Peachtree GaN 1 Beta


Before I start my post here is my current system for reference:

Auarlic Aries G1 --> Denafrips Terminator or SW1X DAC --> Audio GD HE1 XLR preamp or Sachs preamp --> various tube amps --> Cube Nenuphar Mini's w/ a pair of REL S510 subs. Cables and power conditioning commensurate with the rest of the system.

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As warmer months approach I have been looking for a cool running amp to replace my Line Magnetic LM-518 and other tube amps for a few months as they run pretty hot.

I've been interested in the GaN FET amps and just purchased a used LSA Voyager 350 Gan FET amp which I should receive in a few days. I've tried class D amps before and while they checked a lot of boxes I just didn't feel drawn in. However, I like to explore so I figured I'd try the GanFET and since the amp has zero feedback and my speakers seem to prefer amps with little or no feedback I figured it be worth checking out.

Today, Peachtree Audio sent out an email inviting users to a beta of their new Gan 1 amp. Here are some excerpts from their email:

 

What is the GaN 1?

In basic terms it is a 200 Watts-Per-Channel (WPC) Power Amplifier designed to be the sole interface between your digital audio device with a variable output, like a Bluesound NODE, and your speakers. The GaN 1 is a simple, pure and cost-effective audio solution: connect the GaN 1 to a streamer and a pair of speakers and you have an amazing Hi-Fi system. That's it...no DAC, no preamp and no input switching. The signal path from the music to your speakers is remarkably short and free of artifacts. Want to hear the intricate details in your music that have always been there, but you couldn't quite make them all out before? Then the GaN 1 is for you!

What makes the GaN 1 so special?

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 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 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 new as similar devices known as "Power DACs" made quite a splash in our industry years ago. But this time around, by executing the concept with GaN-FETs, the bar is raised to an entirely new level.

Key Features at a Glance:

▪ 200 WPC state-of-the-art GaN-FET module
▪ ZERO feedback design
▪ Regulated 450-Watt power supply
▪ Coaxial S/PDIF input with native support up to 24-bit / 192kHz
▪ DAC-less design
▪ Power on/off trigger port
▪ All aluminum chassis
▪ No cooling fans

 

This sounded really interesting to me and since I have a good streamer I signed up for the amp beta only. One aspect that intrigues me is to create an extremely minimal signal path. My speakers are single driver, crossover-less design. Employing the GaN 1 will mean the system will be Auralic Aries --> GaN 1 --> Cube Nenuphar Mini's. Will that lead to a more engaging sound vs the full system? Will the Voyager GaN 350 outperform a tube amp in the full system? Who knows, should be fun to find out....

Now, I have no idea how either of these GaN FET amps will work with my speakers. The Cube Nenuphars seem to prefer amps with low damping and no negative feedback, which is more common with SET tube amps and Class A solid state amps. I'm not sure of the damping factor of the GaN FET amps, but both are Zero feedback designs, and both have way more wattage than I need. For reference, I have a 1.5 wpc 45 tube amp that sounds amazing with the Cubes, so high wattage is not required. I am interested though in what these amps will sound like compared to my tube amps, and I am particularly interested in what the streamer direct to amp Peachtree will sound like.

I am also looking to acquire a First Watt SIT-3, which is a great match with the Cubes, but now that they are no longer produced prices have gone above my current comfort level. If I can get one I will throw it into the experiment.

The Peachtree won't be shipped until sometime in June, or possibly later. In the meantime I will get the LSA Voyager in the next few days. I might even be able to get it hooked up this weekend so stay tuned, should be an interesting experiment...

abd1

Showing 14 responses by thespeakerdude

Smart people learn from the mistakes of others and build on the knowledge they gained from those mistakes. Others keep repeating those same mistakes over and over. You can't build on existing work if you don't know what that existing work is. The person who "already know how things are", is the person that refuses to make use of all the knowledge that is at our finger tips, preferring to just wing it, while proclaiming those that educate themselves stagnate.

I am with @kuribo on this topic. I read the manifesto, which I later learned was written by @ricevs after I made my comment. I am not an EE, but I have been involved in professional speaker development and management of for closing on 2 decades. I am technical enough to have picked up more than a few things. It is not hard to see that was @ricevs is writing about is a laundry list of audio cliches. In our products, we are responsible from everything from the input, which is often digital today, to what comes out of the drivers. We know, in great detail, everything that affects the sound coming out of the speakers. None of the items on that list of modifications would even begin to be a consideration unless there was an identified fault to start. There is as much chance, probably more, of creating a new issue as there is of fixing an unidentified issue that probably does not even exist.

