Fan noise differences between LX II and larger products

Power Amps
1

I just purchased a new LX II amp to power a Boss GX-10 modeler utilizing both channels for stereo sound. For context, I only play in a home studio environment, thus there is no ambient noise.

Upon first powering on the LX II, the internal fan immediately activated. As has been discussed by others, the fan noise is unfortunately, simply too loud to bear.

That being said, is the fan noise from the 2/50/2 or 2/90/2 any quieter given the larger internal space volume and assumedly slower fan speeds?

2

Hi Calif,

Welcome to the forum!

Whether the 2502/2902 fans are quieter depends on your particular brand of noise intolerance. Some people hate higher pitch fan noise and others hate low pitched noise. These fans are generally perceived as producing lower noise because of the lower noise frequency or because you can manually set them to a slower speed.

2502/2902 fan:
Speed - 1500/3200 RPM
Airflow - 32CFM
Noise - 38dB

LXII fan:
Speed - 3600/7200 RPM
Airflow - 8.9 CFM
Noise - 29dB

The purpose of the fan is not to cool the tubes. It’s to make sure the external package temperature never exceeds the safe limit at its hottest point. As you can see, the LXII with two smaller fans running at twice the speed of the 2502/2902 fans only produce half the airflow with 10dB lower measured noise.

So, if you’re not running the power amp very hard, you can run the 2502/2902 fans at slow speed and reduce the noise effective output.

Cheers,

Dave

3

Thanks for your reply, David. A few follow-ups:

  • Are the noise levels that you listed based on the high or low speeds?
  • One thing I noticed, is that when I turned on the amp last night, the “higher” speed seemed to kick-in within a very short timeframe (like 30 seconds later…). This is from a cold start. Also, I set my modeler’s output level to its highest setting and had the volume of the amp barely off zero (*again, I am playing in a silent home studio).
  • Perhaps the amp is overkill for what I’m looking for. Otherwise, would it make sense to swap the internal fans for a higher-end product such as a Noctua? I don’t know the sizes of the fans installed in the LX II, but models from Noctua that have similar airflow readings appear to have roughly half the noise level. Seems like a relatively inexpensive solution?