Fosi Audio BT20A Pro Amplifier Review

[Deleted member 48726]

In a way your reply concerns me even more now...

Rolling Op-amps in Gustard H20 Headphone Amplifier

I reviewed the Gustard H20 which is a high-end headphone amplifier yesterday. Its owner kindly sent me some high-end op-amps to "roll" in there to see what difference it makes. The task was pretty easy. The top screws come out of the H20 and if you tilt the unit, the lid falls out exposing...

www.audiosciencereview.com

Rolling (replacing) Op-amps in Topping D10 DAC

This is a study of whether changing op-amps in a DAC makes a measurable difference. Taking a lead form "rolling" tubes in tube products, a trend has started in replacing op-amps -- sometimes with much difficulty -- to improve performance of solid state products like DACs. A few months ago I...

www.audiosciencereview.com

Anybody OP amp rolling?

There are many products touting OP amp rolling capability. Anybody doing it? Is it snake oil?

www.audiosciencereview.com

Up to the company, but my suggestion to not appeal to this crowd stands. No one should need to replace any parts to achieve their "desired sound" and there should be no need to tweak a completed device after purchase. I hope you don't take this post the wrong way, as it is intended as constructive criticism.


JSmith

It's an option!
If you like it stock, fine. Don't do anything. If you like a specific opamp, you can change it.

Why this has to be turned into a problem and conspiracy for some is beyond me.

 

[I know (almost) nothing]

It's an option!
If you like it stock, fine. Don't do anything. If you like a specific opamp, you can change it.

Why this has to be turned into a problem and conspiracy for some is beyond me.

Agreed, it’s simple marketing. It allows them to be touted by all the YouTube guys that proclaim “AND it has upgradable op amps!!”, but that fact alone will offend others. My guess is that to their chosen market, it will generate more sales than not.

 

[Extreme_Boky]

Different OPAmps will sound slightly... different. My favourite is AD8066... its very low input bias current is not really important here.... but it does require an adapter and it doesn't like Vcc/Vee higher than + and - 12V. But, it sounds wonderful. Ahhh that brings memories...

I like the fact the OPAmps can be rolled.... great fun. Don't change it!!

 

[grogi.giant]

Up to the company, but my suggestion to not appeal to this crowd stands. No one should need to replace any parts to achieve their "desired sound" and there should be no need to tweak a completed device after purchase. I hope you don't take this post the wrong way, as it is intended as constructive criticism.

Giving socketed op-amps opens another niche of the market, while doesn't do any harm. Having them socketed costs almost nothing, but turns one negative to positive (CAM will definately mention how this is important).

 

[Joe Smith]

The Aiyima A04 and A07 amps are also socketed, as are many of their newer amps. Seems like the way things are going. I swapped 5532's for 4562's, no difference to my ear, a $16 experiment.

 

[Soulsounds]

The Aiyima A04 and A07 amps are also socketed, as are many of their newer amps. Seems like the way things are going. I swapped 5532's for 4562's, no difference to my ear, a $16 experiment.

Many people tell that swap can get better punchy bass and clarity in the sojnd.. but I don't know.. I have the a07, but I I didn't replacement the Op-Amps yet.. but I would like..
The Audiophile sometimes is for diy and testigo to get the right sound for our ears.

In the bt20s pro test.. most of that opamps tested sound very different In term of clarity, bass, and soundstage and instrument separation, I would like to earn the test with 4562s opa1656 and opa2210 super betas Op-Amps..

 

[Head_Unit]

99 or 69 [watts] makes a big difference.

if nobody said it already, no. It's only like 1.5 decibels, which is a barely noticeable volume step. To notice a really worthwhile difference you need more like 3X the power (!!!)($$$). Fortunately few people truly understand that hearing is logarithmic, so AVR makers can get you to spend more for 105W up from 95W, or Emotiva can sell you an outboard amp with, well, not much more power than the AVR has in the first place

 

[Head_Unit]

We are entering the era of cheap amplifiers. Sometimes it’s very difficult to me to accept this kind of reality.
Waiting for the next era of cheap loudspeakers which is also small sized but big sound.

I'm waiting for the era of cheap surround decoding with noise levels as low as DACs. With built-in adjustable digital crossovers with time delay please. And whipped cream with a cherry on top.

OR the era where "subwoofer outs" all have corresponding built-in highpass filters...

 

[Head_Unit]

A HIGH PASS FILTER OPTION

yes @Fosi Audio I agree-as a loudspeaker engineer "subwoofer outputs" without highpass make me gag, since few folks running a sub have such big speakers they don't need the highpass. Even first order, whatever. Aside from that this looks like great work (and looks nice, not juvenile like some Lepai or Pyle stuff for example). Thumbs up!

 

[Fosi Audio]

The Fosi representative active here hinted that they might have some new design coming up with a vented case. I'll be interested to see how that develops. If paired with a board design that lets the caps be further away from the power chip and heat fins, plus quality caps and inductors, could be what a lot of us have been looking for...

Please take a glance at our next new model- the V3 @sound67

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

 

[solderdude]

Please take a glance at our next new model- the V3

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

Funny how a recordplayer is used in the picture and even mentioned as a music source yet the amp does not have an MM/MC input. (the shown recordplayer does have built-in RIAA amp)

Was there a linear volpot in the previous versions ?

 

[JktHifi]

Please take a glance at our next new model- the V3 @sound67

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

Texas Instruments (TI) is clearly the winner here.

 

[312elements]

Please take a glance at our next new model- the V3 @sound67

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

I’ve been really curious to see what company would do this first. This is very cool and one of the first new products I’ve been excited about in a long time.

 

[tomtoo]

Please take a glance at our next new model- the V3

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

Funny how a recordplayer is used in the picture and even mentioned as a music source yet the amp does not have an MM/MC input.
Was there a linear volpot in the previous versions ?

Yes, the need to serve the tt audiophiles was to big. At least in the marketing department.

 

[312elements]

Please take a glance at our next new model- the V3

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

Funny how a recordplayer is used in the picture and even mentioned as a music source yet the amp does not have an MM/MC input.
Was there a linear volpot in the previous versions ?

A lot of turntables, especially in the budget class have built in phono preamp.

 

[tomtoo]

This v3 looks nice, lets see whats the price?

 

[Guddu]

Please take a glance at our next new model- the V3 @sound67

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

@Fosi Audio

This is from Fosi product page, needs correction - inaccurate description/details.

 

[solderdude]

A lot of turntables, especially in the budget class have built in phono preamp.

The shown turntable (AT-LP60X) has a pre-amp in it. People expecting to connect their old recordplayers will find it does not work.
A lot of cheapies these days indeed do have a pre-amp or even BT or USB out these days.

 

[tomtoo]

@Fosi Audio


View attachment 280002

Its a pre out, and for audiophiles it should be chinch. This 3.5mm stereos are garbadge. At least this is my experience in the last 40 years. This 2$ would not change much. And having a long time reliable connection is worth a lot.

 

[grogi.giant]

Please take a glance at our next new model- the V3 @sound67

Fosi Audio V3

Using a minimalist design language, focusing more on enhancing the sound quality and performance of the product, making it the best-sounding power amplifier of Fosi Audio to date.

www.fosiaudio.com

That is a lot of PRE-INPUTs... You might consider updating that photo...

But apart from that - it looks class. I love it and you're definately going in the right direction with the styling and building principles (using case as heatsink, ventication etc)!