The Worlds First Fully Comp PL 400 Using White Oak Components !!!!!

[Gepetto]

Was Micro easy to work with. ??

They were a dream to work with Lee, just had to wade through thousands of possibilities and samples to come up with one that worked optimally for this application. Took about a month to get narrowed down to this shoulder washer.

Those folks in Flippin are awesome.

 

[Skratch]

Getting there.

 

[Gepetto]

Getting there.

Nice Mark
You are doing some pretty work there.

It is pretty daunting looking at a nekkid chassis though

 

[laatsch55]

I see your place is up for a visit, your bench is way to damn neat....I can fix that....

 

[Skratch]

I see your place is up for a visit, your bench is way to damn neat....I can fix that....

You haven't seen left or right of my bench, It looks like yours.

 

[laatsch55]

Whew, had me worried there for a second.,

 

[Gepetto]

Whew, had me worried there for a second.,

The always get that way when a project is underway...

 

[laatsch55]

Haven't seen yours like that....

 

[Gepetto]

I clean up the mess before the camera comes out...

 

[laatsch55]

Kinda misleading isn't it.......///////??????

 

[Gepetto]

Kinda misleading isn't it.......///////??????

Here is the current messy bench...let's start a contest.

 

[laatsch55]

got ya both mess down...

 

[laatsch55]

OK, got the last pair of 21193/94's in the right channel on the 400. Been doing some SERIOUS listening at Mach 4 and up. Joe, I think on most Shpongle I prefer the Fully comp bass to the quasi. There are a lot of bass components to a Shpongle recording and the fully seems to be in better control. Is this a subjective opinion with some basis in physics of the design???

 

[Gepetto]

OK, got the last pair of 21193/94's in the right channel on the 400. Been doing some SERIOUS listening at Mach 4 and up. Joe, I think on most Shpongle I prefer the Fully comp bass to the quasi. There are a lot of bass components to a Shpongle recording and the fully seems to be in better control. Is this a subjective opinion with some basis in physics of the design???

The quasi has to deal with significantly differing gains on the top and bottom half of the half bridge output Lee, and the difference that that local feedback loop contributes on the bottom half. The full comp has the same voltage gain on the bottom and the top half of the bridge, namely "1". The three stage Darlington (formed by Q10-Q11-Q13 on top and Q7-Q12-Q14 on the bottom) provides no voltage gain but does contribute significant current gain.

The quasi also bootstrapped the drive for the lower half from the output itself through R35, R34, D13 and C18, where the full comp version derives the lower half drive directly from Q5 alone.

Glad you like the sound Lee. I have been going back and forth and I too notice a pleasing difference. Still enjoy both but the full comp seems richer.

 

[laatsch55]

There's enough difference that the Laatsch household will have to have one of each( if not several) in the 400 and 700 varieties...

Thanks again Joe, ya done good, REAL good....

 

[laatsch55]

So what does Q15, Q17 and Q16, Q18 do?? Hang out and be groovy till someones needs some help?? Rather facetious, obviously they share in the current duties, but does the darlington config get compromised in any way having a longer tail??

 

[laatsch55]

So, still got plans for the hooks in the 700 light board or is that moot with a fully comp 700?

 

[Gepetto]

So what does Q15, Q17 and Q16, Q18 do?? Hang out and be groovy till someones needs some help?? Rather facetious, obviously they share in the current duties, but does the darlington config get compromised in any way having a longer tail??

Q15 and Q17 share along with Q13 with their contribution balanced out equally by the emitter resistors.
Q16 and Q18 share along with Q14 with their contribution balanced out equally by the emitter resistors.

I should have put the ellipsis after Q13 and Q14 in my earlier post.

 

[Gepetto]

So, still got plans for the hooks in the 700 light board or is that moot with a fully comp 700?

The thought is not dead yet Lee...

 

[laatsch55]

Just bustin your balls Joe. It appeared that hadn't been done today............and all bets are off by the 3rd straight C on the rocks... My humble apologies....kinda.....sorta....