Affordable GaN FET amp from Peachtree Audio


Peachtree Audio is offering a Beta Test program for their new GaN 1 amp (not to be confused with their GaN400) and it's being offered at a substantial discount ($1299 instead of $1999) just for being part of the Beta Test group. It has only one digital coax input and that's it. 200 Watts/channel, zero feedback, and no DAC since the GaN FETs handle that.

All the best,
Nonoise

128x128nonoise

There are a few obvious restrictions to its utility.

It only has one input, so that's what you need to be looking for.

It needs to be operated with a source unit (typically a streamer) with a variable output/volume control.

The source unit needs to have the right type of output socket to match the Peachtree unit.

So there's an obvious reason why they bundle it with the Bluesound unit.

cool concept (but not having a usb digital in is a miss imo)

mini gan 5 is only $750 at full retail though... very similar internals i would suspect

Yes, it only has one input, but, as they state in the description, you can always use the many inputs of the Bluesound or a similar device. I posted this as there's been lots of discussions of folk who's only interest is in streaming or CD playback and those who'd like to experience the sound of a GaN FET amp without the steep price of entry. Then, there's the purists who would like to forego the use of a DAC and hear the signal as intended (just amplified).

All the best,
Nonoise

I'm very intrigued and did sign up.  I'll be able to use my Rose 150B and easily switch between the GaN 1 (DAC less) and the XLR outs (via 9038 Pro).  I have several Class D amps (nCore, Purifi, Mini GaN5) that I can eval.

All my music listening in now streaming, so this should be a fun endeavor... 

 

 

This is interesting. Thanks for bringing it up!

Does anybody know how these GaN amps behave in terms of distortion vs power? I recall Hypex UcD and Ncores kept distortion very low up to about 50% of nominal power and then increased rapidly until nominal. So I tend to think an Ncore 400 or my UcD400 should be used up to 200W. I wonder if 200W GaN should be used up to 100W to keep distortion very low?

I'm considering a GaN amp in my active system (SET top end, class A/B midrange, UcD midbass) and this would be an interesting option taking s/pdif from the soundcard and bypassing the DAC stage. Further digging on how clocking might affect this stage differently from the paths converted to analog.

Fun times!

I looked at this earlier in the week, while price is attractive it’s certainly not for me. Not even the 2nd or 3rd room system where I have been using a pair of SONOS Play 3 with their Sub for 15 plus years. I find SONOS unbeatable for the sound and ease of use. 

@nonoise 

OK, color me curious...How in the world can a GaN amp be fed a digital signal and amplify that signal and have it be an analog output without a D to A conversion taking place?  

And if that D to A conversion is taking place (me thinks it has to be) then the GaN amp is incorporating a DAC (of whatever strip you wish to call it).

By extension does this mean that any GaN amp doesn't need a DAC and can be fed a straight up digital signal.

Very curious!

Regards,

barts

 

Reading their website, the GaN 1 is trickle down from their GaN400. From earlier threads, in my mind Peachtree's GaN400 is very similar to the LSA Voyager, of which there have been plenty of positive comments. Has anybody had the opportunity to listen to GaN and Voyager?

@nonoise 

There is a coax in on that GaN that would come from your DAC. In the case of the Bluesound, it has an internal DAC. However you could insert an external DAC between the Bluesound and the GaN. Volume control could be via either the DAC or the Bluesound depending on the DAC. (I have a Border Patrol DAC so manage volume via the Node2i when streaming)

If you're pure digital I can see the utility. OTOH if you have an analog source like a TT, you're SOL I think.

Happy listening

 

Using the Bluesound or DAC for volume control usually leads to bit stripping.  Some DAC  have a good volume control.  I don't remember what kind that is or what brand DAC has these.

@musicfan2349 

If you use the digital output of the Bluesound Node, you ARE using it's internal DAC. The only way to not use it is to use the analog outputs, which there are not analog inputs on the Peachtree amp. So the question remains, if I use the digital output of my Lumin streamer into this amp, what device is doing the digital to analog conversion? No DAC needed according to the OP, but I'm having a hard time figuring that one out.

daledeee1's avatar

daledeee1

329 posts

 

Using the Bluesound or DAC for volume control usually leads to bit stripping.  Some DAC  have a good volume control.  I don't remember what kind that is or what brand DAC has these.

