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New Fosi Audio V3 Mono vs Topping PA5 II vs Topping PA7 (inc. 'Plus' versions)...and Aiyima A70

Sokel

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Do you guys have any example of this music material where it goes from 80 to 115 and back to 80 ? I would like to listen to this.
To give you a better (famous) example here's all 24 beautiful minutes of 1980 Simon Rattle's/Bournemouth Symphony Orchestra Mahler's 10th Fifth Movement Finale:

Simon Rattle.PNG

Played at an absolute humane level,no extremes.
(C) weighting so to capture some low content that it has,fast 125ms capture so the changes are easily visible.
Caveat is that this is the LP,I wish there was a digital way back then to maybe capture it in all it's grandeur (and not mess with it afterwards :mad: )
 

Abstracted

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I can use some advice from the amp gurus here:

I bought a Topping PA7 (not Plus) for $269 USD a month ago. It's been working fine without any issues. No overheating, no abnormally loud switching. I'm using it to drive my front L/R speakers from my Onkyo RZ50 pre-outs. Speakers are Gallo Strada II's. The impedance curve to follow.

Question: I'm still within the return period. Should I return the Topping for reliability concerns, and replace it with two V3 Monos? What are the pros and cons of doing so?

New Record Day -Gallo-Acoustics-Strada-2-Measurements.png
 

staticV3

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Question: I'm still within the return period. Should I return the Topping for reliability concerns, and replace it with two V3 Monos? What are the pros and cons of doing so?
Afaik, there have been no major complaints with the PA5II and PA7.
Seems like Topping have worked out the kinks for round 2 of their Class D Amps.

With your Gallo Stradas, there would be no advantage in power or noise either way.
The PA7 seems a bit cleaner than the V3 Mono WRT multitone distortion.
 

Abstracted

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Afaik, there have been no major complaints with the PA5II and PA7.
Seems like Topping have worked out the kinks for round 2 of their Class D Amps.

With your Gallo Stradas, there would be no advantage in power or noise either way.
The PA7 seems a bit cleaner than the V3 Mono WRT multitone distortion.
Yeah, and the channel separation on the PA7 is excellent as well, which negates having mono blocks.

I initially got caught up with the V3 Mono hype, but in my situation, I now don't see the point to switch.

Which amp will be least affected by the ohms dipping below 4 at >14 KHz?
 
Last edited:

staticV3

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Which amp will be least affected by the ohms dipping below 4 at >14 KHz?
The impedance dip shouldn't be an issue for either of them, as sounds at 14kHz and up are usually very low in level:
Spectrum_of_music_for_reviewing.png

That being said, when hammering the output, the V3 Mono seems to tolerate <4Ω loads better.
 

Matt_Holland

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Yes.

And, comparing Amir's measurements with the TPA3255 datasheet, 5A seems to be sufficient to completely saturate the chip at 4Ω, 48V PVDD

At 2Ω however, the 10A supply may be able to eke out an extra 100 watts or so:
https://www.audiosciencereview.com/...us-versions-and-aiyima-a70.53485/post-1938499
If your speakers drop below 4 Ohm then it might be beneficial to have more current available?

Also, how does EDPR affect things? I’ve seen EDPR curves on some speaker tests suggest equivalent loads at certain frequencies to be horribly low, like sub 2 Ohm? Does this also justify having an overkill PSU?

More is more thought, right ;)
 

SMen

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Anything with a 6” or larger mid-bass driver I’d say.

Have as much clean power as you can afford I say.
Actually, speakers with smaller drivers are less efficient and need more power. Larger drivers can be much more efficient and often require less. 10inch and 12inch Tannoys come to mind, that go super loud with just a couple of watts.
If your speakers drop below 4 Ohm then it might be beneficial to have more current available?

Also, how does EDPR affect things? I’ve seen EDPR curves on some speaker tests suggest equivalent loads at certain frequencies to be horribly low, like sub 2 Ohm? Does this also justify having an overkill PSU?

More is more thought, right ;)
And yes ... my understanding is that going down in Ohms needs more current. However, the V3 mono's using the 3255 in PBTL mode are current limited (I may be corrected here by a resident expert) so actually there is not much difference between a 48volt 5a per unit, and a 48v 10a per unit, which is why Fosi are promoting the 48v 10a with split power cable to use with 2 units.
 

