Digital Amplifier Project

[panson_hk]

I am working on an commercial active speaker project that will use VIA VT1736 USB controller, TI TAS5548 audio processor and TAS5612LA class D output. I also want to make it available to the DIY world. Any comment?

 

[doctormord]

Good!

 

[Neil Davis]

Active speaker amplifier?

This could be a great amp for active speakers. It would be especially nice if the amp could be mounted to a plate for heatsinking, so the assembly could be mounted to the back of a speaker.

I've got a lot of working code for designing active speakers using the ST309 multichannel amp, and it wouldn't take much to adapt it to the TAS5548. I'd be glad to provide the firmware and software for this program or to collaborate in some way.

 

[mikey_audiogeek]

I would be very interested in a board that has the TAS5548, I2S input, USB connection for control of the DSP parameters, an on-board MCU for interface and storage of DSP parameters, and an interface board that has SPDIF/AES/TOSLINK and volume control via IR

I think this may be too much to ask!

best regards,
Mike

 

[panson_hk]

I've got a lot of working code for designing active speakers using the ST309 multichannel amp, and it wouldn't take much to adapt it to the TAS5548. I'd be glad to provide the firmware and software for this program or to collaborate in some way.

I would be very interested in a board that has the TAS5548, I2S input, USB connection for control of the DSP parameters, an on-board MCU for interface and storage of DSP parameters, and an interface board that has SPDIF/AES/TOSLINK and volume control via IR

Hi Neil,

Thanks for your comment and willing to do firmware. I look forward to having a join project.

Hi Mike,

Your suggestion is actually I am working after, more or less. The amp will accept multiple input both analog and digital.

Please see picture of the test board. The board does not have everything but 5548/5558 and 5612.

Cheers,
Panson

 

[panson_hk]

The amp section TAS5612 of the board is working. I use TAS5548 EVM to feed the PWM signals to TAS5612. I will populate the TAS5548 section next.

 

[RAndyB]

I also want to make it available to the DIY world. Any comment?

I have been hoping for something just like this.

Andy

 

[panson_hk]

Here is my TAS5548+5612 board operating with an Arduino board being a host controller. Signal source is from VIA VT7136 USB audio streamer. I have tested it for 24-bit, 192 kHz.

foobar + upsampler, VIA ASIO driver, 5548 native 192 kHz processing.

 

[mikey_audiogeek]

Very cool!

Quick question: Why the 5612LA?

(5612A seems to have slightly better performance.)

Cheers,
Mike

 

[panson_hk]

I looked for an older part (TAS5716) initially for single multiple channels. TI suggested 5612LA for new design as 5716 is "old". Now I can do high-power steren the other hand, I need two 5612 for stereo active 2-way (full bridge).

One 5548 (96 k processing) can drive four 5612 (stereo, full bridge) for an active four-way project. What do you think?

 

[mikey_audiogeek]

Active 3/4 way is what I need! Can I suggest something? Have the power stages on a separate board - this would allow use of different power stages.

I am actually interested in trying the TAS5548 as a DAC - it might be interesting to reconstruct the "analog" waveform from the PWM output (via a LP filter) and see how good it sounds...

 

[panson_hk]

The 5548 EVM has an headphone output which is LP filtered PWM signals amplified by an opamp. I have not done any measurement to this output. We could use 5548 as a preamp with analog outputs for linear (Class AB) amps.

 

[panson_hk]

The first version PCB as being tested is essentially flawless. Board size 218 x 90 mm, 2 mm thickness, 1 oz copper, 2-layer gold plated.

I would like to offer 10 free boards to the diyaudio members. If you are interested, simply reply here. You only need to Paypal me US 10.00 for air-mail shipping and provide your postal address via PM.

I will send you schematic and current Arduino code via PM.

 

[mikey_audiogeek]

PM sent!!!!

 

[mikey_audiogeek]

Payment sent

Can your Arduino control the TAS5548EVM?

(haven't played around with the Arduino yet; it's been a few years since I did some stuff with the Basic Stamp)

Cheers,
Mike

 

[panson_hk]

I received it.

Do you mean TI's TAS5548 EVM? TI offers a GUI called PurePath Console to control the EVM. It allows you to do everything graphically. I have used this Console GUI and the TI EVM to control my TAS5548 board to verify Arduino code. The I2C on the TI EVM is disconnected from the onboard TAS5548 and routed to my TAS5548 board.

I am using Arduino Mega2560 board for this project. Photo shows my latest test setup. A rotary encoder for volume control and a keypad for input selection, mute, etc.

 

[mikey_audiogeek]

Hi, yes TI's TAS5548 EVM.

I have PPC and have used it to run the EVM and test functionality. However the EVM doesn't retain settings so it must be connected to PPC every time it is powered up. I am looking for a solution that can automatically "boot" the TAS5548 on powerup and load the biquad settings.
Cheers,
Mike

 

[panson_hk]

Yes, you can use any external MCU with I2C to boot TAS5548 EVM with your biquad settings. Do you use it as part of your system or project?

 

[mikey_audiogeek]

Just used for testing purposes so far. I use a MiniDSP 2x8 DSP with 3x MiniAMP boards (I2S PurePath Class D amp chips, 2x20W), however could see that the TAS5548 was possibly a more "elegant" solution and would allow use of some lower-distortion output stages.
Unfortunately I don't have the expertise to control the TAS5548 from a separate microcontroller, this is where i need to purchase some help

 

[panson_hk]

Well, you can use my Arduino code to control it (EVM). Do you have PurePath Console GUI?