Fosi v3 Mono Amplifier Reliability

[threej]

Have two USB-powered 120mm fans (generic from Amazon) set to medium speed --each beneath one V3 with about an inch between amps. They never get more than slightly warm, regardless of how hard I push them, but ran hot without fans. It concerned me enough that I ordered the fans immediately. I also switched from a shared PSU and added another Fosi 48V 10A PSU, with an extra filter to have one on each. These amps (fed by a ZD3 and ZP3) power A/D/S M15 speakers nicely, and I am very happy with them and with the sense that a reasonable sum can provide significant musical enjoyment. They have replaced Tandberg 3002a/3006a pre/power amps and the DAC in a Squeezebox Duet -- which, in today's dollars equate to a considerably greater outlay but which do not provide commensurate sound improvement, if any.

 

[Blew]

Have two USB-powered 120mm fans (generic from Amazon) set to medium speed --each beneath one V3 with about an inch between amps. They never get more than slightly warm, regardless of how hard I push them, but ran hot without fans. It concerned me enough that I ordered the fans immediately. I also switched from a shared PSU and added another Fosi 48V 10A PSU, with an extra filter to have one on each. These amps (fed by a ZD3 and ZP3) power A/D/S M15 speakers nicely, and I am very happy with them and with the sense that a reasonable sum can provide significant musical enjoyment. They have replaced Tandberg 3002a/3006a pre/power amps and the DAC in a Squeezebox Duet -- which, in today's dollars equate to a considerably greater outlay but which do not provide commensurate sound improvement, if any.

How much noise do the fans create?
The V3 Monos use the chassis as a heatsink, so they're designed to be much warmer than traditional amps.

If you can afford to spend a little extra, replacing the Squeezebox Receiver with a Raspberry Pi + piCorePlayer to attach to your ZD3 via USB is a significant improvement in capabilities to support > 48KHz, resampling, better wifi, and potentially DSP.

 

[threej]

If you can afford to spend a little extra, replacing the Squeezebox Receiver with a Raspberry Pi + piCorePlayer to attach to your ZD3 via USB is a significant improvement in capabilities to support > 48KHz, resampling, better wifi, and potentially DSP.

Time to pull out my old Rasperry Pi and try your suggestion. Thx.

 

[Connor1a]

How much noise do the fans create?
The V3 Monos use the chassis as a heatsink, so they're designed to be much warmer than traditional amps.

If you can afford to spend a little extra, replacing the Squeezebox Receiver with a Raspberry Pi + piCorePlayer to attach to your ZD3 via USB is a significant improvement in capabilities to support > 48KHz, resampling, better wifi, and potentially DSP.

Do you have a link with the tech directions to build something like this? TYVM

 

[threej]

Do you have a link with the tech directions to build something like this? TYVM

I can provide one: https://www.picoreplayer.org/

 

[threej]

How much noise do the fans create?
The V3 Monos use the chassis as a heatsink, so they're designed to be much warmer than traditional amps.

The fans, running on medium (middle of three speed settings) are inaudible. The V3s ran hot to the touch beforehand. Now they are tepid. I imagine, as with all things electronic, that less heat will be good for them. BTW, now have my Raspberry Pi up and running PiCorePlayer to replace the Duet

 

[Firulais71]

Hello everyone. I plan to use two Fosi V3 Mono amplifiers to power a set of 3-way speakers with 94dB sensitivity at 8 ohms. As you know, there are basically two ways to power the V3s:

Option 1: A shared 48V-10A power supply feeding both amplifiers via a voltage divider.
Option 2: A separate power supply for each amplifier, which could be 32V-5A, 48V-5A, or 48V-10A.

Since I've read user reports indicating that higher-capacity power supplies significantly increase operating temperatures, I'd like to know which power supply (from the options mentioned above) and amplifier configuration you recommend. I also plan to install fans on the top and bottom of each amplifier to improve heat dissipation.

¿Have you observed significant differences in temperature, stability, or durability between these power supply options?, ¿is the power loss with lower voltage/current power supplies actually audible or relevant for high-sensitivity speakers (say, above 90dB at 8 ohms)?

Thank you in advance for your attention.

 

[threej]

Hello everyone. I plan to use two Fosi V3 Mono amplifiers to power a set of 3-way speakers with 94dB sensitivity at 8 ohms. As you know, there are basically two ways to power the V3s:

Option 1: A shared 48V-10A power supply feeding both amplifiers via a voltage divider.
Option 2: A separate power supply for each amplifier, which could be 32V-5A, 48V-5A, or 48V-10A.

Since I've read user reports indicating that higher-capacity power supplies significantly increase operating temperatures, I'd like to know which power supply (from the options mentioned above) and amplifier configuration you recommend. I also plan to install fans on the top and bottom of each amplifier to improve heat dissipation.

¿Have you observed significant differences in temperature, stability, or durability between these power supply options?, ¿is the power loss with lower voltage/current power supplies actually audible or relevant for high-sensitivity speakers (say, above 90dB at 8 ohms)?

Thank you in advance for your attention.

