Fosi Audio Box X5 Phono Preamp Review

[quocheiser]

Sheesh @Fosi Audio absolutely crushing it!

 

[antcollinet]

Very Impressive - even more so, for just around 100 notes. If I hadn't already got my waxwing, I'd be buying this right now.

 

[taleoffice]

I order it last week, it should arrive tommorow, im excited!
And thank you again for the review @amirm

 

[totti1965]

Maybe you have to search a little bit, to get it even better:

I would really like to see a test of Michael Fidler MM-Phono Stages.
He is from England.
Some guys claim, he has the quietest Phono Pres in the world from a measurement standpoint:

Welcome

Classic Audio ltd by Michael Fidler

michaelfidler.com

You can also switch the bass frequency at which it turns from stereo to mono - for better fitting to the the stuff they do when they master the records for vinyl.

The MC Pre was already tested here and is extremely good for MC:

Classic Audio MC Pro Phonostage Review

This is a review and measurements of the Classic Audio MC Pro by Michael Fidler. It was sent to me by the company and costs US $850 (£650/€750). As non-fancy enclosures go, this is pretty nice looking and with some unusual features such as low frequency blending to reduce noise, mono switch and...

www.audiosciencereview.com

There are two cool YouTube videos about that out there, without the usual bla bla bla. Here is the one for the MC Pre (The first time I have heard from Michael Fidler was in December, so perhaps something new also for you guys!)

 

[AudioSceptic]

This is a review and detailed measurements of the Fosi Audio Box X5 stereo Phono stage. It was sent to me by the company and costs US $109.99.
View attachment 420488
Company manages to bring a touch of class in a category that is universally utilitarian with those rounded corners and orange power button. Flexibility is provided by supporting both Moving Magnet (MM) and Moving Coil cartridges with different gain settings:
View attachment 420489

The gain setting is sandwiched tightly between the input and output RCA jacks. But company has wisely put in a tall knob to allow for relatively easy adjustment.

I forgot to take a picture of the AC transformer that is rated at indicated 16 volts.

Fosi Audio Box X5 Phono Measurements
It was quite a pleasant shock to see complete lack of distortion in our dashboard resulting in superb level of performance:
View attachment 420490

If the mains noise was not there, it would likely do even better. As is, it essentially ties with the best phono stage tested:
View attachment 420491

Moving coil at much higher gain naturally has more noise but still respectable:
View attachment 420492

Also impressive and very important, RIAA equalization is superbly done:
View attachment 420493

What's more there is good bit of headroom into treble region (my standard is > 100 mv @ 1 kHz):
View attachment 420494

Measuring distortion alone, we see that it is vanishingly low, at the level of good DACs and much better than many phono stages:
View attachment 420495

Conclusions
There are a lot of value oriented phono stages. Fosi innovates by bringing best in class performance while packaging the unit in an attractive enclosure while keeping the cost very reasonable. There is nothing more to ask!

I am happy to recommend Fosi Box X5 phono stage.
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Amir, shouldn't the Classic Audio (Michael Fidler) phono preamps be in the comparison table?

 

[AudioSceptic]

Maybe you have to search a little bit, to get it even better:

I would really like to see a test of Michael Fidler Phono Stages.
He is from England.
Some guys claim, he has the quietest Phono Pres in the world from a measurement standpoint:

Welcome

Classic Audio ltd by Michael Fidler

michaelfidler.com

You can also switch the bass frequency at which it turns from stereo to mono - for better fitting to the the stuff they do when they master the records for vinyl.

There are two cool YouTube videos about that out there, without the usual bla bla bla. Here is the one for the MC Pre (The first time I have heard from Michael Fidler was in December, so perhaps something new also for you guys!)

<https://www.audiosciencereview.com/...classic-audio-mc-pro-phonostage-review.47139/>!

 

[totti1965]

Amir, shouldn't the Classic Audio (Michael Fidler) phono preamps be in the comparison table?

He tested it. It was MC. I corrected my text.

 

[Jimi Floyd]

I read that the input resistance is 47k for MM and 100Ω for MC, but without any information on the MM loading capacitance it is not possible to take into consideration the possibility of buying a phono preamp. @Fosi Audio you must supply the input capacitance figure. If it is very low it is OK even if not adjustable, one can always add some externally, and modern MM all require a very low one anyway, but is it? Also, I think @amirm should think about getting the equipment needed to perform the input capacitance measurement.

 

[AudioSceptic]

He tested it. It was MC. I corrected my text.

Sorry about that. The SINAD is still excellent, though.

 

[GeekyBastard]

Crazy good bargain price for this level of performance.

 

[FrantzM]

Crazy good bargain price for this level of performance.

At that price ($109!!!! ) and level of performance, it would be a great opportunity to buy one and use it with my Yamaha YP-D8 that has been gathering dust for many years now ... that is, ... if If I were getting less lazy,
Darn !! Fosi is churning gear that are getting from good to absurdly great. And at prices that can be only described as "cheap"...
Wow!

