*SHOP for Fosi Audio V3* - amzn.to/3PkrK2g 48V 5A Power Supply - amzn.to/3L68Olc *RELATED VIDEOS* Fosi Audio BT20A-PRO Review - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-b1zFuLK655g.html More Power in than Out? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-c7QELbpKMuI.html Mini Amps Video Playlist - is.gd/walminiamps *TEST BENCH EQUIPMENT* SMD / D'Amore Engineering Amp Dyno (AD-1): is.gd/wccad1 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 AMM-1: is.gd/wccamm1 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_
If you change that skinny wire that you plugged into the $300 power supply to a much thicker wire like I did you will get an extra 82 w and it's panel will put out/ roughly 235 certified 243 uncertified on each Channel you have to change that wire it's too skinny for that much power
I have one of these. Cost £82 from fosi direct with the 48V supply 😊 it's very good for the money. Earlier today I played most of dj dropping bass arsenal album at very high volume on my tower speakers with Zero thermal issues or notable distortion.
I actually bought Fosi Audio BT30D Pro after seeing other models on your channel, I chose BT30D Pro because it has a powerful sub channel and can also be used with active subwoofer and run at 2 ohms
I am looking to buy a 30D Pro and wish to learn if I can connect my active powered sub woofer and run the same. What shall be the connection wiring. Also what can we use the Pre-out point for?
The TPA3255 chip itself is a dynamite product. It was originally developed for pro-audio, and sound reinforcement in powered speakers. You will find it in all kinds of places including high-end AV gear, ICEPower modules and even high end stereo equipment. The concern is that a lot of these lower priced implementations are also exercises in price and corner cutting.
Your Mini Amp videos are one of my favourites as well. I´m somehow always very interested in these devices. Please keep on doing your fantastic job, pal!
I have them Elacs (Tower version) in my Home Theater and absolutely love them! Upgraded everything around them but not felt the need to upgrade them yet. Fantastic bang for the buck!
Do yourself one small favour ... check the case temperature when you have it turned off ... If it's warm, the chances are the chip is still operational. There is a design flaw in the TB-10d that prevents it from going into the RESET, soft-off mode and the amplifier can actually play music while it's turned off. There are other problems as well... but they're not as apparent as this one. Yes, I've notified Fosi about them and they claim they're working to fix them in the next version.
Interesting But you might want to try Thicker gauge power wire when connected to lab power supply as the thinner factory wire may limit current and therefore power .also with the pre out you use the volume control on Fosi to set the balance / level between the mains and the sub and use to music device to raise /lower volume
14:50 That all sounds correct for 48v 20a at 2 ohms. It is limited by the power supply max current and the resistor settings for the chip. You might have better luck at 2 ohms with the power supply set to between 32 volts and 36 volts and max 20 amps.
For your bench supply, id suggest getting some 5525 connectors with screw terminals on them. You can use 14AWG wire with them and improve your results futher. I found in the past that the voltage drop across a 3ft line of 20AWG is pretty significant at 6+ amps. Hope this helps!
Many folks confuse voltage and current and assume if you've got the voltage you're good to go. Too many don't understand the statement you made. They also don't understand the current spikes caps in amps can cause making that voltage drop from the supply even worse while those caps try to recover. I've been in the electronics field for 25+ years, so I get it. Now all that said going to a larger wire gauge may not improve the peak wattage given these exact tests, however it wouldn't hurt to find out. It's really about how well the caps in the amp recover under the test circumstances.
@@jeffm2787 Also, keep in mind that sine wave testing is not music playback. The full on every cycle clipping we use in testing would destroy some power supplies but that is only a very brief moment in music. Figure that with most reasonable music you will only be producing about 25 watts on average with intermittent clipping. Even on this brick walled crap people listen to nowadays it's unlikely you will average more than about 50 watts per channel from the 48volt supply before you get clipping. One of the recommendations I made to Fosi is about properly implementing the CLIP_OTW and FAULT pins on the TPA3255 chip to give a "pro audio" style warning on the front panels of these amplifiers. Properly done, the chip will support the blinking "Clip" and "Protect" lights that you see on most pro-level amplifiers and since these are data signals, they could also be used in DSP to manage maximum output. The chip also has current limiting ability that can be programmed to safe values for whatever power supply it's using.
