The standard fans has two wires, one red and one black. They are connected to the board via a 2-pin connector, as you can see in the fourth picture. However, most, if not all, computer fans have three-pin connector so you can't just connect them to the board just like that without any modifications. What I did then was to cut off the wires to one of the standard fans so I had the 2-pin connector in one end and then just bare wires in the other end. I googled which cables on the 3-pin computer fan I needed to connect to and then I simply cut off the 3-pin connector and soldered the 2-pin connector there instead.
Or well, to be exactly right I connected my fan controller, not the fan itself, to the board but it works exactly the same just that you have to do it twice while I only did it once because I can connect both of the fans to the fan controller and thus only needing one connection to the amplifier board.
However, without a fan controller your fans will be running on 12v (I'm assuming that's the voltage since it is standard in the computer world) so make sure you get fans that are still quiet on 12v because most fans are not. You could also solder a resistor (I don't know what values though) on one of the wires running to fan and in that way reduce the voltage to like 9, 7 or 5 volts. Be careful though, some fans do not run on low voltages like 5 or 6 volts.
Edit: The rubber screws came with the fans. The deal with the rubber screws is that they help reduce vibrations. Fans vibrate, especially as you increase the rpm. With rubber screws less of the vibrations are transfered to the rest of the amplifier case and that way you can further reduce the noise a little bit. I don't know if it actually makes any audible difference though so you could just go with normal screws.
Well, that might be the case. However I'm running the fan controller on my max since the fans were dead silent anyways even on max power.
agencies are not worth their monies - still nobody knocking on my door, although i am a terrorist with my i NUKE, based on what my neighbours say if I play my music too loud.... and too often do I play loud , too often for my poor ears...
anyway I think I am going to try seriesing the fans first, than swapping thr fans if the former does not work. Do not intend to put a controller in. Noise can be accepted to some degree, since my other amp is xti6002, also not silent, for now I am not going to tinker with that one. knock 10db off the inuke fan noise somehow, and I am happy.
anyway I think I am going to try seriesing the fans first, than swapping thr fans if the former does not work. Do not intend to put a controller in. Noise can be accepted to some degree, since my other amp is xti6002, also not silent, for now I am not going to tinker with that one. knock 10db off the inuke fan noise somehow, and I am happy.
Well, some of us are on a tight budget. Of course, if I had the money I would buy some better stuff. Maybe something like a pair of McIntosh MC2KW. But for now, the iNuke NU6000 will have to do the job instead.
selecting good cheap no name stuff (not all cheap things are good!) is a good way to cut off unproductive parasites from the food chain, i. e. fashion millionaires selling only their brand/ label to the same children produced clothes to make it "worth" 25 times, marketing gurus, hifi and cable sound whackos, advertising companies that do exactly nothing to produce goods and services, in that way I do serve mankind well by cheapskating. never buy what is advertized on tv otherwise you pay the tv channel not the product. sadly, most guys cannot follow this argument.
Today I pulled almost what power my speakers can continuously bear, maybe 1 or 2 dB less. The consumption of the iNuke from the 230VAC network is about .25Amps under no load, about 1Amp RMS under the above mentioned condition.
Reasons:
1. Class D has high efficiency, no linear mode for any semiconductor.
2. Other than linear output stages, Class D (and Class I) will recycle reactive power from the speakers into the DC capacitors, thus drawing from the PSU only what real power the speakers burn into heat, plus the small losses of the full bridge.
3. The typical music signal has high peak power, but low average power. The peak voltage at the speakers can be about 120V, but the RMS value is about 20 - 25VAC.
So that is the condition I need to sustain with less airflow or low noise fans. Would it be possible to go fanless? I don't think so.
Reasons:
1. Class D has high efficiency, no linear mode for any semiconductor.
2. Other than linear output stages, Class D (and Class I) will recycle reactive power from the speakers into the DC capacitors, thus drawing from the PSU only what real power the speakers burn into heat, plus the small losses of the full bridge.
3. The typical music signal has high peak power, but low average power. The peak voltage at the speakers can be about 120V, but the RMS value is about 20 - 25VAC.
So that is the condition I need to sustain with less airflow or low noise fans. Would it be possible to go fanless? I don't think so.
I have now opened the inuke6kpfc.
Primary voltage is 318Vdc, no PFC, with 4 x 2200uF paired in series, total 318V/ effective 2200uF.
Secondary is 2 x 80VDC, each has about 10600uF of storage, for a total of 160VDC / effective 5300uF.
At startup, the whole unit has 22Centigrades, both 12V fans are getting 5.8Vdc each from the inukes fan control. Fans are Minebea Motoring Manuf Corpor. 12V 0.38A. Is there a chance that they start at half that voltage also? This mod would be easy and cheap.
Primary voltage is 318Vdc, no PFC, with 4 x 2200uF paired in series, total 318V/ effective 2200uF.
Secondary is 2 x 80VDC, each has about 10600uF of storage, for a total of 160VDC / effective 5300uF.
At startup, the whole unit has 22Centigrades, both 12V fans are getting 5.8Vdc each from the inukes fan control. Fans are Minebea Motoring Manuf Corpor. 12V 0.38A. Is there a chance that they start at half that voltage also? This mod would be easy and cheap.
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In addition, the unit has 5kOhm in parallell on each secondary rail what gives a pre-load of 2.4watts total, the main dc / dc converter will suck 3 or more watts at standby ADDITIONALLY for this waste heat load. I think I ll at least scale that down to 10kOhm per rail by removing 2 of the 4 10k resistors.
So it looks like 40 CFM for the fans is the least to get stable performance.
