I'm about to take a journey into repairing this 3 Channel ICE amp. It's got a bunch of fun components I am not familiar with like Direct Stream Digital chips. It also has some onboard Digital Signal Processor which I haven't identified yet.
I am not familiar with ICE amp circuits other than they are a type of PWM amplifier so I'm assuming they require a ton of high frequency filtering on the output. I'm also assuming that the output of the DSD chips probably directly feed the ICE amp signal since DSD is also essentially PWM or creating an averaged AC signal using high frequency ~2MHz binary pulses.
These amps are from a personal 3 way reference quality speaker I designed around 12 years ago. I have had them in storage for about a year, they still sound great; however, I noticed some rustling staticy noise coming from the subwoofer that was some what intermittent.
One day I was demoing the speakers for somebody and I noticed the subwoofer surround had a strong DC bias to it even thought there was no obvious distortion.
I turned them on the next day, I started noticing a hot electronics smell. I have two 8" Peerless SLS 830667 drivers in differential mounting so the magnet is exposed on the backwards mounted driver. I noticed the drivers surround was again pushing out and the keeper plate was very hot, and shut them off.
On basic examination of the circuits I noticed that one of the electrolytic filter caps for the DSD chip on the signal board had a brown crust of what looked like flux around it (I doubt it was flux since it's a through hole mounted cap).
I tried swapping it with one of same value. Removing this Era of led free solder resulted in some bunged up pads on the ground side. I don't think the board is multi layer but its hard to tell. It appears to have ground continuity but after a quick power up test it seems scratchier than before.
I need to conduct some trouble shooting and Tracing on this amp, I can't find much info about ICE amps or working on them.
I will post as many pictures as I can to ask help and document the process, since ICE amps are very very cool and It's a shame there is very little info on them in the wild.
I'm not sure the best way to proceed with these PWM/ICE amps.
I am assuming I may need a dummy load to observe the output signal represented properly? But maybe I don't? Does anybody here know how the PWM/ICE amp would become contaminated with DC? Intuitively I would guess that something is just sending all high pulses into the output stage, but there still appears to be low end of the music present so it can't just be sticking to a constant high bit signal?
I would greatly appreciate any help with this one, its a 100% personal passion project.
Attached is a Shot of the speakers from 12 years ago along with some slightly OP subwoofers I designed.
I am not familiar with ICE amp circuits other than they are a type of PWM amplifier so I'm assuming they require a ton of high frequency filtering on the output. I'm also assuming that the output of the DSD chips probably directly feed the ICE amp signal since DSD is also essentially PWM or creating an averaged AC signal using high frequency ~2MHz binary pulses.
These amps are from a personal 3 way reference quality speaker I designed around 12 years ago. I have had them in storage for about a year, they still sound great; however, I noticed some rustling staticy noise coming from the subwoofer that was some what intermittent.
One day I was demoing the speakers for somebody and I noticed the subwoofer surround had a strong DC bias to it even thought there was no obvious distortion.
I turned them on the next day, I started noticing a hot electronics smell. I have two 8" Peerless SLS 830667 drivers in differential mounting so the magnet is exposed on the backwards mounted driver. I noticed the drivers surround was again pushing out and the keeper plate was very hot, and shut them off.
On basic examination of the circuits I noticed that one of the electrolytic filter caps for the DSD chip on the signal board had a brown crust of what looked like flux around it (I doubt it was flux since it's a through hole mounted cap).
I tried swapping it with one of same value. Removing this Era of led free solder resulted in some bunged up pads on the ground side. I don't think the board is multi layer but its hard to tell. It appears to have ground continuity but after a quick power up test it seems scratchier than before.
I need to conduct some trouble shooting and Tracing on this amp, I can't find much info about ICE amps or working on them.
I will post as many pictures as I can to ask help and document the process, since ICE amps are very very cool and It's a shame there is very little info on them in the wild.
I'm not sure the best way to proceed with these PWM/ICE amps.
I am assuming I may need a dummy load to observe the output signal represented properly? But maybe I don't? Does anybody here know how the PWM/ICE amp would become contaminated with DC? Intuitively I would guess that something is just sending all high pulses into the output stage, but there still appears to be low end of the music present so it can't just be sticking to a constant high bit signal?
I would greatly appreciate any help with this one, its a 100% personal passion project.
Attached is a Shot of the speakers from 12 years ago along with some slightly OP subwoofers I designed.
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