Fosi Nailed It / NEW BT20A Pro Amp Review

[@MattCoykendall1]

Fosi provided a coupon code for the rest of the month, promo code: 20APROMKT20 for 20% off. As much as I like the large gear for whatever reason these small desktop sized amps, DACs, streamers are a lot of fun. How are you using yours? Primary system, garage, bedroom, kitchen?

[@ufarkingicehole]

Are those polk 705s o5 703s? What has been your favorite pairing for them? I have the 705s with aperion super tweerers

[@MattCoykendall1]

I actually own the LSIM 705 703 and 706 center. I am using the 703 and 706 in a 3.1 in one room and the 705 is idle at the moment. They like a bit of power, really a well built beautiful speaker series though. They are a warm sounding relaxed speaker, pair well with amps that tend to liven things up a bit. I am sure I will find a way to get the 705's back in the rotation, always enjoyed them.

[@ufarkingicehole]

@@MattCoykendall1 I'm currently using a Cambridge cxr200 on the top and crown xls 2502 for the bottom. Adding the Aperion super tweeters helped open the top up a bit. Thomas from Thomas and Stereo likes his Gallion tube amp with his 707s and I'm positive a rouge audio chronus mag 3 would work as well. Thanks

[@MattCoykendall1]

@@ufarkingicehole Thomas and I chatted a couple weeks back, I shoul get the Gallion in at some point for review, might be a couple months though as all the review samples are currently out. Thanks for the pairing info.

[@danielcarlsson615]

Just ordered today. Hope to change my old nad 3020 from 79 with this in my kitchen and sell it. Hope to get more than the cost of Fosi. Takes less room on the board ?

[@jimbo4203]

I got this amp a week ago and hooked it up to my Sonys and then to my Polk xt20 's and it sounds great ! I just have it in the living room with my other stuff , its so small that you can put it anywhere

[@MattCoykendall1]

Yeah no excuses on audio equipment taking up too much space with these! How do you like the xt20, I actually have a pair of those as well.

[@jimbo4203]

@@MattCoykendall1 I love the Polk's ! Plenty of bass and they eq'd up good too

[@ChrisDIYerOklahoma]

I bought two of these for my portable speaker projects. This amplifier sounds superior to all the others (literally dozens I have used/tested). The sound is linear, clean, with excellent stereo imaging. Very lifelike. As for added power, I use a 10-amp 12/24 to 36v step up booster. I tried a 48v booster...it goes into clipping/shutdown mode when sound levels are high. It seems as is it doesn't like 2-ohm loads. However, using 36v seems to be it's "sweet spot" when it comes to input voltage/current. I haven't noticed any clipping (all things being equal). Pretty impressive little amplifier...

[@andrewarthurmatthews6685]

Nice well paced , informative, balanced review of this remarkable piece of kit that I have just ordered to run my new Pioneer CD player and pair Celestion book shelf speakers . For the size of my room with a low ceiling this system ought to suit my needs

[@mikecampbell5856]

Another great review. I have a Fosi P1 tube preamp in my tape monitor loop of one of my receivers. I can instantaneously switch it in and out of my system. I can't really hear a difference so I turned up the bass and use it when I'm listening to headphones and it works great. I like looking at the tubes too so I'm glad I bought it. It's quality is top notch.

[@MattCoykendall1]

That's a great idea! I have been looking at tube gear lately, hopefully have some items for the channel in the coming months.

[@dgdave2673]

Good review Matt. The use case exactly the locations you mentioned. I would not use this for my audio room, HT or any critical listening. That said for under $100 cannot recommend any other amp that’s better than this Fosi.

[@MattCoykendall1]

Agreed, these are great for all the smaller "extra" spaces

[@ENGLISHISBEST]

I do have one if these cheaper amps in my bedroom hooked up to q acoustics 3020i speakers, they are good but for that higher quality I still prefer the Rega, Marantz, cd6007usb & pm6007 & Bowers & Wilkins which these cheaper amps cant re-create. They do have a place but not in the lounge, maybe the summer house or spare room.

