Fosi Audio BT20A Pro Mini Amp TPA3255 Review and Power Output Test

[@ryanmalin]

Im using a mini amp for my computer speakers. Its only 50w x2 but it pushes my 2 12 inch 3 way speakers just loud enough for the police to be called so Im happy with it.

[@1pcfred]

The Police? Roxanne you don't have to put on the red light.

[@aloneangel507]

What is the RMS power of the amplifier? And how much rms power speakers are they?

[@myquietreviews]

@@1pcfred That was funny 😂😂😂👍🏿

[@michaelbowman7398]

These mini amps are definitely getting nice. Thanks to you for weeding out the good ones from the bad

[@fosiaudio]

And your suggestions can make us even better.

[@Idiotsincarshere]

@@fosiaudio newbie here, can this run 6ohm bookshelf speakers? if yes what's the expected output? keep up the great work!

[@NuriBass69]

Just bought a Fosi amp for the garden shed, so glad I stumbled upon this video

[@freedblowfish3705]

Bought fosi cause you, you guided me down a rabbit hole, got 4 need at least 6 more, and wiim minis

[@mtayfur83]

I bought new Dali Spektor 2 bookshelf speakers to listen to quality music. Therefore, I needed a good low-budget amplifier that could drive this speaker, and since I was satisfied with the Fosi Audio BT20A amplifier I had used before, I now ordered the Fosi Audio BT20A PRO and am excitedly waiting for it to arrive. Thanks for the review. 

[@wal]

*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* Update - Fosi Audio BT20A Pro Power Supply Tests: kzbin.info/www/bejne/rXvIgoJjepaIZ8k Fosi Audio M0-3 Mini Amp: kzbin.info/www/bejne/raOlgXSGaNOiopI Aiyima A07 Mini Amp (TPA3255) : kzbin.info/www/bejne/oXPMnmWgbKyga9E Douk Audio M1 Pro Mini Amp: kzbin.info/www/bejne/jYOynmqgf8eVaK8 Mini Amp Video Playlist: bit.ly/3IMdtbN Amp Dyno Modes Explained: kzbin.info/www/bejne/h2HQZ4Gpd5J7fsU More Power Output than Power Supply?: kzbin.info/www/bejne/mWi0dn-YpbCAq6s *VIDEO INDEX* 0:00 Intro 0:36 Unboxing 1:30 Features 3:08 Specifications 3:43 Amp Dyno Tests 32V 5:22 Amp Dyno Tests 48V 7:18 More Power Out Than In? 7:40 Pre-Amp Output Tests 8:55 Bluetooth Connection 9:22 Sound Tests - Song Demo's 10:46 What's Inside? 12:36 Pros and Cons 13:39 Final Thoughts 14:20 EXTRA Test *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_

[@Toid]

Awesome Test! Loved the video as always! Keep up the great work!

[@Random_4400]

I have the BT30D PRO and i must say i am very impressed by how much power it puts out, good amps for even the biggest of bookshelf speakers!

[@TFOTLITBOK_P1_7]

I'm running a pair of Bose 251's and a Velodyne 8" sealed sub enclosure with that same model and I completely agree with you. For the cost it is quite impressive. Very clear audio quality and plenty of power.

[@thehotrodstation3313]

I have one as well pre 2000 polks with passive subwoofer. And Holy crap for the size very good amp

[@zavatone]

I've got a few 700 watt amps, one 1000 watt amp + one 250 per channel amp that I use on one set of 4 ohm speakers right below one of a Fosi preamp and alleged 160 watt amp. I have to admit that aside from the pop when turning them on and off, they are certainly decent units when compared to the big boys.

[@ceeweedsl]

We have a BT30d Pro driving Sony bookshelf sscs-5 with 10" passive sub and are getting plenty of full sound for our small dance events. Large outdoor patio. Excellent sound. Look forward to upgrading the power supply. I think that's where it matters, not op amps.

