Davebassics Posted March 9, 2017 Share Posted March 9, 2017 There are posts on forums to do with this already but I am yet to find the answer I am looking for. I practice quietly with little atmospheric noise. The Fan noise from my LMIII is loud enough to be annoying to me. I am a sound engineer so maybe I am a little more tuned to notice these sorts of things that normal. I have so far replaced the fan three times with three different models. The last one I tried was an identical fan to the original for real electronics (Mark bass's service representatives in the UK). None of these solved the problem. So I am now just beginning to believe that it is normal to have this noticeable fan noise. I bought the amp second hand so have no experience of what it was like when it was new. There are several reports on the internet that Mark bass fan noises are "quiet", "silent" etc. I was wondering if any LMII owners would be willing to measure fan noise from their amps to try and get a bit more of a objective reading on how loud the fan should be. We could do this using a SPL phone app maybe? Not the most fool proof way of getting a noise measurement but it would be better than nothing. Is anyone willing to give this a go? Hopefully I'll be able to work out whether or not I am trying to fix a problem that doesn't exist before I start debugging the supply line to the fan! Quote Link to comment Share on other sites More sharing options...
6v6 Posted March 10, 2017 Share Posted March 10, 2017 I've got a Lm3 and never noticed any fan noise tbh, I do mostly use it in a band though. I can try to measure the volume in a home environment later. Quote Link to comment Share on other sites More sharing options...
GreeneKing Posted March 10, 2017 Share Posted March 10, 2017 I've 2 Markbass LM amps. A Tube 500 and a LMII. I don't use them for home practice as I've a TC Electronics BG250 1x15 combo for that. I have set up my MB amps at home at low volume and the fan noise is a bit annoying. Personally I don't see it as a problem because I'm expecting them to operate out of their natural environment imo. There're also the benefit that the TC amp has a aux in and a headphone out. Horses for courses in my opinion. Of course you may have a particular amp problem but if you've tried several fans it doesn't sound like it. Peter Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted March 10, 2017 Share Posted March 10, 2017 At such quiet volumes the amp should hardly be generating any heat at all. You could fit a small switch to turn the fan off for quiet practice, or fit a thermal switch to the heatsink to turn the fan on when it gets mildly warm. Alternatively, play through headphones! Quote Link to comment Share on other sites More sharing options...
Davebassics Posted March 10, 2017 Author Share Posted March 10, 2017 Thermal switch isn't a bad idea. I don't feel any hot air from that fan even after a couple of hours practicing. Does anyone have a schematic for LMIII? Wondering if the fan speed is variable depending on heat? If so it could be that the fan is just constantly running at full speed. There is always the chance I am just being hyper sensitive to fan noise but I'd like to get a noise reading to compare. I will take a noise reading of mine tonight and see what I get. Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted March 10, 2017 Share Posted March 10, 2017 If it's not getting hot after a couple of hours, maybe putting a soft pillow over it might do the trick. Obviously, I wouldn't recommend that if it were generating any noticeable heat Quote Link to comment Share on other sites More sharing options...
Davebassics Posted March 10, 2017 Author Share Posted March 10, 2017 Not the most scientifically correct experiment in the world but ... Using the Keuwlsoft s-01 Android App, took a 20 second measurement from around 1 meter behind the fan. It averaged at 58.80dBA (Decibels A-weighted). According to: [url="https://www.endpcnoise.com/cgi-bin/e/decibels.html"]https://www.endpcnoise.com/cgi-bin/e/decibels.html[/url] 60dBA is a noisy lawn mover at 10m. Quote Link to comment Share on other sites More sharing options...
markstuk Posted March 10, 2017 Share Posted March 10, 2017 My thunderfunk with it's fan switched on is around 54 dBA - and with it off about 50 dBA.. Using the same app at the same distance, but that assumes the calibration is accurate.. Quote Link to comment Share on other sites More sharing options...
mcnach Posted March 14, 2017 Share Posted March 14, 2017 [quote name='Davebassics' timestamp='1489049213' post='3253913'] There are posts on forums to do with this already but I am yet to find the answer I am looking for. I practice quietly with little atmospheric noise. The Fan noise from my LMIII is loud enough to be annoying to me. I am a sound engineer so maybe I am a little more tuned to notice these sorts of things that normal. I have so far replaced the fan three times with three different models. The last one I tried was an identical fan to the original for real electronics (Mark bass's service representatives in the UK). None of these solved the problem. So I am now just beginning to believe that it is normal to have this noticeable fan noise. I bought the amp second hand so have no experience of what it was like when it was new. There are several reports on the internet that Mark bass fan noises are "quiet", "silent" etc. I was wondering if any LMII owners would be willing to measure fan noise from their amps to try and get a bit more of a objective reading on how loud the fan should be. We could do this using a SPL phone app maybe? Not the most fool proof way of getting a noise measurement but it would be better than nothing. Is anyone willing to give this a go? Hopefully I'll be able to work out whether or not I am trying to fix a problem that doesn't exist before I start debugging the supply line to the fan! [/quote] I've owned two LM3 and a CMD121P combo (essentially an LM3 in combo form). You can hear the fan. I think the reason why some claim it's quiet/silent is twofold: 1) there are much louder fans in amps out there, and 2) most users would use it in an environment where the fan noise is masked with other sounds. I suspect there's nothing wrong with your amp. Quote Link to comment Share on other sites More sharing options...
