wondom bru5 pc dsp configurable TPA 3255 "300w x 2" mini amplifier

[Blink Too Fast]

Received my BRU5 today (New Jersey, USA). Ordered 8 days ago on AliExpress, including a weekend and Christmas.
I paired it with a 48v 5A power supply.

I am an existing REW software user, and am comfortable using this for time alignment and PEQs.

I used the ACPWorkbench software on the AliExpress item page. At time of writing, this was ver 2.24.2. Link
I also used a version of the software I found linked on Reddit. At time of writing, this was ver 2.33.0. Link

Both installed without issue. Both worked. v2.33.0 is a little more polished, but had similar functionality.

The only functionality I wanted was the EQ.
Ran REW; measured with a UMIK-1 mic; pressed EQ; typed the f, G, & Q settings for each filter from REW to ACPWorkbench.
Also added a high-pass filter at 24Hz to offer at least some speaker protection

Done. It worked as intended.
Pressed "Downloader" > "Save Configuration to Flash"
I since watched the Wondom video that says not to overwite PEQ0 or PEQ1, so I may or may not reset to factory and use PEQ2-PEQ9 instead.

There are 20 PEQs (10 PEQs on the preamp, and 10 PEQs on the poweramp)
Right and Left channel EQs are linked. I do not see a way of setting them independently in 2.24.2 or 2.33.0.
It is possible to increase the preamp and poweramp gains in the software. I did to experiment, then returned them to zero.

When bluetooth is connected, and volume dial full, I can hear a hiss about 18" from the speakers. For comparison, I also have Fosi V3 which has hiss at 3", and Topping PA7, which has no hiss with my ear touching the tweeter.
When bluetooth is not connected, and volume dial full, there is an ethereal sound that can be heard throughout the room when music is not playing. This can be removed in the software by setting [music noise suppressor 0x81] > [Ratio 4; Threshold -62dB; Attack 1ms; Release 100ms]. At first listen, I cannot hear it impact the music.

I tested with modified Zenith Circle of Sound Z565 speakers, which have a strong colouration, REW, and a UMIK-1 mic.

Chart shows before and after. It works.

Chart shows thumbnail of the 1x highpass and 9x PEQ settings used for the REW screenshot above.

 

[Blink Too Fast]

I paid Arylic for ACPWorkbench, too. For my $20 ($17 with code), I received the OLDER and less polished version 2.21.14.
Save your money.

With further listening, the noise suppressor I activated to reduce the odd noise when bluetooth is not connected, which when I think about it is probably the ADC, is simply a noise gate. I can hear it cutting in and out with songs that fade out to zero. I can also hear the odd noise under very quiet sections.
The choppiness can be removed by increasing the release time to 500ms. But won't eliminate the noise during very quiet sections of music.

I wonder if I can poke around inside the amp and find an I2S or SPDIF in...?


In the software are various effects options that at ASR we would shun...
...but I'm using and enjoying the Stereo Widener

 

[Blink Too Fast]

I wonder if I can poke around inside the amp and find an I2S or SPDIF in...?

Yes, there are both. That'll be a project for a rainy day. Will either cannibalise an RCA socket, or add a new RCA / 3.5mm / Toslink depending on space and how lazy I'm feeling.

Datasheet Link here from an earlier post in this thread. Press the "View More" button.

 

[CedarX]

Yes, there are both. That'll be a project for a rainy day. Will either cannibalise an RCA socket, or add a new RCA / 3.5mm / Toslink depending on space and how lazy I'm feeling.

Datasheet Link here from an earlier post in this thread. Press the "View More" button.

A version of the MVSilicon BP1038B2 SDK is available on GitHub: https://github.com/leadercxn/bp1048_sdk_v0.1.12
The documentation appears to be Chinese-only. Another project for... a blizzard week (!!!): develop full access command line tools and bypass ACPWorkbench altogether...