What do you think of this one (I am thinking of the "H" version):
Datenblatt LFM1580 - PDE-LFM1580-V33
What do you think of this one (I am thinking of the "H" version):
Datenblatt LFM1580 - PDE-LFM1580-V33
current state of my inuke mod:
fans replaced by arctic f8, airflow inverted, sucking from front, mainly because i dont want to get the air blown into my face if I sit in front.
1 hour continuous sine wave 120hz power tested into 4.5ohms on hi line 230V, about 22°C room amb.
exactly 45Vrms, 10A, 450W, both channels driven simultaneously. no 4 ohm resistor was avail.
Any attempt to increase further resulted in thermal on off cycling of the left channel after some minutes.
I conclude, that the class D output part is therefore capable of 2 x 800W into 8 Ohms - the mentioned 10A - both channels driven, continuously, even with arctic f8 2000rpm instead original 4000rpm fan.
BUT the power supply is most likely not, the LLC transformer was quite hot after one hour test with only 900W total output. i am lacking 8 ohm resistors to do this test.
conclusion: for that power level, around 400W into 4 ohms or maybe around 500, 600 into 8 Ohms, both channels continuously driven, I can recommend arctic f8 with airflow inverted, as long as the room temp is moderate of course. remember that the slow blowing lo noise fan will only hurt continuous temp limited "average" power capability, not at all the burst rms peak capability what is around 2000w into 4 ohms.
fans replaced by arctic f8, airflow inverted, sucking from front, mainly because i dont want to get the air blown into my face if I sit in front.
1 hour continuous sine wave 120hz power tested into 4.5ohms on hi line 230V, about 22°C room amb.
exactly 45Vrms, 10A, 450W, both channels driven simultaneously. no 4 ohm resistor was avail.
Any attempt to increase further resulted in thermal on off cycling of the left channel after some minutes.
I conclude, that the class D output part is therefore capable of 2 x 800W into 8 Ohms - the mentioned 10A - both channels driven, continuously, even with arctic f8 2000rpm instead original 4000rpm fan.
BUT the power supply is most likely not, the LLC transformer was quite hot after one hour test with only 900W total output. i am lacking 8 ohm resistors to do this test.
conclusion: for that power level, around 400W into 4 ohms or maybe around 500, 600 into 8 Ohms, both channels continuously driven, I can recommend arctic f8 with airflow inverted, as long as the room temp is moderate of course. remember that the slow blowing lo noise fan will only hurt continuous temp limited "average" power capability, not at all the burst rms peak capability what is around 2000w into 4 ohms.
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Hello everyone!
First of sorry for digging up an old post.
I purchased a nu6000dsp today from the states and i reside in NZ. Needless to say its the wrong voltage. I have been told o can use a step down transformer with power rating of no less than 650w. (this directly from behringer)
But i read in the previous post that there are jumpers inside the amp to be switched to 220-240v?
Could anyone explain or shed some light in to how i could flip this amp to work on the 220-240v outlet and what fuse would i need for the breaker? If at all possible
Many thanks
Neilio
First of sorry for digging up an old post.
I purchased a nu6000dsp today from the states and i reside in NZ. Needless to say its the wrong voltage. I have been told o can use a step down transformer with power rating of no less than 650w. (this directly from behringer)
But i read in the previous post that there are jumpers inside the amp to be switched to 220-240v?
Could anyone explain or shed some light in to how i could flip this amp to work on the 220-240v outlet and what fuse would i need for the breaker? If at all possible
Many thanks
Neilio
I have replaced the stock fans on my NU3000, NU4-6000, NU12000 with Noctua NF-R8 Redux 1800. They have 1, 2 and 3 fans respectively. The NU3000 has a small fan shroud, the NU4-6000 has no shroud, and the NU12000 has a shroud and a fan tunnel joining one rear fan and the front fan. Paradoxically the modified NU3000 is slightly the noisiest and the modified NU12000 the quietest, with the NU4-6000 somewhere in between. I agree with a YouTube fan swap video that the fan shroud is probably the cause of the noise on the NU3000, but it is now very small. Typically, the vinyl roar from my turntable is louder than any of the fan noise, so I can't complain. Also the transformer buzz from nearly all of my Class AB amps is louder/as loud as the fan noise. I do NOT recommend the 1200 rpm Noctua fans. They had difficulty starting on the Behringer supply, which is less than 12 V on start up. So far there have been zero problems with overheat shutdown. The Noctua fans have a reputation for low noise and long life. I am overjoyed to be free of the stock fan racket.
6-years (MOL) follow-up
Nearly six years into the NU3000 mods, I've not had any troubles with the NU3000 pair. They do have whisper quiet fans in them, most of this time. The NU6000 died after a few years, but I think it was not fan related. (It also had quieter fans installed.) I have had good similar luck with a NU4-6000 with quieter fans. Except for the short-lived NU6000, I am quite satisfied with my INukes, but don't push them hard at all with home listening.
Nearly six years into the NU3000 mods, I've not had any troubles with the NU3000 pair. They do have whisper quiet fans in them, most of this time. The NU6000 died after a few years, but I think it was not fan related. (It also had quieter fans installed.) I have had good similar luck with a NU4-6000 with quieter fans. Except for the short-lived NU6000, I am quite satisfied with my INukes, but don't push them hard at all with home listening.
There's a jumper on the circuit board - if you can't find it you shouldn't do the mod!
However, you'll need to also change the fuse (to one that pulls less current) and possibly also upgrade one of the downstream chips.
Mine blew up some time after modding with a voltage change and quiet fans. One of the circuit traces shorted with the case. I'm not sure if it was an input voltage issue, a problem with the mod, or a problem with bad case design. But still, you'll not have any warranty...
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