mcnach Posted March 14, 2017 Share Posted March 14, 2017 [quote name='MoonBassAlpha' timestamp='1489145082' post='3254701'] At such quiet volumes the amp should hardly be generating any heat at all. You could fit a small switch to turn the fan off for quiet practice, or fit a thermal switch to the heatsink to turn the fan on when it gets mildly warm. Alternatively, play through headphones! [/quote] That's not a bad idea. It would allow quiet operation and as long as you remember to switch it back on when using it in anger it should be ok. Maybe wire it so that when you turn the amp off the switch reverts to normal "fan on" mode. Quote Link to comment Share on other sites More sharing options...
Davebassics Posted March 14, 2017 Author Share Posted March 14, 2017 I am almost satisfied that there isn't anything wrong with the amp, it is probably operating within normal noise specs. I like the idea of installing a switch but I wouldn't want to affect the resale value of the amp. I'm definitely happy with the amp bar the fan noise. I'll have a look and see if I can make a reversible modification to it. Quote Link to comment Share on other sites More sharing options...
GOM Posted March 16, 2017 Share Posted March 16, 2017 (edited) My Ampeg fan started to make quite a bit of noise - not noticable when playing but a pain when at home practicing. Find out the fan voltage (and size) and have a look at [url="https://www.quietpc.com/acoustiproductsfans"]https://www.quietpc....stiproductsfans[/url] and see if they have an equivalent. I can't hear my fan at all now after having replaced it. Edited March 16, 2017 by GOM Quote Link to comment Share on other sites More sharing options...
compresssion67 Posted February 28, 2021 Share Posted February 28, 2021 Newegg sells a quiet fan for like 14 -16 us dollars. I finally replaced the crap fan that came with my Little Mark Ninja combo. That thing was stoopid loud for a case fan - drive a human crazy. The brand name I used was Noctua (advertised premium quiet fan) but it came with a 3 pin plug instead of the 4 pin in the amp, so had to swap. Night and day difference with the noise factor though. Made the amp usable again, I'm in a small studio setting and it was not good. Hope it helps. Quote Link to comment Share on other sites More sharing options...
Dan2030 Posted January 17, 2022 Share Posted January 17, 2022 Hi I got a Markbass mini CMD 151 combo and I got a noisy cooling fan problem too, I went on Noctua site and found a lots of fan but most of them have 3 or 4 pins connecters, the fan in my amp works with 2 wire 1 red and 1 black do you think that there's a model that would do the job in my amp, going via Markbass is really not a good way to have a problem solve... I know I could replace it, but I don't know witch one to choose. Thank you Quote Link to comment Share on other sites More sharing options...
mybass Posted January 17, 2022 Share Posted January 17, 2022 I got this one as a spare from https://realelectronics.co.uk as a direct replacement. Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 21, 2022 Share Posted January 21, 2022 On 17/01/2022 at 01:56, Dan2030 said: Hi I got a Markbass mini CMD 151 combo and I got a noisy cooling fan problem too, I went on Noctua site and found a lots of fan but most of them have 3 or 4 pins connecters, the fan in my amp works with 2 wire 1 red and 1 black do you think that there's a model that would do the job in my amp, going via Markbass is really not a good way to have a problem solve... I know I could replace it, but I don't know witch one to choose. Thank you I've just fitted this Noctua model in my Markbass Combo 121 Lite Alain Caron and it's working flawlessly : https://www.amazon.co.uk/Noctua-NF-A6x25-FLX-Premium-Quiet/dp/B009LEKGGE/ It comes with all the adaptors needed, but you'll have to use the 3 to 4 one and transfer the black and white wires to the Markbass connector, nothing extraordinary to do with a decent soldering iron. I've used the Ultra Low Noise Adaptor to reduce the fan noise by 18 dB !!! compared to the stock Markbass fan. Here are the measurements made 5 centimetres away from the fan to get useable measurements, so the measured noise is not correct as it's way too close. 1. Markbass original fan (already quiet Fonsoning) : 2. Noctua at maximum speed (no Ultra Low Noise Adaptor) : 3. Noctua at minimum speed (with Ultra Low Noise Adaptor) : This is the original fan : Quote Link to comment Share on other sites More sharing options...
iPlay5 Posted October 29, 2023 Share Posted October 29, 2023 Same. I have Little Mark III and it the fan noise was out of control. I installed the Noctua, link below. The fan still ran constantly, but it was whisper quite. https://www.amazon.co.uk/Noctua-NF-A6x25-FLX-Premium-Quiet/dp/B009LEKGGE/ref=mp_s_a_1_1?crid=151U2PT27QSXI&keywords=B009LEKGGE&qid=1642796933&sprefix=b009lekgge%2Caps%2C129&sr=8-1 Quote Link to comment Share on other sites More sharing options...
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