You are right. I don’t listen to people who don’t know the difference between Class D and a digital amplifier. I don’t listen to people who make wild claims so obviously false. I don’t listen to people who post manifestos on the web filled with easily recognized errors.

I do listen to the many speaker designers, acoustic physicists, and EEs i work with who in total have many hundreds of years of audio work experience. I listen to our panels of experts listeners working in controlled conditions. I listen to my customers who include mixing, mastering and recording engineers, and even artists.

Call me crazy.

My vote is with the guy who has built a Class D architecture from the ground up and "the other guy". I don’t place much faith in someone who does not know the difference between Class D and a digital PWM like amplifier.

@kuribo , fraud or charlatan may be a bit harsh. In result there may be no difference, but I believe the person in question faithfully believes what they believe though the lack of knowledge is obvious in the writing and the hubris is shocking to me personally. The best people I work with in audio are very confident but also very humble in their abilities. They would never think to make such claims.

If we make a change to a product and a difference can be heard by anyone, we can always measure a change. Always. Those best people I mentioned, they usually have a very good idea what it is before we have the measurements. It does require having measuring equipment.

However, all parts SOUND different.....no matter how they measure.

There is NOTHING in the specs of a Caddock resistor that mentions low harmonic distortion.....just that it is a non inductive part

 

Are you sure you want to stick with these statements?

@arafiq +10,

@donnylovely , we are responsible for our action and what we write.

This has been refuted by hundreds of posts all over the net.

 

@atmasphere,

As the GAN1 is a PWM amplifier controlled by digital timing signals mainly, and not attempting track an analoig signal with high precision as would be required in a Class D amplifier, would the GAN1 be less sensitive to some of the issues you have indicated?

Some of that was over my head, but I have people who can explain it to me. Thank you.

@ricevs have you delivered the modified unit back to the customer? You keep describing the GAN1 as Class D analog switching. I do not think that is correct. Class D and PWM are not the same.

@ricevs , it would probably be best not to post links to technical articles you do not fully understand. I was trying to be nice before and give you a way out. Class-D and PWM are not the same thing. A Class-D amplifier may use PWM. However, that is not what you said, you said this,

"The GaN1 is the DAC.....it changes PCM directly to PWM (class D analog switching)".

Class-D may use PWM, but PWM is not Class-D. Put in simpler terms, an Orange is a fruit, but not all fruits are Oranges.

Class-D is an amplifier architecture. Peachtree may call it Digital Class-D, but that is marketing. There is no such thing as "Digital Class-D". You are more accurate to call it a power DAC as you did because that is what it is. They call it an amplifier but it does not amplify anything hence why it cannot be a "Class-D" amplifier.

Did you measure the switching frequency on your oscilloscope? I was curious as to what it was.

 

What the heck are you talking about.  Nitpicking? I expect someone going in with a soldering iron and modifying someone else's amp to be an expert and understand what things are. Paragraphs of flowery language does not excuse that requirement. Caveat emptor. @atmasphere 's prior warning is ever more salient.  

@donnylovely - No, I know I am not an EE, but I have quite a few who work for me and I have managed a lot of projects with EE involved. I understand my limitations especially when working on someone else's equipment. This is not a simple tube or transistor amplifier. @atmasphere who is an EE I believe and an expert has discussed the issues of modifying a Class-D amplifier when you don't have the proper tools or experience.

You only need one fuse in an amp to protect it.....It has a fuse on the power supply....you DO NOT need two fuses in a row. 

 

How about you run that by UL, or ETL or TUV.  I assume you don't understand what that first fuse is for, but the one on the power supply is not a replacement. 

 

Upgraded the output wire and eliminated the extra output coils (not needed). 

For those ASR types.....none of these mods are measureable.....the amp will measure the same before and after the mods.

@atmasphere do you care to comment? I think the removal of an output filter for Class-D will be very measurable. I guess when you don't have to worry about compliance testing, anything is possible. @atmasphere what would happen if you hooked these up to a big electrostatic speaker or something like a Magnepan? Aren't these switching at frequencies right in the middle of the AM band and then hooked up to all that wire in the speakers?  Aren't those speakers big capacitors? What is going to happen without those filters?

 

2. Covered the external fuse with copper foil.......noiticeably more musical and correct.....costs nothing. It has another fuse on the power supply inside so this external fuse is not needed.

I think what you meant to say is it is not needed for anything other than safety. If you are going to break EMI compliance, may as well go all in and break safety compliance too.