[@mullinperformanceaudio5902]

Clean little unit. I love these palm size amps putting out $1000 watt amp numbers from the 90'.s

[@chijiokepenny2100]

I purchased this mini amp after seeing it being tested here on your channel to run a set of KEF Q150 I had sitting around. This little guy sounds great and does a good job running them. Will purchase the 48v 5a power supply when it's available!!!

[@johnniebeard8647]

I'd never heard of this amp without this chan.thanks BIG D

[@doctormidnight]

Thanks so much for fufilling my request to do reviews/measurements of these little guys. My SMSL SA-300 is an absolute banger and has driven everything I've thrown at it, even a 4 ohm speaker with an 86 dB sensitivity.

[@purplehazeffc]

I also would like to see SMSL products tested. I've got the SMSL AD18. 100% awesome amp for the $$$

[@wcg66]

Im super impressed with my Fosi and Ayima amps based on the TPA 3255. They are powerful enough for me but more importantly, they sound really good. On my Ayima, I’m using a 48V 10A amp supply. I don’t need that much but presumably, it provides plenty of headroom.

[@andrzejjozwiak6412]

Kolego możesz podać dokładny symbol tego zasilacza.

[@K0Kaz]

This has definitely been a surprising product category. I was skeptical early on, since I had an early Blaupunkt Tripath car amp that sounded terrible (and quit working). But I was happy enough with my first Topping TP30 mini amp that I upgraded to a SMSL Q5 Pro, and been considering upgrading again.

[@wal]

These amps for some reason get a ton of interest on my channel. I love to test home and car audio but it seems most of the home audio (other than these), don't perform well for me.

[@hardtymz2517]

Man, NO ONE had those class T Blaupunkt but I remember them in catalogs. No one knew that tech at the time and wanted to be the guinea pig. Ugly plastic things but tiny and could hide them under a seat. Ahead of their time. At least now I know they weren't that great thanks to you. Lol. Even eBay would always tell me "wtf are those things?? And, yea, we don't have any nor ever will." The best sounding big class T for home audio was by far the 1st Gen (non tilted logo) Topping TP60. Never seen an amp that could max out and still get louder and no distortion in sight. wow!

[@LuminairPrime]

@@wal What's special about these small no-name amps is that they're cutting the legs off the scam artist audiophile companies that have been selling this stuff for 10x more money all our lives

[@richardwilliams2179]

I’m impressed with a number of these D class amps impart because it’s a desktop… not out to please larger crowds…. These will fill a modest size room with plenty of sound

[@denisohbrien]

These are great little products, my separates system eventually just became an amp and Bluetooth dongle, and now it's just one of these little amps with built in Bluetooth, sounds plenty good enough for Bluetooth audio and goes plenty loud with some good speakers. The big plus is the size and simplicity. Big fan.

[@NathanOakley1980]

Lovin the distortion testing. 😊

[@murrayshekelberg9754]

May have to pick one of these up. I never would have imagined so much power in such a small setup would be possible in my younger days in the 80s and 90s. Looks like really clean volume as well.

[@stefanweilhartner4415]

they didn't use switching power supplies and did not have class D amplifier chips.

[@murrayshekelberg9754]

@@stefanweilhartner4415 true, but the Skar has a glaring lack of vibration protection. It is a common point of failure with those.

[@joentell]

Thanks for the tests! I will refer to you in my review.

[@wal]

Awesome, can’t wait to see your vid 🤙

[@tatialo37]

Yay! Another great amp test!!!

[@markshade8398]

I remember in the 70s and 80s when a 100 watt per channel home stereo amp was huge and weighed a ton. So much change in the audio world.

[@especialistqap]

100 watt from vintage amp sound better than 100 watt from new class D amplifier

[@markshade8398]

@@especialistqap agreed but still amazing.

[@hardtymz2517]

when the huge power supply brick is factored in, they're not so tiny anymore. i wish they did this all in one chassis. it's annoying.

