FOSI V3 Amp: WATTS of FUN!

United States of Analog transforms to the Saturday Morning HiFi Fun Club for a quick look at this powerful amp! Here's some GEAR I OWN and RECOMMEND: (affiliate links that keep my channel ALIVE)

My TIMEX Retro Chronograph watch!!!

FOSI V3 Digital Amplifier

Klipsch Forte IV (own and recommend)

Klipsch RP-600m II (own and recommend)

Klipsch The Fives (own and recommend)

Onkyo RZ50 ATMOS Receiver (own and recommend/unbelieivable VALUE right now)

Douk Little Bear Switcher with Big VU Meters!

Nagaoaka MP-110 MM Cartridge

Ortofon 2m Blue MM Cartridge

Hudson Audio Record Weight

DACS and headphone Amps!

SONY SS-CS5 SPEAKERS

WIIM MINI STREAMER

WIIM PRO STREAMER

[MrBenherrmann]

If you don't mind my chiming in here - I've long since discovered that for those Chi-Fi amps that allow for Op-Amp change outs (sort of like tube rolling, with the exception that your Op-Amp rolling), replacing the typical stock NE5532 op amps that they install with better ones, can make a world of difference.

For example, with the V3, it has 2 changeable/replaceable Op-Amp slots. As I did with the Fosi BT20A Pro before it, I changed out the stock Op-Amps in the V3 with the absolutely gorgeous Sparkos Labs SS3602 "Discrete" dual channel Op-Amps (the V3 takes two of them). Now, right up front, both Op-Amps will cost more than the V3 itself, but the improvements in sound quality are quite noticeable - that being a smoother, fuller sound with wider sound-staging and more depth.

Sure, there are a wealth of other Op-Amps that you can experiment with. There are two types of Op-Amp categories: 1) The most common variety found in many amplifiers and other audio components are the "IC" based types (which is what the stock NE5532 Op Amps inside the V3 are) - these are characterized by being very small and less expensive (running anywhere from $2 up to approx $40 like the MUSES02 versions). 2) The other category is the "Discrete" variety - these are typically larger (and the Sparkos Labs versions are much larger). Two of the best known and reviewed discrete manufacturers are Burson and Sparkos Labs. The Burson selections are smaller (about twice the size of the IC based versions), and the Sparkos Labs Op-Amps are larger, being some 3-4 times the size of the little IC types.

Op Amps are very simple to change out, however, do keep in mind, you must know which end points in what direction - otherwise, you will instantaneously burn out the Op Amp and even hurt the amplifier itself if you insert them backwards. Each Op Amp has a direction indicator on it so you know how to put it in - it's that simple.

Read up on this. All I can add is that the addition of discrete Op Amps can make a huge difference. , If you wish to stay with the smaller IC versions, I strongly recommend the approx $40 MUSES02 version. Unless you have tin ears, changing out the Op-Amps in these Chi-Fi mini amplifiers can make a world of difference.

Sorry - just wanted to chime in here. Since the V3 is now one of the most popular selling of the Chi-Fi amps on the market, knowing how to make it even better is nice information to share.

Ben Herrmann
North Carolina

[jimfarrell]

Like you I had no need for a V3 but they kept sending me offers till my resolve cracked. Also I did want the bigger power supply for my op amp modded BT20A Pro and it ended up only slightly more expensive to get the V3 with bigger power supply than the power supply alone.
The bigger supply makes a big difference to the grunt on board and helps reduce that thinness.
Incidentally, I think you have broken new ground. I can't think of a single YouTube hifi video to feature a Bose product other than noise cancelling headphones. Bose are normally used as a synonym for crap.

[anthonytube]

Ordered one! Okay more importantly we should never stop playing and eating sugary cereals! I need to find my old hot wheels and go crazy!! :-) Thanks for the video!

[JR-hoqm]

Would be cool if a company like Fosi built a true beast of a amp. A true 300 watts for 350$ could be kinda fun! Great video!

[Simon_Hawkshaw]

Great childhood memories and a good start to the day. Love the 'HiFi Fun Club' Thanks for sharing this with us all. A great time was had 'playing' with both new and old 'stuff' by all. Take care, Sir.

[cbayardelle]

If the amp didn’t sound good, the Bose speakers are the problem, I had a pair many years ago, pretty bad speakers. The Fosi put out 191 watts per channel measured by Audioscience. excellent amp, drives elac speakers that drop to 3.7 ohms imaging & soundstage on the elacs ub 5 are amazing, the speakers do a disappearing act. Magic never happens with Bose speakers.

