Premium Audio Mini GaN 5 Review (Stereo Amplifier)

[DanielT]

These threads always derail shortly after starting. The pattern repeats itself across the board.

Thanks for taking the time and money to do this. If I read your post correctly - unit was sent directly to Amir for testing?

That escalated quickly...

 

[mdsimon2]

Don't you think linearity across several parameters should be applauded over big success in few of them?

What's the point of having a low noise DAC when you're faced with non-linear distortion in the form of an ESS hump?

I'm not saying that all analog circuits should have their noise floor raised so that flaws are swept under the rug but i think it's important that when we're talking about Hi-Fi that things like load dependency and frequency dependency should be prioritized.

I am saying I do not care about THD+N frequency dependence if THD+N is low in an ABSOLUTE sense across all frequencies. I do not see why you would want worse THD+N performance just because it has less frequency dependence.

To use your ESS hump example I would prefer a DAC that has an ESS hump but has better IMD across all levels than one that does not show the ESS hump but has worse IMD performance across all levels.

Michael

 

[Bob from Florida]

Yes, with Amir’s name as the recipient. If it’s great, he posts it to me, if not he posts it back to the manufacturer after they authorise the return. That seems fair to me for a small manufacturer shipping direct. For stuff off Amazon etc I think it would be fair to do similarly but without the intent to keep at all.

Since he had problems of a functional variety on start up - this stimulates my mind in the DOA direction. Hopefully the OEM will address this. Despite all the heat sink concerns it did seem to have potential.

 

[Bob from Florida]

That escalated quickly...

LOL

 

[mcdn]

Since he had problems of a functional variety on start up - this stimulates my mind in the DOA direction. Hopefully the OEM will address this. Despite all the heat sink concerns it did seem to have potential.

Highly unlikely - there are no reference designs from anyone that perform as this device was claimed to. Not Infineon, not TI, not Hypex, not Purifi, not anyone. Basic thermodynamics makes the claimed performance pretty much impossible in the enclosure size even without the floating heat sink silliness.

 

[abdo123]

To use your ESS hump example I would prefer a DAC that has an ESS hump but has better IMD across all levels than one that does not show the ESS hump but has worse IMD performance across all levels.

why would you prefer the one with the ESS hump when the fact that the hump is non-linear will make it more likely to be actually audible?

I'm genuinely curious as this is a very bizare opinion from my perspective.

 

[DanielT]

If you know how works and have time and feel to help a newcomer. Link to new thread below.Did not want to take it in this thread. OT and that ...

Does the same brand, model of amplifier, speakers measure the same?

If you take X number of the same amplifier and speakers (brand model) and measure them. Given that there is nothing wrong with the amplifiers / speakers, how much do they measure the same then? New amplifiers / speakers namely. I can guess that it differs depending on the quality of the...

audiosciencereview.com

 

[tomtoo]

I dont get it?
This thing is far away from proclaimed parameters.
Headless panther.

Imo @amirm is much to soft with this. If i buy a car where it is claimed it has 300HP but has only 100HP on a test stand.
Headless panther.

Its not on @amirm to look where the problem is. Its on the manufacturer to look for that, and to explain it to the public.

 

[abdo123]

@boXem | audio @mdsimon2

the newest GaN based amplifier by @orchardaudio beats the Purifi in terms of THD frequency dependency. Even in absolute terms with regard to residual noise the Purifi has 11.5 uV vs the Orchard's 44 uV. GaN has a lot of promise and i don't think it's a good idea to disregard them because of one phony 'designer'.

 

[mdsimon2]

why would you prefer the one with the ESS hump when the fact that the hump is non-linear will make it more likely to be actually audible?

I'm genuinely curious as this is a very bizare opinion from my perspective.

I am saying I prefer DAC with lower IMD (across all drive levels) and hence lower non-linear distortion across all drive levels.

I would need to see some evidence that says variation in distortion is more important than absolute low level of distortion. I know that the brain can do weird things so I understand that there may be some threshold where this occurs but I have not personally seen anything like this.

Michael

 

[Bob from Florida]

Highly unlikely - there are no reference designs from anyone that perform as this device was claimed to. Not Infineon, not TI, not Hypex, not Purifi, not anyone. Basic thermodynamics makes the claimed performance pretty much impossible in the enclosure size even without the floating heat sink silliness.

I went back and reread the beginning of this review. The trouble Amir had getting it to function is my basis for thinking DOA. The OEM being a small company probably needs to send another unit to prove their power output claims. The heat sinks criticisms are silly. Not meeting published specs by large margins are more concerning.

 

[PeteL]

Don't you think linearity across several parameters should be applauded over big success in few of them?

What's the point of having a low noise DAC when you're faced with non-linear distortion in the form of an ESS hump?

I'm not saying that all analog circuits should have their noise floor raised so that flaws are swept under the rug but i think it's important that when we're talking about Hi-Fi that things like load dependency and frequency dependency should be prioritized.

Hi think the point is, if noise is High, you wouldn't see the ESS bump, you wouldn't see the frequency dependancies, and noise is the most audibly noticable flaw in a design, in a day and age where massive digital attenuation is often used combined with not always perfect gain structure.