@@Douglas_Blake_579 Agreed, it's a very complex situation. Using what looks like 28 awg wire that's probably CCA isn't a good way to start IMO. Scope the power rails while 'testing' is a good place to start. I'm a big fan of the TPA series of Ti chips, however unlike the amps that run off 12 volts with a boost regulator internally to help stabalize the power rails these really do count on those power bricks and the wire feeding the amp to supply a constant steady voltage even under peaks in the output. I'm with you on the average end user, however this was a test situation. Using a higher current cheap looking bench supply and using crap wiring wasn't very impressive. In the end it all just doesn't matter much if at all.
@@jeffm2787 Just to give you some idea how ill-informed the average consumer is... I got a call the other day about a failed A07. When I mentioned the V3 he pipes up _"I don't want none of that Digital crap. I'm staying with the good stuff"_ ... where do you even start with that?
Fosi Audio have a 240W 48V/5A GaN power supply now, for $30 more than the standard 48V/5A. Would love to see you test its power claims and put it up against the regular power supply.
Cheaper to buy two of these amps and just bi amp your speakers on the stock power supplies. You’ll never face a scenario where those extra few volts make a life changing difference in audio.
These little chip amps are sure getting nice. I'm waiting for one that offers USB and optical input with built-in DSP, so I can tune it via computer for specific speakers. Who knows - there may be one like that available already...!
found one from CJL called the BRU5, theres also one from arylic called the B50 the arylic one has the most inputs and outputs so that might be the better one for you lol, the CJL is about 1/3rd the price though colpared to arylic with the CJL's TPA3255 chip arylic has a sub out, CJL doesnt, if that matters (or buy 2 SJL and use 1 for sub amp and the other full range)
@@10010Linus The B50 is using the TPA3116d2 chip which tops out at 50w/ch on 8 ohms 10% distortion, or more realistically 35w/ch, 8 ohms, 0.1% distortion. Don't expect it to even get close to what the V3 does.
Three deal breakers on the V3 ... 1) The power switch on the volume control. It will be failure prone because it's passing the power supply current and it's rather inconvenient since you have to reset the volume every time you turn it on. 2) That fixed level output on the back. Lord knows why they would even include that since it's useless for anything except daisy chaining amplifiers and Y cables are often more convenient. 3) The Op-Amp sockets. They look like the good quality aero-space type but they are not. The gold coloured guides on the socket should act like a funnel directing the op-amp pins down into the contacts, but the inner edge of the guide is a flat surface and unless you get the pins started into the holes perfectly you will end up bending the pins on your chip and possibly destroying it. If you're rolling op-amps in this thing, take your time, use a magnifying glass and get all 8 pins started into the center holes, not just sitting on the gold coloured guides, before you even think about pressing it into place. Fosi seems to be developing a reputation for good ideas but bad execution. I've also run into design level issues with the TB-10D that I've notified them about and supplied corrections for. Currently, I'm waiting for them to let me know when the fixed version of the updated version will be available.
Nice job and congrats on that new power supply. They provide the voltage these micro chip amps need. I tried out this amp a while back and thought it sounded like crap. I could NOT get it to sound good. All things being equal, I swapped back to Douk Audio and the sound was cleaner. My point is, the Chinese "experiment with the market" ...so many of these type mini amplifiers out there. They use our reviews (videos) for product development. The best sounding ones are the 100w x 2 amps with the 24v max power input with the Texas Instruments chip. For most listening, 30 watts clean per channel is plenty loud. Hook up some high SPL PA/DJ speakers to these amplifiers and you'll get some cheap loud sound levels. I like the sound of most digital chip amps. Class D amps still sound off to me. Class AB sound the best. Your 2-ohm test at the end was COOL! Impressive. My problem/issue is finding a "quiet" 12vDC to 48v step up booster for my builds. Most introduce audible noise vs using a 120vAC adapter
The TPA3255 used in the V3, TB10D, BT20 and BT30, A07, A07pro and on and on, is not an experimental chip. Check the spec sheets... it is a very capable amplifier originally developed for pro-audio use but now also widely adopted in home theatre, high end stereo and lord only knows how many DIY boards. The TPA32x series is the next generation to the TPA31x series from Texas Instruments. They've added enhanced feedback and distortion control mechanisms that actually work. The problems we encounter are mostly in 2 areas ... 1) The Chi-Amp market tends to underestimate their output filter designs. Often the series output coils saturate well before clipping occurs and oh boy do some of them get hot! 2) The control signals for the TPA32x series chips appear to be widely misunderstood. I've had issues with amplifiers that will not go in to RESET and remain active even when the front panel switch is n the off position. I've also noted that many of the DIY modules have the Clip and Protect LEDs in the always on state rather than having them dark unless there's a problem, which just destroys their utility as monitoring features. All that said, I seriously doubt any of these chips have been aimed at the automotive market. Most of the features and requirements are far more indicative of home audio (TPA31x) and pro audio (TPA32x) targets. You may be able to quiet the boost converter but that's going to take some serious filtering at both audio and longwave RF frequencies.
