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Fosi v3 Mono - User Impressions | Owner's Thread

Hi all. I have 2 x PSB Imagine Surround S bipoles for side surrounds, yet to be installed.
(Presonus actives for all other channels).
These side surrounds will be 1.8m on either side of the MLP in a 3.5m wide x 5.5m deep room.
Pre-pro will be an Anthem AVM70, balanced cables to the amp.

How would these compare to the Topping PA5 II or SMSL AO200 Mk2 ?

Thanks in advance!
Audibly? Sound identical, or so close as not to matter.

Then you just need to compare the power specs.
 
Hi all. I have 2 x PSB Imagine Surround S bipoles for side surrounds, yet to be installed.
(Presonus actives for all other channels).
These side surrounds will be 1.8m on either side of the MLP in a 3.5m wide x 5.5m deep room.
Pre-pro will be an Anthem AVM70, balanced cables to the amp.

How would these compare to the Topping PA5 II or SMSL AO200 Mk2 ?

Thanks in advance!
Any of your picked amplifiers will just work fine, in general. However, SMSL AO200 II will have slightly lower power availability then others.
Here are few things to consider:
- All non-PFFB TPA3255 amplifiers have more or less similar performance, load-dependency shouldn't be a concern and you will have AVR/processor's room correction as well
- All PFFB TPA3255 amplifiers have more or less similar performance, technically superior but shouldn't present any real benefit in this used case
- Ideally, I would like to use power amplifier without any additional processing, not even volume knob if possible

Fosi v3 mono pair is a good choice here, and Fosi ZA3 is equally good as well if sticking with Fosi. Both have auto or triggered ON/OFF.
I would personally avoid PA5 II or AO200 II, in this used case.
 
Hello Everybody. I also joined at the kickstarter campaign and chose double Muses chips at checkout because I dont need the cables or the tools at all. But on the one hand I did not realise that there are 2 chips to be swapped per amp and on the other hand do not think the muses make any relevant difference worth their price but might at least be easy to sale. Maybe someone of the V3 owners wants to go all in with 4 of them.
When throwing the muses out, what would be the best and most reasonable op amp to throw in? Stock seems to be NE5532 which is rather old and cheap, could it be worth getting for example some OPA2134 for their far better THD+N? Any other suggestions of NE5532 compatible op amps?
 
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Just saying...
I ended up buying a pair of 2nd hand Marantz MA6100 monoblocks, plus an Integra DTR 7.8 to try out dual-monopole mode with my PSB Imagine Surround S bipoles

We won't be able to press them into service until the room is finished in a couple of months.

I suspect both units would easily beat the F3... Thoughts?
 
Just saying...
I ended up buying a pair of 2nd hand Marantz MA6100 monoblocks, plus an Integra DTR 7.8 to try out dual-monopole mode with my PSB Imagine Surround S bipoles

We won't be able to press them into service until the room is finished in a couple of months.

I suspect both units would easily beat the F3... Thoughts?

Best if you remain convinced of that and don't try the comparison :)
 
Hello Everybody. I also joined at the kickstarter campaign and chose double Muses chips at checkout because I dont need the cables or the tools at all. But on the one hand I did not realise that there are 2 chips to be swapped per amp and on the other hand do not think the muses make any relevant difference worth their price but might at least be easy to sale. Maybe someone of the V3 owners wants to go all in with 4 of them.
When throwing the muses out, what would be the best and most reasonable op amp to throw in? Stock seems to be NE5532 which is rather old and cheap, could it be worth getting for example some OPA2134 for their far better THD+N? Any other suggestions of NE5532 compatible op amps?
Leave stock in place. There is no audible benefit to be had rolling op amps in line level circuits.
 
Leave stock in place. There is no audible benefit to be had rolling op amps in line level circuits.
I would leave them in place if I HAD them. But because of choosing the muses I suppose not to get all 4 5532s. And if I have to get some OP amps anyway this would be a chance to go for something newer / better. Would not mind to spend a few Euros per chip instead of 2€ for all 4.
 
I would leave them in place if I HAD them. But because of choosing the muses I suppose not to get all 4 5532s. And if I have to get some OP amps anyway this would be a chance to go for something newer / better. Would not mind to spend a few Euros per chip instead of 2€ for all 4.
That would defeat the whole purpose of these amps.
Their strength is price,ruin that and be left wondered why you didn't get a nicer amp with the sum.
 
