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ZOUDIO AIO4CH: 4-channel amplifier with DSP and Bluetooth

I want to introduce a new product I have been working on for the past years.
It's now available for pre-ordering, which will be shipped in the end of februari, in order of payment.

ZOUDIO AIO4CH: 4-channel amplifier with DSP and Bluetooth



Features:
-4x45W class D amplifier (can also be configured as 2.1 or 2.0)
-Bluetooth V4.2 APT-X with True Wireless Stereo
-Configurable DSP
-Easy to use Windows configuration tool
-Small format with high efficiency

Screenshot configuration tool:
Inteface3.jpg


As can be seen, a lot of the settings can easily be changed, such as:
-Start and maximum volume
-Battery protection voltages
-Input (left/right/mono) and output (4.0/2.1/2.0) configuration
-13 general filters (equalizers) en 5 filters per channel (crossovers)
-2 equalizers which can be enabled with a button (e.g. indoor/outdoor, bass-boost)
-Volume dependant (dynamic) equalizer
-Delay per channel

This thread can be used for questions about specifications and how to use the products. Remarks and suggestions for improvement are also welcome for this and future products.

Productpage (datasheet, configuration tool download, ordering): click here
 

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You say "...5 filters per channel (crossovers)". What crossover filter types will the user be able to select from?

Are shelving filters one of the EQ or crossover filter types available? First and second order shelving?

From the spec sheet I see THD+N @ 1W listed as 0.05%. It's more important to know the noise floor, since that influences whether high sensitivity drivers can be used like a CD+horn. What is the measured/expected noise floor of the system?

Can you provide more info on the amp section please? "4x45W" in this day and age really doesn't tell you much. Is that at 10% distortion, 1%, into 8R/4R/2R, with what rail voltage, etc. etc. This will determine how well the amp will work with low sensitivity drivers that need more power.

Thanks for posting about the product, it seems interesting enough to want to know more about it in detail.
 
@CharlieLaub
The filters are biquads:
-1st/2nd order HPF/LPF
-Bass/treble shelf
-Notch/peak

The chip thats used is the TAS5825M. The implementation is almost identical to the TI EVM, of which the measurements can be found here: http://www.ti.com/lit/ds/symlink/tas5825m.pdf

I have yet to measure the actual distortion levels of this board.

@oon_the_kid
The amplifier is the TAS5825M, which also handles the DSP. The amp input is I2S, which comes from the BT module, but is also broken out via a 3-pin female header.
 
Lukteveld,

Very interesting product you have there. I have always been looking to get something like this to appear on the horizon. Was considering getting the EVM for one of the TI all digital chip at one time.

Likely to get one.

Have a few more question:

1) If I understand it correctly, input is by I2S. That means I would need a Spdif/toslink to I2S converter for it to accept input from either of these sources?

2) How do you switch input so that it can switch from Bluetooth to the external I2S (Spdif/Toslink)?

3) There also seems to be a 3.5mm input, is that analogue input?

4) Does it have any analogue line level output? That I could connect to a subwoofer.

Oon
 
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The input stream is provided by a bluetooth module. Its either a bluetooth stream or the analog input (usually 3.5mm jack), but a header for I2S is provided if you want to hook up an external digital source.

Seamless switching from bluetooth to an external I2S source is not supported. Either the bluetooth module provides I2S, or you disable it and let an external source provide I2S
 
The input stream is provided by a bluetooth module. Its either a bluetooth stream or the analog input (usually 3.5mm jack), but a header for I2S is provided if you want to hook up an external digital source.

Seamless switching from bluetooth to an external I2S source is not supported. Either the bluetooth module provides I2S, or you disable it and let an external source provide I2S
How do we go about doing it? By using a DPDT switch or something like that. BTW, not sure what bluetooth chip you are using in your using. If it is Qualcomm CSRA64215, Spdif is already built in, just need to program it.

Oon
 
The input stream is provided by a bluetooth module. Its either a bluetooth stream or the analog input (usually 3.5mm jack), but a header for I2S is provided if you want to hook up an external digital source.

Seamless switching from bluetooth to an external I2S source is not supported. Either the bluetooth module provides I2S, or you disable it and let an external source provide I2S
Is there any line level analogue output that can be used for subwoofer?

Oon
 
You could use a PCM5102 DAC board from eBay and hook it up to the onboard 3.3V and I2S pins. It should be possible, but I have not tried it myself.



Do you need 4 speakers and a subwoofer? A common 2.1 configuration is possible out of the box with this board.
Hi Lutkeveld,

1) is the volume control implemented at the stage yet, or is it implemented in the dsp in the amplifier chip. Your proposal for the PCM5102 DAC is viable provided the i2S signal had already gone through volume control.

2) I am aware that your amp can be connected to a 2.1 configuration, however there is something you overlooked. Most subs are powered. Hence the need for analog out. Unless of course one is to Diy , which is a pain in the a*s...


Oon
 
Can I/one set BD modulation and Fsw ?

Yes, you can if you want. Its 1SPW/768khz by default, but you can set it to BD/384khz for slightly higher audio quality in exchange for higher idle power consumption.

Hi Lutkeveld,

1) is the volume control implemented at the stage yet, or is it implemented in the dsp in the amplifier chip. Your proposal for the PCM5102 DAC is viable provided the i2S signal had already gone through volume control.

2) I am aware that your amp can be connected to a 2.1 configuration, however there is something you overlooked. Most subs are powered. Hence the need for analog out. Unless of course one is to Diy , which is a pain in the a*s...

1) volume control is done in the amp, so not yet in the I2S signal
2) There is no sub out, but maybe it can be done with a high to low level converter?
 

fdenys

Member
2009-07-23 5:02 pm
Lutkeveld, interesting product!
Question: In a four channel setup, can two channels be configured as (rear) surround sound amplifiers? This would eg require the two rear channels to be setup as a basic Haffler surround sound simulator (left front channel minus/subtracted right front channel).
I understand a minor delay-option is programmable, which might enhance the effect (like the dolby surround scheme)
Is the subtracting option availabe?
Fred