Owner says he has seen a lot of this amp model with a similar problem. What happens is under high load (1~2 ohms) pulled to clipping (Clip LED on), the amp completely freaks out and draws about ~200-~300A (13-14vDC at amp terminals) current from my bench. Output on the scope goes absolutely wild. At first, I thought this amp was actually OK because it reacts relatively normal for a Class-D, that is until it hits clipping. Then all heck breaks loose. Im honestly surprised the amp is surviving pulling this kind of current.
Rail is +-70vDC
Output clips at about 65vAC
Seems to me, this amp may actually be clipping too early on.
Has anyone seen this before? Its a Type-3 classD with 14 pin drivers. Rail voltage too low? Rail caps are 100v.
Rail is +-70vDC
Output clips at about 65vAC
Seems to me, this amp may actually be clipping too early on.
Has anyone seen this before? Its a Type-3 classD with 14 pin drivers. Rail voltage too low? Rail caps are 100v.
This amp is using an unregulated supply. Waveform on the PS fet gates look fine out to full tilt.
Have you seen any other of this type (21844) amp act like this or is it only this make/model?
2 or 4 21844s?
2 or 4 21844s?
I've seen a few of this style but every time seems to stump me actually. I seem to only be able to fix these by guessing or if there is something mis-soldered and such. I did not test the driver ICs. There are only 2 in this amp.
When it 'freaks out' does it draw the same current no matter whether it's on 1 ohm or 2 ohms?
If you drive it hard into clipping, will it do the same with 4 ohms?
Did the amp ever work normally?
If you drive it hard into clipping, will it do the same with 4 ohms?
Did the amp ever work normally?
I mean, the more I play with this amp I actually believe everything is working completely normally. At 4-ohms, it made about 960w at clipping. It draws about 95A.
The owner seems to think the amp should not be messing up (Shutting down he said) when it clips hard.
Let me do wattage tests at 2-1 ohms and get back to you.
The owner seems to think the amp should not be messing up (Shutting down he said) when it clips hard.
Let me do wattage tests at 2-1 ohms and get back to you.
The amp will draw about 140A when driven into clipping at 4-ohms.
I just dont know if this is normal or not. The owner is telling me the amp is not acting normal, but has very little basis for comparison. The amp is allowing itself to clip so deathly hard thats its not definitive for me to say if there are any actual problems; while being on the fence of reality vs in the customer's court.
I know something like a JL1000/1 wouldn't allow itself to clip so roughly but that would not be an apples comparison.
The owner said he's seen it before. Do the amps never work properly or do they start to act this way after working normally, initially?