Powerbass xtr 4000d

[mnhiphop101]

Is this how the power supply squarewave is supposed to look?

 

[mnhiphop101]

Sorry about the upside down picture

 

[Perry Babin]

It looks like only one bank bay be driven. Do both banks look the same?

 

[mnhiphop101]

yes all 4 banks look the same

 

[Perry Babin]

What do the gate signals look like?

 

[mnhiphop101]

This is with the fets removed

 

[Perry Babin]

The signal needs to be loaded. If the FETs are not in the circuit, load one location gate to source with a 0.047uF cap or something close and re-post.

 

[mnhiphop101]

Here's what it looks like loaded.

 

[mnhiphop101]

This is what u meant right?

 

[Perry Babin]

Yes ( I think, from what I can see at that angle) but you have to probe the gate with the capacitor connected to it.

 

[mnhiphop101]

That's at the gate with the fets in.

 

[Perry Babin]

If this has a standard power supply with grounded FET sources, ground the scope probe to the source of one of the FETs and probe the gate leg of the same FETs.

 

[mnhiphop101]

Ok. Here's what it looks like now.

 

[Perry Babin]

That's a lot better. Does the drain look better when grounded to the source.

If this is a regulated power supply, lower the 12v power supply voltage to force the duty cycle to as near 50% as it will get.

 

[mnhiphop101]

I looks a little better but not normal.

 

[Perry Babin]

That appears to be near 14v. Did you try lowering the voltage?

 

[mnhiphop101]

my power supply is set at 12.4v

 

[Perry Babin]

Go lower.

 

[mnhiphop101]

That's at 10v

 

[Perry Babin]

OK. That didn't clear it up.

What's the duty cycle? Measure on the gate.

Does this amp have snubbers on the primary windings?