Ampeg BA112 V2 Fan Noise Reduction

[jpBassin]

Hello bass talkers,

I picked up a new Ampeg BA112 V2 a few weeks ago to serve as my practice amp and so far I've really enjoyed the amp. The best features of the amp in my opinion are it's tone and the convenient kickback/front-control setup. The worst feature of the new BA112 in my opinion is the fan noise.

It's a small fan and likely not a problem in many venues but it's really annoying for how I've been using the amp which is low-volume playing in a small hardwood floored room. Beyond the relatively loud volume of the fan noise to quiet playing the fan also has some high-pitched overtones that cut and are noticeable even when the bass gets loud enough to drown out the normal fan noises.

I considered sending the amp back but it's so good outside of the fan noise that I instead ordered and installed one of the only compatible fans that I could find in hopes of improving the noise problem. That new fan has cut the fan noise down to a level that I can live with and most importantly it eliminated the higher pitch sounds that had grown particularly annoying. Since talkbass.com has been so helpful I wanted to share a few details on the fan swap in case they help someone else with a BA112 v2 looking for ways to cut down on the fan noise. I'd love to hear about ways to cut the noise even further if any are known.

Here is the replacement fan that I installed:

"Delta AUB0524VHD 5020 50mm 5CM DC 24V 0.15A"
Delta AUB0524VHD 5020 50mm 5CM DC 24V 0.15A Server inverter PC Case Cooling fan computer case cooler - Newegg.com

Here are the specs on the original fan:

"DA05020B24M dc 24V 0.10 A shenzhen huaxia hengtai electronic co ltd"
Link Removed


The new fan has the same blade shape/etc. and the only noticeable difference is that it spins at a slower rpm. I shortened the power lead on the new fan so that it matches the length of the original and also had to reverse the wires in the plug since the polarity was reversed. I also installed the new fan using rubber mounts instead of the original screws but I don't think using the rubber feet made any noticeable difference or improvement. The new fan pushes less air but you can still feel air coming out of the side-vent on the amp and I don't think the difference is enough to cause problems in any but the most extreme heat situations, if then. At low volumes in climate-controlled spaces a fan may not even be needed but I'm not sure on that and didn't want to test it.

I've attached a few photos showing the old/new fans and also the technique that I used for pulling the rubber feet into the new fan in case anyone wants to use them and has trouble.

As a bonus you can see how the BA112 looks with white piping since I also changed that out now that I'm modding the amp and probably voiding warranty.

 

[Haxel]

I also found the fan noise a bit annoying. Very good amp, the fan noise was really the only neg on what could have been, at least for me, a perfect amp.

My solution was a little different from jpBassin's. I found a little 24v (same as fan) digital temperature controller with relay for $11.50 on Amazon (https://www.amazon.com/gp/product/B076YD8H19) and mounted it to the back of the grill.


It has two displays, one for set temp and one for current temp both of which you can see through the grill. I have it set to turn on at 90* F but using it as a practice amp at volume 2, it never gets warm enough to turn on. I can access the buttons to set the temp through the grill but it runs pretty much room temp at practice volumes so I haven't needed to change it.

I made a little wiring harness so I can remove the controller and return it to 100% original. The wiring harness was put together with odd connectors from old computers. It works fine but it's a bit of a bodge job. I've ordered some leads with connectors--when they arrive I'll redo the harness and take pictures.

There's a small amount of hum in the amp (depends on settings) but it's much, much quieter without the fan running.
Haxel

 

[Haxel]

Here's a detail of the spacers used to mount the controller to the grill.

I had a box of black nylon spacers. You can buy them in hardware or electronics stores. These came from Microcenter. They have a section in the store for electronic kits and IoT stuff.

The 1" spacers leave enough room to maintain airflow. They lined up perfectly with the slots in the grill so no holes are necessary.

The black nylon screws give it a neat, stock appearance.
Haxel

 

[BassmanPaul]

Yes it’s safe to say that you have voided your warranty. You have also compromised the cooling path for the amp. If you push your amp and if you’re lucky the amp will shutdown to save itself. If you’re not lucky you’ll need to buy a new amp.

