I'm powering 2 dual 10" folded horns at 2ohms, only 600w though. I'm yet to try max power, though. No heat at all, I've never felt heat out of the iNuke3000DSP. I've powered both 8 ohm channels to the max it will let me; One 4 ohm max and 8 ohm max, Right now I'm doing 2ohm at 600, and 8ohm at max. Next weekend I will be bridging and testing 8 ohm at max it will let me, from 10hz to 200hz.
Oh, and I wasn't able to get around to testing the power output :c
Oh, and I wasn't able to get around to testing the power output :c
Now we're getting into DIY territory 
One could get one of these amps and change the feedback to post filter.
That would also adjust the DF.
This thread is about the iNuke12000 which is stable at 2 ohms.
The current models don't say they are stable at 2, but maybe DIY modding could lower the power supply voltage for better stability at 2 ohms for the other models.
Change a few caps, And come up with some DIY ways to heatsink quietly.
These could be good DIY project amps! They are at the price point.
One could get one of these amps and change the feedback to post filter.
That would also adjust the DF.
This thread is about the iNuke12000 which is stable at 2 ohms.
The current models don't say they are stable at 2, but maybe DIY modding could lower the power supply voltage for better stability at 2 ohms for the other models.
Change a few caps, And come up with some DIY ways to heatsink quietly.
These could be good DIY project amps! They are at the price point.
Now we're getting into DIY territory
One could get one of these amps and change the feedback to post filter.
That would also adjust the DF.
This thread is about the iNuke12000 which is stable at 2 ohms.
The current models don't say they are stable at 2, but maybe DIY modding could lower the power supply voltage for better stability at 2 ohms for the other models.
Change a few caps, And come up with some DIY ways to heatsink quietly.
These could be good DIY project amps! They are at the price point.
Agreed!
The iNuke3000, and iNuke1000 are 2 ohm stable. For the 3000, I know the channel will shut off if too low of an impedance is detected. I don't know how low the impedance needs to be for this to happen. Being that the 6000 is only 4 Ohm stable It might cut the channel before you can get 2 Ohms. A easy way to mod the 6000, would be to take a look at the iNuke12000's power supply. (when it comes out that is) I'm sure the 6000 and the 12000 will be a similar setup. but for 399 you could get a 10kW amp.
For the cooling, perhaps it's possible to slap some liquid cooling meant for high performance CPU's being over clocked. These start as low as $50. Obviously it wont be easy being that the connection is meant for a CPU, but I'm sure its doable.
"One could get one of these amps and change the feedback to post filter.
That would also adjust the DF."
I'm still learning about DIY amps. What would this do? And what is DF?
Regarding the feedback tapoff point, I have a feeling that some other extremely well-regarded PA amplifiers also do the same (not seen any schematics, just something I suspect from having chatted to their guys).
Granted, it sounded like an odd idea. I assumed the problem was that it was difficult to get global stability with a multiple-pole output filter. Taking the negative feedback tapoff before the filter you can use an integrator and have a single dominant pole as in a conventional amp.
At that point the best you can do is to estimate what the actual output, post filter, is at the top of the audio spectrum and compensate for it with some "hidden" (from the user) DSP.
But then I might be wrong.
===
Regarding power ratings, does anyone know of a simple resource or article explaining the current standards for rating amplifier power output (I had a quick look on the web a while back, but found nothing useful). It's easy to find amps with output ratings exceeding their rated power draw by a factor of 2 to 4. I'd not accuse any reputable manufacturer of fudging the numbers, but they're obviously using ratings other than a the "all day" continuous sine wave power that the unsuspecting DIYer might expect.
Granted, it sounded like an odd idea. I assumed the problem was that it was difficult to get global stability with a multiple-pole output filter. Taking the negative feedback tapoff before the filter you can use an integrator and have a single dominant pole as in a conventional amp.
At that point the best you can do is to estimate what the actual output, post filter, is at the top of the audio spectrum and compensate for it with some "hidden" (from the user) DSP.
But then I might be wrong.
===
Regarding power ratings, does anyone know of a simple resource or article explaining the current standards for rating amplifier power output (I had a quick look on the web a while back, but found nothing useful). It's easy to find amps with output ratings exceeding their rated power draw by a factor of 2 to 4. I'd not accuse any reputable manufacturer of fudging the numbers, but they're obviously using ratings other than a the "all day" continuous sine wave power that the unsuspecting DIYer might expect.
