Are the tube cards removable?
try swapping them and see if the noise moves to a new channel, could be a bad tube!
try swapping them and see if the noise moves to a new channel, could be a bad tube!
A bad tube does sound like a possibilty.The tube cards are souldered in,no way to change them easily.......Robert
Have you tried moving all of the pots and switches through their entire range to see if it makes a difference in the distorted channel?
Does the channel ever play cleanly?
Does the channel ever play cleanly?
There are no switches,there are only two gain control pots(one for each channel) and there is no change when turning them up and down.The distorsion is always present.........Robert
I found that tube's heater often dead in this amp. Look at the tubes from the top, see if there is orange points glowing. If not, then the heather is dead.
What probe are you using?
Do you see a trace when the beam finder button is pressed?
Set the trigger mode to auto. Does the scope produce a trace?
If not, turn the intensity up a bit until you have a visible but not overly bright trace.
Do you see a trace when the beam finder button is pressed?
Set the trigger mode to auto. Does the scope produce a trace?
If not, turn the intensity up a bit until you have a visible but not overly bright trace.
Push the Ch2 button in. All others in that column should be out.
The trig. view should be out.
Center the trace.
Set the ch2 vertical amp to 5v/div (one click clockwise).
Set the probe to 10x.
Clip the probe connected to the ch2 input to the calibration bar on the front of the scope.
Set the red knob in the middle of the ch2 vertical amp control to the fully clockwise position.
Adjust the trigger level until you get a locked waveform displayed.
Post a photo of this setup.
The trig. view should be out.
Center the trace.
Set the ch2 vertical amp to 5v/div (one click clockwise).
Set the probe to 10x.
Clip the probe connected to the ch2 input to the calibration bar on the front of the scope.
Set the red knob in the middle of the ch2 vertical amp control to the fully clockwise position.
Adjust the trigger level until you get a locked waveform displayed.
Post a photo of this setup.
You need to clip the tip of the probe to that point.
Set the coupling switch (under the vertical amp control) to DC.
Set the coupling switch (under the vertical amp control) to DC.
Photo?
I want to confirm that the scope is working properly before we begin troubleshooting.
Do you have a test tone CD or a sine wave generator?
I want to confirm that the scope is working properly before we begin troubleshooting.
Do you have a test tone CD or a sine wave generator?
I may have a CD that has test tones.But I cant find it,will have to search.My laptop is the only cd player I have.....Robert
If that alligator clip is connected to the probe, it's shorting the cal signal to ground. Only connect the tip of the probe.
That's 50v/div. You don't have probes with the pin that tells the scope that you have 10x probes. You'll use the other scale.
If you're going to use the lighted scale, set it to 0.5v/div.
That's 50v/div. You don't have probes with the pin that tells the scope that you have 10x probes. You'll use the other scale.
If you're going to use the lighted scale, set it to 0.5v/div.
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