Hoping you had a solution involving a home sourced larger heat sink. I am going to use higher quality thermal paste when I replace the op amps- also considering solid-state thermal pads that are sometimes better than paste, but I will see because they’re expensive
Do you mean: upgrading the internal heat sink with a larger one..? That is a brilliant solution… an easy for for Fosi to implement moving forward… but no. I have thought of simply adding a heating to the outside of the case though. I will be dining a follow up video where I reapply paste to the current heat sink, also when I upgrade the op amps too.
@ yes-I meant a larger block to replace that oddly small bar that’s about as wide as the amp but only seemingly an inch or so deep. I don’t really consider it a “heat sink” so much as a “heat transfer bar” But if that entire small bar surface isn’t even covered with thermal paste-it’s not even acting as “big” as it is physically-that would explain why there have been so many reviews on the Fosi site with blown amps (usually one of a pair bought blows within 3 days)-Im thinking they are probably using cheap paste and daubing only a small blob rather than applying it evenly to the whole bar ( cheap assembly line job versus nice manual effort). It’s like having an 8 gauge copper wire but the connector is a 24 gauge strand🤣🤣. The other issue seems to be the 10 amp power supply with the splitter. Douglas pointed out there can be some sort of instability with that setup. So I got the individual supplies. But I like his point not everyone needs all the power available with 48V and maybe 40 V would be a nice idea to mitigate the heat with a modest diminution in power. The heat is the big issue with this amp, and almost everyone thinks better op amps make a difference. Everyone prefers either the Sparkos or the muses02. Heat sink to outer case: well this makes some sense but I think the big issue is the delivery of the heat from the chip to the case-if it isn’t delivered well to the case, it won’t make a difference if you attach a better sink on the case… or if you use fans for that matter-one of the reports was that the amp that blew had a case that was *colder* than the good one-this is because the heat wasn’t being delivered off the chip properly. We NEED the case to at least get hot if the chip is producing a ton of heat… once it is receiving the heat properly, then an external sink/fins/fan will help…
I purchased these monoblocks early on and immediately noticed the heat issue. I first experimented with a variety of Op-Amps - both IC-based and discrete versions (Sparkos Labs). I must say, from my observations, although the V3 mono's get ridiculous warm (hot) to begin with, they get even worse (at least in my environment) with the discrete Sparkos Labs versions installed. Don't know if that is voltage related or what? I had to subsequently replace those with some IC-based MUSES02 op amps, which I perceived "may" have brought down the heat just a tiny bit. Then I tried several power supplies (I have a ton of those on hand), using the 32V, 36V and 48V (5A) varieties. I noticed no difference in the heat ceiling using any of those. So I went back to using the Fodi 48V-10A version with the splitter, powering both of them. I then opened the case and added more thermal paste - still, all to no avail - the heat was still there. I ordered these fans (thanks to the reviewer for that) and they came today - very quiet - and the V3 mono's sit perfectly on top of them. Personally, I believe that Fosi tried to get this product out of the door too quickly. Forget trying to release something new every other month, which appears this is what Fosi and Aiyima tend to do. Instead, focus on reliability, sound, quality parts, and other variables (i.e. heat). The size of this mono-block design is just too small. If they released this as the same (or similar) size as the ZA3 (with vent openings on both the bottom and top - not the sides), then this heat issue would NOT have been a problem. It is what it is - other than the heat issue, I'm loving the sound I'm getting, however, knowing that the long-term reliability (due to the heat) is suspect, I am concerned about that.