Tomi, for the power ratings, are you talking about when it says:
Power consumption @ 4 ohms 620W
Because that's 1/8 Power. Or are you talking about:
"USA / Canada 120V~, 60Hz (25A)
UK / Australia / Europe 220-240 V~, 50/60 Hz, (12A)
Korea / China 220-240 V~, 50/60 Hz,(12A)
Japan 100 V~, 50/60 Hz, (25A) "
Power consumption @ 4 ohms 620W
Because that's 1/8 Power. Or are you talking about:
"USA / Canada 120V~, 60Hz (25A)
UK / Australia / Europe 220-240 V~, 50/60 Hz, (12A)
Korea / China 220-240 V~, 50/60 Hz,(12A)
Japan 100 V~, 50/60 Hz, (25A) "
The fellow testing noted the difference between the low duty cycle and relatively high peaks of music vs. continuous sine wave. The PS will draw less current on music even though it is peaking at "full power". He also noted that the amps reduce output when confronting a low duty cycle signal within I think he said 6dB of full power (rail voltage essentially).
DF = damping factor.
A measure of the ratio of the output impedance of the amp vs an 8 ohm load. A DF = 1 would be an output impedance of 8 ohms. That would be a zero feedback tube amp.
Moving the feedback point to after an output network would try to make the output look like the input, ie. flatten freq response and reduce distortion introduced by the output filter. But there is the issue of phase shift, delay and related issues that make stability a potential issue.
I suspect this is why they did it the way that they did.
It should have nil effect on at least 5kHz and down. Above that the response is load dependent.
What the tester in the nice article apparently did not try was reactive loads at any frequency. That's where we separate the good, the bad and the ugly.
DF = damping factor.
A measure of the ratio of the output impedance of the amp vs an 8 ohm load. A DF = 1 would be an output impedance of 8 ohms. That would be a zero feedback tube amp.
Moving the feedback point to after an output network would try to make the output look like the input, ie. flatten freq response and reduce distortion introduced by the output filter. But there is the issue of phase shift, delay and related issues that make stability a potential issue.
I suspect this is why they did it the way that they did.
It should have nil effect on at least 5kHz and down. Above that the response is load dependent.
What the tester in the nice article apparently did not try was reactive loads at any frequency. That's where we separate the good, the bad and the ugly.
One poster here who runs subs with iNUKE fanless.
The biggest concern I ever had with my 3000DSP is the fact that no matter what I do to it, it never gets warm.
A million ways to slice, dissect, ponder over specs, and thats cool, but somebody show me a better value than iNUKE DSP.
WRT the OP, if I ever had need for a 12K watt amp I would not hesitate for a second.
Bear, you would like this amp, guaranteed.
I am [one of] those who run the NU3000 (two stacked, currently) fanless. The top will get warm to the touch but not too hot. I have four cats, and i really should find a way so that they can enjoy a warm spot to sleep on
Soldermizer, I thought about removing the fan, but it doesn't bother me. So I decided it would be safer to keep it. Just out of curiosity, would you have bought the NU4-6000 instead if it was out?
On aside note, MCM pushed back the date the NU4-6000s are backordered till. The new arrival date is "March 3rd". It probably will be pushed back again.
Behringer Rack Mount Digital Amplifier - iNuke Series - 1100W RMS x 4CH | NU4-6000 (NU46000) | Behringer
Quiet replacement fans are cheap and easy. Behringer iNuke NU1000 Amp Amplifier Fan Swap How To w/ PICS - Home Theater Forum and Systems - HomeTheaterShack.com
Speaking for the sloth lobby, to use no fan at all is easier still!
... Would I have bought a NU4-6000? Even though I said I might, a few messages back, a year ago I was more in the market for two separate amps for two different rooms. For just one system needing biamping, of course either would work. I would want to find out if the NU4-6000 can go fanless like the NU3000 could.
... Would I have bought a NU4-6000? Even though I said I might, a few messages back, a year ago I was more in the market for two separate amps for two different rooms. For just one system needing biamping, of course either would work. I would want to find out if the NU4-6000 can go fanless like the NU3000 could.
mr. doom, I remember seeing that post when I first got the amp. Also saw a video of a guy doing it too. I'm pretty sure removing the fan/changing the fan would void warranty. Maybe after my warranty is up ill mod the fan.
Soldermizer, Sorry I forgot we talked about that already. Like i said I'd go with the NU4-6000 only if it had DSP and I had a lot of speakers to power. Else I'd stick to two units for more flexibility.
Soldermizer, Sorry I forgot we talked about that already. Like i said I'd go with the NU4-6000 only if it had DSP and I had a lot of speakers to power. Else I'd stick to two units for more flexibility.
Good point abcdmku. As for needing high power, I think the NU3000 is (are) great for that. Much ado is made of continuous RMS watts but ... peak power maybe is the more important. In my case, one NU3000 driving (per channel) 2x Bose 901 II (=4 ohm load nominal) will peak (0 dB) easily on fairly loud music. This is not surprising since I have about 30 dB of boost at lowest frequencies and also a dBX expander. It is "far out man" as Chong would say, to have a fanless box that can put out 1500 watts (albeit briefly)...the trick is how loud can I play it before it goes into thermal protection.
