Fosi Audio V3 Mono Amplifier Review

[Talisman]

Quick question for those that may have more technical/engineering knowledge than me...

For the past couple of years I've been using an Aiyima A07 essentially as a power amp to run the main L and R speakers in my home theater setup, using my HT receiver as a preamp to control volume, etc. I keep volume knob of the A07 set at around 75% of total output, and this gets my speakers as loud as I would want to hear them without any obvious distortion, noise, etc.

Given that these new Fosi V3 monoblocks are based around the same amp chip, would there be any audible benefit to swapping out my A07 with a pair of these (increased punchiness, better channel separation, etc)? A higher SINAD score and/or power output is meaningless to me unless it actually translates into audibly better sound at low to moderate listening levels.

One practical consideration that does attract me to the V3 monoblocks is the inclusion of a standby mode, but I'm not sure if this alone would justify making the switch.

The technical improvement is notable, but unless you have speakers with a particularly critical impedance curve, you will hardly hear a difference in everyday use.
If you don't hear any noise, if there's enough power, and if you don't perceive an altered frequency response with your A07, the gearbox isn't very useful.

 

[jdg78]

The technical improvement is notable, but unless you have speakers with a particularly critical impedance curve, you will hardly hear a difference in everyday use.
If you don't hear any noise, if there's enough power, and if you don't perceive an altered frequency response with your A07, the gearbox isn't very useful.

Thank you, very helpful.

 

[Kayshot]

The technical improvement is notable, but unless you have speakers with a particularly critical impedance curve, you will hardly hear a difference in everyday use.
If you don't hear any noise, if there's enough power, and if you don't perceive an altered frequency response with your A07, the gearbox isn't very useful.

Do you happen to know if the Revel M106 could be considered to have a critical impedance curve? I know they are 8 ohms, but know nothing of curves.

 

[Inertiaman]

but it matters to me, because I like to run 8-ish Ohm industrially built DIY "audiophile" two-way bookshelf speakers

now that is an oxymoron!

 

[olieb]

Do you happen to know if the Revel M106 could be considered to have a critical impedance curve? I know they are 8 ohms, but know nothing of curves.

Revel M106 Bookshelf Speaker Review

This is a review and detailed measurements of the Revel M106 bookshelf speaker. It was kindly purchased and drop shipped to me. It is not a new sample but came to me with full packaging and protective wrapper. The M106 costs US $1,000 each or $2,000 for a pair. It is only sold through dealer...

www.audiosciencereview.com

The curve looks not easy to drive but the interesting part for driving with a TPA3255-amp is in 8-20 kHz where the curve is rather smooth/flat (≈ 5Ω). There should no problem of FR because of load dependency.

 

[Rafaille]

Do you happen to know if the Revel M106 could be considered to have a critical impedance curve? I know they are 8 ohms, but know nothing of curves.

The answer is there: https://www.audiosciencereview.com/...ds/revel-m106-bookshelf-speaker-review.14363/

To my limited understanding they do not seem particularly difficult to drive. Apart maybe from the dip around 50Hz, assuming you expect them to reproduce that sort of bass...

 

[sl1982]

I have a set of these in my walls. Do you think the v3 mono could drive them well?

https://www.monoprice.com/product?p_id=42829

 

[GoDawgs]

I have just joined the forum, I've been reading various posts about 2 weeks now. I found you AFTER I had received my Hifiman Ananda Nano headphone and read the reviews here on your forum . Live and learn... After reading the review here I have just joined the Kickstarter campaign for the Fosi Audio V3 Mono. I've ordered 2 amps and 2 power supplies for less than $225 total, shipping is scheduled for June 2024. I'm going to show my extreme ignorance here, will I be able to use a subwoofer with these 2 mono amps? I see that they only have outputs for 2 speakers when using both amps. I've seen diagrams for car audio mono amps with multiple speaker outputs, but is it feasible with a set up like the Mono V3 (only 2 speaker outputs total), and a pair of JBL A130 speakers?

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[EddNog]

I have just joined the forum, I've been reading various posts about 2 weeks now. I found you AFTER I had received my Hifiman Ananda Nano headphone and read the reviews here on your forum . Live and learn... After reading the review here I have just joined the Kickstarter campaign for the Fosi Audio V3 Mono. I've ordered 2 amps and 2 power supplies for less than $225 total, shipping is scheduled for June 2024. I'm going to show my extreme ignorance here, will I be able to use a subwoofer with these 2 mono amps? I see that they only have outputs for 2 speakers when using both amps. I've seen diagrams for car audio mono amps with multiple speaker outputs, but is it feasible with a set up like the Mono V3 (only 2 speaker outputs total), and a pair of JBL A130 speakers?