A pair of fans (set to middle of three speeds), one below each V3, never bring the temperatures beyond mildly warm to the touch after six or seven hours at moderate volume. I use a pair of 48V 10A supplies. When cranked, they do not get hot to the touch driving A/D/S/ M15, 90db-sensitivity 8-ohm speakers at considerable volume.

 

[Firulais71]

A pair of fans (set to middle of three speeds), one below each V3, never bring the temperatures beyond mildly warm to the touch after six or seven hours at moderate volume. I use a pair of 48V 10A supplies. When cranked, they do not get hot to the touch driving A/D/S/ M15, 90db-sensitivity 8-ohm speakers at considerable volume.

Hey Threej, thanks so much for your attention to my question. Great advice! I've decided to build it like you suggested, with each V3 having its own 48V 10A power supply, and cooling each amplifier with fans pushing air from above and below. I'll be pairing it with the ZD3 DAC and the Fosi ZP3 preamp. ¿Would you change any components of that chain? I can stretch my budget by about $300 more if necessary.

Greetings from Peru.

 

[threej]

Firulais71, you are duplicating my setup. FWIW, I make use of their balanced connections. I have been mightily impressed with the quality of sound from these units. If you still use vinyl, their X5 Phono Preamp is very nice.

 

[Firulais71]

Firulais71, estás duplicando mi configuración. Por cierto, utilice sus conexiones equilibradas. Me ha impresionado muchísimo la calidad de sonido de estas unidades. Si todavía usas vinilo, su preamplificador de phono X5 es muy bueno.

Hi Threej, yes, I plan to connect these components with XLR cables to minimize interference, noise, and other signal parasites. At least, that's what the experts say, so it's worth following their advice.

Regarding my sources, I only listen to digital music: Tidal, the several thousand FLAC files I have on my server (almost all 24 bit), rips of my old CDs, and various DSD files. I never got into vinyl; it's too impractical for me. I just want to get home, click a button, and have my music start playing as I open a beer. My dad is a huge vinyl fanatic; you should see him spend entire afternoons in his studio reconfiguring his turntables, changing cartridges and needles, adding counterweights to the tonearms, testing different phono preamps, and a thousand other things. I respect his passion, but that format is too complicated for me. But as long as he's happy, I'm happy too.

Best regards.

 

[Rotel75]

I'm surprised so many people are worried about the temp. and add cooling.
Is a warm case really a bad thing? Maybe most other amps/designs are bad at transfering the heat out...

 

[Firulais71]

I'm surprised so many people are worried about the temp. and add cooling.
Is a warm case really a bad thing? Maybe most other amps/designs are bad at transfering the heat out...

Hi Rotel75, regarding the Fosi V3, many comments and reviews state that these monoblocks get very hot, perhaps too hot considering that class D units should be very energy efficient, unless they have poorly designed heat sinks, of course, and perhaps that's the case here. I'll check when my units arrive. While -at least for now- I haven't read about any V3s short circuiting due to high temperatures, we can't forget that excessive heat (outside of "normal" and constant parameters) is one of the biggest enemies of electronics. It accelerates component wear, increases resistance, which causes energy loss that in turn generates more heat (that vicious cycle called the Joule effect), reduces efficiency, can degrade insulation, and in the worst cases, cause failures, short circuits, and even fires. I know; it's happened to me with other electrical equipment.

That's why I plan to use fans on the V3s. I don't know how they're built internally, so I'm going to open them up. If I see that they use thermal paste, I'll replace them with good quality paste or thermal pads. By minimizing the operating temperature of my next V3s, I'll not only avoid potential failures but also extend their lifespan. They're inexpensive devices; the investment is small, but I still want them to last for years.

Best regards.

 

[Nopiano]

I'm surprised so many people are worried about the temp. and add cooling.
Is a warm case really a bad thing? Maybe most other amps/designs are bad at transfering the heat out...

Yes, I’ve wondered similarly. Sure, the Fosi monos run hotter than most amps, but as you say the case is the heat sink. In typical full sized amps not many folk have had the case open and felt the heat sink!

 

[norcalscott]

I use AC Infinity S1 fans on top of my Monos that blow up and away from the amps (medium speed is almost silent) and the case gets significantly less warm than without them. I know the case is a heat sink, but my feeling is that the life expectancy of these kinds of electronics in general can be extended a good bit by keeping the units cooler. It may not make a difference, but I try to keep things as cool as possible, and it can't hurt. I already had the fans so in my case was an easy decision.

 

[Petrushka]

What are your thoughts on the extended warranties sold by Amazon (Asurion)? They currently have a deal where you pay 17$/mo and everything you purchase is covered by an extended warranty. They even grandfather in anything you’ve purchased in the prior 12 months. I come from a school of thought that 99% of the extended warranty plans aren’t worth the money, but for 17$/mo perhaps it makes sense. As a reliability testing guy, I’d be interested in your opinion. Thanks!

I nigh get an extended warranty if it’s direct from Amazon. I bought an extended warranty through Amazon on a vaccuum cleaner, and when I tried to use it, the process was more trouble than it was worth.