For about a year now I've been telling people not to go over 36 volts with these fully enclosed amplifiers. The reason is simple... a heat sink inside a box becomes a heater. But the V3 monos have issues ... 1) When running 2 of them from a single supply, there is a known issue with instability due to the added resistance of the power cables. Fosi produces a little box that is supposed to address this issue... but the best answer will always be to run them on two separate power supplies. 2) The heat spreader on the bottom is too small and usually only has a dab of grease in the middle. You can help this considerably by disassembling the case, wiping away the old heat sink grease and replacing it with a thin layer of new grease that covers the entire heat spreader before re-assembling. 3) The upper case vents are hampered by the coloured plastic inserts. Disassemble the case, remove them and put them aside, then reassemble. 4) Heat rises... it's not going to roll off under the case. it is going to want to move up through the case. Simply put extra tall rubber feet on the top and flip the thing over so the heat spreader is at the top of the case. == But, overall the very best solution is to use a pair of 36 volt, 5 amp supplies, one for each amplifier. At 36 volts they don't produce enough heat to self-destruct and you don't need all the fancy crap about fans and external heat sinks ... although taking the inserts out of the case side vents is still a good idea. At 36 volts you will get 65 clean watts on 8 ohms and 130 on 4. This is more than enough for even large rooms with decent speakers.
This is brilliant feedback..! I love it and will do every step you recommend. These amps are to good to just let self destruct… I didn’t get them to just throw away… Awesome feedback! Thank you..!
I run the 48v in much more demanding setup than speakers (running either shakers or DIY Hovereze subs) and have zero issues by just having a small fan from the left side pushing and on the right side pulling running at low speeds. The fan are big enough to do this for a couple of them stacked. That usage is WAY more demanding than your typical bookshelf as I am pushing very low frequencies down to single digits
@Douglas_Blake_579, I have read your posts on many threads about these amplifiers- and I appreciate your comments. I decided to buy separate 48 V 5A power supplies, figuring this would be better than the single 10 amp supply with the issues you mentioned. I did not see any good 36 or 40 V supplies out there for cheap- I guess I could source them from Aiyima (36v). Just yesterday, I did some research into thermal paste and once again your comments are pretty golden - I did not know that they were skimping on the thermal paste which I will address when I replace the op amps. I like your suggestion about removing the color inserts which block airflow. Although I’m not too keen on turning them upside down and inverting the feet… will consider this if I notice in normal usage them getting overly hot- I did notice they got pretty hot playing them normally as it is- and maybe they will get hotter with better thermal paste, indicating improved heat transfer… I think I will investigate 36v or 40v power supplies before I decide to invert the units, although I have to say, I tend to be running them at higher volumes, so I’m going to assume that the larger power supplies will be much lower distortion at the volumes I am running. I am also considering using solid-state thermal conductive sheets - though those tend to be much more expensive than just buying high-quality paste and being liberal with it. I ordered the Noctua NT-H2 which is well-regarded and presumably better than the stock paste. I am avoiding the very highest thermal conductivity “Liquid Metal” pastes that are electrically conductive just to ensure I don’t fry these things due to some spillage on the board… I was wondering if the “heat sink” (metal bar) could be replaced with something larger or would this be pointless because it needs better design to radiate -so better coupling to the case, but also a case with more surface area such as a Fin-type design… basically I don’t think we should regard the metal bar under the amp chip as a “heat sink” so much as a heat transfer bus-so it’s not really an internal heater -but a heat conduit to the case, which is actual heat sink. So I do think a larger conduit with much better paste-interface (or solid state thermal couple sheet (such as made by Thermal Grizzly or Honeywell) would probably be helpful…
I certainly thought of that... and a great idea. Specifically in this case: in their normal rack space things are tight and the heat gets trapped in there, which magnifies the problem. This is why I preferred the idea of forced air... it is simply more aggressive. In fact. Since removing these amps from the rack to film this video, I put in another class-d amp in their place to keep the system running while I shot this video, and the upcoming feature of the V3Mono... The heat i the restricted rack caused that other amp to cut in and out intermittently... confirming that the aggression of forced air over passive fins may be the better choice in THIS setup. However, in a more open space, I would certainly try passive heat-sinks... Great IDEA, thanks foe suggesting it!
