The idea was to have multichannel audio still functional. I am not sure if you could have left and right on zone 2 preouts while utilizing all the other surround speakers. Granted i have never attempted it yet.
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Fosi Audio V3 Mono Amplifier Review
- Thread starter amirm
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After looking at the service manual i dont think this is in my skillset. While i do know how yo solder i have no clue where i would need to tap into.
Cal_Cobra
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Fosi just added a V3 FAQ on their Kick Starter page: https://www.kickstarter.com/projects/fosiaudio/fosi-audio-v3-mono-power-amplifier/faqs
Guddu
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Finally
According to the manual you can activate Zone 2 with a button. I would be surprised if it deactivated the main zone, only one way to find out though....
If it works, you will probably have to consider the delay between the different channels, that could be trickier.
Them being monoblocks and having two need two for stereo.
There is actually a pretty decent answer to this in their newly posted FAQ:
-Ed
@Fosi Audio congratulations on landing APOS distribution!
Actually this is also answered differently. @great04
The "design benefit" is in bold from the FAQ
When powering a V3 Mono device, would using a 48V/10A power supply provide a higher power output than a 48V/5A power supply?
Based on our measurements, when powered by a 48V/10A power supply, there is no significant increase in power compared to using a 48V/5A power supply. This is because the power has essentially reached the maximum supported by the TI TPA3255 amplifier chip with a 48V voltage input. Increasing the current further does not directly enhance the power output. However, using a 48V/10A power supply compared to a 48V/5A power supply can provide a higher current capacity and greater safety margin for the amplifier. This increased current capacity effectively reduces voltage drops in power lines and internal circuits under high loads, improving the response of the amplifier when handling dynamically complex audio signals. Moreover, the higher current output means that the system is less likely to overheat or shut down due to current overload when facing peak loads, thereby enhancing the overall reliability and stability of the system. Additionally, opting for a more robust power supply can alleviate the operational stress on various components of the amplifier, prolong the lifespan of the equipment, and offer more flexibility for potential system upgrades in the future.
My small issue with this is that Aiyima have a 48V/10A GaN supply that is much less expensive than the Fosi 48V/10A.
So there is a design benefit, and a profit benefit, which is fine ... but in a marketplace ASR could assist in comparing the impact of these power supplies with regard to measurements of the complete amplifier units.
We could power two v3 Monos with two 48V/10A supplies from Aiyima for the reasons/benefits in bold from Fosi, but for much lower cost - if we had the measured performance information relating to the power supplies!
The power supplies cost as much as the amplifiers or more.
For good reason perhaps or not, I'm a 'believer' in the importance of power supplies.
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wyup
Active Member
Why not use RCA to XLR adaptors instead of RCA input for better performance?
RCA inputs have additional and innecessary gain as well as op-amp 'converter'.
XLR has enough input impedance to drive single-ended voltage.
RCA inputs have additional and innecessary gain as well as op-amp 'converter'.
XLR has enough input impedance to drive single-ended voltage.
I was wondering this too but it seemed so obvious I figured I was missing something.
Abstracted
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Anyone willing to bet we're NOT going to hit the $300K mark by the deadline?
hello_again
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Likely won't hit the $300k mark, but if they can pull another $25k in organic sales, the you just need to convince about 900 backers to add (1) Muse02 add on and your right at the $300k threshold... so I'm saying there's a chance. What's strange to me is there seems to be little participation from Japan or Korea. Would have figured there would be more interest, maybe Fosi needs to send some Asian influencers demo units.
what? We're at almost 85% to final goal of the campaign, and there's still 90% of the time left. So i'd say it shouldn't be a problem? I assume that there is more press/media coverage/attention coming in whole next month, and news in style of "spectacular success of kickstarter audio campaign, audiofile holy grail for normies, check it out, thers still time for you to pledge and be a part of history" .
.Why do you think they put that op-amp there, to waste money?
You will lose quite a bit of output if you just feed se into the xlr. It will work, but it won't be better. You would need an active rca-xlr converter instead of an adapter. The 'innessary' gain and op-amp ARE your active converter, before they feed it into the balanced circuit of the amp.
So no, don't do that. It's a workaround for an amp that only had xlr in, it's not an improvement over Fosi's design.
PlasticDoc
Active Member
This is indeed a well done FAQ.
The answer to: "How are you synchronizing the TPA3255 oscillator between the monoblocks in order to avoid Class D "Beat Tones" ? " ,
should have been a simple and honest: "We don't.".
This is another reason why the Fosi V3 Stereo PFFB will be a superior value proposition for the average consumer in comparison to the Fosi V3 Mono.
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With 36 days left?
Wow! ... Take a free day, go to a park and enjoy some beautiful outland.
wyup
Active Member
They've put the additional opamp mostly to provide more gain, if you need it, but you can bypass it. The fact is the XLR input has 9db more SINAD performance.
You don't need active converters. Hypex amps work balanced internally, and they advise users to use XLR adapters for unbalanced signal, which works well and has no penalty.
V3 amp has 20db gain for XLR, which is more than adequate for most 2V sources and volume requirements at home. RCA input has 25db and 31db with the gain switch. If you need that gain, ok, but my point is you may get better sound quality with XLR 20db gain, with less noise, and you don't need to attenuate that much for the same volume. Both opamp gain and source attenuation intruduce noise, which we can bypass by using XLR input.
But the point is that at those synad levels it is already practically impossible to hear anything.... Sinad is not an infinite parameter of sound quality, a Sinad of 140 does not indicate a "sound quality" better than 100.
Once distortion is so low and noise cannot be heard from the listening position in quieter musical passages, further increasing Sinad provides no benefit to sound quality.
I think this is a good point, but for me it just ticks an additional feature box. 20db and then options of 25db and 31db should anyone need it.
I think Fosi were criticized by a commentator for not having high enough gain with another model so they have simply covered all bases.
The Sylph Audio models have sometimes 14db gain into balanced and my understanding that this with the goal of better Sinad / measurements.
I'm interested that Fosi have hit 100 or 101 Sinad with higher gain.
I'll be using balanced ... and thankful the volume is not deafening with the volume control at the 9.00 o'clock position.
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