Abstracted

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And yes ... my understanding is that going down in Ohms needs more current. However, the V3 mono's using the 3255 in PBTL mode are current limited (I may be corrected here by a resident expert) so actually there is not much difference between a 48volt 5a per unit, and a 48v 10a per unit, which is why Fosi are promoting the 48v 10a with split power cable to use with 2 units.
Good to know, because I couldn't resist ordering 2 V3 monos + 2 5a PSs (and was debating 2 10a).
I suppose I can always sell the PA7 or or find a use for it elsewhere in the house :p
 

GNK

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I don't understand why people think Aiyima or Fosi is more trustworthy than Topping. Topping's PA5 was a flaw, but that can't be a reason to give credit to Aiyima or Fosi.
Topping has been successfully provided in-China repair service throughout the past, they give a reasonable customer service, and their products do not seem to show how failure rate except for PA5. Maybe people's complaint is about their price tag?
Many Aiyima's products showed channel imbalance problem, and Fosi used to write their product's spec as 300W+300W while providing a 32V 5A power adapter.(tb10d)
My point is that in order to determine the credibility of a company, you need to do objective research over a long period of time and across many products. Which is impossible for a small company with a short history. Then at best you can only have confidence in a company if they guarantee adequate post-sales support (and I haven't seen Aiyima or Fosi do that).
 

DavidM1

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I don't understand why people think Aiyima or Fosi is more trustworthy than Topping. Topping's PA5 was a flaw, but that can't be a reason to give credit to Aiyima or Fosi.
Topping has been successfully provided in-China repair service throughout the past, they give a reasonable customer service, and their products do not seem to show how failure rate except for PA5. Maybe people's complaint is about their price tag?
Many Aiyima's products showed channel imbalance problem, and Fosi used to write their product's spec as 300W+300W while providing a 32V 5A power adapter.(tb10d)
My point is that in order to determine the credibility of a company, you need to do objective research over a long period of time and across many products. Which is impossible for a small company with a short history. Then at best you can only have confidence in a company if they guarantee adequate post-sales support (and I haven't seen Aiyima or Fosi do that).
I think all of these companies have demonstrated that measuring well is an effective way of being noticed in the market. Kudos to them for identifying this path and to ASR and others for encouraging it. Although Topping has impressed with the brilliance of their designs the L90 Discrete and PA5 failure rates were shocking. Fosi has emerged as a company that is remarkably quick to gather market information, engaging even more directly with potential buyers than the others. So far, their reputation is intact and their market responsiveness encourages the perception that they are less likely to risk brand damage or make use of corporate aloofness when problems arise.
 

Aaronb1138

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I don't understand why people think Aiyima or Fosi is more trustworthy than Topping. Topping's PA5 was a flaw, but that can't be a reason to give credit to Aiyima or Fosi.
Topping has been successfully provided in-China repair service throughout the past, they give a reasonable customer service, and their products do not seem to show how failure rate except for PA5. Maybe people's complaint is about their price tag?
Many Aiyima's products showed channel imbalance problem, and Fosi used to write their product's spec as 300W+300W while providing a 32V 5A power adapter.(tb10d)
My point is that in order to determine the credibility of a company, you need to do objective research over a long period of time and across many products. Which is impossible for a small company with a short history. Then at best you can only have confidence in a company if they guarantee adequate post-sales support (and I haven't seen Aiyima or Fosi do that).
Topping's flagship LA90 and LA90D (Discrete) both had significant rates of failure, many more with the latter. The LA90D in particular was probably one of the first sub $1k ultra high quality and relatively high power monoblock (bridgeable from stereo) capable amps and many considered it an endgame amp based on performance. I had planned to buy one and figure out if I needed the power output to buy a second down the line. By the time many readers here were ready to pull the trigger, the early adopters were already reporting issues including potentially speaker destroying static and squeal output.

Teardowns of Topping PA5s showed that they died due to taking a very nice custom discrete amp in place of the typical NE5532s op amp stage and coating it with conformal coating and a lid to the point that it overheated in a just plain dumb and failed attempt to prevent the topology from being copied.

And then there is the hassle that Topping availability in North America and Europe is all over the place and through Shenzen Audio, KGUSS (Amazon), and other sellers with variable return and RMA policies. At $800 for an LA90D, consumers want to buy direct from the manufacturer* and in some cases get RMA cross-shipping or at the very least, fast RMA service with paid shipping, not months without product after having to foot shipping bills. (*or a vendor with proper support)

All of that said, I like Topping and may revisit their products in the future, but you can't fault people from being reluctant with close enough offerings more widely available and better reliability and service history. A pair of LA90Ds would be my endgame best bang for the buck amp setup for stereo, though that lead is narrowing.

Failures are far less tolerated than spec sheets we know will have some fibbing. Spec sheet liberties can be resolved by waiting for a competent review like Amirs' here and managing one's own expectations. Burned out bricks cannot be resolved so directly.
 

Guddu

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Topping's flagship LA90 and LA90D (Discrete) both had significant rates of failure, many more with the latter. The LA90D in particular was probably one of the first sub $1k ultra high quality and relatively high power monoblock (bridgeable from stereo) capable amps and many considered it an endgame amp based on performance. I had planned to buy one and figure out if I needed the power output to buy a second down the line. By the time many readers here were ready to pull the trigger, the early adopters were already reporting issues including potentially speaker destroying static and squeal output.

Teardowns of Topping PA5s showed that they died due to taking a very nice custom discrete amp in place of the typical NE5532s op amp stage and coating it with conformal coating and a lid to the point that it overheated in a just plain dumb and failed attempt to prevent the topology from being copied.

