Here's the last chapter with the schematics. It's for 2 models, the 1000 and 2000 with a few revs of each. The whole thing is nearly 600 pages which is too big for here. If you need the rest I can send in pieces later.
Several posts have been removed on safety grounds.
Please remember this is a diy oriented forum and ideas will be picked up and used by those who have no understanding of the safety implications involved.
Please remember this is a diy oriented forum and ideas will be picked up and used by those who have no understanding of the safety implications involved.
I already mentioned that it is illegal and dangerous.Not discussing the issues anywhere can be way more dangerous and transformer isolation in toroids is often poor...
At the same time of offering dangerous indications I also offered a solution to minimize dangers ... On these grounds all switching mode supplies should be banned here because there's at least one capacitor in every each smps that once shorted any smps ca kill you if you touch the metal case or the output ground.Haven't you heard about kids being killed by their iphone chargers due to rubber chord isolation being damaged? Normally you should be able to safely touch any output ground of any smps yet people died.
Just try connecting two identical smps outputs in series and you'll see which capacitor I'm reffering to.
I remember one smps i was testing that showed one particular defect a few months after sales.The output current protection reading op amp and its circuitry was found incinerated and nobody in the post sales service department figured out why as the voltages there ranged in the millivolts range.
As i was the test engineer of the product before sales I found the reason at some point .The decoupling cap(150nF...or so) between output ground and input ground should have been specd at least 630v dc yet the design engineer found that it was cheaper to use 250v dc caps if they passed the 2kv test...so he relied on the fact that the cap manufacturer sold 250v specd capacitors that were testing better until one day when a new batch of capacitors came in and they spec'd only up to their datasheet limit on the testing line so the product couldn't leave the factory doors and get fried a few months after when the wrong capacitor would find its voltage spike match in the real world...Of course the test department got new more tasks and the designer got the wages raise as usual...
At the same time of offering dangerous indications I also offered a solution to minimize dangers ... On these grounds all switching mode supplies should be banned here because there's at least one capacitor in every each smps that once shorted any smps ca kill you if you touch the metal case or the output ground.Haven't you heard about kids being killed by their iphone chargers due to rubber chord isolation being damaged? Normally you should be able to safely touch any output ground of any smps yet people died.
Just try connecting two identical smps outputs in series and you'll see which capacitor I'm reffering to.
I remember one smps i was testing that showed one particular defect a few months after sales.The output current protection reading op amp and its circuitry was found incinerated and nobody in the post sales service department figured out why as the voltages there ranged in the millivolts range.
As i was the test engineer of the product before sales I found the reason at some point .The decoupling cap(150nF...or so) between output ground and input ground should have been specd at least 630v dc yet the design engineer found that it was cheaper to use 250v dc caps if they passed the 2kv test...so he relied on the fact that the cap manufacturer sold 250v specd capacitors that were testing better until one day when a new batch of capacitors came in and they spec'd only up to their datasheet limit on the testing line so the product couldn't leave the factory doors and get fried a few months after when the wrong capacitor would find its voltage spike match in the real world...Of course the test department got new more tasks and the designer got the wages raise as usual...
Last edited:
Self healing capacitors can be a pain on the a** as they don't give out themselves as being the cause for some isolation damage caused defects in smps and even linear supplies...standard isolation transformers are the safest if correctly executed, but you don't have the noise coupling between primary and secondary windings talks for nothing...In many cheap transformers the isolation safety is a probability depending on the number of winding turns , isolation thickness spread and heavy use in high heat...
By the way, the price for that smps using wrongly specd caps was 7000 dollars and just 4.5 kWatts ! You'd buy it thinking at this price it should have been the safest thing to use not knowing the manufacturing and design choices behind...nor the 60% fallure rate after one year of use that only the post sales service department knows.
By the way, the price for that smps using wrongly specd caps was 7000 dollars and just 4.5 kWatts ! You'd buy it thinking at this price it should have been the safest thing to use not knowing the manufacturing and design choices behind...nor the 60% fallure rate after one year of use that only the post sales service department knows.
Last edited:
Not exactly, but I received a qsc1850 HD for spare parts some while ago and it's damn heavy...I think they used the same transformer for the 2450 model...People don't realize power transformers weight for their dream amps until they need to move it around...
They used the same VA rating as the 2450, but lower volts. The 1850 was optimized for 4 ohm bridge operation. I don’t consider the 2450 heavy at all anymore - I have several and the Behringer clones. They replaced the USA1310’s which were heavier. Want heavy? There‘s the 5050, which I also have. Want even heavier? Try the Crest 8000 and 9000 series, or the CA series. I know exactly what a rack with 3 CA18’s and an RMX5050 weighs. Over three hundred pounds, but it rolls just fine. Easier to transport than a single horn subwoofer for which the rack can drive eight. All of it H-class. If you tried to get the same power all class AB it would be double the weight - but the big problem would be powering it. It would take the whole 50 amp distro just to power the subs. Where would you plug the rest of it?
No fork lift, but a truck and trailer with a RAMP is a necessity.
No fork lift, but a truck and trailer with a RAMP is a necessity.