[Gallium Nitride amplifier] Impressions of the Mini Gan 5 by Premium Audio, pictures / video inside

[Tks]

I also think copper is better here.

Slower than gold, but very reliable.

Just because I'm probably missing the joke, but the gold heatsinks aren't actual gold. I said copper from a non-joking perspective simply because it's a great heatsink material (though a bit heavy compared to aluminum). Unfortunately, it seems the makers would rather pick up some gold painted passive heatsinks rather than something more serious with perhaps heatpipes or vapor chambers. Kinda sad really.

 

[antennaguru]

We could debate for hours on transparency ... I tend to try the amps and I make my idea afterwards.
that being said, if you like numbers, take a look at this comparison:

https://docs.google.com/spreadsheets/d/1ZlTOYxmPs938gqHjtDABkWS-MApu7uJjzIGnJ2Elm6Y/edit#gid=0

That is an amazing list compilation of 425 amplifiers. A shame IMO the list is stack ranked by SINAD though, as IMO that's a misleading "Single Figure of Merit". Who's even going to hear the difference between the top ranked at 118dB and the list's median ranked (212 down the list) of 76dB SINAD?

I get that a single figure of merit is convenient for listing purposes, but IMO it only reflects who's willing to turn up their negative feedback to get a higher spot on such a list.

To me it's like losing your keys at night and then only searching under the streetlight for them because the visibility is better there...

 

[wwenze]

misleading "Single Figure of Merit"

That's what I told my wife. She wasn't convinced.

 

[daniboun]

Is GaN going to become price competitive someday soon or is it something that can't be made cheaper?

Yes, just take a look @ the RevoGan 8020
it is a Russian Mono Gan module

https://vk.com/wall-200674514

Given @ $270. / per Module

 

[daniboun]

Just because I'm probably missing the joke, but the gold heatsinks aren't actual gold. I said copper from a non-joking perspective simply because it's a great heatsink material (though a bit heavy compared to aluminum). Unfortunately, it seems the makers would rather pick up some gold painted passive heatsinks rather than something more serious with perhaps heatpipes or vapor chambers. Kinda sad really.

I had a thermal camera under my elbow ... I just returned it, a shame! I could have made up my mind. In any case, I can tell you that the amp heats up very, very little and less than my Purifi.

With my Purifi amp :



hebergeur photo

 

[Tks]

I had a thermal camera under my elbow ... I just returned it, a shame! I could have made up my mind. In any case, I can tell you that the amp heats up very, very little and less than my Purifi.

With my Purifi amp :

hebergeur photo

Fair enough. I'm just quite anal about thermal performance in many audio devices because this industry doesn't take it serious. Even if a device isn't breaching some sort of operating temperature range of the components, it's simply a matter of fact that I'd prefer overbuilt thermal solutions since most people purchase audio devices they hope will serve them for years. And not have designs one would see in throwaway devices.

Then again, with how cheap and how tight electronics margins are, I guess things failing more consistently/frequently is somewhat a requirement of this sort of economy we live in the present day.

By that Purifi though, yeesh.

 

[antcollinet]

It's a subjective catch all. There is no line on a meter or number on a dial where a "transparency" light turns on. One person's view is different to another's. No detail on which characteristics are included or excluded. No detail on respective weightings of contributing factors.

It's a buzzword thrown around by people trying to sound intelligent, but it has the opposite effect.

Isn't it an objective "THD+N below the level of audibility"? That is how our host uses it if I'm understanding the reviews correctly.

 

[daniboun]

I'm just quite anal about thermal performance in many audio devices because this industry doesn't take it serious. Even if a device isn't breaching some sort of operating temperature range of the components, it's simply a matter of fact that I'd prefer overbuilt thermal solutions since most people purchase audio devices they hope will serve them for years. And not have designs one would see in throwaway devices.

This is not wrong) hoping in any case that my Mini Gan holds in time, that's all I ask)

 

[VintageFlanker]

It's a buzzword thrown around by people trying to sound intelligent, but it has the opposite effect.

Someone has to tell our host how stupid he looks, then...

If I declare my amplifier "transparent", what does that tell you, specifically?

Transparency does mean what it means: once you've got similarly-featured amps for your needs (that includes power) and you cannot audibly distinguish one from the other(s), whatever how hard you try (or want) it.