[@Grommet2007]

@@hardtymz2517 The separate power supply removes a possible source of noise from the amp's chassis.

[@markshade8398]

@@hardtymz2517 even then they are considerably smaller and lighter than the usual 35+ pound home audio amps of the 70s and 80s that were usually about 15+ inches wide, 12+ inches deep and 4+ inches tall. But I do understand your point.

[@411LED]

Nice B~D... I've been tinkering with these little demons for the last few years and it seems like the 3255 is maturing quite nicely. Gotta luv the interchangeable OP amps the boards are now using as well as the tubes. I found the best way to remove OPs is with a balanced wiggle/pull on each open end using one tweezer like tool. Yes indeed most of the included power converters claims are unreliable so my solution was to snatch up an adjustable 48V~10A transformer...

[@411LED]

@@gags730 Not to discredit your knowledge, since the TPA3116 became readily available for the past 5yrs they've been available. Simplicity is a matter of joining some small amps with a Home Theater preamp.

[@4LED]

@@gags730 A person gets what is given and if not, then it's time to move on. With B-D's channel, it's easy to realize his reviews show mutual respect to all, except maybe himself and/or manufactured items.😁 As for suggestions: You stated experience with Puters and auto sound so go with the flow on what you know by Using a 2nd Computer/Laptop Add a HiFi 5.2 Bluetooth Audio Adapter w/LDAC,APX device such as Qualcomm=1Mii/BluDento ($50) Then use a 5.1 USB sound card. IMO the most reliable 5.1 class D amps are offered by Douk/Nobsound, Aiyama, Fossi. Separates will give the advantage of upgrading due to rapid evolution: There are 5.1 class AB amps with many options offered by no name and cheap A$$ companies like Pyramid, Pyle etc. Note China has the worse Quality Control and it's senseless to order one from there. Keep in mind try not to purchase the latest claimed greatest hardware, rather the next best because it will save $'s.

[@halseyballistic]

Great review! Purchased one of these little bad boys and use it daily for music and watching tv. Works very well as a 2.1 set up.

[@sleepyboytx]

I have the BT30D 2.1 non pro version and I've been extremely impressed with it. It's driving Two Dayton Audio Bookshelves and a Skar audio 8" and it's by far the best and clearest sounding home system I've had to date!

[@jimjones3287]

how do you get it to run the skar since there's no low pass filter?

[@sleepyboytx]

@@jimjones3287 adjustable sub frequency and volume level. It blends in very well for what it is. I'm also using it for my computer speakers and the sub is under the desk if that helps.

[@jimjones3287]

@@sleepyboytx oh the version you have is 2.1 channels (2 stereo + subwoofer output), the one reviewed here is only 2 channel stereo.

[@EcSsAwS]

I been using a NOB sound Bluetooth amplifier I seen in your videos well over 2 years ago now It’s still kicking and does great. Powers 2 Fisher cabinet speakers 4ohm each (. 2 10s 6” mid 3” tweet per cabinet)

[@skyoreece9805]

I would be worried at 48v psu as those caps where rated only at 50v. Maybe if they where 63v etc... would be ok but I wonder have any failed at 48v. Keep up the good work x

[@hardtymz2517]

good call.

[@dennissinger7880]

Sure electronics make 63V My aiyima tpa3251 work whith 36V but have 63V to , verry nice

[@frizzlefry1921]

Like just about everything now days, redline engineering a.k.a. planned obsolescence at its worst...

[@fosiaudio]

The caps in Fosi Audio V3 is 63V, it is Japanese NCC capacitors. You can have a look.

[@Grommet2007]

What I've found with some of these small amps is that the dual plugs can work, but you'll need to use them a bit differently. Instead of using one per channel, use one dual plug for the positive connections and one for the negative connections. Then insert them accordingly (one dual plug into the positive terminals, and one into the negative terminals).

