Problems on Fosi Audio BT20A PRO volume potentiometer

[GGC]

Greetings everyone. Long time reader of these forums and would like to start by thanking everyone for the wealth of very knowledgeable information that you generously share here.

I have recently purchased a Fosi Audio BT20A PRO, my second amplifier from this vendor. Unfortunately, while the BT30D Pro amplifier that I first purchased presented an extremely nice build quality, with tight but buttery-smooth potentiometers, the same did not happen with the BT20A PRO, which presents a wobbly volume knob. The shaft of the potentiometer has a considerable side to side slack, making its operation feel very unprecise and provides a frustrating feeling of lack of quality. I am attaching a video showing this problem.

When I reached out to Fosi, they told me that "compared with the single-section design, this type of double-section potentiometer is relatively loose, but its function is normal", that "this behavior is a characteristic of the button", and that the "issue with the knob is not a defect but rather a characteristic".

Could other owners of the BT20A PRO please let me know if they also notice slack on their volume knobs?

Many thanks!
G.

 

[Martinvb]

Yes, same here. Seems like some units are more affected than others. Amp works in all other respects as expected, so I decided to leave it at that (although I do agree that the defect does not match the overall good finish of the unit).

 

[GGC]

Thanks, Martinvb. What surprised me was not seeing this issue discussed until now in the detailed 24 page thread on the amplifier review. Appreciation of the (usually) very nice Fosi construction quality has always been noted in these reviews. Does this suggest that initial units had a proper potentiometer but now there is a batch with a faulty one?

 

[GGroch]

Mine has a little wobble that I had not noticed until your post.

I assume this difference is because the volume knob also works as a BT Pairing button when pushed. The treble/bass knobs do not have this 2nd function and do not wobble.

I have two other devices with volume controls having push functions. Both the SMSL M300se and Nobsound 08 Pro preamp have some wobble. The SMSL wobbles a bit less than the Fosi, the Nobsound about the same. So I think Fosi is correct, some wobble is normal. I can't tell from your video if your's wobbles more than expected.

 

[anthony 5]

Mine also has the slight wobbles on that volume knob again Fosi tells me normal

 

[Dempsey]

Hello everyone i cant seem to find a thread that im looking for , i have a pair of krk rokit 5’s gen 4 , 3 years old from brand new hardly used , however recently 1 works absolutely fine no issues, the other one powers on but no sound comes out ? After turn on off cables in out for about 10min or so the sound comes back on , has anyone experienced or heard anything like this ?
Many thanks

 

[anthony 5]

Hi my bt20a pro has a slight pop sound coming from speakers when shutting down amp does anyone have that problem fosi tells me this is normal because of two capacitors thanks

 

[gasolin75]

Hi my bt20a pro has a slight pop sound coming from speakers when shutting down amp does anyone have that problem fosi tells me this is normal because of two capacitors thanks

yes

Fosi Audio BT20A Pro Amplifier Review

This is a review and detailed measurements of the Fosi Audio BT20A stereo class D amplifier based on TI TPA3255 IC. It was sent to me by the company and costs US $99.99 with 32 volt power supply. Despite its low cost, the case gives a feeling of quality. I am not usually fan of tone controls in...

www.audiosciencereview.com

 

[SSS]

Be suprised by the complaints. What do one expects from a 120 $ amplifier? McIntosh build quality? Of course a knob should be tight, but a blob at turn-on or -off is normal also at other amps if there is no disconnetion from the speaker with a relais.

 

[gasolin75]

Be suprised by the complaints. What do one expects from a 120 $ amplifier? McIntosh build quality? Of course a knob should be tight, but a blob at turn-on or -off is normal also at other amps if there is no disconnetion from the speaker with a relais.

Nothing on my fosi audio BT20A it's a 75 euro amp

 

[SSS]

Nothing on my fosi audio BT20A it's a 75 euro amp

You were lucky.

 

[gasolin75]

Use an upgraded power supply, mabye thats why