Sure, that doesn't exclude that all amps would be in fact equally bad, but let's assume we already have the data to tell they're measuring good "enough".

And no, I'm not taking to the "all amps sound the same" road, because they don't.

 

[mcdn]

Maybe the flying heat sinks are there to hide something embarrassing? There certainly isn’t space under them for the claimed hundreds of discrete components.

 

[daniboun]

Maybe the flying heat sinks are there to hide something embarrassing? There certainly isn’t space under them for the claimed hundreds of discrete components.

Don't think so, it is a design update issue for me.
The amp sounds extremely good.

 

[daniboun]

Hi,

Got the answer from ClassDaudio :

"Yes, I already addressed this in the last email. We have been working on this amp for over two years. We did use to have the heatsink over the GaN FETs and using thermal compound and also thermal pads. What we found kind of by accident is the amp actually ran a little cooler having the heatsink raised above the FETs like it is and drawing a little heat away from the PCB. The GaN FETs can run at over the rated power without a heatsink, but taking some of the heat from the PCB does help with cooling. This is not a design problem or error."

So you can compare VS again the one from Premium Audio :

"The inductors were changed because as most know, there is a world-wide chip and parts shortage. The original coils we used were back ordered for months. These toroids have the exact same performance as the others we used. We did just got a few thousand pieces in (that were ordered for months). The toroids actually run a little cooler and performance is exactly the same. As for the as you called it flying heatsinks, we originally had them mounted on the FETs with thermal pads and other, but found the amp actually runs a little cooler like this. The heatsink raised like this draws some heat from the PCB and the FETs can run at rated power without heatsink. "

 

[Raindog123]

 

[Matias]

That's a impressive and comprehensive list. Did you make that?

I created and maintain that list. Don't forget the 2nd tab with the best value "confetti charts" too.
https://docs.google.com/spreadsheets/d/1ZlTOYxmPs938gqHjtDABkWS-MApu7uJjzIGnJ2Elm6Y/edit#gid=0

 

[daniboun]

I created and maintain that list. Don't forget the 2nd tab with the best value "confetti charts" too.
https://docs.google.com/spreadsheets/d/1ZlTOYxmPs938gqHjtDABkWS-MApu7uJjzIGnJ2Elm6Y/edit#gid=0

Very very nice work ) you re the best man )))))))))))

 

[Matias]

Very very nice ) you re the best man )))))))))))

I am noone. But to @sweetchaos I raise my beer and salute, he has the most comprehensive lists of lists.

 

[mcdn]

Hi,

Got the answer from ClassDaudio :

"Yes, I already addressed this in the last email. We have been working on this amp for over two years. We did use to have the heatsink over the GaN FETs and using thermal compound and also thermal pads. What we found kind of by accident is the amp actually ran a little cooler having the heatsink raised above the FETs like it is and drawing a little heat away from the PCB. The GaN FETs can run at over the rated power without a heatsink, but taking some of the heat from the PCB does help with cooling. This is not a design problem or error."
…

What’s puzzling to me is how anyone with the ability to design and manufacture a novel discrete class D amp, could at the same time believe that a heat sink could be more effective when not in contact with the thing it’s meant to cool. Anyway, @daniboin could you remove one of the heat sinks and take a photo?

 

[MaxBuck]

What’s puzzling to me is how anyone with the ability to design and manufacture a novel discrete class D amp, could at the same time believe that a heat sink could be more effective when not in contact with the thing it’s meant to cool. Anyway, @daniboin could you remove one of the heat sinks and take a photo?

I think the idea is that the heat sink (better described as a heat exchanger) is in conductive contact with the hot parts, regardless of appearances, and that its configuration enhances radiative transfer to the environment.

 

[daniboun]

What’s puzzling to me is how anyone with the ability to design and manufacture a novel discrete class D amp, could at the same time believe that a heat sink could be more effective when not in contact with the thing it’s meant to cool. Anyway, @daniboin could you remove one of the heat sinks and take a photo?

Since the amp is under warranty and the inductors are are glued and damped by the Heatsinks, I could not do it immediately sorry.

 

[daniboun]

I think the idea is that the heat sink (better described as a heat exchanger) is in conductive contact with the hot parts, regardless of appearances, and that its configuration enhances radiative transfer to the environment.

It can be a rational response) Honestly the correct answer is going to be difficult to find, unless I can get my hand on a thermal camera to understand the thermal flow under full load when listening.