Working on this monster which is not making enough rail voltage (+/-11vDC). Pulse drive on the PS fets is very weak. The amp only draws 0.3A from the bench, but most of that is likely from the FAN, display board, and a few LEDs.
TL494
1. 0.002
2. 3.113
3. 3.740
4. 0.058
5. 1.483
6. 3.405
7. 0
8. 14.22
9. 0.014
10. 0
11. 14.2
12. 13.04
13. 4.96
14. 4.96
15. 1.991
16. -0.453 (YES, Negative)
R76 and R77 are missing. Do you know the value of these two resistors?
TL494
1. 0.002
2. 3.113
3. 3.740
4. 0.058
5. 1.483
6. 3.405
7. 0
8. 14.22
9. 0.014
10. 0
11. 14.2
12. 13.04
13. 4.96
14. 4.96
15. 1.991
16. -0.453 (YES, Negative)
R76 and R77 are missing. Do you know the value of these two resistors?
Post a good quality photo of the component side of the entire main board and the component side of any driver boards if no one can help.
Not class D.
Look at the flash files in the MAAudio folder in the tutorial. Those are likely regulator resistors and may have been left out to increase rail voltage. You'll have to see what's driving pin 3 high.
There are some pins, when driven below 0v can cause the 494 to do strange things.
Look at the flash files in the MAAudio folder in the tutorial. Those are likely regulator resistors and may have been left out to increase rail voltage. You'll have to see what's driving pin 3 high.
There are some pins, when driven below 0v can cause the 494 to do strange things.
Oh lol. I was looking in the wrong folders. I'll report back if I have another q.
Yes as soon as I opened this amp, I was like - this isn't class D. Surprised the cover is see-through. Figured a lie and hide it - guess the manufacturer forgot to hide it. That said its a pretty large analog amp. Not my fav though.
Yes as soon as I opened this amp, I was like - this isn't class D. Surprised the cover is see-through. Figured a lie and hide it - guess the manufacturer forgot to hide it. That said its a pretty large analog amp. Not my fav though.