 

[Haxel]

Thanks, Paul. OP had a new amp but mine's used so no warranty at risk.

Regarding the airflow, the fan doesn't blow directly out the grill so the airflow is unlikely to be compromised. It's more about pressure than direct airflow.

Considering your point though, it's probably better to measure the temp near the cooling fins in the cab than near the electronics where I have the thermocouple now. The fan is at the back of the electronics "drawer" and basically moves the air out of the cab (where the aluminum cooling fins radiate the heat) and pressurizes the space around the electronics. Then the air escapes out the grill.

The way this is designed, the fan doesn't blow directly on anything for cooling. It just moves the air from one place to another so the heat doesn't build up. If there's no heat build up in the space around the cooling fins, there's no reason to run the fan.

Thinking aloud here, the fan is probably only necessary when the amp is laid down in the 60 degree mode. Otherwise convection (chimney effect) would move enough air to avoid heat build around the cooling fins. When the amp is laid down, the grill is near the bottom in the wrong place to convect the heat out. The design of the enclosure prevents placing the grill in the optimum spot for both set ups so a fan is needed.



I'm not the only one to comment about the annoying fan noise on this amp. For me at least, this is a reasonable solution.
Regards,
Haxel

 

[jpBassin]

Looks like a nice solution to the fan noise Haxel. For practice duty especially your would be nice as it eliminates all noise. My quieter fan doesn't annoy me so I'm not motivated, but I'm tempted to try your setup at least to have a thermometer in there to monitor.

I'm curious what the temps run in these amps in different scenarios and how you should set the "on" temp for the fan controller. Seems like a good idea to keep an eye on it if you ever get into a situation where you push it hard enough to generate some real heat. With the temp readout you should get a good idea of how essential and effective the fan is on these things. Let us know if you notice any patterns with yours, like extreme heat above a certain volume level or similar.

My amp continues to work flawlessly and the fan annoyance is a distant memory though I've still not pushed it very hard. It's great for the light volume levels I've used it at though (mostly below 4 with a passive bass).

 

[Haxel]

Nice to hear from you, jpBassin!

My playing/volume habits are much like yours. So far, the temps haven't risen enough to run the fan.

I am planning to move the probe into the space near the cooling fins though since that's what really matters (it's in the component tray now).

My suspicion is that the fan is only required at high volumes or perhaps when the cab is in the 60 degree monitor mode when the grill is positioned to prevent convection. I'll also run it that way and see if the temp goes up.
Haxel

 

[Haxel]

JpBassin,

I've moved the thermocouple to the backside of the component drawer, between the power supply and the cooling fins and got some new temp/volume data for you.

Playing with amp upright at volume 2, Scrambler on, everything straight up, the temp goes from 70*F to just under 75 after 30 minutes of moderate playing.

In 60 monitor mode, volume setting 4 will cause the fan to kick on after 15 minutes playing. It stays on for about 20 seconds and cycles once per 2-3 minutes. Fan is set to turn on at 90.

In upright mode, with volume set to 6, the fan will also turn on, run briefly and then turn off.
(Edited to remove "conclusions")

Haxel

 

[agedhorse]

Without sensing the actual heat sensitive components, everything is a speculation based on guesses.

There are some interesting and incorrect assumptions being made about how thermal cooling works. These are reasons why manufacturers void warranties on modified products.

 

[Haxel]

In light of agedhorse's comments, I've removed my "conclusions," which were of course speculative.

Before anyone considers modifying their amp in any way, they should heed the advice about warranties and understand the risk of potential damage.
Haxel

 

[JimmyM]

I don't get the complaints about fan noise. Never have. Most fans aren't nearly as loud as background noise in any home. My refrigerator runs louder. My AC unit is louder. And as soon as I start playing, I don't even hear the fan whatsoever.

 

[Haxel]

Good point, JimmyM.

