Hello I have a Kicker zx700.5 that I got at a yard sale. Amp2 seems to work fine but amp1 outputs have very low volume in comparison like it's muted. Sub works fine. I can hear something buzzing on the amp but I haven't located it yet. Any suggestions? Thank you
Here are some measurements I took from the preamp board to speaker ground:
Fr in -18.3 mv
Fl in 9.6 mv
Rr in -19.3 mv
Rl in 10.0 mv
-15v -14.14 v
+15v 13.95 v
Rem 11.51 v
Gnd a -4.5 mv
+ Batt 11.63 v
Gnd p -4.5 mv
Rem- bas 12.3v
Sub in 15.3 mv
Sub pre -4.4 mv
Here are some measurements I took from the preamp board to speaker ground:
Fr in -18.3 mv
Fl in 9.6 mv
Rr in -19.3 mv
Rl in 10.0 mv
-15v -14.14 v
+15v 13.95 v
Rem 11.51 v
Gnd a -4.5 mv
+ Batt 11.63 v
Gnd p -4.5 mv
Rem- bas 12.3v
Sub in 15.3 mv
Sub pre -4.4 mv
Attachments
Have you tried operating all pots and switches through their entire range while listing to the low-level channels to see if there was an intermittent problem?
Yes, it seems all the switches and pots function but all attempts to reveal an intermittent issue were unsuccessful, the volume remains consistently lower from Amp 1.
You need PapaZBill to give definitive answers. I don't have this diagram.
That said, the front and rear should be close. Use y-cables to feed all 4 inputs and follow the signals through the circuit. I would suspect that the front and rear are essentially copy and paste type circuits.
Some of the kicker amps have an input sensitivity switch. Does yours?
That said, the front and rear should be close. Use y-cables to feed all 4 inputs and follow the signals through the circuit. I would suspect that the front and rear are essentially copy and paste type circuits.
Some of the kicker amps have an input sensitivity switch. Does yours?
I haven't tried feeding both inputs so I will try that next. Yes, there is an input sensitivity button that you press in if you use a high level signal from the source unit. There is also the fader switch which you press in when two inputs are used. I will try feeding the high level signal and see what happens and report back. Thanks!
Tried every combination of inputs (high and low level) and still amp 1 has low output. If I turn the amp 1 gain all the way up and amp 2 gain all the way down, the outputs are approximately equal.
Have you tried mapping the signal then comparing the levels at corresponding points to see where you were losing signal on the weak channels?
Do you see any burned traces?
Do you see any burned traces?
I have an oscilloscope now. I'm looking at the signals coming from the preamp with a 500 hz 0.3 v square wave input. To my untrained eye they look quite different. The order is FR, RR, FL, RL starting with the first photo. FL and RL have noticeably higher amplitude.
In the meantime I swapped the output transistors (front to rear) and it made no difference. I also tried pulling q301 in the output section for FR and it made no difference.
Any ideas?
In the meantime I swapped the output transistors (front to rear) and it made no difference. I also tried pulling q301 in the output section for FR and it made no difference.
Any ideas?
Attachments
Yes, RCA. The oscilloscope wouldn't auto adjust with a sine wave and it would with a square wave so that's what I used.
Take it off of auto and use it by setting the vertical amplifier to 5v/div, the timebase to 2ms and drive a 50Hz sine wave signal into the amplifier. Set all crossovers to the highest frequencies. Subsonic to lowest.
Adjust the trigger level if it doesn't trigger. If it still won't trigger, go to 2v/div.
Adjust the trigger level if it doesn't trigger. If it still won't trigger, go to 2v/div.
Go higher. When you see clipping in the preamp section, there is too much signal.
Try getting the scope to trigger on the signal source without the amp on.
Are you adjusting the trigger level manually?
Try getting the scope to trigger on the signal source without the amp on.
Are you adjusting the trigger level manually?
PapaZBill is who you need at this point. At least there's something to work with.
Is the 300 series channel the low channel?
Do you have a 5.6k resistor feeding signal to all of the muting JFETs?
If so, is the signal level the same (in general, measured with a multimeter set to ACV) on all of those?
At the speaker channels, how much weaker is the weak channel than the others? ACV for each?
Is the 300 series channel the low channel?
Do you have a 5.6k resistor feeding signal to all of the muting JFETs?
If so, is the signal level the same (in general, measured with a multimeter set to ACV) on all of those?
At the speaker channels, how much weaker is the weak channel than the others? ACV for each?