I see a common mistake in these comments about the power leads for these amplifiers. These amplifiers are NOT for cars and they are NOT for driving super-bass rigs in your basement. These are a home HIFI amplifier for use with your PC, record player or, more commonly, your TV set. The thing is that everyone is estimating the power leads as though the amp is going to draw it's full 20 amps continuously.... But that isn't how music behaves... The average power is actually quite low, even though you are occasionally clipping a snare shot or explosion sound. With only a 10db dynamic range in your music that 200 watts dyno measurement drops all the way to 20 watts of average power... At 20 watts on 4 ohms that amplifier will draw about 2 amps from the supply. (and make sound loud enough to damage your hearing) There is no reason to wire it up for 200 continuous watts unless you intend to power a siren.
I have a little Grey fosi in my boombox I built for work. Gets signal from my old deck, a pioneer mvhs512bs, they power two pioneer pro 8s. They rock. Sound great and put out a bunch of sound. And mine the 160x2@4ohm
thx for the tour, its funny what design priorities have done. Of course most home amps are receivers where the power supply is incorporated in the chassis, because of whatever reasons led to the standard stereo component being that big. the only problem i've had with this crop of mini amp is the pot used for volume goes crunchy within a year of all the ones i've tried....
the reason why videos like these are so popular is due to very few people actually doing this kind of testing on them. I guess being slightly shy of the rated power output is a heck of a lot better than the package saying its 600w but only outputting 20w yeah the fixed line output is not ideal, BUT all is not lost as many subs have a pass through, where you run left and right the speaker wire from the amp into the sub and hook the standard speakers up to the sub and the sub gets its signal from there.
The big power supply was probably being limited by the micro thin wires you used to connect it to the amp. You should know that those baby wires can't effectively supply the 20 amp potential of the big power supply. It would have been great if you showed how may amps were being drawn from it under load, I'll bet that it was well below 10a.
@@Synthematix That depends on many factors, but the highest I've seen stated was 450 amps. Regardless, that has nothing to do with my comment nor the limiting factors of an amplifier or its power supply.
you could probably get to those ratings (power) if the DC cable from the power supply to the amp had heavier wire , but that would be hard to do because of the connectors etc
Bought a similar amp from fosi that has a sub level and freq knob on the front as well as bass and treble adjustments. I was skeptical because of the size of the amp overall but was pleasantly surprised at how much power it actually has. Powers two 25 year old sony towers no problem
I have the Douk Audio M1 Pro amp and I like how it has the RCA pre-out and it's controlled by the volume. Perfect for running my Sony SS-CS5 bookshelf speakers and my Sony SA-CS9 powered subwoofer. Sounds great!
Love your videos. Keep up the great work! I cannot think of a scenario where you would not want variable output. The amp is small and compact, perfect for desk use. If you want a 2.1 system where you adjust the volume as needed, the sub would stay at a non changing volume. How did that make sense in their design phase????? Do they expect you to use the fixed line out to feed another amp for speakers in another room? That is more the landscape of a full A/V receiver. I find most of these low cost, direct from china, have all these weird compromises that make no sense like turn on/off pop, fixed outputs, or no line level output for a sub, etc.
I checked a couple other fossi amps with "pre out" jacks and those are variable. I think, someone screwed up big time on the design of this one and forgot to make it variable.
I have one on order with the 48v power supply, the bluesound node n130 is used as the pre amp so has the connectivity the Fosi is short on including the sub. This is hopefully going to replace the NAD 2200 you dyno'd before with incredible power on tap. see how it gets on. the reason is other half leaves the NAD on and it's burning 78 watts in idle.
When these little apps get into this price territory, especially with the power supply upgrades, the only advantage is really just size over getting a two-channel receiver from Sony or Yamaha... Especially with all the additional features a real two-channel receiver would have, like multiple inputs a remote control Bluetooth built in etc.
it does exactly what an amplifier is meant to do, amplify. in my case i picked one of these up to take the place of a Rotel 2 channel receiver that i was using only for it's amplifier channels. this chip amp sounds far better than what was a quite spendy 2 channel receiver. I'm using it to power the bass bins of some Klipschorns biamped with vintage Dynaco tube amps powering the mids and highs, and a miniDSP flex doing preamp duties and of course, DSP. theis cheap little amp is a serious competitor to actual audiophile components that cost thousands of dollars. to compare it to a cheap 2 channel receiver is really selling it short.