For the sake of offering a better option... What do you propose is better advice to cool your amplifiers? Sincere question? I have an in-depth video series coming which will include many other options to cooling amplifiers, which include some passive options, taller feet, adding mass, and heat sinks, etc. It sounds like you have some great options I'd like to cover in that series. Please do share your ideas? And YES... Thanks for the click! Don't forget to subscribe! I'm not being a smart ass... I am sincerely looking for great ideas that I can share with others, your feedback is valuable!
I was afraid to add noise to a HiFi setup, the entire point of HiFi is to improve sound… I get it… with that said: I am shocked how quiet these really are.
They do use the same chip, you are correct. I have to suspect that the 48volt, 10amp power supply is a factor; feeding so much current through it makes a difference… plus in my case, in regular use, they are tucked away too tightly, and I have really starved them of air in there. In fact, while these amps have been out to shoot video, I substituted my A07max to pitch hit… they simply shut down on me when they got too warm. So I’m guessing my tight cabinet is a big reason why here. With that said, many other claim their v3monos run hot too.
@@deviklovecraft3835 The amplifier is not going to draw 10 amps constantly. It will draw what it needs for a given loudness. Most of the time it will probably be using less than an amp of current, even at above-conversational levels. You could use a 48 volt 50 amp supply and this would still be true.
@@deviklovecraft3835 Yes it is... but not for the reasons most people envision. The problem is one of limiting heat production. The best way to do that is to simply turn the voltage down... it reduces the power somewhat and cuts the current significantly, which ends up producing less heat. Old technician wisdom: A heat sink in an enclosed area becomes a heater. This is why I generally recommend these mini-amps should be run on no more than 36 volts.
Hoping you had a solution involving a home sourced larger heat sink. I am going to use higher quality thermal paste when I replace the op amps- also considering solid-state thermal pads that are sometimes better than paste, but I will see because they’re expensive
Do you mean: upgrading the internal heat sink with a larger one..?
That is a brilliant solution… an easy for for Fosi to implement moving forward… but no.
I have thought of simply adding a heating to the outside of the case though.
I will be dining a follow up video where I reapply paste to the current heat sink, also when I upgrade the op amps too.
@ yes-I meant a larger block to replace that oddly small bar that’s about as wide as the amp but only seemingly an inch or so deep. I don’t really consider it a “heat sink” so much as a “heat transfer bar” But if that entire small bar surface isn’t even covered with thermal paste-it’s not even acting as “big” as it is physically-that would explain why there have been so many reviews on the Fosi site with blown amps (usually one of a pair bought blows within 3 days)-Im thinking they are probably using cheap paste and daubing only a small blob rather than applying it evenly to the whole bar ( cheap assembly line job versus nice manual effort). It’s like having an 8 gauge copper wire but the connector is a 24 gauge strand🤣🤣. The other issue seems to be the 10 amp power supply with the splitter. Douglas pointed out there can be some sort of instability with that setup. So I got the individual supplies. But I like his point not everyone needs all the power available with 48V and maybe 40 V would be a nice idea to mitigate the heat with a modest diminution in power.
The heat is the big issue with this amp, and almost everyone thinks better op amps make a difference. Everyone prefers either the Sparkos or the muses02.
Heat sink to outer case: well this makes some sense but I think the big issue is the delivery of the heat from the chip to the case-if it isn’t delivered well to the case, it won’t make a difference if you attach a better sink on the case… or if you use fans for that matter-one of the reports was that the amp that blew had a case that was *colder* than the good one-this is because the heat wasn’t being delivered off the chip properly. We NEED the case to at least get hot if the chip is producing a ton of heat… once it is receiving the heat properly, then an external sink/fins/fan will help…
I purchased these monoblocks early on and immediately noticed the heat issue. I first experimented with a variety of Op-Amps - both IC-based and discrete versions (Sparkos Labs). I must say, from my observations, although the V3 mono's get ridiculous warm (hot) to begin with, they get even worse (at least in my environment) with the discrete Sparkos Labs versions installed. Don't know if that is voltage related or what? I had to subsequently replace those with some IC-based MUSES02 op amps, which I perceived "may" have brought down the heat just a tiny bit.
