Phase Linear 200 rebuild

[kl0neMan]

Excessive Dc offset usually comes from Q1, Q2, Q3, Q4

Watching the unloaded amplifier output on the scope as I bring it up on the variac, I get increasing +DC with respect to return. If I bring the AC up high enough, I start seeing +DC on the scope channel where I am monitoring input. It is occurring on both channels.

 

[kl0neMan]

It does not smoke. I have to wait for my loads to arrive for a full up test. I have triggered the protection circuit a couple of times and it comes right back after a delay. I tried to upload video, but it failed, sigh.

 

[Gepetto]

It does not smoke. I have to wait for my loads to arrive for a full up test. I have triggered the protection circuit a couple of times and it comes right back after a delay. I tried to upload video, but it failed, sigh.

Try dragging your video clip over Dan. That usually works.

 

[kl0neMan]

Try dragging your video clip over Dan. That usually works.

Will do, after I figure out what is going on with my computer. It is stuck on an OS reinstallation at the “11 minutes to go“ mark...

 

[kl0neMan]

Finally, after much ado, and delay is a sample of the video.

 

[kl0neMan]

Hmm. It appears that I have failed to upload the video once again . I just tried again (via dragging it into a message composition window). I saw an "Oops! We ran into some problems." dialog after the transfer completes. I must have missed seeing that last time - Ugh.

 

[grapplesaw]

I’m setting out to rebuild the 200b sitting on my self for 10 years. Many have stated the poor performance of the series one and b , the series two is compatible with a series ll 400 and 700 in basic design . My goal is a tweeter amp
well this one not a series ll so I’m gutting it and fitting a rev E board I have. This is just right size to fit in.
it’s going to be full complimentary with addition of extra output to drive the mj21195/96 pairs

gathering parts for December build. And one idea is the vu meters that I have. No idea what they came out of as they are 113 x82 mm just smaller that the 400 and 700b

should be strat forward build

thing that may need addressing are resistors in protection circuit and possibly power supply section

 

[grapplesaw]

This amp has delay on with speaker protection
the protection circuit is a little curious as the main power output to the board that I senses has different values from left to right channel R57 and R58 on b and r1 and r2 in series ll schematic attached

the other thing will be thermal bias control added via bias transistors added

 

[laatsch55]

That's a Ser 1 meter..

 

[grapplesaw]

That's a Ser 1 meter..

Thanks Lee , never seen them this size
These two a smaller that all my other 400 meters

they are 4-3/8 wide instead of 4 -1/2