Fosi Audio V3 Mono Amplifier Review

[burkm]

But it will lower its internal temperature if the heat is been taken off faster. won't it ?

 

[SMen]

I don't know - I don't have data on ADC performance over time.

If I were to guess I would say digital could audibly perfectly record vinyl probably from the early 80s. Some early CD players had 14 bit converters. 14 bits still has 84db of dynamic range - which matches or exceeds that of vinyl. Even if ADC's of the day only had 14 bit, they'd probably still be transparent to vinyl. But even by the Mid 70s, 16 bit 50kHz recording was in use in studios. By 1980 the redbook standard had been released in 1981 Sony released gear that could be used at home for recording redbook standard digital to VCR tape.

Here's an interesting thing, I don't want to go off topic (but just in passing), but I am pretty sure that digital has taken a while to be better at recording sounds closer to silence.
Distortion goes up. So ironically the noise floor of analogue probably helped!

All I can say is that the ADC's on the market for doing anything like recording vinyl were pretty dire (subjectively).

It is only in the past couple of years I got one - actually the Audient Evo 4, where I would not want to walk into a room and say whether it was the record or the recording playing. Not expensive - a shade over 100 euros now.

But when one is talking about the recording itself ... 'I think I'll just do a little noise removal here or there' - just a 'smidgeon of processing' ... and generally the result is worse ... even if the noise measurements are better.

And then there is 'loudness' ... all the dynamic range measurements are rendered pointless by digital loudness (peak limiting) introduced into the recording. I've had some horrors come up on my screen looking at the wave form. So even if people criticize vinyl with it's dynamic range - the variation between peaks and troughs can all too often be much better.

All beautifully revealed by my Fosi V3 monos

Now if I have got my perceptions of dynamic range all wrong, I will stand corrected ... but I don't want cannons going off in my living room ...! Just the sense of them going off.

 

[antcollinet]

But it will lower its internal temperature if the heat is been taken off faster. won't it ?

Yes - anything upstream of the thermal interface material (TIM) will operate at lower temperature (steady state) if the TIM is working better (lower thermal resistance).

But anything downstream of the TIM won't (at steady state) change temperature. There will be a short term (very short if my expectations are correct) difference in rate of rise.

 

[antcollinet]

All I can say is that the ADC's on the market for doing anything like recording vinyl were pretty dire (subjectively).

But non subjectively - why on earth would that be. Dire Straits Brothers in Arms was recorded fully digitally in 1985 - with audio quality (including noise floor) vastly exceeding that possible on vinyl. So absolutely the ADCs used for that are easily capable of recording anything on vinyl without any audible degradation whatsoever.

Many other fully digital recordings were made much earlier, as mentioned above.

But when one is talking about the recording itself ... 'I think I'll just do a little noise removal here or there' - just a 'smidgeon of processing' ... and generally the result is worse ... even if the noise measurements are better.

And then there is 'loudness' ... all the dynamic range measurements are rendered pointless by digital loudness (peak limiting) introduced into the recording. I've had some horrors come up on my screen looking at the wave form. So even if people criticize vinyl with it's dynamic range - the variation between peaks and troughs can all too often be much better.

None of which has anything to do with the straight capture of a vinyl recording to digital and subsequent playback without any degradation.

 

[SMen]

Here's some qualified guessing:

Audibility thresholds of amp and DAC measurements

Introduction A recurring theme on ASR is whether or not the various measured qualities of the devices are audible. In this post, I'll present some clear and visual thresholds for when those imperfections can be considered a potentially audible concern. I will not explain the basics of amp/DAC...

www.audiosciencereview.com

A like is not good enough. VG. Take me off this thread a while!

 

[SMen]

But non subjectively - why on earth would that be. Dire Straits Brothers in Arms was recorded fully digitally in 1985 - with audio quality (including noise floor) vastly exceeding that possible on vinyl. So absolutely the ADCs used for that are easily capable of recording anything on vinyl without any audible degradation whatsoever.

I'm not sure that this is relevant. It's a great album though. There are just so many great recordings (and lousy ones across all technologies).

None of which has anything to do with the straight capture of a vinyl recording to digital and subsequent playback without any degradation.

It is very relevant to comparisons and sweeping statements - and also distortion rising the closer you get to recording silence. And, indeed, the dynamic range we hear.

Here's some qualified guessing:

Audibility thresholds of amp and DAC measurements

Introduction A recurring theme on ASR is whether or not the various measured qualities of the devices are audible. In this post, I'll present some clear and visual thresholds for when those imperfections can be considered a potentially audible concern. I will not explain the basics of amp/DAC...

www.audiosciencereview.com

Which makes this all the more interesting. I was banging on about left right channel balance a page ago! We are much more sensitive to this than I thought!
And about dynamic range...

