This amp came in with one bad emitter resistor and some bad solder connection.I took care of that.All 4ch play good audio but the bias circuit in this amp does not work.I turn all the ports both directions but the current draw did not change.
The marking on the amp fade away so i can not get the model but i got something close to it with the same board number.I follow the steps on the manual but no change.
I did not run the amp for long but i think if i do it will distort when it starts to heat up.
any ideas?
board number x09-5150-10
Service manual to big to upload
KENWOOD KAC-846 SM Service Manual free download, schematics, eeprom, repair info for electronics
The marking on the amp fade away so i can not get the model but i got something close to it with the same board number.I follow the steps on the manual but no change.
I did not run the amp for long but i think if i do it will distort when it starts to heat up.
any ideas?
board number x09-5150-10
Service manual to big to upload
KENWOOD KAC-846 SM Service Manual free download, schematics, eeprom, repair info for electronics
It should be less likely to distort when hot.
I'd run it into a load until it was hot to see if the bias pots make a difference when hot. When heating it up, remove the signal at regular intervals to confirm that the idle current hasn't changed significantly.
I'd run it into a load until it was hot to see if the bias pots make a difference when hot. When heating it up, remove the signal at regular intervals to confirm that the idle current hasn't changed significantly.
Sadly the bias design will make the idle current increase to maximum range of the bias circuit if the adjust pots go bad. You might try testing the pots to see if they work correctly.
The ports test ok in circuit
With all the ports fully counter-clockwise wise the amp will run ok but if i try tun it at full power it will cut in and out.If i give the port quarter turn and run the amp it will stat to distort after some time.
The ports still don't change the idle current after am heats up
With all the ports fully counter-clockwise wise the amp will run ok but if i try tun it at full power it will cut in and out.If i give the port quarter turn and run the amp it will stat to distort after some time.
The ports still don't change the idle current after am heats up
Try driving one channel at a time to full power to see if one channel is causing it to cut out.
Are you sure that you have enough current to drive the amp to full power?
Are you sure that you have enough current to drive the amp to full power?
I run it in bridge because I only had two 2 test speakers. I will try it on channel.
I used a 32 amp linear supply. The amp meter on the supply did not reach to the max before the amp cut out. The amp is acting like when you try to run a amp hard with a in line limiter .
I get 0.000 across emitter resistor no matter where I set the port even after the amp has heat up. maybe I am over looking something
I used a 32 amp linear supply. The amp meter on the supply did not reach to the max before the amp cut out. The amp is acting like when you try to run a amp hard with a in line limiter .
I get 0.000 across emitter resistor no matter where I set the port even after the amp has heat up. maybe I am over looking something
I check the transistor in circuit did not find any shorted.
I try one channel at a time they still cut out the same way.
I try one channel at a time they still cut out the same way.
If all channels cause it to cut out with only one channel playing at a time, I'd think that the problem is possibly somewhere else, like in the undervoltage protection. If you increase or decrease the supply voltage, does that affect anything?
I think this amp has multiple problems.
Today I set all ports fully counter clock-wise and re install the bottom cover and run the amp at a volume where it does not cut out. After about 20 minutes it starts to distort. If I remove the bottom cover and run it at the same volume after about 45 minutes of playing it I get no distortion.
I did not get any part over heating. I will vary the voltage to see what will happen
Today I set all ports fully counter clock-wise and re install the bottom cover and run the amp at a volume where it does not cut out. After about 20 minutes it starts to distort. If I remove the bottom cover and run it at the same volume after about 45 minutes of playing it I get no distortion.
I did not get any part over heating. I will vary the voltage to see what will happen
i run it at 11v and 14 volts it act the same way.
Anything i can do to the bias circuit to get the channel idling at 25mv?
or i should give up on this one.
Anything i can do to the bias circuit to get the channel idling at 25mv?
or i should give up on this one.
Confirm that you still have negative rail voltage on the output transistors and driver when it distorts.
Also confirm that the signal feeding that channel's differential amp input is clean.
Also confirm that the signal feeding that channel's differential amp input is clean.
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