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

ScofieldKid

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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.

WRT to the power supply issue, if I were running those, I personally would get two of the 48v 5a supplies. I mean, half the point of doing mono is the flexibility of having the capability to locate the amp near the speaker. Or the benefits of having independent components.

In terms of the 10A being useful, Williston Audio Labs did a comparison of supply on resistive loads. And Erin did some of this stuff as well on Erins Audio Corner but on the Za3 in that case. So it does seem like the 48v 5a per-box is fairly optimal.

Reminder on the Pa7 Plus, is the 52v 6.5a. A different beast, but it does have some of the features you are asking for. Not sure how good the Aiyima A70 will be when it drops, but that's the other form factor that looks pretty interesting. Availability, form factor, features are all things I look at.
 

TikBLang

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WRT to the power supply issue, if I were running those, I personally would get two of the 48v 5a supplies. I mean, half the point of doing mono is the flexibility of having the capability to locate the amp near the speaker. Or the benefits of having independent components.

In terms of the 10A being useful, Williston Audio Labs did a comparison of supply on resistive loads. And Erin did some of this stuff as well on Erins Audio Corner but on the Za3 in that case. So it does seem like the 48v 5a per-box is fairly optimal.

Reminder on the Pa7 Plus, is the 52v 6.5a. A different beast, but it does have some of the features you are asking for. Not sure how good the Aiyima A70 will be when it drops, but that's the other form factor that looks pretty interesting. Availability, form factor, features are all things I look at.
"I personally would get two of the 48v 5a supplies"
This makes sense. if one goes bad, at least you can listen to one channel audio. When will this be available for purchase?
 

ScofieldKid

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"I personally would get two of the 48v 5a supplies"
This makes sense. if one goes bad, at least you can listen to one channel audio. When will this be available for purchase?
For the Fosi V3 Mono, I think you have to go through the Kickstarter page. Looks like it is open for 3 more weeks.
For the Topping you can get the PA7 or PA7 Plus from various places now.
For the Aiyima A70, they are just finishing up production. So we're waiting for that one.

Only thing to add, you could go super max, and run two of the 48v 10a(max). But I personally wouldn't do that, as I think these boxes are already running near the limits. It is something some folks may try though.
 

dagfinn

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For me...

Fosi - no gain control is a drawback when gain staging. Having two powersupplies is more messy. No local dealer/warranty.
Aiyima - also no local dealer and no local warranty. Not the best performer, on paper (but probably good enough).
Topping has gain control and a friendly local dealer, which means I get 5 years warranty by law :). $300/700 for SOTA performance...
I own 2x PA5II and one PA7 Plus, all running as part of a 4-way active system. Very happy about them :).
 

Rob_in

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Anyone else asks for another amp they can do it themselves. :rolleyes:;)
I know you're not going to like this, but... ;)

When looking at the class of amps mentioned here, while power/noise/load dependency seem similar I prefer the look of distortion measurements from MPA-S250NC. Eg:


... or if I've read this wrong, someone gonna tell me the differences will be inaudible or one of the others is actually better for some reason?
 

Ace123

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That will depend on the tolerance and heat extraction of those parts of the design which are under strain when heavily loaded. This usually includes PSU components and output devices. If the manufacturer significantly over-specs the components such that they are not driven beyond their tolerance and are not overheated, then heavy use should be not have a significant impact on longevity.

In practice, picking component tolerance is a cost/benefit task and so heavy loading may reduce lifetime. Meanwhile, poor heat extraction will definitely have a longevity consequence.
I'm very concerned that the heat that the A70 is throwing off is going to fry everything and shorten its life span considerably. It's interesting to see the good reviews on some of the FOSI products because I hated the one I bought, the DA2120C.
 

Guddu

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I'm very concerned that the heat that the A70 is throwing off is going to fry everything and shorten its life span considerably. It's interesting to see the good reviews on some of the FOSI products because I hated the one I bought, the DA2120C.
Is it really that concerning?
What’s the case temp on normal use? Is it possible for you to check with infrared thermometer?
 

sarieri

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I think the crosstalk measurement and the pattern of Multitone is much more important than SINAD. In terms of PFFB implement, Topping is doing 19dB feedback there which is second to nobody as far as I know.
 

Ace123

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Is it really that concerning?
What’s the case temp on normal use? Is it possible for you to check with infrared thermometer?
105 degrees fahrenheit on the the top, 110 degrees on the sides and bottom. I've put it up on blocks now.
 

ScofieldKid

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