[@madmax2069]

Yup

[@Grommet2007]

@Douglas Blake Been using that technique for years with my Dayton chip amp, LOL. The extra stiffness provided by using dual plugs makes sure that there's a lot less risk of a plug moving around and causing a short as a result. Just make sure to insert the dual plug at the top with the ends of the wire facing up, and the one at the bottom with the ends of the wire facing down. No unsightly tape required. ....

[@Ramsaaaa]

Recently picked up a BT20A Pro, could't resist pairing it with a MiniDsp2x4HD and another Fosi V3 for a bi-amp two way (8" SB woofer+Tectonic 1.25" full range). Just astonished by the quality. For under $600 total, a low-distortion 100WPC biamped 2-way with DSP. I can't speak highly enough of these Fosi amps.

[@dancingwiththedogsdj]

Big D! Ok, is it just me or haven't you been doing a little more nearly every episode/between episode stuff and diving deeper into this stuff that probably a lot of us didn't even know we needed or would find helpful or at least interesting! Love it bro!! 🍻🌎❤️🌮🎶 What's next!? Your own line?????? You're just gathering data to make something good, ain't ya? I wonder how long it will be until we have a signal processor/amp based on newer A.I. with ChatGPT built in 🤔😁 P.S. - Big "D" amp: Small size, exceeds power ratings, oversized speaker terminals, solid reliability/cost, easy to repair, Tiffany style RCA jacks, high efficiency, REASONABLE plain and simple. 🤯

[@iikatinggangsengii2471]

hm if its my signature id like vision ears to develop it

[@troyg3831]

Promo code wasn't working for a while but Just tried it again and it's working now. Guess when they said the 10th they meant give or take 4 hours. Been looking for a little amp for my theater chair but these rarely get a reliable review so Thank you BigD! I hope my chair will soon be Bumpin'! lol

[@gregmorris2022]

Would love to see you test an Emotiva home audio amp.

[@nunyabizznizz7326]

thank you for the honest review......never skip your content 👍👍

[@VochoTalacha]

I have a 2.1 fosie audio amp that supports passive subs. The damn thing sounds very nice but it keeps on cutting the highs and mids if I crank the volume. I've used several power supplies to give it more juice and none of them stop it from cutting out. This is a shame.

[@steveschwartz9421]

Just checked, these are shipping with a 24V/4.5A power supply for the non-pro, the Pro comes with the 32V 5A Power Adapter; about $20-$30.00 difference. Found a 48V 5A PS for $25.99. Buy the non pro and the better PS for the price of the Pro unit unless someone wants to mess with the op amps. (Iregardless?, c'mon, common use yeah but really, regardless is proper.) Love your vids, appreciate you diving in where no men dare to go - smoke'n!

[@gruanger]

Where did you find the 48V power supply

[@MrMatthewstrike]

The non pro is max 24v and a different chip (TPA3116 instead of TPA3255)

[@steveschwartz9421]

@@MrMatthewstrike Missed that, and that matters. In that case, I would opt for the pro with the 48V/5A PS. Anyway you slice it, about $30.00 difference from the stock version of either w/the pro unit giving you additinal features too. ;)

[@wal]

The pro is the same price with my discount code and it has line level outputs. Well worth going pro IMO. Discount code in pinned comment and video description

[@JailDoctor1]

I bought the earlier version of this Amp. Great and it still works. I like Class D amps but...........

[@hindesite]

Bought a BT20A to replace an old Hitachi HA-3 amp, for use alongside my PC; have just bought the BT20A Pro to replace that, so I can replace my 30 year old NAD amp in our lounge. Impressive, been messing about with or working in audio since I was a kid, so seeing these amps is pretty interesting.

[@capcyvasile]

Using the amp as we speak. Bought it cause i had some passive speakers laying round my home and really impressed by the power and to my necessity i sold my krks active speakers

[@insidechocolatewithjimothy5313]

It's great to hear Billy Bob Thornton doing such great reviews.

[@pawnch83]

More mini amp content, such a great subject.

