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Peachtree GAN400 Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 74 28.1%
  • 2. Not terrible (postman panther)

    Votes: 160 60.8%
  • 3. Fine (happy panther)

    Votes: 24 9.1%
  • 4. Great (golfing panther)

    Votes: 5 1.9%

  • Total voters
    263

amirm

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This is a review and detailed measurements of the Peachtree GAN400 stereo balanced (input) amplifier. It is on kind loan from a member and costs US $2,499.
Peachtree Audio GAN400 GAN Amplifier review.jpg

I am not generally a fan of peachtree audio product looks but this one in coffee stain looks pretty good. Other than a power switch, not much else is there. Ditto on the back side:
Peachtree Audio GAN400 GAN Amplifier balanced Class D XLR review.jpg

The claim to fame of this amplifier is use of GaN transistors which in theory simplify the design of a class D amplifier (a bit) and improve its efficiency (a bit). And in theory, it can also produce lower distortion (in open loop anyway). The drawback is much higher cost of the transistors compared to MOSFETs. Let's see if the performance is there.

Peachtree GAN400 Measurements
I performed all of my testing using XLR input. Let's start with our usual input of 1 kHz with output into 4 ohm to the tune of 5 watts:
Peachtree Audio GAN400 GAN Amplifier XLR measurements.png


There is fair bit of inconsistency between the channels with respect to SINAD. I switched my loads and issue persisted so it is not my setup. Averaging the two we get 84 dB which is slightly average for all amps tested but not where performance should be:
Best class d amplifier review.png


Frequency response is disappointing as it shows load dependency:
Peachtree Audio GAN400 GAN Amplifier XLR Frequency Response measurements.png


This means that the high frequency response will be speaker dependent which is not good. I expect this kind of performance in ultra budget amplifiers (under $100), not at this price.

Noise performance is good but again, not where it should be:
Peachtree Audio GAN400 GAN Amplifier XLR SNR measurements.png


Same for multitone distortion:
Peachtree Audio GAN400 GAN Amplifier XLR Multitone measurements.png


Crosstalk however, is superb indicating two independent amplifiers:
Peachtree Audio GAN400 GAN Amplifier XLR Crosstalk measurements.png


There is lots of power both at 4 and 8 ohms:
Peachtree Audio GAN400 GAN Amplifier XLR Power 4 ohm measurements.png

Peachtree Audio GAN400 GAN Amplifier XLR Power 8 ohm measurements.png


As noted though, the curve starts to go up prior to clipping which means distortion is increasing.

The amplifier more than meets its 400 watt spec at 1% THD:
Peachtree Audio GAN400 GAN Amplifier XLR Max and Peak Power 4 ohm measurements.png


The shape of THD+N graph is very smooth which perhaps could be attributed to GaN transistor design:
Peachtree Audio GAN400 GAN Amplifier XLR Power vs Distortion vs Frequency measurements.png


There is no pop on power up but there is when you shut it down:
Peachtree Audio GAN400 GAN Amplifier XLR Power on pop and off measurements.png


The amp is stable on power up so no need to leave it on:

Peachtree Audio GAN400 GAN Amplifier Warm up measurements.png


Peachtree GAN400 Power Stress Test
With the owner's permission :), I subjected the amp to varying load angle (phase) and down to 2 ohm impedance. It did very well:
Loadbox Output.jpg

Variations of ±60 degrees did not bother it at all at either 4 or 8 ohm. A bit strangely, at 2 ohm it would not run with 0 load angle but did produce half the output at other angles (hard to see in the 3-D graph). Since minimum impedance is 2.5 oh, we can't fault it for this. FYI I tested a couple of amps at my disposal and the both got quite unhappy with varying phase angles, shutting down and such. Whereas the GAN400 marched through this test without once going into protection.

Conclusions
I just bought a 65 watt GaN based USB-C charger and am amazed at how small it is. The buzz from there has travelled to audio and has resulted in GaN based amps like this Peachtree. Alas, there is no performance advantage that can be seen in this implementation. Noise+Distortion is only slightly better than average and far cry from top performing amplifiers we have tested in the past. Combine this with quite high price of $2,500 and this is a difficult offer to swallow. Good news is that there is plenty of power at 400+ watts independent of the load (4 or 8 ohm).

Personally I don't see a reason to pay so much for this level of performance so I can't recommend the Peachtree GAN400 amplifier.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Hypex and Purifi models with tons of clean, load-independent, cheap power have taken away any chance from designs like this. And rightly so. There was a time when between
- power
- economic saving
- quality
we had to pick two, but that's not the case anymore.
 
Thanks for the reivew.
On a first glance, Peachtree amp500 is cheaper and offers more power and performance.
Also, nicer veneer in my opinion. I guess amp500 is not based on GaN tech?
 
In the Power Cube I see 60 Vrms into the 4 Ohm - is it correct? Then maximum power should be 60*60/4 = 900 W!
 
You can see the load dependency already starting at 3k giving a slope or a rise in very wide band depending of speaker impedance this is potentially audible ? This is leads to unpredictable performance with your speakers and you should not have to do home auditions for amps ? And then you change speakers ? This also means that two people’s listening impressions of this amp even if done in a controlled ABX way can’t be compared unless they have the same speakers.
 
In the Power Cube I see 60 Vrms into the 4 Ohm - is it correct? Then maximum power should be 60*60/4 = 900 W!
I thought it was high too. Will take a look....
 
Did you get another dummy load ?
Yes, it is mother of all dummy loads going down to 1 ohm! It weighs some 60 to 70 pounds.....
 
Thank you for the review, Amir. I found the test interesting. I'm now starting to understand why I like the Crown XLS 1500 over many other amps that have a better SINAD. The Peachtree GAN amplifier has a higher SINAD but apparently it is only lower in noise than the Crown. The multitone for the Crown is better than that for the Peachtree.

Would it be possible to see the high frequency spectrum for the Peachtree? The main selling point for using GAN transistors is their ability to have a higher switching frequency but so far I haven't seen it in any existing product. The Topping PA5 has a 600mhz switching frequency without GAN transistors and I haven't yet seen a GAN amplifier exceed that figure. Thanks again for the review!
 
Frequency response is disappointing as it shows load dependency:
Peachtree Audio GAN400 GAN Amplifier XLR Frequency Response measurements.png


This means that the high frequency response will be speaker dependent which is not good. I expect this kind of performance in ultra budget amplifiers (under $100), not at this price.
Exactly, 1 dB fluctuation in the audio region is unacceptable at that price, even a average 70s amp did better than that.
 
That power stress test is super useful information, a lot of speakers have minimum impedance in the 3-4 Ohm range, but enough phase angle to become problematic. Would love to see some AV receivers subjected to it.

The 3D graph doesn't seem intuitive though. Is there an option for 2D plots, with the different impedance loads being different coloured traces, phase on X axis, and voltage on Y axis?
 
What a dissapointment. Gan should offer so much - it clearly fails to deliver here. Apart from power, similar or worse performance to amps at 1/5th the price. (That load dependence)

Nearly double the price of much better performing Purify/Hypex amps with similar power.
 
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