The question about the fan volume was triggered by a thread where a MW SPV-300-48 was really annoying due to a constantly running fan that was clearly audible during operation. The solution was to retrofit a 45 Ohm resistor to reduce the volume in the long run. https://www.diyaudio.com/forums/class-d/287470-tpa3255-diy-discussion-design-etc-91.html#post5573119
However, due to the modification, there is of course no guarantee in case of technical problems. I have therefore ruled out the MW SPV-300-48.
I'm currently thinking about whether I should use an LRS-350-36 or HLG-320H-36A. Of course, the LRS-350-36 is cheaper, but the main differences are the cooling system and the efficiency. The prices for Germany include 19% VAT. The prices in $ are without VAT.
I am particularly interested in the LRS-350-36. According to the technical data, the fan of the LRS only starts to run at a temperature of 40 degrees Celsius.
What are the experiences in practice regarding the noise level of the fans with MW?
However, due to the modification, there is of course no guarantee in case of technical problems. I have therefore ruled out the MW SPV-300-48.
I'm currently thinking about whether I should use an LRS-350-36 or HLG-320H-36A. Of course, the LRS-350-36 is cheaper, but the main differences are the cooling system and the efficiency. The prices for Germany include 19% VAT. The prices in $ are without VAT.
I am particularly interested in the LRS-350-36. According to the technical data, the fan of the LRS only starts to run at a temperature of 40 degrees Celsius.
What are the experiences in practice regarding the noise level of the fans with MW?
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I used the LRS-350-48 with the TI 3255EVM board for several months and never had the fan turn on, so I'd call that experience quite good. This was with 104db speakers in a small room.
On the other hand, I tried using two of the 24v versions in a Pass class A amp, and the noise was incredible, with the fans running full time.
Depending on your actual current requirements, you might be able to use the LRS-200, which has no fan, but does have a nice mesh-type open case, along with, if necessary, a small silent computer fan and you'd have silence. Good luck with your build.
On the other hand, I tried using two of the 24v versions in a Pass class A amp, and the noise was incredible, with the fans running full time.
Depending on your actual current requirements, you might be able to use the LRS-200, which has no fan, but does have a nice mesh-type open case, along with, if necessary, a small silent computer fan and you'd have silence. Good luck with your build.
I just bought a pair of Meanwell UHP-500-48 to power two TPA3255 amps. It's fanless. Costs a little more, but you get peace of mind that there will be absolutely no fan noise. Give the UHP line a look.
Thank you for your answers. There were some interesting answers. It is not surprising that the fan of the LRS 350-36 does not start with a loudspeaker with 103 dB efficiency. What is important for me to know is whether the noise (SNR) of the LRS 350-36 was audible with this 103 dB loudspeaker.
I'm asking because I'm planning to use a compression driver as a 110dB horn with a TPA3255. And here, as little noise as possible is called for. Actively separated below there is a woofer module for the frequency range up to 1000 Hz.
Another loudspeaker is in the usual 88..90dB range. All drivers are actively controlled via DSP software (Acourate).
It would be interesting for me to hear whether the fan of the LRS 350-36 is disturbing in operation with usual 88..90dB speakers.
Passive cooled power supplies like the LRS 200 series or the UHP-500-48 are of course a possible way to avoid the SMPS fan.
For heat dissipation, I will install slow-running PC fans that are not audible in volume.
I'm asking because I'm planning to use a compression driver as a 110dB horn with a TPA3255. And here, as little noise as possible is called for. Actively separated below there is a woofer module for the frequency range up to 1000 Hz.
Another loudspeaker is in the usual 88..90dB range. All drivers are actively controlled via DSP software (Acourate).
It would be interesting for me to hear whether the fan of the LRS 350-36 is disturbing in operation with usual 88..90dB speakers.
Passive cooled power supplies like the LRS 200 series or the UHP-500-48 are of course a possible way to avoid the SMPS fan.
For heat dissipation, I will install slow-running PC fans that are not audible in volume.