[@Zodliness]

@Williston Audio Labs - I've been into reducing the physical footprint of the amplifiers that I use in my various portable audio projects. Recently I've been using the Focal four channel mini car audio amp at £250 a pop. Attached to an external mains 30amp 12v power supply, the bass line supported by a Stinger 10 Farad competition cap. Running a pair of 15" 250w subs. These smaller but equally good units would make pretty good donors for many 'mid-power' projects. Thanks for the great review. Keep em coming!

[@dgdave2673]

Take these reviews with a big spoon of salt. I have this little ChiFi amp, it’s wonderful for what it is for desktop listening, casual game room setup etc. but let me be clear, it’s no match for even a entry level, but well built, well priced offerings from Cambridge or Emotiva etc. The Emotiva Mini X-A100 that I also own beats the snot out of this little bugger in terms of superb midrange weight, bass depth and tightness and well resolved treble and separation. But for $80, this BT20a Pro does hold a surprise or two on how well it still can drive medium to large speakers. Anything upto 11 O’clock position sounds good. Beyond that it loses its composure, but it’s already pretty loud 90db by then. Try this for fun and you may find a use case.

[@xtraflo]

What a Great Microphone to capture that sound!!

[@DJBossCreations]

I love the way that Elak sounds amazing in my headphones

[@wal]

They are amazing speakers!

[@TheMatsushitaMan]

8:04 Panasonic (Matsushita), my favourite brand of home appliances! I'd love to have their test equipment too.

[@fritzkabeano1969]

Still glad I got the Aiyima A08 pro with the same 3255 Ti power chip BUT it comes with the 36v/6amp power brick and it has better bluetooth codec coverage (aptx hd and LDAC). That can be bought for $110 on sale.

[@heyaa8384]

Fosi BT20A pro mu yoksa A08 pro mu ?? hangisi ses kalitesi olarak daha iyi bilginiz varmı ??

[@reconbbs360]

I have a Aiyima A07 with upgraded Op amps from Sparkos labs. Also rocking a 48v 10A LPS. It powers my speakers in my workshop. It's a straight up beast.

[@fritzkabeano1969]

Where and how much did you pay for your LPS if you don't mind me asking?

[@reconbbs360]

@@fritzkabeano1969 I got mine from a electronics website called digikey. Involves some DIY like wiring in a power cord and locating proper gauge 5.5/2.5 barrel connector. It has a built in fan which was loud so I replaced that with a noctua. I'd say all in I was at around $150.

[@reconbbs360]

@@fritzkabeano1969 It was a meanwell 48v se 450 if I remember correctly.

[@reconbbs360]

@@fritzkabeano1969 Smart move would be to just go to hifimediy and purchase the 48v power brick from them. That's 100 bucks

[@fritzkabeano1969]

@@reconbbs360 That would be an expensive move and then you'd have to make the smart move and ventilate the encloser better. For the cost/watts gained the 36v/6amp power brick is the best choice.

[@timmy707707]

Works well unless you desire some low end. Pretty much a toy. I have a Marantz 2015 running my studio monitors...swapped it out for one of these. The Marantz is back in service.

[@TechGorilla1987]

I have the Kinter K2020A+ Tripath amp on a pair of Bose bookshelf speakers playing through a TASCAM USB audio interface. I'm consistently amazed how much power this tiny box has.

[@vahanyazarian5582]

Thanks for video. Amazon has the Fosi 48V power supply separate for$49.99.

[@ewingaaron1]

"irregardless" lol sorry Big-D gotta rib you a little. Love the content as always.

[@wal]

Ha! Knew da Engrish teachers would cringe!

[@smalltimer4370]

Love that old school distortion meter!

[@balee7774]

I have the original. I use it for a desktop solution with a polk sub that allows line level input and output. Paired with neumi bookshelf speakers, it sounds wonderful. It sounds better than both my Sony and pioneer $400 receivers, but those are 5.1 systems and don't play 2 channel sound as well.

