I want to White Oak a Phase Linear 400 Series I

[laatsch55]

I think Marantz when I see the blue, was never around Mac gear. After you seat each output, check case to chassis with your meter to see if there is continuity. YOU DON"T want continuity, and the case itself is the collector. This will tell you if the mica is still insulating.

 

[ksrigg]

OK, thanks...I'll do that. I've cut down on the amount of compound I use after seeing your ouputs. I use it very sparingly now. I do make sure there is enough to cover all the metal, but not enough to push much out when the transistors are seated. Ever used the ceramic insulators? I saw them recently and they look cool but are like 50 cents each...I realy do not like the mess associated with thethermal compound, but if it is the best stuff to use, that's what we will use..I wanna tryt the ceramic though, It looks so cool..

 

[laatsch55]

The best heat transfer still occurs, even after all these years , with mica.

 

[ksrigg]

Success !!! I couldn't stand it and had to go outside and put the outputs in the amp and test bias and DC offset. The bias came up at about 340mv on each channel, and after letting the amp warm up the number went higher and then lower, and I finally dialed it in at 350 mv for each side, and the pots are both pretty much in the middle...I measured DC offset at the screw terminals for Don't board, and both channels read 10.2 mv...This seems a little high, as I know we want that number to be a close to zero as possible. So, if there anything I should do, or is this a safe number?

I

 

[NavLinear]

Here is some information regarding heat sinking with a slant towards audio. I copied this from a web site and I didn't bookmark it - so here is what I archived on my hard drive.

Good reading - Dennis

 

[Gepetto]

That is a very safe number Sutton, and they likely both are -10.2mv rather than +10.2mv. Correct?

10.2mW amounts to only 0.013mW of DC dissipation in your speakers

 

[laatsch55]

Sutton, Phase did not recommend messin with em till offset was 75mv. So ten is wonderful.

 

[ksrigg]

Excellent. The bias was right on to. With the amp cold and just turned on it was about 345 on each channel. after warming up the number got to probably 355 or 360, and then settled down to about where it started, I did have to turn the pots slightly to get them to 350, but they are both basicall in the middle of the pot's range.
Why woul a WOPL 500 have meter deflection when a sourc is playing....but no music? Upon unplugging repluggin the unit in, sound appears...What is up with that? Is the DCP relay kicking in on start-up and than on removing power and reapplying power it un-trips? It's just bothering me. No biggie, but it doesn't seem right...

Any one ever seen this happen?

 

[Skratch]

Sutton, Does the DCP relay click in after about 2 seconds when you power it up. It sounds like the relay is not pulling in so that is why you see the meters move without any music coming out. Do you have around 60 volts AC on pins 2&3 on the bottom 3 connector ?