In series.
I found some notes that I didn't know I had. I have to try to figure out what they mean. I'll post later.
With the 4 outputs and the two clamping transistors, did the voltages on the op-amp IC9701 change?
If you drive audio into the RCAs, does it now drive through to the output of that op-amp?
I found some notes that I didn't know I had. I have to try to figure out what they mean. I'll post later.
With the 4 outputs and the two clamping transistors, did the voltages on the op-amp IC9701 change?
If you drive audio into the RCAs, does it now drive through to the output of that op-amp?
With Q4401-4404 out, and Q9701/9702 also out, the voltages are still exactly the same as before.
I always had audio output from IC9701 to the base of Q9701 and Q9702. The problem is that the audio does not make it to the collector of Q9701 and Q9702.
Even when directly inputting audio to the collector pads of Q9701 and Q9702, the audio does not make it to the inputs of the driver ICs.
I am ordering some parts from Mouser tomorrow and want to know whether there are any parts I should order for this amp proactively?
I always had audio output from IC9701 to the base of Q9701 and Q9702. The problem is that the audio does not make it to the collector of Q9701 and Q9702.
Even when directly inputting audio to the collector pads of Q9701 and Q9702, the audio does not make it to the inputs of the driver ICs.
I am ordering some parts from Mouser tomorrow and want to know whether there are any parts I should order for this amp proactively?
What I am calling "audio" is ac voltage fluctuations that are non-existent with the deck volume on 0, they increase in amplitude as the volume of the deck is turned up, and they are at their highest when the deck volume is all the way up. I assume this is the audio signal.
These AC voltage fluctuations make it all the way to the base of Q9701 and Q9702 despite there being - 4.46v on pin7.
In the service manual IC9701 states that:
Pin1 2.13, I have - 4.25
Pin2 2.2mv, 25mv
Pin3 2.4mv, 0.0
Pin4 - 4.95, - 4.96
Pin5 0.4mv, 0.0
Pin6 - 2.1v, 25mv
Pin7 - 2.18v, - 4.46v
Pin8 4.97, 5.05
These AC voltage fluctuations make it all the way to the base of Q9701 and Q9702 despite there being - 4.46v on pin7.
In the service manual IC9701 states that:
Pin1 2.13, I have - 4.25
Pin2 2.2mv, 25mv
Pin3 2.4mv, 0.0
Pin4 - 4.95, - 4.96
Pin5 0.4mv, 0.0
Pin6 - 2.1v, 25mv
Pin7 - 2.18v, - 4.46v
Pin8 4.97, 5.05
Did some scope testing before reading your latest post. It seems as if everything making it to the base of Q9701 and Q9702, from the RCA connectors, is a square wave. Is that supposed to be so?
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The first three pics are from my ipod with a 20hz to 20khz incremental sweep. 5ms/1v
The last pic is a 1khz tone from the ipod. 50ms/200mv
I will try to inject a signal at the collector of Q9701 and Q9702.
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The first three pics are from my ipod with a 20hz to 20khz incremental sweep. 5ms/1v
The last pic is a 1khz tone from the ipod. 50ms/200mv
I will try to inject a signal at the collector of Q9701 and Q9702.
Do you read a short between pin 1 and VSS on that IC?
Is it pulling to a straight line because the vertical amplifier setting is too low on the scope?
Is your signal source damaged and not able to drive 10k?
Do you have a series resistor? If so, does the signal get pulled down on both sides of the resistor?
Remember, everything beyond the transistor Q9701 is referenced to the negative rail. (don't ground your scope to the negative rail). That's one reason that you need the capacitor.
Is it pulling to a straight line because the vertical amplifier setting is too low on the scope?
Is your signal source damaged and not able to drive 10k?
Do you have a series resistor? If so, does the signal get pulled down on both sides of the resistor?
Remember, everything beyond the transistor Q9701 is referenced to the negative rail. (don't ground your scope to the negative rail). That's one reason that you need the capacitor.
There is no short between Pin1 of IC9702 and any other pin of the IC. None of the ICs have shorts between the pins.
The scope is set at 10ms / 5v.
Don't think either the CD player or the ipod is damaged as they work properly in every other scenario. I do not know if they can drive 10k, also unsure exactly what that means...
Not sure if I am feeding the signal properly or using the components properly. There is a pic of the capacitor and resistor that I am using. A 10k is pictured but I tried a 1k also with no difference. The signal gets pulled down on both sides of the resistor, but only the amplifier side of the capacitor.
The pics below illustrate what is happening.
The second pic is of the signal after the resistor and capacitor but not connected to the amp yet.
The third pic is what happens to the signal as soon as I connect the signal to the collector pad of Q9701.
The first pic is the capacitor and resistor that I am using.
The scope is set at 10ms / 5v.
Don't think either the CD player or the ipod is damaged as they work properly in every other scenario. I do not know if they can drive 10k, also unsure exactly what that means...
Not sure if I am feeding the signal properly or using the components properly. There is a pic of the capacitor and resistor that I am using. A 10k is pictured but I tried a 1k also with no difference. The signal gets pulled down on both sides of the resistor, but only the amplifier side of the capacitor.
The pics below illustrate what is happening.
The second pic is of the signal after the resistor and capacitor but not connected to the amp yet.
The third pic is what happens to the signal as soon as I connect the signal to the collector pad of Q9701.
The first pic is the capacitor and resistor that I am using.
Attachments
If they drive headphones, they can drive 10k. I don't know why you get no signal on the collector of Q9701. Is this with or without the jumper to pin 6 of the inverter?
The collector should be near the negative rail. The IC it's driving is powered by 10v referenced to the negative rail.
Try going to a 1k ohm series resistor.
The collector should be near the negative rail. The IC it's driving is powered by 10v referenced to the negative rail.
Try going to a 1k ohm series resistor.
I didn't know I was supposed to insert a jumper to pin6 of the inverter. I am connecting pin6 of which IC, to where?
I was using the preamp output of the deck, then the line out audio from the ipod, then finally the headphone jack from the ipod.
It does the same thing with 10k or 1k resistor.
I was using the preamp output of the deck, then the line out audio from the ipod, then finally the headphone jack from the ipod.
It does the same thing with 10k or 1k resistor.
Tried a different capacitor and a 1k resistor, same thing is happening. Is there something else I can do to feed the signal into the amp?
According to the schematic, pin6 of IC9702 feeds pin13 of the same IC. The collector of Q9701 connects to Pin1 of IC9702 so I am a little lost regarding a jumper.
According to the schematic, pin6 of IC9702 feeds pin13 of the same IC. The collector of Q9701 connects to Pin1 of IC9702 so I am a little lost regarding a jumper.
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