[@hipidipi20157max]

I dont know but Marantz is too expensive to compare. Summer house of course are for rich people.

[@SameerGurung1975]

How do i use the preout to connect dual subs.. Possible? Will appreciate your help. Great video btw

[@ramondelgado6778]

3.5 mm to RCA (female) adapter. Then run male RCA to your subs. Done. However, the pre-out is not variable. So, the volume knob on this amp will not raise or lower the volume of the subs, meaning you will have to adjust the sub volume from the sub's own volume control. This was a big mistake by Fosi on my part.

[@seanfillier9204]

Hey Matt, what is your opinion on using the BT20A Pro to power a pair or outdoor speakers in a gazebo? I like the idea of using the Bluetooth to play music from my iPhone

[@dgdave2673]

It will do it easily and a good use case for this amp. I own one btw.

[@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.

[@glenniz1]

Discovered your channel just twenty minutes ago, I'm truly impressed!

[@MattCoykendall1]

I appreciate the watch, glad you enjoyed it!

[@MichaelBeeny]

I would not recommend using 48 volts with amplifier, even more so into 4 ohms. It will overheat, as the case has poor ventilation, and the chip will be in over temperature limiting. Might even shut down. Don't expect 300 watts!! With the supplied power supply, you will get about 65 watts into 8 ohms per channel. Note most of these amplifiers also have fake 5532s (easily tested) With these facts in mind, still a good amplifier for the money.

[@hipidipi20157max]

what do you mean by fake? Tested how?

[@MichaelBeeny]

@@hipidipi20157max Many 5532s from China are fake. (not really 5532s) This is how I tested them. kzbin.info/www/bejne/gKbRnGSNfJV-bsksi=23EdFEvIsLJVsJ_G I hope this helps.

[@nishantranabliss]

Thanks for the wonderful video. The pre out in it, is it variable can be controlled through volume control of the amplifier ?

[@MattCoykendall1]

This is not variable unfortunately.

[@nishantranabliss]

@@MattCoykendall1 thanks for responding. I was planning to buy it to use it with bookshelf with subwoofer. But it not being variable output, will make using active subwoofer with it challenging.

[@greatpix]

How does this sound compared to the Fosi TB10D (improved) which I own?

[@ramondelgado6778]

Great questions!

[@gurmeetsinghkalsi]

How long a continuous play it can handle ? Like can we play for a continuous 8-10 hours ?

[@philjagdon6774]

Can someone help me here. I love just listening to music I want to buy this model , can I stream from my Mobile to play Spotify and what's the difference and amp that has a DAC ? Thanks

[@ramondelgado6778]

This amp can serve as an all in one, if you are OK with streaming Bluetooth from your phone, tablet, PC, etc, straight to the amp, then you don't need anything else. If you are a critical listener, than that's where the rabbit hole begins. If you want higher resolution streaming, you will want to add a WIFI streamer and then an external DAC (to do a better job of decoding the signal and improve the sound even further....this unit does not have a built in DAC only 1 analog RCA input and it has BT built in.).

[@NeilBlanchard]

The swappable op-amp is great - if there is only room for a DIP8 monolithic chip, there are definitely many options, or if there is a bit more room, then something like OPA627 dual mono modules can take it to a very high performance level for about $6-8. These are the best (in my opinion) that TI/Burr Brown has to offer. If you want to go crazy, then the Sparkos SS3602 - IF it fits - would be a big improvement.

[@MattCoykendall1]

Thanks for the suggestion Neil, I am going to put in an order for the OPA627 modules, thats the perfect price range for something like this. The Sparkos is certainly interesting as well but your getting into a price nearly the same as the amp. Depending how the OPA627 goes I may pick up the Sparkos just for the sake of experimentation.

