3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier

[nodigital]

A thread for discussion and capability discovery of the DSP enabled amplifier from 3e Audio

https://www.3e-audio.com/finished-amp/tpa32xx-all-in-one-amplifier/

Built around the Sigma Audio ADAU1701 DSP, it offers programmable control of the audio allowing speaker and room correction combined with a Class D amplifier in a one box solution.

Auto switching between RCA (Analogue) and Bluetooth (Digital) input sources - when no audio or no play from Bluetooth, it will auto switch to RCA source.

Has on-board header for programming that requires a USBi programming interface (Available from 3e Audio soon after the amp is available, or from a variety of other sources in the form of freeUSBi).

Connection for the DSP is a standard USBi connector

Free USBi driver installation guide from 3e Audio and the FreeUSBi guide from Free DSP. Note the special steps with Win10 FreeUSBi driver installation that requires disabling of driver signature enforcement.

Note the SDA and SCL should have 2.2 kΩ pull-up resistors on the lines connected to them. The voltage on these signal lines should not be more than 3.3 V. If connecting a board such as the easily available CY7C68013A, the additional 2.2k resistors need adding.

SigmaStudio is the programming development environment - https://www.analog.com/en/design-center/evaluation-hardware-and-software/software/ss_sigst_02.html
with included DSP functions such as automatic speaker EQ - https://wiki.analog.com/resources/t...udio/toolbox/adialgorithms/automaticspeakereq

Using REW to sample the output from speakers its possible to use the auto EQ function in SigmaStudio to design a correction filter and upload to the amplifier, exampled here: https://ez.analog.com/dsp/sigmadsp/f/q-a/64304/adau1701-sigmastudio-rew-auto-eq/362660#362660

 

[Lorenzo74]

Funny is that the first real digital (class D+ DSP) amplifier is brought to us by Nodigital.
happy to contribute.
do we know when the tpa3255 version will be released?
as previously stated could be a giant killer if properly implemented.
especially considering that the minidsp shd power is actually built on the same chip.
my best
L.

 

[BillG]

A thread for discussion and capability discovery of the DSP enabled amplifier from 3e Audio

https://www.3e-audio.com/finished-amp/tpa32xx-all-in-one-amplifier/

I've had my eye on this as well, as I like cheap, clean power. I only wish it had a remote control, and a couple of more inputs. Granted, these issues can be worked around - a remote controlled power outlet, and input switcher/DAC would do - but it would be convenient to have them onboard. I've see that a few other manufacturers are starting to implement the TPA32XX chips now, perhaps they'll up the feature sets on their offerings...

 

[somebodyelse]

Application note for the USBi programmer - it's mainly providing USB to SPI and I2C conversion, so the 10 pin box header does expose those for alternative programming and/or control options. Both of these interfaces are widely available on SBCs like the Raspberry Pi, as well as Arduino, Blue Pill STM32 boards, ESP modules and so on. The initial route used by HifiBerry for the BeoCreate was sigma_tcp which can run on the Pi and makes the DSP available to SigmaStudio over the network.

 

[nodigital]

From reading so far, I think it'll be possible to create a wifi interface for it using a Wemos D1 (Or equivalent). From a straight USB connection, the very cheap EZ-USB FX2LP CY7C68013A boards off AliExpress work with SigmaStudio so should be applicable, albeit with potentially the need for 2k2 resistor in the data line connections to the amp, ala freeUSBi.

 

[A800]

Wait...
Black wire to red connector and vice versa?

 

[m_g_s_g]

I’ll be following this thread. I’m interested in the potential of this box as a cost effective option to convert a passive two way speaker into a full active one with digital crossover. It is cheaper than the FusionAmps/miniDSP PWR-ICE alternatives and with better quality than the Dayton DSPB boards.

Add an Audinate AVIO adapter and you even could have a Dante enabled monitor.

 

[A800]

I would check the phase/polarity though.

 

[somebodyelse]

I would check the phase/polarity though.

It's trivial to flip it in the DSP, so a non-issue as far as I'm concerned.