 

[Lux_ury]

But it will lower its internal temperature if the heat is been taken off faster. won't it ?

A few points for people

Hot air will always follow into cooler air ambient is important. Lower the better.

The material will have differing coefficients like copper will have better absorption than aluminium.

The speed at which molecules excite varies according to environment.

 

[Sokel]

I'm not sure that this is relevant. It's a great album though. There are just so many great recordings (and lousy ones across all technologies).



It is very relevant to comparisons and sweeping statements - and also distortion rising the closer you get to recording silence. And, indeed, the dynamic range we hear.


Which makes this all the more interesting. I was banging on about left right channel balance a page ago! We are much more sensitive to this than I thought!
And about dynamic range...

Why not be a part of the equation and find out for yourself even better:

Listening Test

www.klippel.de

Puts the mind in rest once and for all,without guessing.

 

[SMen]

Why not be a part of the equation and find out for yourself even better:

Listening Test

www.klippel.de

Puts the mind in rest once and for all,without guessing.

Yes I know this. Will be delighted. I have also measured my hearing (used to pretty regularly, must do again).

But:

Taking balance between channels specifically rather than distortion. How consistent are the V3 monos outputs (for example) between units and batches of units? Measuring one in isolation does not measure this.

I think we are on page 173 ...

The two I have sound very well matched (subjectively) ... I have just bought a phono stage and a volume control where the emphasis is on very tight channel matching.
These work very well with the monos. Channel matching has often been an issue for me so +1 for my pair anyway - and my perception of far better balance with the new gear in this combination.

DAC's these days all seem to measure spectacularly well - nothing these days seem to come with balance controls! I suppose room correction can handle a fair bit.

 

[Bernard23]

Probably - most likely the gain of the two amps is different. Try the V3 mono on the higher gain setting.

If you are on the balanced input this is limited to 20dB which is on the low side - so not surprising you need more volts from the source. (ZA3 is about 26dB on XLR)

Getting slightly nervous about pairing a Wiim ultra with the V3 Monos. The Wiim is limited to 2V output

 

[Bernard23]

Yes I know this. Will be delighted. I have also measured my hearing (used to pretty regularly, must do again).

But:

Taking balance between channels specifically rather than distortion. How consistent are the V3 monos outputs (for example) between units and batches of units? Measuring one in isolation does not measure this.

I think we are on page 173 ...

The two I have sound very well matched (subjectively) ... I have just bought a phono stage and a volume control where the emphasis is on very tight channel matching.
These work very well with the monos. Channel matching has often been an issue for me so +1 for my pair anyway - and my perception of far better balance with the new gear in this combination.

DAC's these days all seem to measure spectacularly well - nothing these days seem to come with balance controls! I suppose room correction can handle a fair bit.

Every digital and analogue device I own to play music has a L/R adjustment.

 

[courtesy]

Getting slightly nervous about pairing a Wiim ultra with the V3 Monos. The Wiim is limited to 2V output

This the combo I am using and it works well. Driving Ascend Acoustics Luna v2's.

 

[Bernard23]

This the combo I am using and it works well. Driving Ascend Acoustics Luna v2's.

Presumably at the 2Vrms output setting on the ultra?

 

[Brian Hall]

Probably - most likely the gain of the two amps is different. Try the V3 mono on the higher gain setting.

If you are on the balanced input this is limited to 20dB which is on the low side - so not surprising you need more volts from the source. (ZA3 is about 26dB on XLR)

Yes, was using balanced out of the DMP-A6. I just moved the V3 monos back to my office setup and using the ZA3 in stereo mode for the main setup's stereo mode.

Was using a Loxjie A40 in there. Moved that to a new bedroom setup. The Loxjie has more apparent power than the ZA3 and V3 monos.

 

[Brian Hall]

Getting slightly nervous about pairing a Wiim ultra with the V3 Monos. The Wiim is limited to 2V output

The V3 monos still have plenty of power. I was just surprised at needing to use a higher level on the preamp vs the ZA3.

 

[DCinATX]

Long time lurker, first time poster.

The F3M solved a problem for me. Namely, my Rega Brio was underpowered for driving a newly acquired pair of Buchardt S400 MKII speakers. My first thought was that these speakers had too much bass energy for my basement listening room. Turns out, the amp simply couldn’t drive the speakers tightly.

