Adding a temperature controller to my amp fan ?

Discussion in 'Amps and Cabs [BG]' started by Nunien, Jan 22, 2022.

  1. Nunien

    Nunien

    Mar 22, 2020
    Hi, I got an EBS Reidmar 250 and the fan turns on to full speed at the moment I turn the amp on. I find it a bit noisy, even after replacing the fan by a new one (with same specs).

    I think maybe it doesn't actually need so much cooling when I play at low volumes, so I'm planning to add one of those very cheap controllers that goes between the 12v socket of the amp board and the fan. It has a temperature probe and a buzzer that I might not use. From what I understand, you can tune the temperature thresholds.

    s-l1600.jpg

    What do you think ? Good idea ? Bad idea ? What is the max temperature to set for the amp ? Where to set the probe, on the D class chip ? Should I use a fan whith rgb leds ?
     
  2. callofcthulhu

    callofcthulhu

    Oct 16, 2012
    Bad idea.
     
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  3. Aloe

    Aloe

    Apr 10, 2016
    Ukraine
    I have a 750 and the always-on fan seemed noisy to me as well. I got a quiet Noctua fan (NF-A6x25 FLX) and after consulting with EBS reduced the power with a low-noise adapter (with a resistor) that was in the box with the fan. with the 250 I'd go straight to the ultra-low-noise adapter from the same box, so that would be still always working fan, but a very quiet one.

    please take note that Noctua's 2 to 3 pin converter needed a pin swap to work with my Reidmar, I believe the Noctua's adapter is backwards compared to what Reidmar expects and in this case fan wasn't spinning at all.
     
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  4. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    When designing an amp with fan cooling, all of those questions come into play plus a bunch of additional one.

    What does EBS recommend?
     
  5. lug

    lug Supporting Member

    Feb 11, 2005
    League City, Tx
    I prefer as few single points of failure as I can get.
     
  6. Nunien

    Nunien

    Mar 22, 2020
    Was the Noctua quieter, even at full speed ?
    Also, you are saying that EBS was ok about reducing the speed of the fan for your 750 ? Do they have arguments about that, is there a protection that turns off the amp when oveheating ?
     
  7. Aloe

    Aloe

    Apr 10, 2016
    Ukraine
    frankly I don't remember if I tried this at all or just started with a resistor. I believe, at full speed Noctua moves significantly more air than the stock fan.

    yeah, they confirmed I'll be good. they're very helpful guys, it's always a pleasure to read a response from them.
     
    Nunien likes this.
  8. Jefus

    Jefus Does this amp make my bass sound fat? Supporting Member

    Feb 23, 2008
    Sacramento
    Good call. Anyone who's built their own computer knows how quiet and reliable Noctua fans are. It makes sense to consider them for other applications as well. Add long as they're not seen anyway; the standard color for them is pretty atrocious.
     
  9. Zoffy

    Zoffy Supporting Member

    Jun 7, 2020
    Sacramento CA
    I have an Eden WTX500 that has a fan that sounds like a Harrier jet at takeoff - and it is always on. I don't hear it when I'm playing though. Then again, I used to live next to a city bus maintenance depot and I got to where I did not hear the busses either...
     
    Al Kraft likes this.
  10. john m

    john m Supporting Member

    Jan 15, 2006
    Temperature management within ANYTHING that runs on electricity is a critical part of design work. It is not guess work. You could end up with a fire or seriously degrade the life of your equipment if the (I*I)*R heat is allowed to remain within the device.
     
  11. Ukiah Bass

    Ukiah Bass

    May 10, 2006
    …and I have sold several amps because they were too noisy on quiet gigs and especially in my home studio…..
     
  12. sedan_dad

    sedan_dad

    Feb 5, 2006
    Columbus,Ohio
    Get a old B-15. No fan noise.
     
  13. Tim Skaggs

    Tim Skaggs

    Sep 28, 2002
    Is your thought on how much cooling the amp needs based on any data from the manufacturer or from any temperature measurements you have taken? Why do you think it doesn’t actually need the cooling airflow with which it was designed? @agedhorse replied that cooling requirements would have been considered during design. Heat is probably the #1 killer of electronic components, so if the EBS engineers determined the amount of cooling the amp has now was required to achieve the expected life of the amp, the cooling airflow probably needs to remain as it is.

    I think a safer and probably more reliable solution would be to replace the fan with one that still moves the same volume of air per time unit as the stock fan, but is quieter. At least that would keep the cooling airflow / amp temp the same as designed and eliminate wondering if the amp would survive at a lower cooling airflow.
     
    agedhorse likes this.
  14. Alain Bass

    Alain Bass

    Jun 6, 2004
    Paris France
    On a Markbass Mikromark 801 that I use sometimes at home, I change the fan for a noctua.
    The problem is that the noctua turns quicker than the original one. So the noise is the same.
    Now I could put a resistor to lower the speed, but how to calculate it to have the same speed as the original one and avoid overheat ? So I ended not using it at home.
     
  15. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    As the fan turns slower, the air flow decreases. The balance between air flow, speed and noise is a delicate one.

    Since air flow or a given static pressure changes as the cube of the power, the easiest way to determine if a fan will have similar air flow at a similar static pressure is to be sure the power (or voltage x current) is the same.

    Since the power equation is cubed relative to air flow, this makes variable speed fan circuits more sensitive to the specific fan so that the air flow tracks temperature properly. If chosen wrong, it’s possible for the temperature to increase at a faster rate than the air flow, causing thermal runaway and failure.
     
    Last edited: Jan 23, 2022
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  16. Alain Bass

    Alain Bass

    Jun 6, 2004
    Paris France
    an idea ??
    If you could find one: a stroboscope to mesure the speed of the original one, and do the same to the noctua ;)
     
  17. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Speed doesn’t matter, because changing the pitch and thickness of the fan blade changes the air flow for a given speed.
     
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  18. 6thplanet

    6thplanet Supporting Member

    Aug 17, 2019
    Indiana
    So when are amp manufacturers and Dyson ionic fans going to come together and put an end to this nonsense!
     
    S-Bigbottom and agedhorse like this.
  19. Aloe

    Aloe

    Apr 10, 2016
    Ukraine
    you don't need the speed, you need the airflow. get the number for a stock fan and get the number for Noctua (they commonly publish the specs for their fans with their low-voltage adapters that's basically a resistor, the values of resistors in their adapters are googlable).
     
  20. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Just be sure that the air flow is at comparable static pressures, because in some designs this too is important. Air flow varies with static pressure when everything else is held constant.