Phase Linear Model 300 Series Two overheating on one side at low volumes

[George S.]

I've also seen a optional faceplate description and drawing in some PL amp manual that had provisions for retaining the handles and small cut outs for rack mounting bolts. Can't remember where I saw it.
The 700 I just WOPLed has these cut outs. Whether the spacing conforms to some industry standard I don't know.

 

[jtatknox]

Here's what I came up with based on your suggestions...

They are sitting on 1U 10" shelves w/ the rubber feet pulled off the bottom. I have them separated from the component above by a 1/2U grill for ventilation.

Two things that could be better: 1) obviously they aren't anchored to the rack and 2) the screws that anchor the shelves to the rails bump up against the screws that hold the handles on. I am thinking of getting low profile screws for both so that I can push the amps in even further but for now they are just a little proud. I might also screw them directly to the shelves using existing screws and screw holes (nondestructive).

Overall rack components top to bottom:

1F) blank w/ IR sensor
1R) Furman sequencing power conditioner
2F) MiniDSP SHD
3F) NAD CI 580 streaming source
4F) DIY 8 channel DAC – https://audiosciencereview.com/foru...tu-diyinhk-or-other-options.18015/post-974173
5F) 1/2U vent
6F) PL300S2 #1
7F) 1/2U vent
8F) PL300S2 #2
9F) 1U vent
10F) MX880 multichannel amp for outdoor speakers

New filter caps came in the mail yesterday so I will probably install those this weekend and see if that helps w/ some midrange distortion I am hearing on PL300S2 #1. If not, that will take some diagnosing...

 

[Rick.ta.fied]

Hey jtatknox did you ever get the PL300 series II to stop overheating? I just posted another thread and I noticed in this thread here #20 you picture is also missing C111 it is located directly in front of the bias control transistor you have two exposed holes in picture where the C111 (0.0027uf ) capacitor would go. I believe this capacitor C111 is used to stop oscillations in the output and have asked other in my new threat about this capacitor as it was cut out of my amplifier and don't understand why someone would have done this?