And then there is the hassle that Topping availability in North America and Europe is all over the place and through Shenzen Audio, KGUSS (Amazon), and other sellers with variable return and RMA policies. At $800 for an LA90D, consumers want to buy direct from the manufacturer* and in some cases get RMA cross-shipping or at the very least, fast RMA service with paid shipping, not months without product after having to foot shipping bills. (*or a vendor with proper support)

All of that said, I like Topping and may revisit their products in the future, but you can't fault people from being reluctant with close enough offerings more widely available and better reliability and service history. A pair of LA90Ds would be my endgame best bang for the buck amp setup for stereo, though that lead is narrowing.

Failures are far less tolerated than spec sheets we know will have some fibbing. Spec sheet liberties can be resolved by waiting for a competent review like Amirs' here and managing one's own expectations. Burned out bricks cannot be resolved so directly.

I am not defending Topping here but we can't escape from responsibility as a buyer as well, can we?
I personally feel that many are buying a product after seeing good measurements and reviews, however stability or durability of the product is ways a question for pretty much every new products.
While choosing a brand like Topping (and others) which doesn't have local servicing available everywhere, we (kind of) accept the fact that there may be issues in getting RMA or a repair. Major reason is price because we generally seem to get better price vs performance value (at least in terms of measurements), and somewhere we know that we aren't paying huge amount for after sales services.
Topping, in their local manufacturing and primary market location at least, are providing decent after sales support. Their RMA policies for outside locations (like US) are clear as well.
Having said all that, I am a Topping user and I also share the pain when something breaks and services aren't available the way it should be. However I know what I am getting into when I buy their product now.

I don't understand why people think Aiyima or Fosi is more trustworthy than Topping. Topping's PA5 was a flaw, but that can't be a reason to give credit to Aiyima or Fosi.
Topping has been successfully provided in-China repair service throughout the past, they give a reasonable customer service, and their products do not seem to show how failure rate except for PA5. Maybe people's complaint is about their price tag?
Many Aiyima's products showed channel imbalance problem, and Fosi used to write their product's spec as 300W+300W while providing a 32V 5A power adapter.(tb10d)
My point is that in order to determine the credibility of a company, you need to do objective research over a long period of time and across many products. Which is impossible for a small company with a short history. Then at best you can only have confidence in a company if they guarantee adequate post-sales support (and I haven't seen Aiyima or Fosi do that).

Because they haven't burned by them for a product which has failed yet and could not get timely response with enough attention to support.
Also think of the customer's expectations from Topping when they see a very well measured product on much lower money than others, and what happens when that breaks.
 

Dave Bullet

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My guess is the Gala Stradas likely employ a LC parallel notch to maybe tame the tweeter with a FR rise above 10KHz. Looking at the slope. impedance increases again above 20KHz. Not much power will be going into them, but I don't know much about oscillation problems (if any) with Class D amps (or any class) at low impedance above 20KHz
 

audioje

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I am keeping my pa5 ii. For those who need more power, v3 mono seems to be the one.
 

Talisman

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I don't understand why people think Aiyima or Fosi is more trustworthy than Topping. Topping's PA5 was a flaw, but that can't be a reason to give credit to Aiyima or Fosi.
Topping has been successfully provided in-China repair service throughout the past, they give a reasonable customer service, and their products do not seem to show how failure rate except for PA5. Maybe people's complaint is about their price tag?
Many Aiyima's products showed channel imbalance problem, and Fosi used to write their product's spec as 300W+300W while providing a 32V 5A power adapter.(tb10d)
My point is that in order to determine the credibility of a company, you need to do objective research over a long period of time and across many products. Which is impossible for a small company with a short history. Then at best you can only have confidence in a company if they guarantee adequate post-sales support (and I haven't seen Aiyima or Fosi do that).
Quite simply there have been a myriad of problems with various Topping products culminating in the disaster of the first PA5 and customer service, and virtually no complaints about Aiyima and Fosi.
I would say there are no strange conspiracy theories to apply. People give more trust to brands that have shown they deserve it.
 

jayapple

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This is the main reason why I'm considering exchanging my open box PA7 (non-plus for $269) for 2 Fosi's.

Although, I have seen very few complaints from PA7, and PA5 II, owners regarding reliability.
I also like this modular design, as it can be easily replaced if it breaks. However, TOP has some quality stability issues, and once it breaks, the entire system becomes unusable.

Besides, I hope FOSI can design a more aesthetically pleasing system, as it is modular and can be made more visually appealing with two, four, or eight modules as a complete system.
 

TikBLang

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I'm back, and contemplating on considering the v3 mono. this amp would have been my choice if they put two in a 9-inch wide desktop format (half of the 19" inch rack) with an option to order either a balance or RCA input. No 'pots' to save cost and an option to order the high quality 48V/10A brick.
 
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