I would leave them in place if I HAD them. But because of choosing the muses I suppose not to get all 4 5532s. And if I have to get some OP amps anyway this would be a chance to go for something newer / better. Would not mind to spend a few Euros per chip instead of 2€ for all 4.
You can do that of course. But it still won't sound better, and you'll have spent those few EUR per chip for nothing.

I'd also be surprised if FOSI are customising the amps. Pretty certain you'll get a stock amp with the Muses separate.
 
If I get the amps fully equipped with the 5532s they will remain as they are, sure. We'll see. Thanks so far.
 
That would defeat the whole purpose of these amps.
Their strength is price,ruin that and be left wondered why you didn't get a nicer amp with the sum.
I see Fosi focusing on opamp rolling a lot on their FB space, and indeed getting some attraction.
Even if it is nothing but business strategy to keep the audience of that (opamp rolling) likings in check, sending amps without the stock & tested opamp seems a bit strange.
@jannek I would have bought the stock and tested ones if I were you, or even asked Fosi to send them.
If you are a believer in opamp rolling then you are surely free to test whatever you like with the risk of undesired results, there are plenty discrete ones (even exact copy of expensive ones) available on Aliexpress or similar platforms.
 
I see Fosi focusing on opamp rolling a lot on their FB space, and indeed getting some attraction.
Even if it is nothing but business strategy to keep the audience of that (opamp rolling) likings in check, sending amps without the stock & tested opamp seems a bit strange.
@jannek I would have bought the stock and tested ones if I were you, or even asked Fosi to send them.
If you are a believer in opamp rolling then you are surely free to test whatever you like with the risk of undesired results, there are plenty discrete ones (even exact copy of expensive ones) available on Aliexpress or similar platforms.
Just to add….
On A70’s user/owner’s thread, a user has reported some strange sound issues while triggered OFF operation happens.
Again, an opamp change driven issue.
 
If I get the amps fully equipped with the 5532s they will remain as they are, sure. We'll see. Thanks so far.

The muses02 was an additional reward when reaching the stretch goal. It only applies to backers buying two or more units. The wording clearly states “additional”, and there is really no point to (and a logistical headache) sending two different configurations to each customer.

From update #5, may 8:

IMG_2073.jpeg
 
Just to add….
On A70’s user/owner’s thread, a user has reported some strange sound issues while triggered OFF operation happens.
Again, an opamp change driven issue.

Almost certainly the mod has created an unstable amp.
 
Leave stock in place. There is no audible benefit to be had rolling op amps in line level circuits.
Wrong, there is benefits from different opamp since the are built different, with different voltage and different noise rate.
I been rolling opamps for 3 years now and depends on your equipment some sounds better in some amplifier with tpa3255 and some make little improvement. Like for Aiyima07 Max the Muses02 is better and for Fosi V3 stereo sparkos lab ss3602, same go for geshelli akm4499 sparkos ss3602 is superior than Muses02, lme49860, opa2604, opa1656 and opa1692
 
Wrong, there is benefits from different opamp since the are built different, with different voltage and different noise rate.
I been rolling opamps for 3 years now and depends on your equipment some sounds better in some amplifier with tpa3255 and some make little improvement. Like for Aiyima07 Max the Muses02 is better and for Fosi V3 stereo sparkos lab ss3602, same go for geshelli akm4499 sparkos ss3602 is superior than Muses02, lme49860, opa2604, opa1656 and opa1692

Carry out a properly controlled, properly level matched, properly blind, and statistically relevant blind test and you'll find any differences you think you are hearing will disappear.

Your youtube snake oil merchant would find the same if he blind tested also.

Performance of even the cheapest audio op amps are already better than human hearing for line level stuff. As evidenced by the fact that every audio recording you've ever listened to has already gone through dozens of them in the studio gear.
 
what's funny to me is that people are completely unable to approach it from a technical perspective and think that if you put a more expensive component into the system, suddenly the whole system will be better. As if, for example, putting DDR5 RAM into a 10-year-old PC would help it somehow. Or in other words, your Ferrari won't go faster because you change one of its wheels to a larger one. Your Ferrari will go the fastest on the wheels for which it was designed.
 
Carry out a properly controlled, properly level matched, properly blind, and statistically relevant blind test and you'll find any differences you think you are hearing will disappear.

Your youtube snake oil merchant would find the same if he blind tested also.

Performance of even the cheapest audio op amps are already better than human hearing for line level stuff. As evidenced by the fact that every audio recording you've ever listened to has already gone through dozens of them in the studio gear.
The snake oil you tuber don't care about the sales of any opamp they don't own those companies.
15 years on this web page talking about opamp is snake oil. And thousand of user talking about opamps is snake oil.
 
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