[@kyleshelton1636]

If you start doing headphone amps at any point, do the Schit Hel!

[@jeffberwick]

Great review! I'm glad you took it all the way apart, including showing the TPA3255 chip. I would be curious to know if any of these mini-amps are using post filter feedback. TI shows how to do that (Application Report SLAA788A ) to improve the THD at the expense of gain, which can be made up elsewhere in the system. Post filter feedback is nice because it reduces the effect of output inductor nonlinearity and flattens the frequency response if done right.

[@joeyjustin6895]

HEY BUD. ALL CAPS JOE HERE I AM IN LOVEEEE I SAY. WITH YOU FOR BUYING THAT DISTORTION METER I REALLY HOPE TO SEE IT IN FUTURE VIDS. ON HOW MUCH POWER AMPS CAN PUT OUT AT .0005 DISTORTION. IF IT GOES THAT LOW. OR AT LEAST 0.005

[@johnappleby59]

Sent mine back. When playing Bluetooth had to turn source to max and amp volume past 3/4 to get decent volume from my Kef q150.

[@Geerladenlad]

How about to see you test the PS audio Sprout -100

[@jimrusch22]

Love to see an amp like this with XLR inputs, SpeakOn outputs and adjustable gain.

[@jeanious2009]

Nice review, amazing how far we are getting with technology size and package of devices.

[@MrFatman489]

Big D would love to see you check out some of the sure/wondom board amps, been watching for ages because of car audio but recently found your mini amp videos, impeccable as always bud keep it up!

[@kswis]

Clean indeed, very nice unit

[@jeanious2009]

There’s a tool to remove the IC’s, IC PULLER! Works, it still requires a snug pull.

[@wal]

Awesome, I’ll pick one up! Thanks 🙏

[@cragre28]

I am building a super cheap dual 8 inch tower with buyout Dynalab 8's, a cheap tweeter and pre-assembled 3000k crossover. This sounds like a good option for a bedroom or living room stereo system that could double as a simple 2.1 HT set up by adding a sub amp. This would also work well in a classic car with a 4-600 watt inverter. You could hide the amp in a glove box and use bluetooth so no wires to splice in for power and ground.

[@DoItNowMotors]

would liked to have see the current meter on the DC power supply.

[@bruth6138]

As usual, great video. Keep it up.

[@udmbfckx2916]

I just bought mine straight from the vendor with 48V/5A PS. About $100 with discounts and taxes. The deal is that 48V x 5A = 240 Watts. And it turns out that at 7:14 in you video you show in the 1% harmonic distorsion a 168+163 which equals 331 Watts at 1 khz and 1% THD.. Now I know, as an old timer, that: 1) DIN and EIC standards rating at 1khz, 1%THD are both about 33% higher than rated power RMS from 20Hz - 20kHz, and a way much smaller THD (0.03 - 0.1). Ergo this amp is about 248 W total for both channels driven (124+124 avg) @ 4ohms 20 - 20,000 hz This would be the bottom figure.. 2) EIA standards rating at 1khz, 1%THD is about 10% higher than rated power RMS from 20Hz - 20kHz, and a way much smaller THD (0.03 - 0.1). Ergo this amp is about 296 W total for both channels driven (148+148 avg) @ 4ohms 20 - 20,000 hz. This would be the top number, So this PS (48V / 5A ) IS probably underrated at 240 Watts. You also picked as a reference from the Ayima site the rated output power of the 48V / 7.5A combo, which is 360 Watts. Heck this sucker pulled 331 Watts! Quote from ecoustics web site: "The FTC’s 1974 rule specified that stereo amplifiers be rated with both channels driven simultaneously into 8 ohms across a specified bandwidth (20 Hz to 20 kHz) at a specified level of distortion (THD), and that’s how things went until the appearance of multi-channel AV receivers." THESE AMPS ARE NOT AV! THEY ARE PLAIN OLD STEREO! Adding a 3rd line output for subwoofer does not turn them into AV receivers!

