are.
Hello, I am curious to know how the Fosi amp would perform if it was connected to a 48V bank of Lithium batteries. Have you done any tests using batteries? I would imagine that there may be an improvement in sound as there is no noise. Thanks
The big question is. Does the amp distort more when you connect that bigger power supply? I know it must but how much distortion?
How much power it will give at 4 ohms and 8 ohms at 160 w power supply.
So just hook it up to some power tool batteries to get the amparage flowing
Thanks for the updated video! Shame that power supply sucks though.
Did you make sure the switch on the side is 110v and not 220v? Mine came from Amazon switched to 220v. With it switched to 110v I am getting much higher readings from this power supply.
It’s on 110…I think 🤔
Also looked like the negative lead was going the ground terminal, not the V- on the PSU.
I noticed that u hook up the amp To GND and not VVC- Some smps work in dual rail voltage. So you hook it up to GND u will get only half the voltage.
Look closely, the DC negative is properly connected
I bought that identical power supply and use it with my Aiyima A07. Sorry to learn it sucks
I am using this with 48v adapter, can I use a Bose 251 outdoor 6-8 ohms for each channel?
Couldn't you have picked up a fluke?. I have 2 of these Drok units. Is there a cheap way for me to test the output?
will the amp take more than 48 volts ? can you test it to see how much it will take ? these amps are amazing for their size .
Never push a product past its limits, especially when it comes to fire hazards like powered amplifiers! From what I read, Fosi says they are coming out with a better version because even though the chipset works best at 48V 10 amp (and puts out closer to advertised power output), the power handling of the unit is not good enough currently. I think there is a good reason 48V 10 amp supplies are not yet available from them directly, they know it cannot handle that in the current form.
Can you put 2 of the stock power supplies for this amp in parallel as I have 2 of them?
can you measure BT20A Pro rated power output (continuous)?
What do you think if an Ifi Zen One Signature is connected as an auxiliary and used as a Dac, connect a CD, by USB to a PC or streamer and digital to a TV to watch movies and Bluetooth? With a Spektor 2 or Sony CSS5 speakers. To start audiophilia in a 10 M2 living room? Greetings from Argentina!!!
@@jorgenavas6704 that would work great
Im having some buzzing sound when i used that adjustable power supply.
use the black industrial switching power supplies it will work better
Well something it's wrong! And I say that because, you pulled 7.9A times 48v out of that power supply! That means you pulled around 380watt! But your device shows a total of 150watt both channels together! How it's that possible? Have you had I voltage dropping?
I use a 12s lithium battery pack and im able to get 255 watts rms out of the smaller tda3251
Can you comment on the quiescent power draw for this Amp? My BT20A Pro sits at 35C (room ambient about 18C) which seems to indicate there might be a problem, my BT20A was cool at idle.
@Douglas Blake Well I let mine get nice and warm and pulled it out of the chassis and started poking around and the only thing I could find that's getting hot is the heat sink, and it was HOT. The voltage regulator is an XLSEMI XL7015E1 which is rated to 80V and was just warm when I poked it.
Strange occurrence, i bought a similar power supply but not as adjustable it's only 48v 12.5a 600w but you can fine tune the voltage to like 40 or up to about 55 it works very well with the subwoofer version of the aiyima a07 (bridged TPA3255 single 600w mono output) have 2 10" 500w subs connected in parallel al 2 ohms and it powers them very well, (they are still underpowered but i am planning to upgrade the amp to a different one soon) i did try to measure the current draw with a clamp meter but it's limited by the amp at about 9-10a at the power supply before the amp starts to clip badly so sadly i cannot test it's full "48v 12.5a 600w" rating but i can confirm it is at least 10A the voltage doesn't drop at all so i guess you just got a bad or fake one, moral of the story is to be careful because it looks like there are some fakes out there.
Its been a while since this video but you should do a video on the rockville bluamp 21 if its worth it to you. I have mine powering 2 rockville 8s at 4 ohms pretty nicely. Its actually funny as hell lol
Looking at the variable power supply output wiring. You had the output connected incorrectly. The positive + connection wire was correctly fitted to the + terminal. However you had the negative - wire made to the chassis earth terminal, and not the negative terminal of the output. This would massively limit the output voltage.
He wired it correctly. There are 3 screw terminals for each output. 3 for pos 3 for neg. The angle of the camera makes it look wrong but it's correct.
I thought the same thing at first glance but yeah the other reply is correct the print on the case is a bit offset from the terminal strip
You can see why these style of amp are so cheap and small because the power supply and size is where the money is at🤑
Hey buddy! I know you from the car audio channels! Hey I have some interesting questions . How do I join the group and all that so I can pay to send sensible questions? God bless and merry Christmas
hello, I have a possibly naive question. I have a smart plug that measures power consumption. I noticed that the power consumption of fosi bt20a pro (32V) at 50% volume is usually 4-10watt maximum. Is this normal or I have a defective device?
This is class D, it has an efficiency of 90%, that is, 90% goes to power and 10% goes to consumption and heat;. that is, when consuming 4-10W, it will deliver many times more power to the acoustics in fact! if it consumes little, you can turn on the fan heater in that outlet!)))
