Peak Amplification AM-400C2G GAN amp module

[Audiovibes]

Do they mean no extra heatshink or no heatshink at all?

Cause even at 90% efficiency there will be some 30-40W of heat that need to go somewhere for 375W delivery (not counting the PSU looses) .
Something is amiss here.

Total output power: 375 W x 2 channels = 750 W.

- Efficiency: 95.8% = 0.958

- Input power = Output power / Efficiency = 750 W / 0.958 ≈ 783.3 W

- Power lost as heat = Input power - Output power = 783.3 W - 750 W ≈ 33.3 W

So, the amplifier dissipates approximately 33.3 watts of heat at 750 W output power.

The GAN devices use the PCB as a heatsink. That combined with passive air cooling could possibly dissipate 33.3w. But keep in mind that’s probably 375w peak not continuous. Likely not even 1% THD. So the actual heat dissipated would be much less in real world music listening conditions.

 

[Sokel]

Total output power: 375 W x 2 channels = 750 W.

- Efficiency: 95.8% = 0.958

- Input power = Output power / Efficiency = 750 W / 0.958 ≈ 783.3 W

- Power lost as heat = Input power - Output power = 783.3 W - 750 W ≈ 33.3 W

So, the amplifier dissipates approximately 33.3 watts of heat at 750 W output power.

The GAN devices use the PCB as a heatsink. That combined with passive air cooling could possibly dissipate 33.3w. But keep in mind that’s probably 375w peak not continuous. So the actual heat dissipated would be much less in real world music listening conditions.

33W by the PCB alone seems at the very edge, unless is a special big surface one.
And we have to account that heat builds up over time.

We'll probably see it on a test bench, I'm curious.

 

[Audiovibes]

33W by the PCB alone seems at the very edge, unless is a special big surface one.
And we have to account the heat builds up with time.

We'll probably see it on a test bench, I'm curious.

33w for a millisecond before the amp clips and shuts down is likely feasible. If we use Hypex for example with the MP series, the 1% THD rating for the modules are 5x the continuous rating listed in the datasheets.

So if we did the same with these modules that would make them 75w continuous per channel. Or 150w for both channels. So 150w continuous would be the max they could run sustainably over time. Which at 95.8% efficiency would mean only 6.58w of heat dissipated. But even that’s with steady 20hz-20khz pink noise. With music it would be less.

 

[voodooless]

Realistically, with music content, these things could run without a heatsink; of those 33W with music, maybe 3W would be left (10dB crest factor). Probably the idle losses are more than that. Is it a good idea to run without heatsinks? Probably still not. Cooler devices last longer.

 

[Sokel]

33w for a millisecond before the amp clips and shuts down is likely feasible. If we use Hypex for example with the MP series, the 1% THD rating for the modules are 5x the continuous rating listed in the datasheets.

So if we did the same with these modules that would make them 75w continuous per channel. Or 150w for both channels. So 150w continuous would be the max they could run sustainably over time. Which at 95.8% efficiency would mean only 6.58w of heat dissipated. But even that’s with steady 20hz-20khz pink noise. With music it would be less.

For comparable efficiency, Purifi warns about thermals many times at their datasheets.
Low power modules like 200W/4 Ohm can maybe get away easier but the higher power ones, specially for low impedance demands need generous heatshinking to deliver over time.
If we talk merely ms, then sure, doable.

 

[Audiovibes]

In the CEDIA demo in the video I shared, the test conditions were 100w x2 continuous 400hz tone for 2hrs without a heatsink.

 

[Sokel]

In the CEDIA demo in the video I shared, the test conditions were 100w x2 continuous 400hz tone for 2hrs without a heatsink.

View attachment 475240

At 91° C, sure.
The thing is that we have to maintain the 60° C mark for home use.

(and at 91° C for a long period rest of the components won't be happy)

 

[Audiovibes]

At 91° C, sure.
The thing is that we have to maintain the 60° C mark for home use.

(and at 91° C for a long period rest of the components won't be happy)

That’s the amp controller internal die temp. Not the outside of the chassis. I found this information online:

The AM-400C2G module’s OTP is implemented via the IRS20957S, which shuts down the amplifier (disabling gate drive to the GaN transistors) when the controller’s die temperature approaches 150°C. This protects the entire system, including the GaN transistors, from overheating.


• For the GaN transistors specifically:


• They can operate up to a junction temperature of 150°C without inherent shutdown.


• In practice, thermal shutdown would occur at or just below 150°C due to the module’s OTP activation.