[@automachinehead]

they possibly gave you the only one with sumida inductors in it for review ratings but the ones they probably sell en masse won't have the said inductors and have used a different op amp too

[@ChrisDIYerOklahoma]

EXCELLENT review. No 2-ohm load test? Curious how it handles that load because speakers' impedances are all over the place. Things I don't like about this amp 1) the Bluetooth vs AUX input is not selectable. ie -- it overrides either/or. 2) should come standard with a 48v adapter vs the crap 32v ones 3) that copper knob is gayy looking (it can be swapped out). Overall, solid video (always awesome to see what you do!)...looks like a solid little performer with sound quality.

[@wal]

Watch all the way until the end for the 2 ohm test

[@ChrisDIYerOklahoma]

@@wal - OMG, how did I miss that? The amp doesn't like 2 ohms very much

[@jdlech]

VERY NICE use of the distortion meter. Thanks.

[@kennethcoutinho4439]

Good Review does this amplifier average speaker protection

[@Skarfar90]

Damn, this looks like an amazing amp for a bluetooth speaker project

[@przemekskw]

I wonder how it will work with 2x130W 8ohm speakers 🤔

[@miketerpening3880]

I noticed you mentioned these small home amps get a lot of attention on your channel. Another reason these are used a bunch for are for bass shakers for home theaters and mostly sim racing. If you were to do a few episodes of the ButtKicker bass shakers actual amps and if they are properly paired for them. A few episodes of common bass shakers smaller and larger (aura’s and Dayton) wattage requirements compared to the amps that people purchase for them, would get a ton of views about those amps. For example a lot of people run the Nobsound NS01-G paired with two Aura BST-1’s and they swear it works great but don’t understand how severely under powered that amp is for two of those shakers. You wouldn’t need to purchase the bass shakers (Dayton TT25-8’s, Aura BST-1’s or the Buttkicker brand shakers), just share an image of them with their required RMS and test the Amazon common amps / share the data of previous ones you already tested to show which amps they should really be using. These would get a lot of views for you from the gaming communities.

[@jimsuber6784]

Mr Williston, if these watts are "RMS" could this be used for live performance without burning up?

[@cpufrost]

Surprised at the the amount of flat topping going on with the certified tests. Definitely pushing things too hard for this box. I wonder how clean the DC is coming into the unit as those power supplies seem a bit sketchy! GaN based bricks used for high end laptops can deliver 300+ watts continuously and are fairly clean and certainly won't blow up! It would be interesting to test that amp with a decent lab power supply that can allow for the max input voltage and maintain regulation.

[@stefanweilhartner4415]

it for sure offers great value for the money. however, regarding the distortion, i would assume that the power supply section comes through with some distortion once you get to a power level where the 2800µF cap does not have enough capacity to smooth it out. second thing are the output filter coils. they can easy get into saturation at higher output levels. these are the two weak points that i can see from here. and for that money it is not possible to put in some high end coils from coilcraft and bigger low esr caps from panasonic.

[@junglerider007]

Nice informative video! please also do a dyno test and review of the Fosi BT30D

[@bllazzin]

Great review!! What would be an alternative that would solve most of the cons mentioned? Thanks a lot!

[@anthonybarra2391]

Great review thanks big D. These little amps are pretty good. I'm old school , still have my big hot sony lump from the 90s but things move on I guess

[@Budgethifiamps]

Maybe you can try AIYIMA A07 Pro

[@jimfarrell4635]

Just for information. If you are considering upgrading the op amps, you will need two dual op amps. Burson V6 Vivid dual op amps work well but are too tall for the case, so the case will need to be modified to accommodate their height.

[@wal]

Thanks for the info, very useful!