That's not something I can explain. Based on the numbers of "how do I quiet my fan" discussions though, it seems to bother some more than others. Or, maybe people fixate on trivial or non-existent problems and have a compulsion to try to make things "better."

Please don't misunderstand, despite my tinkering, I'm a big fan of Ampeg products. Digging around inside gives me a greater appreciation for the challenges and tradeoffs in designing, building, and selling a successful product at a competitive price. This is a great little amp--I just personalized it--made it a little bit better for me. Think of it as my version of slapping a cool sticker on the side...

If something goes wrong and I "let the smoke out," I'll come back, fess up, and take my lumps. Y'all can even say "I told you so!"
Haxel

 

[Jon Herring]

So I just bought one of these not realizing how loud the fan was... how do you even take the back of this amp off? I can remove the air vent but can’t really get my hand in there to do any work to remove it.

I also thought about just unplugging the fan since I don’t really play that loud for it to heat up that much.

 

[JimmyM]

So I just bought one of these not realizing how loud the fan was... how do you even take the back of this amp off? I can remove the air vent but can’t really get my hand in there to do any work to remove it.

I also thought about just unplugging the fan since I don’t really play that loud for it to heat up that much.

You have to undo a lot of screws on the top that hold in the chassis, then slide the chassis out the back. Won't be able to go too far but should be enough to get to the fan.

BTW, you can get fans that are way quieter. Just get one with the same specs or better.

 

[Jon Herring]

Would I need to have certain tools to replace the fan like a saudering iron or anything like that? I’m not too crafty with things like that haha.

I heard the BA115 has a better fan and makes hardly any noise but it’s $100 more so wondering if that would be better than trying to replace the fan myself or pay someone to do that.

 

[agedhorse]

Would I need to have certain tools to replace the fan like a saudering iron or anything like that? I’m not too crafty with things like that haha.

I heard the BA115 has a better fan and makes hardly any noise but it’s $100 more so wondering if that would be better than trying to replace the fan myself or pay someone to do that.

You might very well be better off buying something that you know fits your needs rather than gambling and experimenting without knowing what you are doing. It may even be less expensive!

 

[JimmyM]

Would I need to have certain tools to replace the fan like a saudering iron or anything like that? I’m not too crafty with things like that haha.

I heard the BA115 has a better fan and makes hardly any noise but it’s $100 more so wondering if that would be better than trying to replace the fan myself or pay someone to do that.

The fan in the BA112 attaches to the circuit board with a molex plug and I'm pretty sure but not 100% sure that all fans of that nature will have the same size plug, so no soldering required. I think anyone who knows how to operate a screwdriver could install one in a short time, but definitely don't do it if you're feeling iffy about it.

And you can always take the option I took...realize that within a few minutes, you end up tuning the fan noise out, and you can't hear it over a band or when you're playing along to recorded music. And then you leave it alone and never have to worry about it

 

[Jon Herring]

The fan in the BA112 attaches to the circuit board with a molex plug and I'm pretty sure but not 100% sure that all fans of that nature will have the same size plug, so no soldering required. I think anyone who knows how to operate a screwdriver could install one in a short time, but definitely don't do it if you're feeling iffy about it.

And you can always take the option I took...realize that within a few minutes, you end up tuning the fan noise out, and you can't hear it over a band or when you're playing along to recorded music. And then you leave it alone and never have to worry about it

That’s true... when playing with other music I guess it gets drowned out but when playing solo it’s pretty loud and especially if I want to record me playing on my phone, you can’t escape that high pitch fan haha

 

[agedhorse]

The plugs are not all the same, and of note is that the polarity is not the same either. It's a total crapshoot. Also, most do not come with plugs. Computer fans are probably not appropriate because they are likely to be the wrong voltage.

 

[JimmyM]

The plugs are not all the same, and of note is that the polarity is not the same either. It's a total crapshoot. Also, most do not come with plugs. Computer fans are probably not appropriate because they are likely to be the wrong voltage.

I'm pretty sure finding a fan is a little easier than this sounds, though