Working on a Dual DA6001 which appears to be just muted. I get very faint audio on speaker terminals at very high input signal voltage. Customer said amp never worked straight out of the brand new box, though the amp is several years old now. It powers up, has rail and regulated voltage. All opamp outputs have audio signal on them, and there is audio going to Pin #8 of the driver board, which is using IR2113 and a new one: HCF4093.
I see a square wave on the HCF4093 at several pins including pin 8.
On the IR2113 I have the following voltages:
1. -68.9
2. -68.9
3. -57
4. 0
5. -0.027
6. 0.330
7. -0.021
8. 0
9. -57.1
10. -57.1
11. -68.2
12. -68.9
13. -68.9
14. 0
I'm not seeing any drive nor signal on output FET gates.
I see a square wave on the HCF4093 at several pins including pin 8.
On the IR2113 I have the following voltages:
1. -68.9
2. -68.9
3. -57
4. 0
5. -0.027
6. 0.330
7. -0.021
8. 0
9. -57.1
10. -57.1
11. -68.2
12. -68.9
13. -68.9
14. 0
I'm not seeing any drive nor signal on output FET gates.
I believe its similar to this amp: https://www.diyaudio.com/community/threads/power-acoustik-gt1-6000d.324106/#post-5479055
I'm not getting square signal on any of the 4093 outputs.
Photo one minute.
I'm not getting square signal on any of the 4093 outputs.
Photo one minute.
Actually I had a good parts amp with a 4093. Replacing it did not help. I’ll have to track backwards a few steps.
Post the DCv on all of the pins of the 4093.
Use the negative rail for the reference for the 2113 or the 4093.
Use the negative rail for the reference for the 2113 or the 4093.
4093.
1. 8.54
2. 8.53
3. 0
4. 11.77
5. 0
6. 0
7. 0
8. 8.52
9. 11.77
10. 0
11. 11.78
12. 0.410
13. 0.410
14. 11.78
Pins 1, 2, 8 are tied together at the PCB
2113
1. 0
2. 0
3. 11.93
4. 0
5. 68.7
6. 70.2
7. 68.7
8. 0
9. 11.67
10. 11.67
11. 0.644
12. 0
13.0
14.0
1. 8.54
2. 8.53
3. 0
4. 11.77
5. 0
6. 0
7. 0
8. 8.52
9. 11.77
10. 0
11. 11.78
12. 0.410
13. 0.410
14. 11.78
Pins 1, 2, 8 are tied together at the PCB
2113
1. 0
2. 0
3. 11.93
4. 0
5. 68.7
6. 70.2
7. 68.7
8. 0
9. 11.67
10. 11.67
11. 0.644
12. 0
13.0
14.0
Looks like a perfect 50% duty 4v square wave but only when I have input signal. Without input signal the square wave is jittering around. I think thats normal for self oscillating type.
4v may not be enough.
Is it 4v from the negative rail or is it floating above the negative rail?
What is the amplitude of the waveforms on the transistor that drives pin 8?
Is it 4v from the negative rail or is it floating above the negative rail?
What is the amplitude of the waveforms on the transistor that drives pin 8?
Might be closer to 5v actually and it is coming from the negative rail.
Q201 Mpsa92 collector is connected to 4093 pin 8. Emitter has about 0.5v square on it from pin 7 of the lm311.
Q201 Mpsa92 collector is connected to 4093 pin 8. Emitter has about 0.5v square on it from pin 7 of the lm311.
What's the resistor value for the resistor connected to its collector and the one connected to its emitter?
What's the amplitude of the square wave on the output of the LM311?
What's the amplitude of the square wave on the output of the LM311?
I didn’t see any resistors between the lm311, a92, and 4093, but there might be one draining somewhere in there. The a92 is directly connected to those ic pins. The output of the lm311 pin7 is only about 0.5v square. The opamp before the lm311 seems ok on inputs and outputs.
I can desolder components easily. I may try throwing a new 311 in. What do you think?
I can desolder components easily. I may try throwing a new 311 in. What do you think?
The transistor needs to shift the level from ground reference to the negative rail reference. This requires the right resistors on the MPSA92. You may need to draw a diagram for the components between the LM311 output and the 4093 pin 8.
You can try replacing the LM311.
You can try replacing the LM311.
I pulled the MPSA92 and the square signal is coming strong off the LM311, so the 311 is probably OK. I dont have in stock a replacement. Output pin showing a 15v square wave referencing ground with the MPSA92 removed. With the MPSA92 installed its only ~1v square though.
Referecing amp general ground
MPSA92 installed:
E: 0.411 <--Very low square wave
B: 0
C: -60.2 <-- ~5v square wave
MPSA92 removed
E: 7.8 <-- ~15v square wave
B: 0
C: -63.8 <-- Flat
MPSA92 is measuring OK off the PCB. I replaced it anyway and still same readings.
Referecing amp general ground
MPSA92 installed:
E: 0.411 <--Very low square wave
B: 0
C: -60.2 <-- ~5v square wave
MPSA92 removed
E: 7.8 <-- ~15v square wave
B: 0
C: -63.8 <-- Flat
MPSA92 is measuring OK off the PCB. I replaced it anyway and still same readings.
Can you find a resistor that goes from pin 8 of the 4093 to the negative rail (pin 7 of the 4093)?
What's its value?
What's its value?