Peace.

 

[totti1965]

Sorry about that. The SINAD is still excellent, though.

But you are simply right! I have forgotten to mention that the Classic Audio MC Pro is already tested.
And @amirm has not mentioned the MC Pro in the list (perhaps because it is just MC and therefore would not top the list).

But the classic audio MC is still the record holder in MC Amps by a margin of about 7 dB, and incredible headroom, I guess.

I have corrected my post up there (#24).

The Classic Audio MM Pro or the much cheaper Spartan 15 - tested by Amir.

That would be a thing!!!

 

[mackat]

I have had this unit for about a week, as I got a particularly good eBay deal on it at the end of the year. It sounds very nice and I believe it is a good value.

Based on some VM540ML measurements I did, I am guessing it has a typical 100-150 or so pF of input capacitance, though of course I cannot say for sure.

At the 66 dB gain 100 ohm MC setting, I do notice some electrical buzz when the volume is turned up without music playing (separate from the typical hiss). Not sure what this is due to, but I do not believe it is my setup.

 

[SMen]

But you are simply right! I have forgotten to mention that the Classic Audio MC Pro is already tested.
And @amirm has not mentioned the MC Pro in the list (perhaps because it is just MC and therefore would not top the list).

But the classic audio MC is still the record holder in MC Amps by a margin of about 7 dB, and incredible headroom, I guess.

I have corrected my post up there (#24).

The Classic Audio MM Pro or the much cheaper Spartan 15 - tested by Amir.

That would be a thing!!!

+ 1 indeed.

I bought the MM Pro last year, and it also has something Michael Fidler calls 'active loading' which I found takes loading concerns out of the equation, or certainly my head, as my go to MM that many might fuss over loading wise, just sounds right.

However, this for me might be Fosi's most impressive product yet. I reckon they could / should do two boxes: 150 dollars or euros each instead of 100, but with the sort of adjustments people want for each (MM MC).

 

[morillon]

hiraga

Hiraga MC Preamp

prepre hiraga 2


famous prepre hiraga 2, a simple and very "validated" diagram, 40years, without load problems... practiced by a lot of enthusiasts in thdg... for those who want to make an mc prepre for their fosi mm ;-)

+ 1 indeed.

I bought the MM Pro last year, and it also has something Michael Fidler calls 'active loading' which I found takes loading concerns our to the equation, or certainly my head, as my go to MM that many might fuss over loading wise, just sounds right.

However, this for me might be Fosi's most impressive product yet. I reckon they could / should do two boxes: 150 dollars or euros each instead of 100, but with the sort of adjustments people want for each (MM MC).

 

[totti1965]

hiraga

Hiraga MC Preamp

prepre hiraga 2


famous prepre hiraga 2, a simple and very "validated" diagram, 40years, without load problems... practiced by a lot of enthusiasts in thdg... for those who want to make an mc prepre for their fosi mm ;-)

For anyone who wants to do the soldering…

 

[RandomEar]

This looks impressive for the money. Good job. @Fosi Audio: maybe you could consider adding a second, slightly more expensive version with a switchable high-pass around 30 Hz and a switchable LF cross-feed for noise reduction around 80 - 120 Hz?

 

[amper42]

Wow... I'm surprised there are still a few who use a turntable?
It takes me back to the Stone Age when we also needed a record cleaner, a place to store albums and had to get rid of albums as they warped. Custom digital playlists whether local or streaming have become my favorite music delivery. No more being locked into playing all tracks on an album or wasting money looking for that favorite phono cartridge. Cheers!

 

[Dmitri]

Wow... I'm surprised there are still a few who use a turntable?
It takes me back to the Stone Age when we also needed a record cleaner, a place to store albums and had to get rid of albums as they warped. Custom digital playlists whether local or streaming have become my favorite music delivery. No more being locked into playing all tracks on an album or wasting money looking for that favorite phono cartridge. Cheers!

And my club is leaning by the door of my cave. Granted, fidelity iis hardly comparable…but some of us oldsters, (and some who are not) still like to spin platters occasionally. ; )
Wonderful review Amir. .
Question. Am I right in assuming that the excellent headroom in the treble region will help mitigate the inevitable ticks and pops? (Realizing of course I am only supporting your argument further amper42)
Not all choices in life need be rational. There’s always room for sentiment!

 

[Power Pop 23]

Wow... I'm surprised there are still a few who use a turntable?
It takes me back to the Stone Age when we also needed a record cleaner, a place to store albums and had to get rid of albums as they warped. Custom digital playlists whether local or streaming have become my favorite music delivery. No more being locked into playing all tracks on an album or wasting money looking for that favorite phono cartridge. Cheers!

I am surprised by how much detail I perceive from the playback of technology developed around the 1940's - dragging a tiny piece of metal or a mineral through a groove of plastic

I don't miss the pops and clicks - especially the pops via headphones.