Then I tried several power supplies (I have a ton of those on hand), using the 32V, 36V and 48V (5A) varieties. I noticed no difference in the heat ceiling using any of those. So I went back to using the Fodi 48V-10A version with the splitter, powering both of them.
I then opened the case and added more thermal paste - still, all to no avail - the heat was still there.
I ordered these fans (thanks to the reviewer for that) and they came today - very quiet - and the V3 mono's sit perfectly on top of them.
Personally, I believe that Fosi tried to get this product out of the door too quickly. Forget trying to release something new every other month, which appears this is what Fosi and Aiyima tend to do. Instead, focus on reliability, sound, quality parts, and other variables (i.e. heat). The size of this mono-block design is just too small. If they released this as the same (or similar) size as the ZA3 (with vent openings on both the bottom and top - not the sides), then this heat issue would NOT have been a problem.
It is what it is - other than the heat issue, I'm loving the sound I'm getting, however, knowing that the long-term reliability (due to the heat) is suspect, I am concerned about that.
Great feedback, thanks.
Are you happy with the MUSES02 inside them?
@@consumertechcheck Yes, I'm quite happy with them.
For about a year now I've been telling people not to go over 36 volts with these fully enclosed amplifiers. The reason is simple... a heat sink inside a box becomes a heater.
But the V3 monos have issues ...
1) When running 2 of them from a single supply, there is a known issue with instability due to the added resistance of the power cables. Fosi produces a little box that is supposed to address this issue... but the best answer will always be to run them on two separate power supplies.
2) The heat spreader on the bottom is too small and usually only has a dab of grease in the middle. You can help this considerably by disassembling the case, wiping away the old heat sink grease and replacing it with a thin layer of new grease that covers the entire heat spreader before re-assembling.
3) The upper case vents are hampered by the coloured plastic inserts. Disassemble the case, remove them and put them aside, then reassemble.
4) Heat rises... it's not going to roll off under the case. it is going to want to move up through the case. Simply put extra tall rubber feet on the top and flip the thing over so the heat spreader is at the top of the case.
==
But, overall the very best solution is to use a pair of 36 volt, 5 amp supplies, one for each amplifier. At 36 volts they don't produce enough heat to self-destruct and you don't need all the fancy crap about fans and external heat sinks ... although taking the inserts out of the case side vents is still a good idea.
At 36 volts you will get 65 clean watts on 8 ohms and 130 on 4. This is more than enough for even large rooms with decent speakers.
This is brilliant feedback..! I love it and will do every step you recommend. These amps are to good to just let self destruct… I didn’t get them to just throw away…
Awesome feedback!
Thank you..!
@@consumertechcheck
You're welcome.
I run the 48v in much more demanding setup than speakers (running either shakers or DIY Hovereze subs) and have zero issues by just having a small fan from the left side pushing and on the right side pulling running at low speeds. The fan are big enough to do this for a couple of them stacked.
That usage is WAY more demanding than your typical bookshelf as I am pushing very low frequencies down to single digits
@shaolin95 sounds like a great setup… I love it!
@Douglas_Blake_579, I have read your posts on many threads about these amplifiers- and I appreciate your comments.
I decided to buy separate 48 V 5A power supplies, figuring this would be better than the single 10 amp supply with the issues you mentioned. I did not see any good 36 or 40 V supplies out there for cheap- I guess I could source them from Aiyima (36v).
Just yesterday, I did some research into thermal paste and once again your comments are pretty golden - I did not know that they were skimping on the thermal paste which I will address when I replace the op amps. I like your suggestion about removing the color inserts which block airflow. Although I’m not too keen on turning them upside down and inverting the feet… will consider this if I notice in normal usage them getting overly hot- I did notice they got pretty hot playing them normally as it is- and maybe they will get hotter with better thermal paste, indicating improved heat transfer… I think I will investigate 36v or 40v power supplies before I decide to invert the units, although I have to say, I tend to be running them at higher volumes, so I’m going to assume that the larger power supplies will be much lower distortion at the volumes I am running.
