More Progress....
Well, i finally did the mod Mr. Babin sugested about voltage regulators, now they are very cool. I´m off to work but i took some pictures with my crappy cellphone.Hope you get an a idea.
R46 and R47 still get very hot. I changed both. New resistors still have the same behavior. I did one thing today. I assembled everything and made the amp plays continously. I am waiting still for magic smoke from the resistor or a small crack, because after 45 minutes of playing they are brown from the center area, obviously very warm. Besides that, the amp still performs very good.
Thinking mounting in my own car, to see how much it will last.
Thanks.
Pics:
Well, i finally did the mod Mr. Babin sugested about voltage regulators, now they are very cool. I´m off to work but i took some pictures with my crappy cellphone.Hope you get an a idea.
R46 and R47 still get very hot. I changed both. New resistors still have the same behavior. I did one thing today. I assembled everything and made the amp plays continously. I am waiting still for magic smoke from the resistor or a small crack, because after 45 minutes of playing they are brown from the center area, obviously very warm. Besides that, the amp still performs very good.
Thinking mounting in my own car, to see how much it will last.
Thanks.
Pics:
Attachments
Used the amp for some time...
Well, i have been using this amps for nearly 4 months without a problem, until yesterday. When i recently repaired it, it was powering a pair of alpine 6x9´s nothing special, and worked well. A week ago i decided to use in my truck a pair of kicker comp vr 12 inch, 8 ohms, in parallel, being powered by the KX500.2 . They worked very well, strong bass. I adjusted the gain and else, and yesterday i was playing some hip hop and the amp got "that smell" i turned off inmediatly, leave for an hour, and discovered that it has no audio. I opened the case and found that one of the resistors i have changed was burnt.
No problem, today i changed the resistor with one of the same value and it and played good again, but after, lets say, 10 minutes, it stopped working. The protection light is on this time, and nothing else happen. What i can do know? here are some pics of the board and the burned resistor.
Thanks in advance.
Well, i have been using this amps for nearly 4 months without a problem, until yesterday. When i recently repaired it, it was powering a pair of alpine 6x9´s nothing special, and worked well. A week ago i decided to use in my truck a pair of kicker comp vr 12 inch, 8 ohms, in parallel, being powered by the KX500.2 . They worked very well, strong bass. I adjusted the gain and else, and yesterday i was playing some hip hop and the amp got "that smell" i turned off inmediatly, leave for an hour, and discovered that it has no audio. I opened the case and found that one of the resistors i have changed was burnt.
No problem, today i changed the resistor with one of the same value and it and played good again, but after, lets say, 10 minutes, it stopped working. The protection light is on this time, and nothing else happen. What i can do know? here are some pics of the board and the burned resistor.
Thanks in advance.
Attachments
Hi Mr Babin, good to hear about you.
When i power up the amp, lets say, 2 seconds after, i can hear (and feel from the speaker cone) a small "bump". If i left powered the amp , this happens every 3 seconds or so.
The amp gets in protection mode from the beggining. Both fuses are OK.
Voltage from the battery is 12.70 V.
Thanks in advance.
When i power up the amp, lets say, 2 seconds after, i can hear (and feel from the speaker cone) a small "bump". If i left powered the amp , this happens every 3 seconds or so.
The amp gets in protection mode from the beggining. Both fuses are OK.
Voltage from the battery is 12.70 V.
Thanks in advance.
Thank you for your quick response. Im currently at work, but do you want me to post the values of the TL494 / LM324 or i´m working too much overtime because i dont have the minimal idea how to do what you require?
I´ll appreciate the proper method to check both pulses and i will post the values.
Sorry, have not a day off since 3 weeks ago...
Thanks in advance...
Update....
Well, it has passed some time since i tried to fix this amp, so i feel obliged to post what happened with it.
From some testing, i changed all TIP35C & TIP36C from one side, and the amp went from protection mode to make some sound, so , no more blown fuses. Needless to say, without all that transistors one side of the amp played well, and the other, obviously, did not work.
The problem now is that i have distorted sound. I have good know rca cable, source, speaker cables, and speaker of course, but the sound is distorted in both channels. If i try to "bridge" i dont get any sound. Only 1 time i got the amp working properly, playing loudly and cleanly, but i simply turned off after a good 3 seconds because i didnt felt it was ok to run the transistors without the heatsink. I checked for cold solders or broken traces in the preamp board, but no luck.
What else i can do? here are some pictures from the progress. Thanks in advance.
Well, it has passed some time since i tried to fix this amp, so i feel obliged to post what happened with it.
From some testing, i changed all TIP35C & TIP36C from one side, and the amp went from protection mode to make some sound, so , no more blown fuses. Needless to say, without all that transistors one side of the amp played well, and the other, obviously, did not work.
The problem now is that i have distorted sound. I have good know rca cable, source, speaker cables, and speaker of course, but the sound is distorted in both channels. If i try to "bridge" i dont get any sound. Only 1 time i got the amp working properly, playing loudly and cleanly, but i simply turned off after a good 3 seconds because i didnt felt it was ok to run the transistors without the heatsink. I checked for cold solders or broken traces in the preamp board, but no luck.
What else i can do? here are some pictures from the progress. Thanks in advance.
Attachments
Ok, if i understood correctly, here i go:
1.- Testing all the rca shields with L- and R+ (the non-bridging speaker terminals)gave me the same readings (near zero ohms), all four readings.
2.- The voltage in the op-amp board was:
GND & +15v = 14.67
GND & -15v = -0.67
I think i have something wrong here....
Thanks again Perry !
1.- Testing all the rca shields with L- and R+ (the non-bridging speaker terminals)gave me the same readings (near zero ohms), all four readings.
2.- The voltage in the op-amp board was:
GND & +15v = 14.67
GND & -15v = -0.67
I think i have something wrong here....
Thanks again Perry !
Well, im back.
I read the previous posts in this topic and yes, the problem were the voltage regulators AND a 470 uF cap, the one in the preamp board, just before the -15V pin. I was getting intermitent voltage and no sound only noise, but i moved it a little and the amp worked very well. I had a cap with similar values laying around and installed it, and played ok! both channels and bridge mode works! obviously from you can see at the pics, the cap is very big and was installed for testing purposes, so i need to go to the electronics store to get a smaller one.
I have now 14.72 from +15V and -14.12 from -15V.
I changed the wires that goes to the voltage regulators.
I hope the amp would work for some time, and if it fails, i will be back. At least i hope somebody can learn from my mistakes !
Thank you Perry! I
I read the previous posts in this topic and yes, the problem were the voltage regulators AND a 470 uF cap, the one in the preamp board, just before the -15V pin. I was getting intermitent voltage and no sound only noise, but i moved it a little and the amp worked very well. I had a cap with similar values laying around and installed it, and played ok! both channels and bridge mode works! obviously from you can see at the pics, the cap is very big and was installed for testing purposes, so i need to go to the electronics store to get a smaller one.
I have now 14.72 from +15V and -14.12 from -15V.
I changed the wires that goes to the voltage regulators.
I hope the amp would work for some time, and if it fails, i will be back. At least i hope somebody can learn from my mistakes !
Thank you Perry! I
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