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You’ll need to identify which subwoofer you’re thinking of, and what you’re going to use for volume control. If you plan to get a preamp to control volume, you can choose one with multiple outputs so one pair of outputs goes to the V3 Monos to drive the speakers and another set of outputs feeds the subwoofer. All subwoofers have line level inputs so that for sure would work. If you plan to use a source with integrated volume control and won’t use a preamp, then you will need to pick a subwoofer that also has Speaker Level inputs which the sub would wire into the speaker level output of one of the V3 Monos.

-Ed

 

[neko8018]

Humm...how can I choose between V3mono and audiolab 8300mb.

 

[GoDawgs]

Thanks, I may have to buy another preamp or choose a subwoofer with the speaker level inputs. I was going to use my IFI Zen preamp/DAC for volume control (only 2 RCA outputs and a 4.4mm balanced out). Again I wish I had found this forum first, but thanks. At least I know it can be done. I'll be eager to hear these amps on these speakers to see how long I can last without buying a subwoofer.

 

[EddNog]

Thanks, I may have to buy another preamp or choose a subwoofer with the speaker level inputs. I was going to use my IFI Nano preamp/DAC for volume control (only 2 RCA outputs and a 4.4mm balanced out). Again I wish I had found this forum first, but thanks. At least I know it can be done. I'll be eager to hear these amps on these speakers to see how long I can last without buying a subwoofer.

Converting from balanced to single-ended can easily be done passively. You can use the 4.4mm balanced out to subwoofer with this:

https://a.co/d/eg4MD0N

EDIT: You will also need to add some sort of in-line attenuator or volume dial to cut the signal down as I just realized your 4.4mm output is amplified, not line level. Something like this:

Amazon.com

So now instead of the original cable I listed, you would use this one instead:

Amazon.com

-Ed

 

[GoDawgs]

My wife is not going to like the idea me purchasing a subwoofer before I even set up my new amps (I'll send her here to the forum if it gets ugly, you can help explain it ), but man, I just ordered a new pair of the JBL A130 speakers (from Japan of all places, no one in the U.S. seems to have any), and I know I'll want lower bass. Thanks! I'll be ordering one of the adapters and a new subwoofer real soon .

 

[EddNog]

My wife is not going to like the idea me purchasing a subwoofer before I even set up my new amps (I'll send her here to the forum if it gets ugly, you can help explain it ), but man, I just ordered a new pair of the JBL A130 speakers (from Japan of all places, no one in the U.S. seems to have any), and I know I'll want lower bass. Thanks! I'll be ordering one of the adapters and a new subwoofer real soon .

I did indicate above https://www.audiosciencereview.com/...o-v3-mono-amplifier-review.53474/post-1964645

how you can use the subwoofer you already have with the iFi Nano.

-Ed

 

[Nahkarankaisija]

Anyone have any recommendations for a preamp to pair with the two Fosi monoblocks? Budget is 300€ and it needs to have a "reliable" volume control so my 99 db efficient DIY speakers don't destroy my hearing should an accident happen and the monos push full watts to the speakers. I was thinking Topping but there were some posts here where the Topping preamp/dac suddenly pushed full volume which I am trying to avoid.

 

[GoDawgs]

Shh, I don't want my wife to know all the secrets.... Yes I did see that, I'm going to brainstorm (okay for me it's more like brain sprinkle), on what and how to set things up. You are most helpful. I hope to be listening to something other than headphones and cheap Bluetooth speakers real soon.

 

[ABAstroUK]

Humm...how can I choose between V3mono and audiolab 8300mb.

I'm in the same boat, wanting to add a bit of extra power to my Audiolab 7000A. For the price, the V3 monos are a no brainer in my opinion.

 

[georgehifi]

I have a set of these in my walls. Do you think the v3 mono could drive them well?

To me not a comfortable load for Class-D like these. Class-D's like Hypex NC500's would breath easier into them.
They dip to 3ohms around 100hz and 1khz and that's without taking any -phase (which they don't show) into account (EPDR) as well which "could" make them even lower impedance load. Cheers George

 

[sl1982]

To me not a comfortable load for Class-D like these. Class-D's like Hypex NC500's would breath easier into them.
They dip to 3ohms around 100hz and 1khz and that's without taking any -phase (which they don't show) into account (EPDR) as well which "could" make them even lower impedance load. Cheers George

I was afraid of that. Hypex is unfortunately out of my budget right now. Do you think the v3 monos would at least be better than a middle range AVR driving these?

 

[georgehifi]

Do you think the v3 monos would at least be better than a middle range AVR driving these?

How longs a piece of string, but at theater sound levels, if I could afford it I'd go with a multi channel amp these seem to be good value

VTV Multi Channel Amplifiers | VTV Amplifier

Cheers George