[michaelwright]

Sitting here with mom... Yes, my mother. She used to sell audio gear at Sears, back in the day... She sold a lot of Bose gear... Both of us simply cracking up! You had so many one liners in there, classic! And the pillows! Keep these Saturday Morning HiFi Fun Club videos coming! What a hoot!

[DA-jwnm]

you review a device that contributes to sound production and all you do is talk.

[vinyljoe]

Haha what I wouldn't give to be thin and confused

[FunFiEmpire]

HiFi Fun Club!! Love it. Want to live it. Sorry to hear the speakers did not work. Did the magic sparkle dust leave the Bose over time? Did you try another set to see if the sound worked with the setup sans Bose?

[tmdillon]

I bought the V3 as the core of my planned soundbar replacement system. I'm building some CSS Torii as the mains. Undecided if I'll go with a sub at all. The wife hates the way they look. I'm going to run a WIIM Pro and Topping DAC as a sort of combined pre-amp. I'm either going to need to use a splitter or a different amp as the wife now want's a turntable in the system and the Fosi only has one analog input.

[Douglas_Blake_]

By measurement ...
Stock 32volt supply ... 55 watts rms per channel on 8 ohms, 90 on 4 ohms with less than 0.1% distortion.
48 volt supply ... 110 watts/ch on 8 ohms, 220 on 4 ohms.

Yeah... real watts... If you want to know what they can really do, hook them up to a decent pair of "workhorse' speakers like the Heresy or L-100... they will surprise you.

[carlsitler]

I already have an Aiyima A07 I rarely use. In the livingroom, I use it connected to the TV via a Prozar dac. It actually sounds outstanding running Mirage OM-9s. Obviously not audiophile like my man cave system.

[Scrufboy]

There is more bad with the pass-through. Please test this yourself if you can.

First... The pass-through works both ways... You can input via the 3.5mm too. Then you would use the RCA as outputs. Just like the Aiyima A07. It is really only a Y cable. Not even a line out.

So here is the nail in the V3 coffin. I found out last night that the RCA and 3.5mm pass-through of the V3 are wired wrong and when another device is plugged into the V3, while conducting an isolated L-R stereo separation test, reveals the crossed signals. This error doesn't happen when you only use the RCA(or 3.5mm) input alone... But as soon as you plug something into the V3 for output... L-R tests reveal the cross-fed signals. When testing, the left channel will play and a reduced signal will play in the right channel too and vice versa. This should not happen. Fosi Audio obviously copied the original circuit layout of the Aiyima A07. The A07 also had this error in their first run... They did fix it... So they say...

For Shame Fosi! You will have to split your signal before your V3 and feed your secondary device that way. You cannot use the pass-through in the V3. The entire first run of this device is junk for anyone needing that pass-through to work as intended. Buyer Beware!

[boatformypotplants]

Hooray! Nilsson Scmilsson showed up again! Jolly good too.

[scottlowell]

WhatI I find hilarious about gatekeeping audio snobs:
Some of the most vaunted audio products have the worst measurements. Wilson watt/puppy 5, D'augustino amp and Passlabs. Lots of frequency anomalies and distortions, but hey, at least they are expensive!

[scottlowell]

I rebuilt a set of that series 601. 5% metal poly cap in the crossover. Much better than stock. I've use PE parts, and the drivers are better than bose. bose had it's era with me, but it comes down to "thump and sizzle", and smearing sound everywhere with no focus.

[JMJM]

This amp truly is a decent little thing! I run mine albeit tweaked with upgraded op amps and psu but damn does it sound great!

[PGRPGRPG]

Aren’t BOSE speakers intended to play in combination solely with BOSE amps…?

[unstablenetwork]

Saturday Fun Club - Set up a headphone rig for my son at his work station. Fluance RT81 Elite/Wiim Pro/Douk T4Pro/Phillips SHP9600 Spinning Billy Joel - The Stranger.

On a separate note - been tempted to add the Fosi V3 to my list of Chi-Fi, but just haven't pulled the trigger. Instead, I bought the HTA200 from Dayton Audio/Parts Express. It's a bit more money, and is a hybrid tube Class A/B integrated amplifier. I haven't seen many reviews on it, so I ventured on my own to check it out.

What's on top of my bedroom Speakers.