Phase Linear 400 issue help!

[enoyes12]

Vandersteen 2CE

 

[laatsch55]

I can pick some up and try it tomorrow. It won't hurt and their cheap. Can you think of anything else short of more testing equipment. Maybe a ground problem?

Could be a lot of things.

 

[laatsch55]

I don't remember. What should it be?

Do you know how to check it?

 

[enoyes12]

I'm not testing with the Vandersteens I'm using some Klipsch in walls I removed from a job, they were free and I don't give a crap if they blow!!

 

[enoyes12]

11.1mV left and 7.4mV right

 

[laatsch55]

Nav, take over would ya, I got some soldering to do...

 

[enoyes12]

I want to add a DC protection circuit if I can figure out this issue. I found a 30V but not sure if it's big enough

 

[enoyes12]

Thanks for your help laatsch

 

[NavLinear]

Shit - just got back from tending to the horses. Thinking about fixing a wounded one but knocking back a Firestone Double Barrel Ale at the moment.

Welcome enoyes12 to our small world - but it's a growing world. Your photos show a nice looking PL 400.

 

[enoyes12]

It's in pretty good shape except someone drilled extra holes in the face to secure it to the wood case (Dumbass!). That and this damn hum I can't seem to fix.

 

[enoyes12]

Ventura huh, we just came back from Cali last weekend. Daughter tried out for America's Got Talent. My in-laws lived there for 3 years. Nice place

 

[NavLinear]

I want to add a DC protection circuit if I can figure out this issue. I found a 30V but not sure if it's big enough

There is a drop in DC protection board that one of the members designed that has saved a speaker or two. It was designed to make a minimum of modifications to a stock PL amplifier so it comes highly recommended. Wattsabundent is the designer and has boards available for the 400. See URL below:

http://home.earthlink.net/~dimlay/id24.html

 

[enoyes12]

Is that filly in your pic the one you were tending to?

 

[NavLinear]

It's in pretty good shape except someone drilled extra holes in the face to secure it to the wood case (Dumbass!). That and this damn hum I can't seem to fix.

Bummer about the extra holes in the faceplate. That can be fixed though. As far as the hum goes it would help to know what the hum frequency is. The power supply is the obvious starting point.

 

[NavLinear]

Is that filly in your pic the one you were tending to?

I wish - don't tell my wife though!

 

[enoyes12]

I was afraid of the power supply being the issue, although why would the left be louder?

 

[enoyes12]

I don't hear anything from the horns only the mids. They are a 6 1/2" mid and horn

 

[NavLinear]

It is unwise to put a grounded plug on a two prong PL. Without a bunch of work on the inside first.

Here is the write up explaining the two prong and three prong power cord concerns. I use the three prong power cord but with the earth ground disconnected for both the PL 400 and Pl 700 amplifiers.


http://forums.phxaudiotape.com/showthread.php/2268-Joe-s-Improved-Grounding-Scheme

 

[NavLinear]

I don't hear anything from the horns only the mids. They are a 6 1/2" mid and horn

So no low frequency noise? Both channels have a hum - but the left is more prominent?

 

[enoyes12]

sounds about right