Zach's 700B Thread

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orange

Veteran and General Yakker
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#142
Zach C. said:
lol, thought I deleted that. I was going to ask if all of these time stamps for real? (Like the 2 something in the morning in the pic)

"Also, are you guys really still up at these obscene hours?"

Everybody I know makes fun of me for being old, since I go to bed so early.

Zach
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Oddly enough, I seem to make many of my desktop captures in that hour, as some brief searching of my files revealed.

I DO sleep nights but am just as likely to be up at 5 am working all night in here or putzing around on the computer.

The electric bill at Casa Orange can make FF's hometown, Chaska, MN's illicit female 'therapy sessions' look insanely cheap and I don't even HAVE a Plase Linear!
 
NavLinear

NavLinear

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Still the same artist but he did take it to another level!!!!! Kinda like it myself - but you're probably getting an idea of where I'm at. Not the kiddie stuff.
 
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Zach C.

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laatsch55 said:
Zach, I thought it was the other way around. Us old folks are done growing, what the hell do we need sleep for. I average 4-6 hours a night is all. Too many 18-20 hours a day in the oilfield when I was a youngin..
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That's what the young tell me, but recently, I'm beginning to see that you are correct. I've been doing well to get 6 hrs myself lately. Just can't sleep any more than that.

sucks. I miss sleep.

Zach
 
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Zach C.

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So, I'm looking at the star ground thing a bit this morning and I've got a question. (or two)

On Mark's diagram, there is a 2.2r resistor between the copper buss bar and the caps on the PS rails on the chassis at the output devices. I've got a couple (1/2W should be more than enough, right?) but I'm curious as to what this is for? I'm guessing that it is to soften the knee on the low pass filter that is the decoupling caps at the PS rails, but why? (if that's even right.) Of course, I can just slavishly do this, but I always like to know WHY.

The other thing is that in "Joe's improved grounding scheme" that laatch pasted, it's clear that it refers to a 400 rather than a 700B. Obviously, its not too hard to extrapolate, but I'm wondering if I really need to run a separate dedicated ground for the input shunt resistors at the coupling switch (R54) as long as I lift them from the chassis. IOW, can I attach the "ground side" of these resistors to the buss between the input terminals, then run a dedicated ground for the inputs. It's easy to run two grounds to the star, of course, but I'm just curious if it's really needed. Thinking about it, it seems unnecessary to me. It's about the same amount of work...I could just try it, but it's a bit crowded over there, and I'd like to avoid any extra opportunities to melt some wires. :smile:

Neither of these is a show stopper either way. Just curious.

Thanks,

Zach
 
laatsch55

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#156
Zach, after you isolate the input ground plane from the speaker output posts, combing the Direct/normal coupling switch with the input RCA ground is fine. But remem,ber, bring that ground to Pad #5 on Joe's board. No input wiring should go to the star ground. That is taken care of by the other channel #5 pad going to star ground.
From EACH SPEAKER OUT NEGATIVE post bring a wire back to the star ground. Don't remember a 2.2ohm resistor any where. There are some .33uf caps but the 2.2 ohm resistor has me stumped. There was a .22 cap accross the BR we've done away with because we've gone with ,01uf accross all 4 points on the BR.
 
laatsch55

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Zach, you are officially a Phoenix member now. We have arbitrairily annihilited your thread with our late night antics. That's what makes us a little different....
 
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Zach C.

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#159
laatsch55 said:
Zach, after you isolate the input ground plane from the speaker output posts, combing the Direct/normal coupling switch with the input RCA ground is fine. But remem,ber, bring that ground to Pad #5 on Joe's board. No input wiring should go to the star ground. That is taken care of by the other channel #5 pad going to star ground.
From EACH SPEAKER OUT NEGATIVE post bring a wire back to the star ground. Don't remember a 2.2ohm resistor any where. There are some .33uf caps but the 2.2 ohm resistor has me stumped. There was a .22 cap accross the BR we've done away with because we've gone with ,01uf accross all 4 points on the BR.
Click to expand...
OK, thanks.

The 2.2r seems weird to me, too. I can't see what good it does, but there is it.



Zach
 

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laatsch55

laatsch55

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#160
. On Joe's board that is a 2.7 ohm that floats the board above chassis ground. that is not external to the board.
 
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