I have the 3 Chanel one in my shop. It’s connected to a Polk psw124 directly since the plate amp blows in them and 2 mtx monitor 10” …. And my neighbor 2 houses down came and complained lol well time to add more power I guess!
I see that maximum voltage for that amplifier chip is 53.5V so try that and see what will happen 😊 (edit:) please put thicker wires for the power supply, those were tiny cannot support 20A for sure.
@@Douglas_Blake_579 Depends on temperature as well, the protection circuits will cut in sooner when hot. Don't expect 53.5 volts under full load - but you can increase input voltage to fight voltage drops through copper traces...
Great video! Some Fosi V3 owners have said that the V3 has a low line output signal compared to something such as an integrated amplifier or home theater receiver and that this reduces the audio quality. Did you notice this? Would this V3 benefit from a preamplifier to get some extra gain in the line output?
That much power to two good home speakers is way beyond what you could ever use. I run a nice older receiver with 30 watts a channel and it will practically run you out of the house with 2 nice Klipsch towers.
So it can work as a 2.1 just need a powered sub with a adjustable volume and make sure the amp is on and at the volume you want it but the preout needs to be renamed as line out instead and maybe next revision of this Lil beast can have the line out fixed to preout with volume control but honestly for about $100 with taxes and shipping (without prime of course) its not bad
Great review. Would def need a headphone output. I've been using my Fiio M17 for almost 2yrs and have really enjoyed using it with all my IEM's and EarCans. Only thing is, the M17 is a "brick" and weighs about 1.25lbs. I was lying in bed scrolling through my music and it slipped outa my hand and smashed my face!! It bloodied my lip, hit my left-eye and made me see LIGHTNING!!
I liked this video and gave you a thumbs-up because I like the power supply😊 but when you're doing the sound quality test on the bookshelf speakers would you be able to show the watts that you're putting to the bookshelf speakers? it might not be easy to set up but just for curiosity's sake.
Do you have a video explaining your testing methods in more depth? I've been trying to learn more about audio equipment as well as building my own speaker cabinets, and I've been overwhelmed with information. Also, I've been struggling to find information that's specific to the applications in which I'd like to build speakers for; like how I always get car audio information when I'm trying to learn about live audio cabinet building.. I'm lost
The tpa3255 will run at 52v fine. Just to be safe give it 50v first and then 52v!. Besure to turn off the current limit in the powersupply. And use proper thick wire for the barrel jack..that one you got will get warm at 3amps. 😂
@@Douglas_Blake_579 if you watch the video carefully you will find they are 63v capacitors. No engineer will install 50v capacitor in a device that runs on 48v because slight over voltage is always expected.
@@KuntalGhosh It wouldn't be the first time I've seen things like 24 volt caps with a 32 volt supply brick. Better to play it safe than watch things blow up...
@@Douglas_Blake_579 yup i had one explode the moment i plugged it in.. typical chinesiums powersupply. I cracked it open and turned out it was a used powersupply with some repairs done to it and put back in a new shell. The design was good the parts quality was good even had active power factor correction for a 70w power brick that they did not even advertise in the ebay listing. Replacing the capacitor fixed it. And it still works.
@@KuntalGhosh Not what I meant ... I was talking about a couple of companies that were using 25 volt bulk capacitors in their amplifiers and selling 32 volt supplies with them.
I am fairly certain the cable used limited the amperage possible to the amp for the test, but I'm not a power fiend I run my fosi amp with the 5 amp adapter it's more than loud enough for me.
If I ever see one of these with a variable line out I’ll be buying it. Numbers are great on this one. But sub is very important to me. And I’m not using speaker level into the sub.
I've got from alliexpress 3255 board with replacable op-amps. Just for 20bucks. So i ordered another one to see where i can push the voltage at, the maximum what i remember was 51V and board went in to the overvoltage protection. You can use 50V PSU without any problems but really, 50V exactly to increase power a bit higher. PSU must to be hard and must to be able to keep up with bass bursts without increasing voltage when the amp asks for more power. And also, those chinesse people really did care about specifications, 3255 chip really can do 300w x 2 but at 10% THD. My board has these specs: 300W per channel 2Ohms 10%THD 280W per channel 2Ohms 1% THD 250W per channel 2Ohm 0.1% THD 210W per channel 2Ohms 0.01% THD All ratings at 50V My board also could be bridged but that is more likely for subwoofers only mode and at 2Ohms it can output in burst tone almost 700W at 10% THD but keep in mind that this chip is very very tiny and sufficient cooling must to be provided to avoid destroying it almost instantly at those powers. Copper heatsink is 100% way to go. Aluminium is for 400W max to keep your ( and mine ) spirit in place
Pre-out is pre-fader output. So the volume control must be meant to be handled before it gets to the amplifiers, the level on the boxes themselves is just for balancing the levels at that point.