[@NeilBlanchard]

@@MattCoykendall1 Right - the OPA627 dual mono modules are quite excellent. I have tried them both in my AkitikA PR-102 preamp, and my Geshelli J2S. The PR-102 had OPA2134 chips, which are very good and are tonally similar, but the OPA627 are significantly better at soundstage and layering and textures. In the J2S, I have compared the OPA1612, the OPA2134, the OPA627 dual mono, and the Sparkos SS3602. That's the order of my increasing preference - the 1612 are fine as far as they go - they are shallower soundstage and less detailed and less layered. The 2134 are fuller sounding, and have more depth and layering, and a bit better dynamics. The 627 are a significant jump up in depth and width and layering. Their detail and textures are very very good. The SS3602 takes it up even more - they have more detail (while seemingly less bright) than the 627, and have an immensely deep and wide soundstage. Layering and textures are just phenomenal. Once you hear this DAC with the Sparkos - you will want nothing less. And I am now trying the Sparkos in the AkitikA PR-102 - and I will be trying a Muses02 op-amp (about $44 from Mouser) soon. After I break it in, I will be deciding whether to spring for the Sparkos SS2590 dual mono - which seems like it could be the last preamp I will ever need.

[@peterlarkin762]

Opa627 is supposed to be very good BUT it hasnt been available for years, most sold today are fakes.

[@peterlarkin762]

@Douglas Blake The 4558 is underrated. That and the 4556. You can parallel these, giving enough current to drive most headphones and it sounds pretty good for the simplicity.

[@NeilBlanchard]

@@peterlarkin762 That would explain the low price. They do sound good,, though. If they are clones, then they are at least available.

[@hipidipi20157max]

Modern Hotwheels suck but Fosi is like the Hotwheels of the 70s-80s. I have the TB10D but may purchase this one soon. But amazon tends to increase prices after I add them to my wishlist

[@PaulDickson7]

Didn’t work on my 30w 100v 8ohm speakers. Not enough power

[@EARLandPEARL-c3i]

"I know they specify the power ratings are @4 ohms in the specs but the description should say 25 watts/channel at 8 ohms and 50w@8 ohms to the sub. Just so there’s no confusion. I like that the power is auto ranging between 2 and 8 ohms. Or is it between 4 and 8 ohms? How are we supposed to know since the description says both. The manual that comes with the product says 4-8 ohms. This unit seems to demand a passive sub. Without a sub the output is pretty thin, even with the bass turned all the way up. I don’t like that the sub output is not a line level output and I don’t like that the input is to RCA jacks instead of 1/8” headphone jack. But I’ll adapt. With the correct adapters. Bluetooth seems strong. The anti-spark feature when you plug in the power is a nice touch. The metal knobs feel substantial and the unit isn’t full of holes for dust to get into."

[@kjgrasp]

I was wondering about the power ratings because it's supposed to be 300w per channel @4Ohms, using the larger power supply, right? Because I have no speakers that need that kind of power and I was wondering what I'd even pair this amp with. You're saying with the 32v power supply you get around 25w per channel @ 8Ohms?

[@ACCORD517]

Great review, Good to know goes well with Buchard.

[@pyntzer]

Hello Matt, is your Yamaha S501 much better than Fosi BT20A Pro? Thank you.

[@MattCoykendall1]

Hey Pedro, its certainly more feature rich being that it is a complete integrated amplifier. The sound I would say is better yes, but its certainly not far behind it if I'm being honest, the Yamaha just offers alot more, as it should when comparing prices, the 501 is around 5x the cost.

[@pyntzer]

@@MattCoykendall1 Thank you so much.

[@iikatinggangsengii2471]

true its not better to be fair just different/rare

[@anthony2010707]

Nice review, have the fosi V3 with the sparky op amp acting as a Power amplifier, i have connected the Douk Audio P1 preamplifier, i am running Q Acoustics 3010, Rel Quake, sound is great.

[@MattCoykendall1]

Thanks for sharing Anthony!