[@BIGGIEDEVIL]

Wow very impressive to say the least perfect for ppl that have minimum room

[@andrewarthurmatthews6685]

Just ordered this

[@Likesoundmusicsong8090s]

Smsl DA-9 and Smsl AO-200 audio class D TPA3255 Sound very good👍👍👍

[@Greywolf74]

So does a pre-out mean that you can control the volume of a powered subwoofer using the amps volume knob or is it the same thing as a line level out?

[@lazzzzze1]

Would like to know this as well.

[@scottreisig]

+1

[@Greywolf74]

I asked this question on a couple other channels that reviewed it and the response I got back both times was yes, the pre-out is variable signal output as opposed to a line level out put that is not variable so you should be able to control the volume of a sub using the amps volume knob. Just FYI

[@saschacubexyz]

Nice results 4 this little guy👍👍👍

[@marioslaz81]

I would like too see a test with 36v 10A power suply. I use a 36v mean well with my bt20a pro and would like to know the differences....

[@soulie1206]

What affordable speakers do you recommend for sustained crankage ;)

[@hipidipi20157max]

I own the Fosi T10D and I love it and bought a second one for another pair of speakers I had. What are the best affordable speakers that can go with it? Does Fosi make speakers?

[@Zebrajellyfishphoto]

Fosi Audio BT20AWonderful video! Your demo sounded great. Please help me understand something. I have owned a simple Sony receiver a dozen years. All I do is stream music from my phone via a Bluetooth receiver into the receiver. Can I get rid of my large Sony receiver and replace it with this Fosi Audio BT30D and do the same thing? I have 3 speakers, which includes a powered sub. I take the speaker leads currently to my sub and then to the 2 additional Left/Right speakers. Thank you!

[@Gadgetdad007]

Which amp do you prefer out of this Fosi Audio BT20A Pro and the Aiyima A07 ?

[@zackjay71]

I have two jbl home subwoofers. Both amps are toast. Was thinking about using one of these and wiring it directly to the speakers.

[@brian6029]

That thing is nice! Can you please test your car amps the same way. I love seeing the distortion meter. 😎👍👍

[@nukedathlonman]

Pulling IC's - I either use an IC puller (dirt cheap on the Jungle store) or carefully use a plain flat bladed screw driver personally.

[@wal]

Found and added to the pinned comment and video description, thank you!

[@nukedathlonman]

@@wal No prob! :-)

[@diana9900-a4]

No 2 order and 3 order harmonic distortion analyse?

[@johnsteger]

Happy Easter everyone

[@terryjones589]

It reminds of the under the dash power boosters for back in the

[@genecase9464]

Ya, I had one of those from the JC Whitney catalog in the late 70's in my '65 Fairlane. 30 x 2 WPC (or so it claimed) separate Bass and Treble controls and about 40% THD! Add that to the 10% THD from the Kraco head unit and it was a good thing the Fairlane had dual glass-packs so I couldn't hear anything anyway! 😳

[@dennislacroix5478]

I'm amazed that you got over 400w out of that power supply. just shy of 9 amps from a 5a adaptor.

[@wal]

Yes it’s a short duration but so is most music people listen to with the dynamics involved

[@redviking1329]

Hey there, hreat review, very in depth and informative. I was wondering if you might review the Fosi BT30D PRO and include a 36V power supply to boost the power. Thanks..

[@scottbennett3119]

Hello, I have enjoyed your channel for years. Does your 20a pro have a little slack in the volume control when turning it back and forth? Thank you.

[@bdown8]

How did you test the pre-out? Did you feed the input with an increasing level signal or was it at fixed level and you raised it with the volume knob on the fosi? I'm just curious about its working, if pre-out has a fixed gain (in a line out fashion) or if is it possible to control it from the fosi volume knob.

[@bhdproduction2007]

this is probably a stupid question but i'm new to this world of audio. My question is about the Ohms. does fosi have a switch mode to help you go from 8ohm to 4ohm or does the FOSI just detectes what speaker is capable of what ohm its rated at? thanks, hope to hear from you soon.