I was curious if two pair of 2SA1943 and 2SC5200 could possibly output 1000 watts at 4 ohms, well 950. I have a Dayton SA1000 rack mounted amp that I got second hand. I know the 1000 watt plate amp couldn’t make power, but I read that the rack amp was okay.
I’ve been reading that some of them have been dying as the capacitors in them are starting to go. I opened mine up to check ESR and such and noticed that this amp only had 4 outputs. I’d figure for 1000 watts RMS it would have 8 at least. I’ve never seen a standard power amplifier rated at 500w @ 8R and 950w @ 4R with only 4 outputs in each channel. It has well over 100 positive reviews, I was just surprised.
Dan
I’ve been reading that some of them have been dying as the capacitors in them are starting to go. I opened mine up to check ESR and such and noticed that this amp only had 4 outputs. I’d figure for 1000 watts RMS it would have 8 at least. I’ve never seen a standard power amplifier rated at 500w @ 8R and 950w @ 4R with only 4 outputs in each channel. It has well over 100 positive reviews, I was just surprised.
Dan
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Well it is a single channel. When I clear my bench I’ll probably bench it. Try at 40hz and then 20hz to see when it starts clipping. I will say that it does drive the woofers I’ve used with it quite well. I’m guessing it’ll be well below 950 watts before clipping starts.
Dan
Heatsink or not, these transistors would leave their SOA in such an application. 1000W on sine means 2000W peak, which is 22A @ 4ohm, and they are rated for 15A only. Not to mention their performance decline quickly after about 4A. The data sheet says they are good for a 100W amplifier for a reason.
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Rule of the thumb for these transistors in class AB amps:
1 pair = about 100W output without great safe margins neither good handling of reactive loads, but doable.
Then, 2 pairs will give you about 200W output.
You don't need to believe me, just look for the schematics of good/well known Pro Amps
1 pair = about 100W output without great safe margins neither good handling of reactive loads, but doable.
Then, 2 pairs will give you about 200W output.
You don't need to believe me, just look for the schematics of good/well known Pro Amps
As a standard class-AB amp, no, two pair is not enough for that power, but I see something on the other side which I suspect is a tracking switch-mode power supply like the Yamaha hybrid amp. Check the filter cap voltage and do the math. But, of course, if you can measure the output, that's the bottom line. If this is a hybrid amp, then the modest heat sink and output transistors makes more sense, but calling it a class-AB is misleading.
That amplifier has a tracking downconverter power supply, which reduces the power dissipation drastically. Four output transistors may very well be fine for normal use. Plus the switching mosfets, of course.
The QSC GX5 amplifier “looks” like a 50 watt amplifier inside, too.
The QSC GX5 amplifier “looks” like a 50 watt amplifier inside, too.
I think it will need a suitable transformer as well, for 1000 W, though tracking supplies are something I am not familiar with.
But what on Earth are you going to do with such a high powered unit?
It is too powerful for most homes, even small theaters do not need 1000W single channel amps.
But what on Earth are you going to do with such a high powered unit?
It is too powerful for most homes, even small theaters do not need 1000W single channel amps.
This is 1000 W PMPO, or, as Morgan Jones said, purely mythical power output.
You can't safely expect more than about 60 W output power from a pair of 2SA1943/2SC5200's, due to their already mentioned poor SOAR. The only positive property of these is they're cheap (but being faked anyway...).
Best regards!
You can't safely expect more than about 60 W output power from a pair of 2SA1943/2SC5200's, due to their already mentioned poor SOAR. The only positive property of these is they're cheap (but being faked anyway...).
Best regards!
Well it doesn’t surprise me that they’re running it into distortion, when you’re talking subwoofers that 1% distortion isn’t such a travesty as it would be on a midrange or tweeter. What does it mean by 1/3 duty cycle? When I was shopping for an air compressor I grabbed a 100% duty cycle for overall quality, but I know with that it would mean you can run the motor 30 seconds on then a minute and 10 seconds off or similar ratio. I’m guessing you’re referring to the filtering caps, they’re 2,200 uF 200V.
I have no reason to not believe you. I’m fixing a Crest right now rated at 450w per channel and it has many more of the same case size, MJL1302 and MJL1382.
Which side are you talking about? Here are some closet pics of the power supply board. The filters are rated at 200 volts.
I also took pics of the board right next to the power supply as it too has 200v rated capacitors.
Once I can get my bench cleared I’ll see if I can’t measure it. If I parallel my dummy loads for a 4 ohm load it can take the power of it gets anywhere close to its rated power. I have many Yamaha PC-9501n amplifiers, I’m guessing this is one of those hybrid amps. While they do have switching power supplies they at lease have a couple dozen outputs in each channel lol.
Lol… there are many, MANY, more people than me that are running much more power, I get what you’re saying though. Depends on what they’re driving. I have a 15” Peerless woofer that uses a (I forget) 7.5” or 8” voice coil that just eats up power. It’s so inefficient. I am now driving it with a pro amp capable of 1400w at the load and still the amp runs out of juice before the woofer. Then I have 18” JBLs that get crazy loud on 300 watts.
To answer your question, I’m building my home theater. This particular amp will be powering a pair of JBL 2245s, giving them hopefully 450w each. Then I have multiple other amps, not entirely sure what will run what, but I need to power a pair of JBL 2242s and a pair of 18” Dayton Ultimaxs and that will complete the sub stage. Obviously the Daytons will need more power and will be handling the sub sonics. Im
Thinking maybe the 2242s to handle the punchy bass, but I’m thinking my mains and center will do fine in that category.
Oh okay, good to know. That’s what I was basically going after. I didn’t know that with the best possible power supply (for the outcome) if only 4 could make the power, but sounds like maybe.
Dan
Okay, well I guess I don’t know that much about switching power supplies. I didn’t realize that they allowed you to get more output power per output device, I just thought they provided enough voltage and current to the rails to avoid using a massive copper transformer and large filter caps.
Dan