 

[Blink Too Fast]

A version of the MVSilicon BP1038B2 SDK is available on GitHub: https://github.com/leadercxn/bp1048_sdk_v0.1.12
The documentation appears to be Chinese-only. Another project for... a blizzard week (!!!): develop full access command line tools and bypass ACPWorkbench altogether...

Thanks. I'm comfortable with ACPWorkbench. It's the eerie noise when bluetooth is not connected that annoys me, so I'm assuming the ADC. ACPW is only used for setting the PEQs, turning on the stereo widener, and enabling SPDIF. Then can be ignored.

I actually received 3x BRU5 amps, so I tried a second one. The eerie noise is not there. I have not tried the third.

This is good - it means I have identified which amp will be the test-bed for the SPDIF modifications

 

[GGroch]

Wondom now has an even cheaper ACPWorkbench compatible amp using the TPA3116. The BRU3P is $17 to the US on Ali Express (so, cheaper than Acrylic sells the software alone). They have added Bass/Treble tone controls and an Aux Line Out, but it is not clear whether that is just a line-in loop, or if it is processed/volume controlled which would be a very useful feature.

It seems odd that Wondom can incorporate DSP + PC interface at seemingly no cost while others do not offer it on even premium models.

Wondom Video on it here:

 

[Blink Too Fast]

Wondom now has an even cheaper ACPWorkbench compatible amp using the TPA3116. The BRU3P is $17 to the US on Ali Express (so, cheaper than Acrylic sells the software alone). They have added Bass/Treble tone controls and an Aux Line Out, but it is not clear whether that is just a line-in loop, or if it is processed/volume controlled which would be a very useful feature.

It seems odd that Wondom can incorporate DSP + PC interface at seemingly no cost while others do not offer it on even premium models.

Interesting. For those not awake, this runs on 12v, is small, and has mounting holes.

It would bring room correction, bluetooth, and amplification, to your car. For $17. Don't even need to buy a power supply.
Can install it somewhere out of sight, and leave the power up full, then control it from your phone via bluetooth or aux-in.
Would be low power at 12v. Use it like that, find a way to give it 24v, or use the outputs as the inputs to another amp.

No, I have no idea why an integrated amp with 20 band PEQ needs treble and bass controls.

 

[dinglehoser]

FYI - there is a simple way to set the device to default to aux/analog input:

1. With the power off, press and hold the pairing button.
2. Turn the power on while still holding the pairing button. Keep holding for 10 seconds.
3. Release the pairing button, then switch the power off.

The next time you turn the device on (and every time thereafter), it will be on the aux input unless you press the button.

Also note - I haven't measured to figure out the exact input sensitivity, but the aux input clips badly when fed a 2Vrms signal. Adjusting the line4/5 input level (or the overall ADC input level) in ACPWorkbench to about -6dB seems to address this and as a nice side effect decreases the janky volume adjustment behavior at the lower end of the range.

 

[dinglehoser]

One more note - the current version of the TPA3255 BRU5 uses 63V power supply caps, so continuous 48V operation is no longer a game of roulette (provides you also address the highly questionable thermal interface between the heatsink and the case). Mine does, anyway. YMMV, probably.

 

[GGroch]

One more note - the current version of the TPA3255 BRU5 uses 63V power supply caps, so continuous 48V operation is no longer a game of roulette (provides you also address the highly questionable thermal interface between the heatsink and the case). Mine does, anyway. YMMV, probably.

Excellent useful information in both posts. My Bru5 is not hooked to speakers at the moment so I could not test it the Bluetooth kill. I did notice that the blue flashing did not cease on mine.

I have done no stress tests, but I thought the concept of pressure fitting the chip to the bottom of the chassis and thermal goop was possibly more effective than tiny fins inside a closed chassis. The Fosi V3 does something like this.

 

[dinglehoser]

Excellent useful information in both posts. My Bru5 is not hooked to speakers at the moment so I could not test it the Bluetooth kill. I did notice that the blue flashing did not cease on mine.

