Mark embarks on the path of complete WOPLness

[MarkWComer]

The bass is the reason I didn't keep the amp. It exhibits less control over the lows compared to a WOPL...I guess I'm just spoilt...

I don't recall that Kraftwerk album hitting the limit on my woofers with the incompletely WOPLed PL400. Just started to listen to the Denon this evening, and I see what you mean. Still, it doesn't sound bad at all. I'll have to remember this for an A/B check when the 400 is finished.

Also- played Joy Division Closer. Side 2, first track "Heart and Soul" begins with a lot of bass. Sounded OK, didn't have volume up a whole lot. Another record for A/B test...

Truthfully, there's a bunch of stuff that I'm beginning to think may exhibit sloppy bass control, so I'll give it more careful listening tests. Will find out in the next week or so while the 400 is in surgery...

 

[laatsch55]

One of my standart tests is Shpongle---"Are you Shpongled" Track 7 DMT, and the Moby "Play" track 4....the Moby is the lowest , most extended bass note I've run into, great test tune....

 

[MarkWComer]

Chapter 2 of the WOPL-izing...

One of the backplane boards populated and wired.

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[laatsch55]

Quite an undertaking isn't it??

 

[MarkWComer]

Quite an undertaking isn't it??

It will be- when I start removing the old stuff from the chassis. This is the easy stuff right now.

 

[Gepetto]

Nice videos Mark. I always enjoy watching your productions

 

[Gepetto]

It will be- when I start removing the old stuff from the chassis. This is the easy stuff right now.

Remember to do all the bare metal checks we had Nelson do along the way and you bring up should be smooth.

 

[laatsch55]

It will be- when I start removing the old stuff from the chassis. This is the easy stuff right now.

I second that!!

 

[Elite-ist]

Thanks for taking the time in recording your progress with this project, Mark. Learning, while getting a bit of comic relief, keeps the instructional video more pleasant. I like the assembly tips you offered, too.

Nando.

 

[MarkWComer]

Remember to do all the bare metal checks we had Nelson do along the way and your bring up should be smooth.

Nelson's thread was just as important as the documentation- lots of info to gather, lots of care to take, and lots of enjoyment as a result!

Thanks for taking the time in recording your progress with this project, Mark. Learning, while getting a bit of comic relief, keeps the instructional video more pleasant. I like the assembly tips you offered, too.

Nando.

Nelson made this easier for me, hopefully I will make it easier for the next guy who undertakes this upgrade. Believe me- Nelson's not in the videos, but he still is a major contributor- along with Lee and Joe's dialog. What I got from you three (and everyone else who commented) is blended into what I'm doing in the videos.

As far as taking my time to do this... well... I have as much fun doing the video editing as I have assembling the project. Comic relief? Actually, it's a product of too much LSD in the '70s, I have a twisted view of things and it makes people laugh for some reason. I'm really not trying to be funny, it just comes out that way- can't help it!

 

[MarkWComer]

2am Saturday...

2am Saturday. I keep odd hours- half of it due to chronic insomnia, the other due to chronic lumbar pain...

Schizophrenics hear voices in their heads, I constantly hear music. This is part of my insomnia, the other part is that my brain doesn't shut down when I try to sleep.

Awake anyway, so I completed the second board and moved a resistor from R5 to R6 on the otherwise completed first board.

Next step: Revising the control board for FC operation, amputate the zobel network from the DC protection board, then teardown the point-to-point after that.

(Film at 11... Stay tuned to these network stations...)

 

[laatsch55]

And so it begins....

 

[MarkWComer]

Easter Sunday- Finished with the circuit boards

Figured out a neat little trick to keep the bias transistors in place while soldering them. ALL the boards are done now, so the fun stuff is over.

Next comes the scary part...

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[nelsress]

Remember to do all the bare metal checks we had Nelson do along the way and you bring up should be smooth.

I second that Joe, with the guidance from you and Lee, it did go exceedingly smooth (knock on wood!). Following the test procedures and being careful, like I know you're being Mark, will end up with an improved and full comp WOPL 400 that should power up and work great initially. Thanks for the kind words, I'm glad my journey was helpful for you.

I too enjoy your videos Mark, the info is good, the tips helpful and, as Nando pointed out, the comic relief is well placed. Keep up the good work!

 

[TMZ2]

Figured out a neat little trick to keep the bias transistors in place while soldering them. ALL the boards are done now, so the fun stuff is over.

Next comes the scary part...

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Wow this is great I have reread this thread a couple times and watched all the videos this will come in handy for so many of us. Thanks and great job!!!

 

[MarkWComer]

Damn- forgot about removing those three jumper wires from the back of the control board...
Wasn't as finished with the modifications as I thought I was...
...but caught in time, at least!

 

[Gepetto]

Damn- forgot about removing those three jumper wires from the back of the control board...
Wasn't as finished with the modifications as I thought I was...
...but caught in time, at least!

Leaving those in defeats the independent channel fusing. A fault on one channel will take out both sets of pico fuses if you leave those in and will drive you nuts trying to figure out where the fault lies.

 

[laatsch55]

Yep........that can happen with them NOT in........to a point....

 

[MarkWComer]

April 6: Chassis stripped, preparing for board addition and wiring

Have to get a few things from the hardware store before continuing, but the chassis is stripped of the point-to-point circuitry now, and I'm planning my wire routes and connections.

Actually, things are going quite smoothly, and I came up with a quick-'n'-dirty means of removing the old transistors. Found a cap on my meter board that looks a bit toasted, so that's gonna get replaced since I have the cabinet open anyway.

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[MarkWComer]

Wiring questions

A few wiring questions:

This is a 400 Series II- LED output meters. There's a red wire and a black wire coming from the meter driver boards- I deduce these are the meter inputs. These connect to OUT1 of their respective L/R backplane boards. There is also a white wire- assumption sez that this connects to the stud ground- correct?

The WA DC board uses an AC connection from a stud on the rectifier- route it above or below the backplane boards? DC connection will be via FUSED_B+_OUT on the R backplane, ground goes to the stud ground in the center of the L backplane.

Speaker outputs (OUT2- yellow wires at the top of the boards) route atop the backplane boards- should I route the speaker grounds coming from the copper strap above or below the backplanes? I know there's an issue here regarding inductance from AC wire proximity (the thermal switch) affecting noise in the amp.

Just wanted to clarify before I burned the house down...