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.
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:
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:
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:
Frequency response is disappointing as it shows load dependency:
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:
Same for multitone distortion:
Crosstalk however, is superb indicating two independent amplifiers:
There is lots of power both at 4 and 8 ohms:
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:
The shape of THD+N graph is very smooth which perhaps could be attributed to GaN transistor design:
There is no pop on power up but there is when you shut it down:
The amp is stable on power up so no need to leave it on:
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:
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/
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:
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:
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:
Frequency response is disappointing as it shows load dependency:
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:
Same for multitone distortion:
Crosstalk however, is superb indicating two independent amplifiers:
There is lots of power both at 4 and 8 ohms:
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:
The shape of THD+N graph is very smooth which perhaps could be attributed to GaN transistor design:
There is no pop on power up but there is when you shut it down:
The amp is stable on power up so no need to leave it on:
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: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.
-----------
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/