[@iblesbosuok]

Pin 32 and pin 35 of the TPA3255 which have a cross section size of 0.27mm×0.15mm each has the potential to carry a current of 8.87A each. In my opinion, that's the weakness of the TPA3255 and the stuffs that apply it, including Fosi. Thank you

[@MarkLada]

What chip would you recommend in place of the 3255? I'm putting together a portable worksite stereo system and I was just about ready to pull the trigger on a board with 3255s..

[@iblesbosuok]

@@MarkLada I just explain potential weakness of 3255 chip. For alertness. Unfortunately I won't recommend any other chips. Sorry.

[@MarkLada]

@iblesbosuok I understand, and appreciate you pointing out the weaknesses of the chip.. I've done a lot of research, and I had not come across the information in your comment anywhere else, thank you.. If my line of thinking is correct.. 8.87 amps at 48 volts is 425 watts.. I'm not going to be pushing the chips that hard, so they should work for my application.. I only need 150 watts out of the front channel and 200 out of the sub, for the speakers I want to run..

[@hcho8164]

Could this be the reason the power supply of bigger voltage is recommended for more power? And could it be possible between TI and Fosi/Douk/Aiyima, the designer implemented current limiter in the design so as to protect the typical customer who don't much modify their gear. What are the odds? ?

[@iblesbosuok]

@@hcho8164 Nowadays, many users get bored quickly. So, this weakness is not a big problem.

[@Mikegritz]

A question, did Fosi Audio ask you to send them your review before publishing or give you a list of talking points? Wondering why so many reviews in this item came out within a few hours of each other with the same pitch. Sounds sponsored like an ad campaign than a review. Are you sponsored by them?

[@MattCoykendall1]

Hey MG, I would be happy to answer that, I am not sponsored by Fosi. There are channel's who are such as cheapaudioman as he mentions in his video, but in my case I was simply sent the product to review. The reason you are seeing all of these at once is because we were asked to release the videos on April 10th as that is when they released the product for sale. They didn't provide a script or talking points, at least in my case I was not influenced to say anything specific about the product. The interaction was simply "would you be interested in reviewing this?" and once I confirmed they sent the tracking information and a link to their product. I will say some companies will try to guide the conversation, this was not the case with Fosi, thanks for asking, its a fair question!

[@Mikegritz]

@@MattCoykendall1 Thanks for the feedback. I appreciate your reviews. 👍

[@MattCoykendall1]

@@Mikegritz Thanks MG!

[@thelowprofile9767]

I thought the same way too. Thanks for clarifying.

[@madstylesnz]

Thinking of buying this amp but I notice there's no vents. Won't it overheat?

[@MichaelBeeny]

On music it should be OK into 8 ohms with the supplied power supply but don't use 48 volts into 4 ohms, it will get very hot.

[@bradrapp3697]

Nice review. Thanks for the promo code, I tried it and it worked. Nice.

[@TeamHoff1]

Hi Matt...more of a qurstion than a comment. Ive just changed my setup and have the Audio Technics 120 paited with the Edifier 1700s. Would something like this imptove the sound or not? If not what are my alternatives? I'm used to a more conventional amp and passive speakers but needed a different setup for my living room. Hope this makes sense.

[@walterramos8656]

Is PLUG P4 5.5 mm x 2.1 mm the same thing as PLUG P4 5.5 mm x 2.5 mm? There is a seller of a 24V 5A power supply, and he describes his power supply with a 5.5mm x 2.1mm plug, and I want to buy one with a 5.5mm x 2.5mm plug and he says that his works ​

[@kellyanderson7115]

Orchard Audio Starkrimson Amps are great! I bought a pair of the 150w DIY Starkrimson amps and a pair of the high-end GaN power supplies. Unbelievable reproduction across the frequency range from deepest lows to highest highs. This setup is so much fun to listen to because it seems as if you can hear "everything". It almost doesn't matter what your listening to because it's so much fun. One thing in particular I like is listening to jazzy music like Marcus Miller's Laid Black.

