I have a rockford fosgate 250m2 that I have replaced all the outputs and powersupply FETS and all leaking surface mount caps. I have bias both channels amp plays audio fine until you reach the 10amp draw range then it clips. anybody seen this issue?
Measuring the DC voltage between the center legs of the rectifiers, does the voltage collapse when it clips?
Does the clipping happen well below the rail voltage?
In the older BD amps that use 10 ohm resistors, I generally leave them as 10 ohms, so, no. It's not too low.
Does the clipping happen well below the rail voltage?
In the older BD amps that use 10 ohm resistors, I generally leave them as 10 ohms, so, no. It's not too low.
or 45 volts with black probe at ground. these are not N versions of the irf540 and irf9540. could it be the newer style fets causing my issue haven had any trouble until this amp.
#5: I don't know.
1. Were the originals the N version?
2. Does it clip early (well before rail voltage) with no load?
3. If you drive one channel at a time, do both clip early?
4. What is the amplitude where it clips?
5. Does the amp still clip at 10 amps when you drive only one channel at a time?
1. Were the originals the N version?
2. Does it clip early (well before rail voltage) with no load?
3. If you drive one channel at a time, do both clip early?
4. What is the amplitude where it clips?
5. Does the amp still clip at 10 amps when you drive only one channel at a time?
I was able to clean the waveform up by increasing the bias. the amp starts clipping and cutting out around the 10amp or so draw. the peak to peak voltage was around 36 volts .
I removed all the outputs and installed the N version for curiosity and it did the same thing except it shorted all the outputs.
I will reinstall the outputs bbn in the morning and Input a 100hz signal and see if it clips on the scope without bbn load. I replaced both of the lm833 ic already
the amplifier does not clip until under load. I can take the 60hz signal and get almost to rail voltage 50v before the waveform begins to clip. the sine wave is a little noisy compared to the typical waveform I can clean it up but have to crank the bias up pretty far but then the chips will be running hot and even then it seems that the bottom of the waveform cleans up more than top portion. could this be an issue in the driver circuit.
Does the heatsink have a lot of noise on it? Some of these amps didn't have a shunt resistor/capacitor between the heatsink and ground and that caused them to be noisy.
its definitely not coming from FETS. I found a pair older Harris 540 and 9540 and tried them and still had a noisy sine wave. even with the older fets with a load on it, amplifier clips or mutes or something
Unless I misunderstood, you said that 10 amps is where it clips, no matter if one channel or both were driven. Is that correct?
Did you check the heatsink for noise?
Did you check the heatsink for noise?
when you check the heatsink for noise, do you mean use the heatsink for ground wire on scope and the audio output
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