 

All Lumin streamers have LEEDH processing built into the app. It is a very high quality volume control that does not degrade the SQ.

 

 

Nice but not a functional fit in my case.  Need to have a phono.  Otherwise….

@barts ,

It’s over my head as well but here’s this from their site:

First and foremost is the GaN-FET amplifier module. It has several inherent advantages in a power amplifier that even the best MOS-FET designs simply cannot achieve. A GaN-FET power stage provides a precise high-power reproduction of the Class-D PWM signal with extremely high linearity. This linearity eliminates the need for ANY feedback, ultimately allowing for the best possible audio quality providing clean, clear middle and high frequencies and a tight, solid reproduction of low frequencies. GaN-FETs track the complex audio waveforms so much more accurately than MOS-FETs resulting in significantly more transparent and natural sound. The difference is something even a casual listener can hear and appreciate. The GaN 1 is also designed so that it does NOT even require a digital-to-analog-converter (DAC). The digital audio signal at the input directs the amplifier outputs to drive the speakers. Although DACs have continued to improve over the years, there is no DAC better than NO DAC! This concept is not a new one as similar devices often referred to as "Power DACs" made quite a splash in our industry years ago, but this time around, using the concept with GaN-FETs raises the bar to an entirely new level.

 

There’s also this from Twittermachines on the Technics SU-R1000 (which uses GaN FETS:

It’s also worth pointing out that there’s no DAC, no digital to analog conversion, taking place inside the SU-R1000. Incoming digital signals are upsampled (to 32-bit/768kHz), sent through a 1-bit Delta-Sigma converter, followed by another stage, the PWM converter, which forms a so-called “ternary” (2-bit) signal out of the 1.5MHz 1-bit signal. So each transistor only has to handle a switching speed of 768kHz/1-bit which is easier to handle in terms of the natural response time of a GaN-FET. I include this information knowing full well that few people will really understand it, yours truly included, so let’s just say that digital remains digital right up to the speaker binding posts.

I read somewhere that Wadia did a similar thing all those years ago but was stymied by the limits of the output devices they had then. It’s still over my head but I can definitely hear the results with my Technics SU-G700. I still prefer going analog in from my SACD player but it’s a close enough call to make me know that a better coax cable can level the playing field, or, maybe not.

All the best,
Nonoise

OK, color me curious...How in the world can a GaN amp be fed a digital signal and amplify that signal and have it be an analog output without a D to A conversion taking place?

And if that D to A conversion is taking place (me thinks it has to be) then the GaN amp is incorporating a DAC (of whatever strip you wish to call it).

By extension does this mean that any GaN amp doesn’t need a DAC and can be fed a straight up digital signal.

ralph at atmasphere or others working with these technologies can probably answer better ...

...but to my understanding the class d amps use pulse width modulation of the output transistors... so the input into that form of power transistor control scheme is digitized by nature... so when you put an analog signal into these units, it actually goes through a-to-d conversion initially, so that the amp module is working off a digital signal it needs to its modulation (downstream control) scheme - and then the amplified output is delivered to the output taps (speaker terminals) in analog form, thus playing music

amps and integrated amps like those from devialet, lyngdorf et al all work this way - you feed in an analog signal, it converts to digital at the input... then the amplification module converts it back to analog with the juice behind it to drive the speakers...

so this peachtree product is simplifying the scheme by taking the digital in only at the spdif rca port... to a-to-d conversion is being done for any inputs

https://digilent.com/blog/whats-the-point-of-a-dac-and-why-do-i-care/

https://www.adam-audio.com/en/technology/pwm/

https://www.eetimes.com/class-d-audio-amplifiers-what-why-and-how-part-5/

@nonoise 

If you use the digital output of the Bluesound Node, you ARE using it's internal DAC. The only way to it is to use the analog outputs, which there are not analog inputs on the Peachtree amp.

I'm sorry sir however, you have that exactly backwards. The analog outputs from the Node2i have passed through the internal DAC of the Node2i. That's why they are an analog signal: They've been converted from 1's and 0's to an analog waveform with left and right channels.

The digital output from the Node2i has NOT be converted as it is by-passing the internal DAC in favor of an outboard DAC or other component which can accept a digital signal.

