Dayton Audio APA1200DSP Teardown (DSP Amplifier)

[Vladimir Filevski]

Please see Figure 8 (Output Power vs Supply Voltage) in BTL (bridge) configuration in the TPA3255 datasheet:
https://www.ti.com/lit/ds/symlink/t...01647&ref_url=https%3A%2F%2Fwww.google.com%2F
For 48 V DC supply voltage and BTL (bridge) configuration, measured output power is about 130 W into 8 Ω and 230 W into 4 Ω, with THD = 1%.

 

[Raindog123]

@Vladimir Filevski Thanks, a good [data] point.

I was just questioning the bridged power limit estimate based on the input DC voltage... But to stay at that 1% distortion - away from clipping and all the associated unpleasantries - will be at [apparently much] lower output power.

 

[Billy Budapest]

Teardown is the right expression.

Tear it down and keep just the board with the DSP functionality, codecs and the case and connections ...

Unless you have documentation about how the control board works, it would be close to impossible to hack it to use with another amplifier and power supply. Even with documentation, it might not even be possible.

 

[Billy Budapest]

What’s up with the disconnected fan at the top of the picture? Maybe it just serves as an air inlet. You can see a foam filter bulging out between the plastic and sheet metal if you look closely. Still, why use an unpowered fan for this?

 

[GWolfman]

Forgive my ignorance, but why are there inductors on the PCB for the speaker terminals (outputs)?

 

[GWolfman]

Is that a fan at the top of the image? There's no wires coming out (from what I can see)!

 

[douede]

..."Jamicon." Not exactly a top brand capacitor although it tries hard to associate with them using that "con" ending.

It also tries to Jam like a Silmic.

 

[mhardy6647]

Speaking of the capacitor, the brand name is "Jamicon." Not exactly a top brand capacitor although it tries hard to associate with them using that "con" ending.

I see a 21st Century business opportunity for sure: Comicon condensors (capacitors).
I'll be starting a gofundme anon.

 

[Sean Ku]

Forgive my ignorance, but why are there inductors on the PCB for the speaker terminals (outputs)?

I suspect they are RF chokes to keep high frequency noise from radiating off the speaker wires.

 

[Billy Budapest]

Is that a fan at the top of the image? There's no wires coming out (from what I can see)!

Exactly. It could just be a fan frame sans motor and controller, just used to secure the foam air filter. Still weird.

 

[amirm]

Is that a fan at the top of the image? There's no wires coming out (from what I can see)!

No there is no fan there.

 

[Doodski]

Well, doubling the voltage makes it 96V. RMS of that makes it ~68V. P=68*68/8=578W (RMS).

Not sure about the current limitation though.

Edited...

 

[restorer-john]

What makes you guys think it's a TPA-3255? It's not even the right package for the TPA.

You can see the solder pigtails from the output MOSFETs clearly- it's more likely a Maxim/IRS style class D driver like the IRS-2092 (16pin)

 

[Igor01]

Power amplifier ICs are placed between the back of the PCB and the heat sink.

 

[Igor01]

Perhaps?

 

[jasonhanjk]

The AC supply on board, is it very close to the heatsink?

 

[Bamboszek]

Forgive my ignorance, but why are there inductors on the PCB for the speaker terminals (outputs)?

Class D requires LC lowpass filter at output to attenuate high frequency switching noise of amplifier.

 

[pseudoid]

The PCB attached to the output binding posts is tweaked...

 

[daniboun]

What makes you guys think it's a TPA-3255? It's not even the right package for the TPA.

You can see the solder pigtails from the output MOSFETs clearly- it's more likely a Maxim/IRS style class D driver like the IRS-2092 (16pin)

View attachment 167006

Agree looks like a IRS2092 chip. See my "whataboutaudio" Italian module

Now in the same category you can compare vs a TPA3255 + integrated DSP

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