[@kellyanderson7115]

One thing to note...I have Volumio on a SBC with a $50 iFy power supply feeding a $1k DAC (S.M.S.L SU-10), a $1.2 k preamp (Schiit Freya+ with Russian tubes) and ~1K speakers (Elac UBR62 Unify Reference), so I've got pretty good gear. It no doubt takes good gear all throughout the chain to really notice how good how good Starkrimson Amps are.

[@jayem1826]

I wish someone would take a look at the Mini GaN 5 from Premium-Audio.. It's small and weighs 5 lbs, but very powerful. It's driving my Maggie's

[@MattCoykendall1]

I will take a peek over at Premium-Audio site, see if I can find a contact.

[@jayem1826]

@@MattCoykendall1 Tom is the contact… by email only

[@quickflik3980]

I wane run some B&W 686 of some fosi amp but idk wich one to get would u reccomend this one or have any other fosi reccomendations?

[@zetakappa75]

Does it go in mute or stand by after a few seconds with no signal and resume playing with a delay ?

[@jari121]

How's the sound quality compared to the Aiyima A07?

[@MattCoykendall1]

The sound itself is very similar (same amp chip) but the the Fosi model will open you up to easier pairings with the tone controls. I personally dont make too many adjustments with tone controls but every once in a while certain speakers need a bump here and there to fit my personal taste. The Fosi should also put out more power than the original A07, it comes stock with a larger power supply so that may influence some speaker pairings.

[@jari121]

@@MattCoykendall1 Ok, thanks a lot for the info.

[@geevee1045]

FYI, the Aiyima A07 and Fosi BT20aPRO both come with the same 32v 5A power supplies. I believe tone controls soak up some power, and that may explain why the Aiyima A07 has more power output. Williston Audio Lab measured the Aiyima A07 at 95wpc@4ohm, and the FosiBT20aPRO at 70wpc@4ohm. But tone controls are a nice option to have.

[@mrsunshine63755]

How about camping ?

[@shipsahoy1793]

Just so you know, there is a “trend” for using the phrase, “nailed it!” as a click bait enticement.😂

[@TalkTimeVault]

I ordered one too. If you could help me out what bookshelf speaker would go with it. Regarding Ohm and watts thanks.

[@danielacosta1998]

What speaker did you end up getting ?

[@2visiondigital]

I understand it does not have Bluetooth switching. Guess they didn't nail that.

[@EsaiasP]

Where is the infinite library of music?

[@edierllamasfixedthis]

Does the volume knob on the fosi control the volume on a sub thru the pre out ?

[@ramondelgado6778]

No sir. Big mistake on Fosi's part by not making the pre-out variable.

[@radomirsretenovic8492]

What is this for? Desktop amplifier. Who needs that?

[@hipidipi20157max]

I do and many people too

[@rosswarren436]

Looking to use this on my desktop to power some small old Polk Audio speakers for my PC. You can't buy low end Logitech computer speakers for that price. And heck, I might roll the op-amps just for fun. They mention "You can replace the two plug-in NE5532 Op-Amps with LME49720HA/MUSES02/OPA26041P/OPA2134PA/LM4562/NJM4556AD Op-Amps to achieve a unique sound quality". Which one among them might be best for a good price to give a nice midrange with some bass? Bluetooth for convenient use is icing on the cake, especially if I ever move the setup to my outbuilding which is too far away to hit my wi-fi.

[@MattCoykendall1]

I am not well versed on op amp replacements but Neil Blanchard commented about the OPA627 as well as the much more expensive Sparkos SS3602. A little further research may be required here as some op amps like the sparkos may need an additional riser to fit properly.

[@MattCoykendall1]

@@rosswarren436 I will check that out, thanks!

[@qddk9545]

The LME49720 is obsolete, and is not that easy to find, but the LM4562 is a proven and very good sounding op-amp for HiFi. It is highly recommended, if you don´t want to spend the money for Sparkos dual opamps.