 

[mdsimon2]

@boXem | audio @mdsimon2

the newest GaN based amplifier by @orchardaudio beats the Purifi in terms of THD frequency dependency.Eeven in absolute terms with regard to residual noise the Purifi has 11.5 uV vs the Orchard's 44 uV. GaN has a lot of promise and i don't think it's a good idea to disregard them because of one phony 'designer'.

Nice!

Any idea what bandwidth was used in the test? Purifi looks quite a bit worse than what is shown in the datasheet for 1 W which as posted by @boXem | audio was THD+N less than 0.001% across 20-20000 (although datasheet is using 4 ohm load). Would also be interesting to see how things look at other power levels.

I am not dismissing the technology but I personally find absolute performance arguments (as you just posted) much more compelling than "well behaved" THD+N with bad absolute performance, YMMV.

Michael

 

[abdo123]

Nice!

Any idea what bandwidth was used in the test? Purifi looks quite a bit worse than what is shown in the datasheet for 1 W which as posted by @boXem | audio was THD+N less than 0.001% across 20-20000 (although datasheet is using 4 ohm load). Would also be interesting to see how things look at other power levels.

I am not dismissing the technology but I personally find absolute performance arguments (as you just posted) much more compelling than "well behaved" THD+N with bad absolute performance, YMMV.

Michael

you can read the full review here: https://audioxpress.com/article/fre...d-audio-bosc-and-purifi-audio-eigentakt-eval1

 

[P_M]

It's not worth GaN...lol

yeah I wouldn't give gan for it....lol

 

[boXem]

Nice!

Any idea what bandwidth was used in the test? Purifi looks quite a bit worse than what is shown in the datasheet for 1 W which as posted by @boXem | audio was THD+N less than 0.001% across 20-20000 (although datasheet is using 4 ohm load). Would also be interesting to see how things look at other power levels.

I am not dismissing the technology but I personally find absolute performance arguments (as you just posted) much more compelling than "well behaved" THD+N with bad absolute performance, YMMV.

Michael

The data I posted is the amplifier module alone with a certainly very nice power supply.
The data posted by @abdo123 is a complete amplifier, with Purifi demo front end and an Hypex power supply. This degrades the residual noise performance by about 12 dB, as a starter.

 

[rdenney]

Regarding the question of whether Amir should have offered the company a chance to respond before publication. The journalist standards argument does not hold up because it conflates different sorts of journalism.

If a story is investigative and/or involves criminal activity, asking for comment is convention.

But not for many other forms of journalism. For good reason. No film or music critic /journalist is under obligation to let the film maker, etc respond first before posting a negative review. for obvious reasons.

Less subjectively, and more relevant here, If a reviewer at at car magazine has a door handle pop off or the car didn’t start properly, or was unable to reach mpg, speed or come close to advertised horse power specs they have no obligation to let the manufacturer respond before publishing a review stating these experiences and measurements. They are reporting their findings as journalists.

Amir is not a credentialed journalist. He is however a writer and has a “public” profile of sorts.

But Nor is he a free QC or testing firm for a company.

He gets a product. He tests said product. He reports his findings. His ethical obligation is to be reasonably conscientious (not exhaustively) in methodology and to not dissimulate the results of his measurements. And that is all. In NO WAY is there any need to contact the company before publishing such findings. None. Nada. Zilch.

Nor is there any imperative to retest, or even engage a company. He is independent and maintaining that is important. It is above and beyond to do so. That he has does this before does not oblige him to do so always.

Also, If a device acts up when plugged into an industry standard testing platform when the vast majority have no such issue, that is not Amir’s problem. Indeed, he could have stopped the review after the first paragraph and given it a form of negative recommendation based solely on it not behaving properly and the operation of its protection circuitry. He is not here to troubleshoot another company’s device.

Lastly, this device has “floating heat sinks”. That alone deserves a headless panther. Like putting speaker wires on mahogany risers. Or putting a battery with one terminal connected (or 2 terminals for that matter) on a speaker cable. Amir is too much a gentlemen however and tests it anyway in good faith. Thank you

I generally agree, but don’t you think that implying the manufacturer made up the specs out of the whole cloth is an implied accusation of misrepresentation and fraud? That is certainly how people posting in this thread are taking it. Mail such products through the US mail and see if it isn’t a criminal matter.

Rick “words mean things” Denney

 

[abdo123]

The data I posted is the amplifier module alone with a certainly very nice power supply.
The data posted by @abdo123 is a complete amplifier, with Purifi demo front end and an Hypex power supply. This degrades the residual noise performance by about 12 dB, as a starter.

Can the choice of power supply effect THD% Data?

 

[pma]

Can the choice of power supply effect THD% Data?

AIYIMA A07 TPA3255 Amplifier Measurements and Review - LM4562 (and OPA2134) option

AIYIMA A07 TPA3255 Amplifier Measurements LM4562 option I received my A07 yesterday, on January 6, 2021, shipped from Italy. Purchased at Amazon.de and as stated on their website, it arrived without a power supply. I am testing the A07 with 2 different power supplies. One of them is a linear...

www.audiosciencereview.com

Yes, it affects THD+N, see the link above, regulated x unregulated PSU.

 

[abdo123]

Yes, it affects THD+N, see the link above, regulated x unregulated PSU.

What about THD on its own (my actual question) ?