Loving the extras big D hey I know Amazon sells a version of this power supply that has adjustable voltage AND adjustable current. Did you pop the case apart to see if there was another pot in there somewhere limiting the current? Also I'd ring out each terminal on that strip to confirm that each screw is actually what it says it is. Great video as always and that is a dope amp regardless of the power output!! :)
Kinda of in strange I wondering if that factory power supply is actually put out 48v it probably rated at that but that not what it's putting out it probably higher voltage. I'm only wondering this because you can get the adjustable in high voltage for no extra charge really IV seen up to 72 v that iv seen at that amp range. usually the price increase by the amount of amp supplyed by the power supplys. Example 48v 15amp 29$ but for a 12v only 100 amp power supply range your talking 250$ even a 12v at 50amp is around 75$ 🤔💯🤯👍✌️🎵🎶
some of those power supply is turn down on the inside most that I repaired current can be turn up!
Hi ! Can you also review the BT30D PRO next?
Damn. I have that power supply and the amp keeps cutting off. Now I know
Try 4 12 volt car batteries
That’s more than 48V since each battery rests around 12.6-12.8VDC
YES. I was going to say this but looked through the comments first. It would be slightly over-voltage, but I expect not to the point of damage. ALSO test at 36V. The point is to see what the best this amp can do with truly clean power. Then other power supplies can be judged against this optimum situation.
YES.
an actual 600W meanwell psu would be good compared to whatever you got here
I am going to assume the power supply is suspect. A lot of the amazon stuff like this can be terrible.
REALITY CHECK! Thank you very much for this! I am from the late 70s when THE GOLD INDUSTRY STANDARD was the watts per channel at 8 ohm at a frequency response of 20hz to 20,000 hz with the other rating being at 1khz which was always highe. At least I can relate to your tests instead of all the marketing BS....."1,000,000 watts per channel!", "I can drive my Klipsch 96 inch woofer with this tiny amp", "The whole band was playing through this amp at Madison Square Garden, it was so loud people were wearing ear plugs!!!"
I am totally baffled by the 48V/10A PS...(Piece of S???) Could it be that there is a limiting factor in the amp itself? Is there a way to test the PS by itself connected to some electronic measuring equipment?
In the meantime I appreciate the 48V 5A Power Supply you tested. Is there an in-between 48V 7.5A version out there, preferably in a power brick mode?
Thanks for the clearing all the marketing hype!
Hi, I recently read somewhere that the ayima power bricks make an audibly mid range hum when used with fosi amps. Has anyone else here has that experience?
I just received a BT20A and they skimped out even further on the PSU, it's now a 24v 4.5a power supply. To answer your question, I do not hear audible noise out of the amplifier. I can put it out on an oscilloscope if you'd like to see what that looks like but by ear, I don't have noise.
@@mitchellroberts7954 Wow! funny I also read somewhere that the 48 volt psu is a must, and also it’s not. I’m surprised Fosi have downgraded the standard PSU as they don’t seem like that kind of company. It’ll encourage people to upgrade tho. PS thanks for the offer I’ll trust your ears!
hi sir, im new to audiophile, planning to buy bt20apro, hook up to speaker and phone. do i need to buy dac?
No, the amp has Bluetooth built in. The amp also has RCA in, so you can get a Aux out to RCA cable if you don't want to use bluetooth but it's not much better than Bluetooth imo. Your phone has a DAC. I would recommend a dedicated DAC if you are listening from other sources such as a laptop or PC that don't have Bluetooth.
Dac on the phone is not powerfull.. the quality also depends on the brand and type. If you want upscale your audiopile experience you should buy a dedicated dac. Donggle dac at least
Dang like always I am late to the party. 4 deep cycle or car batteries in series ought to do the job.
That other power supply, "really sux"😂
so is it any good then? is it bad? cant understand the technical language
The variable power supply isn’t what it should be
@@wal2 is it possible to use another one?
Ok so now everyone thinking Power wheels Chargers are usually pretty beefy🤔
...with a fuktonne of noise.
The one that came with my daughter's Power Wheels Jeep is pretty beefy for sure.
Just can't trust anything they write on the box or label. Always test it as soon as you get it.
Don't buy no name Chinese power supplies. Look up the Mean Well SDR-480P-48. It is a much bigger device.
Very true! Second hand meanwell PSU's off of eBay and whatnot are a staple for hobbyists. Often under $100 for 500-1200w PSU's ranging in voltage from 12v to 48v
How about you tested with a real 800 watt power supply
싸구려 망가진 소리 인데 칭찬 일색
Exposed busted
😂😂 Rockville components and pls put the birth sheet on a picture 🖼️ frame 😂
that power supply is just putting out dirty power is all this is and that's why your getting poor readings
@Douglas Blake do you understand how the amp dyno works ?
that's because just like amplifiers the cheaper companies use MAX ratings on their power supplies just to get a sale
Interesting. Measurements aside, I ordered the 48V-5A supply from Fosi directly to replace the 32V-5A that comes in the box. And it doesn't feel like I'm getting a whole lot more power out of it. Whereas I'm at about 65% I needed with the 32V one, I'm now at about 55% with the 48V version. Should the difference in volume output be so small?
I'm interested in this.
Double the power is 3dB change which may be only slightly noticeable
There should be no sensitivity change with the PSU at all, just you can crank volume up more without distortion.
Ive been looking for a 48v 10a power supply without much success
thanks for that info. I wont bother buying the 48v for the small performance increase.