[@EvanZamir]

Seems like this has been available since 2017 according to Amazon.

[@MattCoykendall1]

Not sure what the deal is, they must have used an old Amazon page to build this listing. It is definitely new!

[@thelowprofile9767]

I think they used a different chip earlier.

[@MattCoykendall1]

Yep, previously they used the TPA3116 on the non pro.

[@bingdong8571]

Change jnobs, op amp chips, etc. Fun

[@MattCoykendall1]

It is fun

[@nirol16]

You should use Tidal

[@MattCoykendall1]

I do! As well as Amazon music

[@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.

[@avpro51]

I got one of these for my son with the 32V smps and a pair of mini monitors and a powered sub running off the speaker outputs. I was SHOCKED at the sound quality. I got a V3 for my workshop, where I also have some Dynaco tube gear. The ST35 is a bit warmer, but the V3 is perfect for its price as a backup and for when I need to save space on the bench.

[@onionknight9431]

no not really

[@hipidipi20157max]

The TB10Dis a very good amp and doesnt overheat like I was expecting I dont put it beyond 12 to avoid damaging my speakers whiche are 25 Watts. For a mid size room is very good.

[@persaifi]

Do you know if pre out is mono or stereo?

[@MattCoykendall1]

Stereo

[@deehive]

preout stereo or mono?

[@MattCoykendall1]

Stereo

[@rtblues]

Can it be used with active speakers?

[@MattCoykendall1]

Looking to add volume control to some active speakers?

[@hipidipi20157max]

Its an amp. Active speakers have their built in amp

[@robertpollak6572]

Hi, I have the aiyima A07 with the Sparko Labs descrete op-amps. Just wondering if anyone will do videos with this new pro amp rolling op-amps?

[@MattCoykendall1]

I will be doing to follow up with the Sparkos op amps I know for certain.

[@angelheart1129]

Received one today Returned poor sound 😢

[@MattCoykendall1]

Not often I hear that on these for the price we pay. Pairing issue with the speakers, actual amp had issues or just not your cup of tea?

[@SlagroomenCornflakes]

I'm not fond of "reviews" with a lot of words, but not much being said. These make me feel like i'm watching an infomercial. Would rather see people go in depth about the product and if possible make comparisons with products in the same (price) categorie. No hate. Just my opinion.

[@MattCoykendall1]

Thanks for the suggestions Lemarr, I will take that into consideration on future videos.

[@revamp777]

Class D still has a harsh sound , $5 cost .

[@jimfarrell4635]

Hi Paul. I think it's unfair to generalise. I run both high quality 300b and el34 tube amps and two good solid state amps outputting 215w and 150w in 8 Ohms, in different systems. I bought this Fosi amp out of curiosity as to what modern class d can do. You know, while it can be a little bright with certain tracks and tone controls at neutral, it sounds remarkably good to my ear and not harsh at all. It won't be replacing any of my ( much ) more expensive amps anytime soon, but it sounds incredibly good for the price, and I haven't changed the op amps yet. Class D has come a long way. I think you might be surprised if you try it.

[@IronMan-jv6md]

Too bad it lacks a HP amp.

[@radomirsretenovic8492]

If you want stereo amplifier receiver buy Marantz Stereo 70s. . Respect yourself and your musical taste. Fosi is cheap garbage

[@anthonycruciani939]

Marantz had great gear no denying that but these days that Marantz tax is super high that many can't or won't pay.

[@hipidipi20157max]

Not true. I have one and my music sounds great and I have great taste in music. Marantz is overpriced for snobs to brag and then insult others who are not rich jerks

[@zengerz]

cool instant sub because I immediatly see you have polk lsim 705/707 like me. For the rest your channel looks good and interesting videos I will be checking out later when I have more time :) Have a great day

[@MattCoykendall1]

Gotta love the ol LSIM series Polks!