 

[spacevector]

So is this the connector to use for programming the DSP? You need to open the top, apply mains power to the unit and then program it? Seems a bit dangerous to me. Can't they bring this out to the back or front panel?

 

[somebodyelse]

That's the connector, and you do need to open the top. You may or may not need to apply mains power - the programmer may be able to supply power for programming via the connector, but we'll need some documentation (or trial and error) to be sure. It's not ideal for your typical consumer, but your typical consumer won't be programming DSP with SigmaStudio anyway, so I don't think it's too unreasonable to assume some technical proficiency.

 

[jae]

A bit of a shame it's not possible to change DSP on the fly, or at least with USB/bluetooth

 

[civi]

A bit of a shame it's not possible to change DSP on the fly, or at least with USB/bluetooth

Its just a minor inconvenience. "Set and forget" is the best way for sound mind.

 

[somebodyelse]

A bit of a shame it's not possible to change DSP on the fly, or at least with USB/bluetooth

Just wait til we get an ESP board in there

Those looking to use it for active crossovers and multiway systems are going to need a way to do things like sync volume changes on multiple amps. The same interfaces would be equally capable of live changes to DSP parameters. We have a number of approaches on both the hardware and software side that should work.

There are a bunch of changes that could be made to the amp to support different use cases - perhaps we'll see some or all in a future amp if this one has any success. A version with option boards for different use cases might be an economic way to do it.

 

[jagercola]

I was one of the first to order this and it's been stuck in customs or that it's cleared customs since the 15th. Hope to see it soon, but not sure if I'm just unlucky or if all China imports are backed up.

 

[raindance]

Wait...
Black wire to red connector and vice versa?

Yeah, looks like a blatant QA issue. Probably makes the stereo very wide sounding

 

[snip3r77]

I was one of the first to order this and it's been stuck in customs or that it's cleared customs since the 15th. Hope to see it soon, but not sure if I'm just unlucky or if all China imports are backed up.

will await your review

 

[nodigital]

That's the connector, and you do need to open the top. You may or may not need to apply mains power - the programmer may be able to supply power for programming via the connector, but we'll need some documentation (or trial and error) to be sure. It's not ideal for your typical consumer, but your typical consumer won't be programming DSP with SigmaStudio anyway, .

Yeah, one of the caveats is whether it'll be programmable 'live'. It is a shame the header isnt on the rear. At least that way it opens up some extension/module options to make it easier to program for the average user - Eg, a plug-in based on an ESP8266 that an app could connect to and upload some predefined configs. As I've mentioned before, that accessibility to changing the DSP defines the orders of magnitude in sales.

I don't think it's too unreasonable to assume some technical proficiency.

That may well be technical profanity if the mains powering causes some nasty side effects

I've asked about the connector - 3e are on holiday and will give some detail on their return. They're very quick to respond, almost realtime, via the AliExpress Contact Seller channel.

 

[somebodyelse]

Yeah, one of the caveats is whether it'll be programmable 'live'. It is a shame the header isnt on the rear. At least that way it opens up some extension/module options to make it easier to program for the average user - Eg, a plug-in based on an ESP8266 that an app could connect to and upload some predefined configs. As I've mentioned before, that accessibility to changing the DSP defines the orders of magnitude in sales.

https://www.hifiberry.com/modify-dsp-registers-on-the-fly/ covers the method using the Raspberry Pi and sigma_tcp. I'm pretty sure the Aurora code covers it via a web interface on the ESP. These are modifying settings in the same general DSP setup - changing a filter frequency, volume setting etc. Loading a whole other config is another option.

 

[nodigital]

https://github.com/MCUdude/SigmaDSP
Interesting source to update the ADAU1701 over i2c using Arduino device from binaries created out of SigmaStudio. The source here's done a lot of the heavy lifting which is a good start. Also shows how to upload other eq filters then change the params. So, with something like an ESP8266 attached its possible to expose the DSP for real-time change of eq. Could wire it up with Blynk for an easy Smartphone GUI to proof of concept changing dsp parameters