SoundStream XXX 6500 gate resistors

[Perry Babin]

It's a regulated supply so you can't expect a 50% duty cycle square wave. Looking at the gate legs will show a reduced duty cycle square wave.

If post 18 is the drain, do you see less ringing if you ground the scope to the source leg of the FET being probed?

 

[Deadly Sones]

Yes. Almost all the ringing was gone after I added the rectifiers actually.

Thanks for everything Perry.

 

[Perry Babin]

I'm not sure I understand. Did you check the drain with no rectifiers (or with the 12v supply so low the amp would go to 50%) with the scope grounded to the source terminal of the FET?

The ringing could be either too little deadtime or a bad snubber.

Don't pull the rectifiers to check but you might try reducing the 12v.

 

[Deadly Sones]

Looks like I'm going to have to get this inductor fixed up first. Was holding it twisted trying to get a picture for you and she sent sparks flying from the inductor.

 

[Deadly Sones]

Initially when the ringing was there I had the probe ground on the neg terminal of the amp. And the probe on the drain with no inductors. After I added the inductors I checked again. It was gone. But that was still at the 13v. I'll do as asked soon as I get this inductor out and fixed.

 

[Deadly Sones]

Ok. Now that inductor is fixed... this is what they duty cycle looks like. Can see a bit of ringing at 11.5v but I've seen worse for sure. 13v looks fine.

 

[Perry Babin]

Those look OK.

 

[Deadly Sones]

Thanks again sir. You're the best!!