• GaN technology’s advantages (higher thermal conductivity than silicon) allow the IGB110S10S1 to handle higher temperatures reliably, but exceeding 150°C Tj risks avalanche breakdown or reduced lifespan.


• If the GaN transistors’ Tj exceeds the controller’s threshold (e.g., due to poor thermal coupling), the OTP would still trigger based on the IC’s sensing, effectively shutting down the module before the GaN devices reach destructive levels.

 

[Audiovibes]

Upon further evaluation, the AM-400C2G appears to just be a copy of the Infineon IGB110S10S1 evaluation board. And we have a full datasheet here:

https://www.infineon.com/assets/row/public/documents/24/44/infineon-ref-audio-ganb-750w-usermanual-en.pdf

 

[wwenze]

95.8% efficiency. 375w X2

750 / 0.958 = 783
783 - 750 = 33 watts

You'll need a heatsink for it. Even if just a tiny one that is bolted to the chassis, it's still a heatsink.

*Continue reading*

200W @ no heatsink.

That makes more sense.

And thus becomes a case study of how marketing becomes mis-marketing.

 

[pma]

Independent test is needed to see how it really works and what are the real parameters. I do not trust company advertising materials.

 

[Audiovibes]

All of our questions regarding thermal performance without heatsink is answered here. The 47w continuous test shows only 60C board temp. And real world music output will never exceed 47w continuous.

 

[voodooless]

At 375W, temps are still rising after 1 min, so no way it's stable without a heatsink.

 

[Audiovibes]

At 375W, temps are still rising after 1 min, so no way it's stable without a heatsink.

Who’s gonna be running it at 375w continuous and 10%THD with music? Even the 47W test will exceed the average continuous heat dissipation the amp will see in real world use.

 

[voodooless]

Who’s gonna be running it at 375w continuous and 10%THD with music?

That's not the point. The point is, they claim it could run without a heatsink with 375W... it clearly cannot, at least not with a continuous signal.

 

[Audiovibes]

That's not the point. The point is, they claim it could run without a heatsink with 375W... it clearly cannot, at least not with a continuous signal.

It could for 1 minute. They didn’t claim continuous output at 375w. That would mean the peak 10% THD figure of the module would be 3000WPC. And they make no such claim.

I had AI do an assessment based on the data in the datasheet and this was the conclusion:

“Based on the comprehensive data from the Infineon REF_Audio_GaNb_750W user guide, the maximum thermal heat dissipation of the AM-400C2G module during typical music playback is approximately 2.06 to 5.22 watts, assuming an average output power of 47 W (reflecting a 12 dB crest factor from the 750 W peak) and an efficiency of 90–95.8%. This low heat dissipation is easily managed without a heatsink, as confirmed by the user guide’s thermal performance data (60°C PCB temperature at 47 W for 30 minutes). The GaN-based design, with its high efficiency and low switching losses, ensures reliable operation well below the 150°C thermal shutdown threshold, making it ideal for high-fidelity audio applications in real-world music listening conditions.”

Hard to argue with that.

 

[somebodyelse]

At 375W, temps are still rising after 1 min, so no way it's stable without a heatsink.

Who’s gonna be running it at 375w continuous and 10%THD with music? Even the 47W test will exceed the average continuous heat dissipation the amp will see in real world use.

And here we descent into the old arguments about how to define rated power, and how much heatsinking is necessary...

 

[Tovarich007]

I'm not focused on "do they need heatsink or not, and at which output max power ?" and I wonder why this discussion started out so central about that.
I mean, what's matters most for me is the fact these amps are super tiny, powerful (even 200w "only" is great for their size and specs), their specs are very good and their efficiency too.

That's quite impressive. It's just amazing what can be achieved now in power/compacity/efficiency/performance.
It's true they're not the only one models to do so these days, more or less. They just push the enveloppe a bit farther than most of their competitors (Icepower, Powersoft, of course Hypex and Purifi, the two latter for pure SOTA performance).

We're living in a new goldend age for electronics.

 

[voodooless]

Hard to argue with that.

I didn't, in fact, I said something similar already:

Post in thread 'Peak Amplification AM-400C2G GAN amp module'

Sep 9, 2025

Realistically, with music content, these things could run without a heatsink; of those 33W with music, maybe 3W would be left (10dB crest factor). Probably the idle losses are more than that. Is it a good idea to run without heatsinks? Probably still not. Cooler devices last longer.

• voodooless

• 

 

[Audiovibes]

And here we descent into the old arguments about how to define rated power, and how much heatsinking is necessary...

The testing has already been completed and documented in the datasheet. Unless someone has third party tests of the module showing different data, the argument is over.