Bass integration is great with the F3M. Since these units came out of the Amazon inventory, I did have to reverse the polarity on my SVS sub. Otherwise, super easy start up. (Luckily, the reverse polarity problem and solution are well documented here.)

 

[Brian Hall]

I wasn't too concerned about the phase being off, but did a "test" for fun (non measured, and not blind).

Moved the Fosi LC30 amp/speaker switch to my office. Same speakers (Sony SSC-S5), but two amps. The older Fosi V3 stereo vs the V3 monos.

The V3 stereo was louder at the same preamp level on the Wiim Ultra. The V3 stereo seemed to have a tiny bit more treble, but the subwoofer bass sounded better.

I changed the phase switch on the subwoofer and now the bass sounds better with the V3 monos, so I guess I did receive a set with the reversed phase. Expected as each only has one QC sticker.

It doesn't seem right to me for the V3 stereo to be louder than the V3 monos since they have more power on paper, but it is. Other than the slightly increased treble, I do not hear any difference in sound quality. I guess the V3 stereo was actually better than I thought it was.

I recommend the LC30 to anyone that wants to do a simple, quick comparison of amps or speakers or have two setups like my main system (stereo and atmos).

Had to compare the V3 monos vs the ZA3 with the LC30. Again the ZA3 is louder as previously determined. The subwoofer sounded wrong with the ZA3 as expected since I changed the phase for the monos. Switching the phase back corrected that for the ZA3.

Did a compare between the V3 stereo vs the ZA3. ZA3 slightly louder at same preamp level. Not as much difference vs the V3 monos. V3 stereo still seemed to have more treble. Both sounded great. Subwoofer phase needs to be the same for the ZA3 and the V3 stereo. Needs to be switched for the V3 monos.

Knowing what I do now, it doesn't seem like there is really any advantage in my two setups to having the V3 monos vs the ZA3 Stereo or maybe even the V3 stereo. All of them sound great.

I've also "tested" all of them driving my new Klipsch Heresy IV speakers. All sounded equally great as did the Loxjie A40 which seems to have the most power of any of them. Still noticed a slight treble boost with the V3 stereo vs all the others.

 

[courtesy]

Presumably at the 2Vrms output setting on the ultra?

Yes

 

[Doodski]

I wasn't too concerned about the phase being off, but did a "test" for fun (non measured, and not blind).

Moved the Fosi LC30 amp/speaker switch to my office. Same speakers (Sony SSC-S5), but two amps. The older Fosi V3 stereo vs the V3 monos.

The V3 stereo was louder at the same preamp level on the Wiim Ultra. The V3 stereo seemed to have a tiny bit more treble, but the subwoofer bass sounded better.

I changed the phase switch on the subwoofer and now the bass sounds better with the V3 monos, so I guess I did receive a set with the reversed phase. Expected as each only has one QC sticker.

It doesn't seem right to me for the V3 stereo to be louder than the V3 monos since they have more power on paper, but it is. Other than the slightly increased treble, I do not hear any difference in sound quality. I guess the V3 stereo was actually better than I thought it was.

I recommend the LC30 to anyone that wants to do a simple, quick comparison of amps or speakers or have two setups like my main system (stereo and atmos).

Had to compare the V3 monos vs the ZA3 with the LC30. Again the ZA3 is louder as previously determined. The subwoofer sounded wrong with the ZA3 as expected since I changed the phase for the monos. Switching the phase back corrected that for the ZA3.

Did a compare between the V3 stereo vs the ZA3. ZA3 slightly louder at same preamp level. Not as much difference vs the V3 monos. V3 stereo still seemed to have more treble. Both sounded great. Subwoofer phase needs to be the same for the ZA3 and the V3 stereo. Needs to be switched for the V3 monos.

Knowing what I do now, it doesn't seem like there is really any advantage in my two setups to having the V3 monos vs the ZA3 Stereo or maybe even the V3 stereo. All of them sound great.

I've also "tested" all of them driving my new Klipsch Heresy IV speakers. All sounded equally great as did the Loxjie A40 which seems to have the most power of any of them. Still noticed a slight treble boost with the V3 stereo vs all the others.

They should sound fantastic. They are a modern class D amp with a good IC chip. What is the comparative expense for the various models you ran in this test?

 

[antcollinet]

Getting slightly nervous about pairing a Wiim ultra with the V3 Monos. The Wiim is limited to 2V output

That will be fine with the RCA input to the mono. Even on the lower gain setting it will most likely drive more volume than you can use. If you select the higher gain, then 2V is more than enough to drive the monos to full power.