Can the Line Out be used for adding the V3 to another amp? I care nothing about using it with a Sub Woofer. I'm an old school 2.0 Stereo Guy. Great video! Love the detail and the sound tests. I subscribed!
I don't get it why you where disappointed with the line out not being variable, i remember when i got my BT30D PRO i couldn't use the line level output because it was adjusted by the amps master volume! As i had a separate amp for my sub it meant that i would be forced to turn the fosi up all the way to deafening levels for my subwoofer to be at max volume, doesn't make sense for a desk setup! I had to use an audio splitter that way both amps would get the full input signal and i can adjust each to my preference In fact i still use that audio splitter setup, I've since upgraded the fosi audio with the aiyima A07 Pro because i got a different amp for the subs thus i didn't need the 2.1 channels of the fosi anymore, but i don't know if the A07 Pro has the same problem, if I'm being honest i never bother with the pre outs on thease mini amps after encountering such issue, I'm glad the V3 is the way it is.
The big let down is definitely not putting a separate power switch on it. Volume knob is a lazy power switch and we’d all like to leave the volume knob alone when everything is set and balanced right in the audio chain. It’s “hi-fi” status goes right out the window with that weird cop out.
that cord you cut to run the 48v at 10 amp test the wires don't look like they can carry enough current without dropping voltage, at the very least you should make that cord as short as possible, when you start pulling that much current I highly doubt your still getting 48v at the amplifier. alternatively you could measure the voltage at the device and turn up the power supply to compensate. but when your not pulling current not sure how it will handle the over voltage.
It's so weird they make the stupid power claims when these little boxes push out very respectable amount of power at 4 ohms. Think about it, if they told us 2x150w at 4ohm and it pushed closer to 200w, we would be happy. But if they claim 2x300w but only do half of that, we're sad.
@@krowwithakay Not to say I agree, but I have 3 amps with the tpa3255 and for the money, they're untouchable. You can get better stuff but stuff that's meaningfully better? Hardly!
You do some great reiviews! Thanks. (I like tone controls) You have tested and heard the fosi audio bt20a pro as well. Is this V3 much better sounding? Thanks
I wonder, is it that the 3.5mm "output" is a parallel input with the RCA inputs? Perhaps mis-labeled as an output? I'm sure someone already beat me to that comment, but that's my thought. Great video and looks like a great little amp! However for my bedroom stereo, I think I'm staying old school with the Carver C-5 pre and a Yamaha P2075 amp.
Had Fosi Audio DAC, worked fine but after a year volume knob started to develop issues (no sound on certain levels) and started to get power surge on USB port errors. It also told Windows to support audio codecs which it didnt support which caused nasty buzz before I found way to disable incorrect codes (which reseted in each Win update). Before that I had Topping AMP/DAC which lasted 2-3 years before died. So dont have much of trust on chi-fi today.
Try power it with a 36v (32-42v) lithium battery or something similar to see what results you get! i use the TPA3255 with a battery (36v 12ah) but i dont know how much i get out of it. The battery should be able to pull at least 1C which equals 12a and with 36v thats about 432 Watts
This is just a power amp, no Bluetooth. Only line-in via RCAs. The Fosi BT20A Pro would fit the bill. Bluetooth and tone controls, lil less power, lil noisier (but still, much much lower noise than most mini-amps).
Nah, it can pass 600v if needed.....but at 48v and 5a, that's enough to convert to a higher a/c rail voltage to move the cone. Very little current is needed to drive a speaker....
@@walyou got it.. and we would rather hear the speakers than look at them although that is cool but through my mahoosive home audio system this amp sounded exquisite on them elac's so your hitting that proverbial nail... thanks man appreciate the content big D, as always 🙏 🔊🔊
Fine if your trying to get 100 watts, not so great if your trying to get 200 x 2. Those are probably not even copper, probably CCA. Could still end up with current spike of 5+ amps on crappy tiny CCA power leads.