Cat-approved heat sink for NU3000
History made! I spent money on something for the cat that the cat actually uses! Since cats like warm things I have tried a couple methods to move my "desk cat" to a top shelf so I shall have more desk top space. Now I have my two NU3000 amps (fanless, so the tops get nice and warm), side by side on a top shelf. I bought a "paver" stone (about 20x20x1 inches, about $7) that now tops both amps. This serves of course as a heat sink. Top it with a towel and install cat. Cat now happy. Next project: how to keep cat from walking on keyboard KIU&XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
History made! I spent money on something for the cat that the cat actually uses! Since cats like warm things I have tried a couple methods to move my "desk cat" to a top shelf so I shall have more desk top space. Now I have my two NU3000 amps (fanless, so the tops get nice and warm), side by side on a top shelf. I bought a "paver" stone (about 20x20x1 inches, about $7) that now tops both amps. This serves of course as a heat sink. Top it with a towel and install cat. Cat now happy. Next project: how to keep cat from walking on keyboard KIU&XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Cats are on break, but guinea pig was available...
Cats are enjoying outside time right now. Besides, just got home and the masonary needs to warm up
Here is a photo. As you can see, a rodent is subbing for a cat. I doubt the cat would cause over-heat, however, the towel could restrict airflow if draped over the edges. The whole idea of this exercise was to allow the amp's waste heat to heat the concrete paver (approx. 20x20x2 inches).
I was listening to some "trance" music and got a thermal even at not apparently too loud volume. This is not the first time, and not unusual (although it was on the amp that I "experimented upon" and I sometimes worry that my half-assed resoldering is failing.)
I just got an incredibly simple evil idea worthy of the Grinch when he figures out his reindeer substitute
What if I put the fan back in the amp, and had a switch for it? If I need to blast music, I have the fan running. If I need quiet, turn off the fan. Experience has shown that the thermal protection works ok. Best of both worlds?
Cats are enjoying outside time right now. Besides, just got home and the masonary needs to warm up
Here is a photo. As you can see, a rodent is subbing for a cat. I doubt the cat would cause over-heat, however, the towel could restrict airflow if draped over the edges. The whole idea of this exercise was to allow the amp's waste heat to heat the concrete paver (approx. 20x20x2 inches).
I was listening to some "trance" music and got a thermal even at not apparently too loud volume. This is not the first time, and not unusual (although it was on the amp that I "experimented upon" and I sometimes worry that my half-assed resoldering is failing.)
I just got an incredibly simple evil idea worthy of the Grinch when he figures out his reindeer substitute
What if I put the fan back in the amp, and had a switch for it? If I need to blast music, I have the fan running. If I need quiet, turn off the fan. Experience has shown that the thermal protection works ok. Best of both worlds?
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Build something? ha ha ha ...
Well, I have managed to kill one of my NU3000. As noted else where, one of my experiments was removing the output inductors and capacitors. That did not work (amp remained in protect). I put them back ... not very skillfully and ... amazingly the amp worked. At least until after the recent "heated cat perch" experiment. I am pretty sure the problem is one inductor (it is visibly loose). I can't seem to make a good solder bond with my limited skills and equipment. I will leave it DOA, for a project later or perhaps sell it as broken (I do that some). Anyway, it is an excuse to BUY MORE ELECTRONIC GADGETS!!! Meanwhile, the cat perch must make do with only 1/2 the heat generated.
Well, I have managed to kill one of my NU3000. As noted else where, one of my experiments was removing the output inductors and capacitors. That did not work (amp remained in protect). I put them back ... not very skillfully and ... amazingly the amp worked. At least until after the recent "heated cat perch" experiment. I am pretty sure the problem is one inductor (it is visibly loose). I can't seem to make a good solder bond with my limited skills and equipment. I will leave it DOA, for a project later or perhaps sell it as broken (I do that some). Anyway, it is an excuse to BUY MORE ELECTRONIC GADGETS!!! Meanwhile, the cat perch must make do with only 1/2 the heat generated.
I thought my eyes deceived me. On Ebay right now, the cheapest NU6000 is: $398. Cheapest NU3000 is: $299. I think the NU3000's have gone up some, the NU6000 is no longer twice the cost (was it ever?) I think it is time to buy a NU6000 and hope my "fan-ectomy" will work!
There is a NU3000DSP (customer return) for $299, same price as a regular NU3000. I was tempted, but I am going for power this time.
There is a NU3000DSP (customer return) for $299, same price as a regular NU3000. I was tempted, but I am going for power this time.
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