I have done no stress tests, but I thought the concept of pressure fitting the chip to the bottom of the chassis and thermal goop was possibly more effective than tiny fins inside a closed chassis. The Fosi V3 does something like this.

Conceptually, I totally agree. At least in my two units, though, the execution left something to be desired - there's just too much of a gap between the plate and the case. I'm going to put a solid, thicker TIM in there and see if that helps.

 

[Blink Too Fast]

FYI - there is a simple way to set the device to default to aux/analog input:

1. With the power off, press and hold the pairing button.
2. Turn the power on while still holding the pairing button. Keep holding for 10 seconds.
3. Release the pairing button, then switch the power off.

The next time you turn the device on (and every time thereafter), it will be on the aux input unless you press the button.

Doesn't work for me, and I tried various combinations of
off-hold-on-wait-release-off
off-hold-on-wait-off-release
off-hold-on-wait-release-press-off

Are there more explicit instructions?

 

[GGroch]

Doesn't work for me, and I tried various combinations of
......
Are there more explicit instructions?

I wonder if there was a firmware update

 

[dinglehoser]

Doesn't work for me, and I tried various combinations of
off-hold-on-wait-release-off
off-hold-on-wait-off-release
off-hold-on-wait-release-press-off

Are there more explicit instructions?

I got these from the official user manual, which is linked on the Amazon listing for the TPA3255 version (scroll down a ways and you'll see the text link). The first should work - it did on both my units. I did notice that it only takes if you hold for at least 10 seconds from the moment you turn it on. Any less and it won't work.

 

[Blink Too Fast]

I got these from the official user manual, which is linked on the Amazon listing for the TPA3255 version (scroll down a ways and you'll see the text link). The first should work - it did on both my units. I did notice that it only takes if you hold for at least 10 seconds from the moment you turn it on. Any less and it won't work.

Thanks.
Doesn't work for me.

The ACPWorkbench linked in the manual at Amazon is ver 2.24.2

Ver 2.33.0 is linked at post #181 on this thread https://www.diyaudio.com/community/...reo-tws-bluetooth-for-speakers.379643/page-10

 

[GGroch]

Thanks.
Doesn't work for me.

Wondom just released a YouTube video that illustrates the process, but also indicates that they made a firmware change in the Bru5 to make it work.

The best solution for me is to tape over the blinking LED and just leave the Bru5 powered on.

 

[Blink Too Fast]

Wondom just released a YouTube video that illustrates the process, but also indicates that they made a firmware change in the Bru5 to make it work.

The best solution for me is to tape over the blinking LED and just leave the Bru5 powered on.

Thanks. I wonder if the firmware update will be released.

 

[Bruce Morgen]

The only 2 things I dislike about the amp are the flashing Bluetooth indicator, and that it defaults to the Bluetooth input on power up. It requires a tap on the "Pairing" button each time to get to Line in.

That's a deal-breaker here. In fact, I'd pay just as much for one without BT and with a conventional power switch!

 

[Bruce Morgen]

I'm guessing switching the unit's power brick on from a mains power strip won't turn the amp on -- if so, that's another deal-breaker here.

 

[Blink Too Fast]

I noticed these $20-$90 DSP amps at PartsExpress, from 2x15W up to 4x100W.

Amps
Small amps
Preamp

The 4x30W looks interesting for a pair of 2-way Zenith Circle of Sound speakers I'm rebuilding with modern drivers.
Mm, or the 4x100 for some Sansui SF-2 I rebuilt as 2-way.
Mm, I have some currently unmolested DCM timeframe 3-way TF700s...

The $20 pre-amp unit looks interesting to insert INSIDE my Fosi V3 amps, which use the same 2x300W core as these Wondoms.
I think I smell an affordable 6x300W DSP 5.1 AV system coming on. Just need a cheap (maybe used) 5.1 decoder that doesn't need to handle video.