Fosi Audio kindly sent me a pre-release version of the BT20A Pro a month or so ago and I have been swapping it around with a few other similar Class D amplifiers that I already have, specifically the other TPA3255 models I have the A07 and the A07 Pro.
I thought I would share my opinions in this thread in the mean time.
If you are looking for something that sounds the same / as good as the Aiyima A07 or Fosi Audio’s own TB10D (with similar output power capabiltiies) but with the extra option of a great tone control implementation and support for bluetooth then this is probably the new best in this class Amp.
It also looks better IMO – without any screw showing. I have attached some pictures
- Great sound – IMO matching the A07 see details below
- Great Tone controls – love the click to show they are in the central position. All the volume buttons are very “satisfactory” – they don’t feel cheap
- Bluetooth implementation is clean – IMO this is better than the A07 Pro (which was very noisy in the model I have)
- Looks nicer IMO than other similar class D amps
- Very small and compact (though this can be a con see below)
Other considerations (possible cons or things Fosi could have done better):
- Bluetooth while it sounds clean (little or no noise compared to the A07 Pro) it just supports the SBC codec (so no AAC or LDAC)
- Bluetooth cannot be fully disabled – but you can disconnect by pressing the power button
- Its a much smaller box than the A07 Pro – so heat might be a problem if played loud for a long time – I imagine if op-amps are swap maybe some extra vents would be drilled into case
Sound over RCA:
This amp with the Tone controls “defeated” (and they have a lovely satisfying click in the central position so you the bass and treble are disabled) sound exactly the same as the A07 – I even went as far as doing a few sweeps with a Umik microphone and REW with both the A07 and the BT20A Pro and got incredible similar graphs. I can post the graphs but mostly they just show my speakers FR (as they should IMO).
With the Tone controls enabled it was able to get a nice sound in my listening space without EQ – I typically just need to lower the treble a little for my own tastes. I can capture some comparisons if people are interested of the max / min of both the bass and treble dials.
Sound over Bluetooth:
This amp was much cleaner over bluetooth than the A07 Pro (or other similar bluetooth implementations I have tried in the past) – my not very scientific approach is to play something totally quiet and listen in the near field to any noise coming out speakers – this amp was the same over bluetooth and RCA as far as that subjective test was concerned. The A07 Pro was not. Hopefully there will be more definitive measurements release here soon.
<b class=””>Some Measurements from Fosi Audio themselves
The measurements are very impressive (check out the link to the product below) and register for 30% discount:.
And for those not wanting to click the link here are the 2 important charts from that page:
And the Sinad is very competitive :
Overall comparisons with the other TPA3255 amp that I compared it with (and this is totally my opinion):
- Compared to the A07 Pro: Bluetooth implementation much cleaner – if similar priced – though not sure what the final price will be – this is the better amp – I do see they have 30% off – though Aiyima do also run lots of deals)
- Compare to the TB10D: It has a better tone control implementation / Bluetooth
- Compared to the A07: If you don’t want tone controls and Bluetooth maybe stick with the A07 ( as no doubt it will be cheaper) but this IMO is a great upgrade.
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