Have an Earthquake MiniD 1000.4 that clips the rear channel output when bridged at 4ohms and at a moderate level of output.
Got this amp in protection and discovered the rear channel TDF8591TH IC was defective. I was not able to locate a single chip from any reputable suppliers so I purchased one from Dalbani Corporation on ebay. I installed the IC and all four channels have clean output. I didn't test the amp bridged or even with a subwoofer before selling bit to a friend. He reported to me that the rear channels are clipping when connected to a 4ohm subwoofer load. I tested the amp and witnessed the same occurrence. The front channels do not have this issue.
Got this amp in protection and discovered the rear channel TDF8591TH IC was defective. I was not able to locate a single chip from any reputable suppliers so I purchased one from Dalbani Corporation on ebay. I installed the IC and all four channels have clean output. I didn't test the amp bridged or even with a subwoofer before selling bit to a friend. He reported to me that the rear channels are clipping when connected to a 4ohm subwoofer load. I tested the amp and witnessed the same occurrence. The front channels do not have this issue.
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Your original post typo's the part number twice. The part in the photo is TDF8591TH NOT TDF8951TH and the datasheet is here for anyone following along at home:
TDF8591TH pdf, TDF8591TH description, TDF8591TH datasheets, TDF8591TH view ::: ALLDATASHEET :::
TDF8591TH pdf, TDF8591TH description, TDF8591TH datasheets, TDF8591TH view ::: ALLDATASHEET :::
My concern is if the IC has a defect, but I am inclined to think that something external to the IC is the issue as the IC plays clear audio on both channels under most circumstances. I am of the belief that a defective IC would not be as functional as this one is.
In my limited experience, this particular issue occured when regulated voltage to OPamps was dropping. I have to check that in the vehicle as voltage drops on my bench supply with my current limiter but the problem does not occur on the front channels and those OPamps are supplied from the same source.
Since it only occurs at high output, the board must be in the heatsink when testing so I can't really check voltages on the IC legs themselves. What else can I check?
In my limited experience, this particular issue occured when regulated voltage to OPamps was dropping. I have to check that in the vehicle as voltage drops on my bench supply with my current limiter but the problem does not occur on the front channels and those OPamps are supplied from the same source.
Since it only occurs at high output, the board must be in the heatsink when testing so I can't really check voltages on the IC legs themselves. What else can I check?
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Why are you testing at high power with a current limiter on the bench?
Are both channels of this IC going into clipping at precisely the same time, as you increase the output level?
Are both channels of this IC going into clipping at precisely the same time, as you increase the output level?