I am also considering using solid-state thermal conductive sheets - though those tend to be much more expensive than just buying high-quality paste and being liberal with it. I ordered the Noctua NT-H2 which is well-regarded and presumably better than the stock paste. I am avoiding the very highest thermal conductivity “Liquid Metal” pastes that are electrically conductive just to ensure I don’t fry these things due to some spillage on the board…
I was wondering if the “heat sink” (metal bar) could be replaced with something larger or would this be pointless because it needs better design to radiate -so better coupling to the case, but also a case with more surface area such as a Fin-type design… basically I don’t think we should regard the metal bar under the amp chip as a “heat sink” so much as a heat transfer bus-so it’s not really an internal heater -but a heat conduit to the case, which is actual heat sink. So I do think a larger conduit with much better paste-interface (or solid state thermal couple sheet (such as made by Thermal Grizzly or Honeywell) would probably be helpful…
Just use a laptop cooler rhat you can put under the amps. That’s what I’m using.
Very smart and simple solution!
@ the best part is that I found them in a thrift store for $5 each.
Why not a heatsink on top? No noise at all.
I certainly thought of that... and a great idea. Specifically in this case: in their normal rack space things are tight and the heat gets trapped in there, which magnifies the problem. This is why I preferred the idea of forced air... it is simply more aggressive. In fact. Since removing these amps from the rack to film this video, I put in another class-d amp in their place to keep the system running while I shot this video, and the upcoming feature of the V3Mono... The heat i the restricted rack caused that other amp to cut in and out intermittently... confirming that the aggression of forced air over passive fins may be the better choice in THIS setup. However, in a more open space, I would certainly try passive heat-sinks... Great IDEA, thanks foe suggesting it!
This is what it looks like when stupid people on UA-cam give stupid advice and then beg for clicks.
For the sake of offering a better option... What do you propose is better advice to cool your amplifiers? Sincere question? I have an in-depth video series coming which will include many other options to cooling amplifiers, which include some passive options, taller feet, adding mass, and heat sinks, etc. It sounds like you have some great options I'd like to cover in that series. Please do share your ideas? And YES... Thanks for the click! Don't forget to subscribe!
I'm not being a smart ass... I am sincerely looking for great ideas that I can share with others, your feedback is valuable!
but noisy.
I was afraid to add noise to a HiFi setup, the entire point of HiFi is to improve sound… I get it… with that said: I am shocked how quiet these really are.
Odd that. My Aiyima A07 max monos only get warm when pushing north of 85 dB. If I'm not mistaken, they use the same chip
They do use the same chip, you are correct. I have to suspect that the 48volt, 10amp power supply is a factor; feeding so much current through it makes a difference… plus in my case, in regular use, they are tucked away too tightly, and I have really starved them of air in there.
In fact, while these amps have been out to shoot video, I substituted my A07max to pitch hit… they simply shut down on me when they got too warm. So I’m guessing my tight cabinet is a big reason why here. With that said, many other claim their v3monos run hot too.
@@consumertechcheck Aha ! I bet you're right , the 48 V power supply may be the chief issue
@@deviklovecraft3835
The amplifier is not going to draw 10 amps constantly. It will draw what it needs for a given loudness. Most of the time it will probably be using less than an amp of current, even at above-conversational levels.
You could use a 48 volt 50 amp supply and this would still be true.
@@deviklovecraft3835
Yes it is... but not for the reasons most people envision. The problem is one of limiting heat production. The best way to do that is to simply turn the voltage down... it reduces the power somewhat and cuts the current significantly, which ends up producing less heat.
Old technician wisdom: A heat sink in an enclosed area becomes a heater.
This is why I generally recommend these mini-amps should be run on no more than 36 volts.