So the question remains, if I use the digital output of my Lumin streamer into this amp, what device is doing the digital to analog conversion? No DAC needed according to the OP, but I'm having a hard time figuring that one out.

Well I went back to their ad copy in which they state: "The GaN 1 is also designed so that it does NOT even require a digital-to-analog-converter (DAC). "

I too fail to see how you can put out an analog signal to speakers unless somewhere along the way you convert those little 1's and 0's to an analog waveform. Peachtree are doing that, they're simply just not saying they're doing it.

Also, I stand corrected: I forgot the Node2i does have analog inputs so I suppose you could use a phono preamp into it for a TT, thus using the Node2i as a "preamp" of sorts but I'm skeptical as to the sound quality.

I like the Node2i, but I'm not going to hand my TT over to it. 😉

Happy listening.

 

 

@jjss49 

Ah thank you for the citations and clarification on this process! 👌

So the D to A process is still happening, they're being creative with the design to do it with. Slick.

Happy listening.

@musicfan2349

That quote you attributed to me was not mine.
It was ozzy62’s.

All the best,
Nonoise

Doesn't the big Technics integrated do something similar?  It has an ADC for incoming analog signals, then the digital signal can be manipulated if necessary, and then it's handed off to the amplifier section.

Yes it does. In my post @7:57am I cite a reviewers take on the Technics where he describes the process, as best he can. It's the same for my Technics SU-G700M2.

And yes, TacT, Wadia, Lyndorf all do something similar but the GaN FETs are stirring the pot more than ever.

All the best,
Nonoise

Some history:

Tact (Tocatta Technologies) was the first to do this back in the late 90s.....nothing new here. Tocatta Tech was sold to TI and they made chips that Panasonic used in some receivers back in the early 2000s.....Mr. Lyndorf was part of Tact and went on to make the Lyndorf amps (which he still makes and sells).......Technics released their first digital direct amp a few years ago and continues to do the same in cheaper amps and now Elegant Audio Solutions came up their own version of this type of circuit a few years ago and the Peachtree is the first implemtation of these inexpensive EAS boards.

Yes, there is digital to Analog coversion done in these amps....but not in the traditional way......there are NO analog amplifiers (op amps) in the circuit.....and no traditional DAC chips. The digital signal (PCM) is converted directly to PWM (class D type of output stage) directly in software. Tact stated in their white paper back then that this process was "inherently non linear".....hence it took them a long time to get it right.....of course, EAS has their own engineers and we have way more processing power now so hopefully this thang sounds great.

Because there are no analog stages.....there is no feedback....so the distortion measurements of this module are going to be worse than the EAS module in the regular Peachtree/LSA GaN amps. But, as most of us know.......measurements do not tell you much about how good or pure something sounds. If you are a measurements are GOD person then you will want to stick to Purifi, Benchmark and Orchard.....These amps measure REALLY good.......and they also sound really good......as good as this "digital in only baby?".......we shall find out soon.

The amp, like all others, can be modded with better jacks, wires, beefed up power supplies, etc.....for increased sonic wonderment.

Thanks for the history lesson. 👍
Something tells me that with the use of GaN FETs and lots of good old time on their hands (for all the R&D being done), the future is going to look a lot brighter for "digital" amps.

The sound I'm hearing out of my Technics SU-G700M2 is unlike anything I've heard and yet it's all in a good way. As I adjust to the sound and notice what sounds like minor trade offs are beginning to look more like the shedding of bad aspects and maskings and the revealing of more musical information, if that makes any sense.

It's more than a different perspective, but it's still early in the game.

All the best,
Nonoise

The Bel Canto c5i in my upstairs system does a similar trick as I read it ie digital signal driving the class D amp. It’s an “all digital” integrated amp. Lots of inputs including phono. Analog inputs are converted to digital. It’s been a keeper….had it for several years and love it. Small footprint and does  everything just add speakers and inputs. There is a new model now the c6i that I might have to upgrade to at some point.

What I just read online describes the C5i as a normal class D integrated....with built in DAC......not a digital direct to PWM converter.

Starts production next week, I'm excited to get mine. Might get a minidsp flex to go with it. 

i hope this unit isn’t plagued with this problem... absolutely shocking they would let production units out like that... 

 

I saw that a bit ago. I think they said the problem was in the predac. I had the same problem with bluesound node and ares ii. Firmware finally solved it.