Fosi Audio V3 Mono Amplifier Review

[Doodski]

I think of this rather as an "omission", not a modification

I see that and don't doubt it would help if done properly. As @antcollinet stated in post #3222 the application of thermal paste and the integrity of the clamping of the chip heatsink to the chassis needs to be done properly or the situation will worsen and might cause the chip to go into thermal runaway. I don't have the amp in hand and so I can't see what is required and how the reassembly procedure is done but I can say be very careful with the heatsink mounting screws as the materials are soft.

 

[Sokel]

I see that and don't doubt it would help if done properly. As @antcollinet stated in post #3222 the application of thermal paste and the integrity of the clamping of the chip heatsink to the chassis needs to be done properly or the situation will worsen and might cause the chip to go into thermal runaway. I don't have the amp in hand and so I can't see what is required and how the reassembly procedure is done but I can say be very careful with the heatsink mounting screws as the materials are soft.

High end GPUs which is comparable to application advise about 0.4-0.5 Nm of torque.
But it should be specific to the application normally.
Since the device is meant to be opened for various reasons,I think a torque driver would be far more useful instead of the hex one or the silly op-amps.

 

[antcollinet]

I think of this rather as "omission during assembly", not a modification

You can call it what you like, but if the design doesn't call for paste then it is not an omission during assembly.

Now I've no idea whether this amp has been designed to work without paste or not. But if it has, then adding paste is, at best, pointless - assuming the design is competent.

But if you believe the design is incompetent, why would you ever want to pay good money for it.

 

[antcollinet]

High end GPUs which is comparable to application advise about 0.4-0.5 Nm of torque.
But it should be specific to the application normally.
Since the device is meant to be opened for various reasons,I think a torque driver would be far more useful instead of the hex one or the silly op-amps.

I don't think opening the case to fit Op Amps requires separating the heatsink from the base.

 

[Deleted member 72219]

I don't think opening the case to fit Op Amps requires separating the heatsink from the base.

It does.

-Ed

 

[Sokel]

I don't think opening the case to fit Op Amps requires separating the heatsink from the base.

As far as I have seen the pics they slide out the case by unscrewing the bottom heatshink screws.
Owners please correct me if I'm wrong.

 

[Deleted member 72219]

As far as I have seen the pics they slide out the case by unscrewing the bottom heatshink screws.
Owners please correct me if I'm wrong.

The screws on the back panel farthest to the sides and also the two screws on the bottom must be undone. Then the front panel can slide off and the back panel, which is permanently affixed to the PCB, can slide out from the enclosure, which is a full hoop (top, bottom, and both sides), not just a top cover.

-Ed

 

[antcollinet]

It does.

-Ed

As far as I have seen the pics they slide out the case by unscrewing the bottom heatshink screws.
Owners please correct me if I'm wrong.

Damn - I'm sure I'd seen pics with just the top half lifted off. But... even more reason for designing to not need paste.

 

[Deleted member 72219]

Damn - I'm sure I'd seen pics with just the top half lifted off. But... even more reason for designing to not need paste.

I’ve opened up the ZA3s too many times to count. I’ve also opened up original V3 twice and V3 Monos once, and they’re all basically the same (but no volume knob on V3 Mono so those are even easier).

-Ed

 

[antcollinet]

I’ve opened up the ZA3s too many times to count. I’ve also opened up original V3 twice and V3 Monos once, and they’re all basically the same (but no volume knob on V3 Mono so those are even easier).

-Ed

Do the ones you've opened have stock paste applied?

 

[Deleted member 72219]

Do the ones you've opened have stock paste applied?

ZA3s came from factory with thermal interface material applied. V3 and V3 Monos did not have any TIM from the factory.

-Ed

 

[Brian Hall]

I received the replacement today for the one that failed. Got them both hooked up again. Working and sounding great.

 

[hjwh]

ZA3s came from factory with thermal interface material applied. V3 and V3 Monos did not have any TIM from the factory.

-Ed

My V3 monos came with thermal pasre between case and PCB.

 

[Deleted member 72219]

My V3 monos came with thermal pasre between case and PCB.

Were yours kickstarter initial batch or a later batch? Mine were kickstarter release units.

-Ed

 

[hjwh]

Top case temperatures 39 - 40 degC, bottom 41-42 degC while playing at normal volume.

 

[hjwh]

Were yours kickstarter initial batch or a later batch? Mine were kickstarter release units.

-Ed

bought via Amazon.nl

 

[Deleted member 72219]

bought via Amazon.nl

This means they started putting the TIM on at the factory in later production runs. Those of us who were early backers did not yet receive it with the thermal interface material.

-Ed

 

[hjwh]

delivered last week from Italy warehouse

 

[Deleted member 72219]

delivered last week from Italy warehouse

Yeah mine came straight from China.

-Ed

 

[burkm]

It looks to me, as if the use of thermal paste is "standard" by the maufacturer. But it might be sometimes "forgotten". Thus I am checking it by myself. I have done that many times on my (and the company) PCs already and this for quite some time too
Note: Its part of my profession...