Jer's 700B Quasi to Full Comp/Backplane Build

[laatsch55]

Were you playing that "Devil's Music" when she showed up? And just in case you REALLY think you got rid of that hum, I have it on good authority that it's impossible----


NOTE: There is a slight hum when the unit is turned on. Please understand,THIS IS INTRINSIC TO THE UNIT ITSELF !!! ALL 700B's have this hum. There is NO way to remove it. However, once you "crank up" the volume, you won't notice the hum anyway !!

 

[jbeckva]

When in doubt, go direct....

There wasn't any "doubt" as far as the right channel issue, as what I was saying is the left, which didn't have a problem with either HK or DAC, was fine (I had a buzz in the right with or without the DAC). Now the same mouse-fart quietness is as it should be.. both channels.

Read your PM... let me know because I have about 2 hours to fool with it...

 

[Gepetto]

Were you playing that "Devil's Music" when she showed up? And just in case you REALLY think you got rid of that hum, I have it on good authority that it's impossible----


NOTE: There is a slight hum when the unit is turned on. Please understand,THIS IS INTRINSIC TO THE UNIT ITSELF !!! ALL 700B's have this hum. There is NO way to remove it. However, once you "crank up" the volume, you won't notice the hum anyway !!

Jer, I did not think you lived in TX

 

[jbeckva]

Were you playing that "Devil's Music" when she showed up? And just in case you REALLY think you got rid of that hum, I have it on good authority that it's impossible----


NOTE: There is a slight hum when the unit is turned on. Please understand,THIS IS INTRINSIC TO THE UNIT ITSELF !!! ALL 700B's have this hum. There is NO way to remove it. However, once you "crank up" the volume, you won't notice the hum anyway !!

Naah.. just some Excision... hehe

LOL no kiddin.. all PL's got the hum, right?

 

[laatsch55]

That's what the Texas Phase Linear Guru says....

 

[jbeckva]

That's what the Texas Phase Linear Guru says....

He's fullasheeite

Crystal Method... dayum... now THAT's what I'm talking about... "get busy time!!!". We be jammin...

 

[laatsch55]

track 4 is my favorite on that one...

 

[Phase Linear Phanatic]

Jer....I finally got around to testing the third 700B I got in this week today. And it works great. Aside from the volume pots being scratchy when I turn them left or right. Question: Do you guys use de-oxit? Is that what I need to use to fix the issue? I also am curious Jer, as to what your opinion is on light boards. Heck; everybody's opinion? Do most of you go with the white LED's or the blue? I think I may change out the dingy incandescents with a new board. Just think the meters may be clearer with white. Yet....not as cool as blue? Heck: i love em both. Whats the consensus? Having fun with that hum Jer? I think it's that goofy amp? It likes to play tricks on you.  -PLP

 

[Phase Linear Phanatic]

Yeah, we can work something out..

Got shot down Lee. My mistake. They said it was the STAND-OFF'S that were the wrong size and NOT the buss bar's. When I made the inquiry; the engineer nearly had a heart attack I even asked the question and didn't talk to me all day. Gotta love that.

I would have loved to send you one. Now I'm bummed.

 

[laatsch55]

Understand..

 

[jbeckva]

Jer....I finally got around to testing the third 700B I got in this week today. And it works great. Aside from the volume pots being scratchy when I turn them left or right. Question: Do you guys use de-oxit? Is that what I need to use to fix the issue? I also am curious Jer, as to what your opinion is on light boards. Heck; everybody's opinion? Do most of you go with the white LED's or the blue? I think I may change out the dingy incandescents with a new board. Just think the meters may be clearer with white. Yet....not as cool as blue? Heck: i love em both. Whats the consensus? Having fun with that hum Jer? I think it's that goofy amp? It likes to play tricks on you.  -PLP

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Nah, got that hum exorcised! THE POWER OF WIRING COMPELS YOU.. heheh

Anywhoo.. so as far as the lights, hmm.. You know it's all personal preference, IMHO. I like blue since it matches up with the lighted PL logo. White (sorta "silvery".. or "cool white") is nice too. I think both look good - it's just what you'd prefer, and what kind of look you want to end up with.

 

[jbeckva]

More than one way to skin a mink...man I wish you could measure residual noise, would love to see what it is. And if it's quiet on some 9's, it's gotta be quiet.

Best I can do with the test equipment I have is this, Lee. This is at the uS time division to get close to some sort of wave form/trigger to see. The bottom trace is the output. The top trace is supposed to be my ground reference, so you can see I'd need a line conditioner first. Suffice to say, the output's actually quieter than the ground so I think that there would be saying something?



Yeah might get an AP myself... who knows.

 

[Northwinds]

That's awesome Jer! I thought Lee was kidding about the slight hum stuff with the 700s. That would bum me out. This wiring deal and how it affects noise is very interesting and I can see quite integral to a good build. So is your amp done now? Pics of it firing the D9's up would be awesome, I am so happy for you to finally have your FC monster!

 

[Northwinds]

Nah, got that hum exorcised! THE POWER OF WIRING COMPELS YOU.. heheh

Anywhoo.. so as far as the lights, hmm.. You know it's all personal preference, IMHO. I like blue since it matches up with the lighted PL logo. White (sorta "silvery".. or "cool white") is nice too. I think both look good - it's just what you'd prefer, and what kind of look you want to end up with.

Whatever you put in Sally looks awesome!

 

[jbeckva]

That's awesome Jer! I thought Lee was kidding about the slight hum stuff with the 700s. That would bum me out. This wiring deal and how it affects noise is very interesting and I can see quite integral to a good build. So is your amp done now? Pics of it firing the D9's up would be awesome, I am so happy for you to finally have your FC monster!

Yep, pretty much. I think I messed a lil with the 20 db switch, but I'll save that for when I get the other two nut n bolts coming with your stuff this week. Seems the first wiring idea I had wasn't quite where it needed to be, but this scheme seems pretty dern good. I could do this because of not needing the switched outlet, and quite possibly not having the front panel level controls in-circuit. It may not be the same strategy if I do a 700B where the owner wants to keep the controls/outlet, so it's still the classic "YMMV".

Whitey will have the white LED's, so that'll match what you have with Sally.

 

[laatsch55]

MTB=50 microvolts, that's the noise floor? as far as being able to distinguish signal and ground? What am I missing here Jer?

 

[jbeckva]

MTB=50 microvolts, that's the noise floor? as far as being able to distinguish signal and ground? What am I missing here Jer?

50 uS. time not voltage. point was, if my ground ref looks like THAT, then I can't get a drop dead reading. But also the actual signal is still lower than the noise on ground.

It's fOOkin quiet, aaaight?

 

[jbeckva]

Got my pre back up. Wanted to see how quiet the DAC was, pre sounds better especially when ear is not 2 inches away.

 

[laatsch55]

50 uS. time not voltage. point was, if my ground ref looks like THAT, then I can't get a drop dead reading. But also the actual signal is still lower than the noise on ground.

It's fOOkin quiet, aaaight?

Gotcha..the tour 700 wasn't all that quiet IIRC...

 

[laatsch55]

It was also a down and dirty "C" conversion..