Taking the Plunge Into the WOPL 400-II Pool

Thanks George, I see you replaced the twisted pairs with shielded wires for both inputs. Great idea!
And where are the braids/shield wires that go to/from the front pots terminated?
 
This is a 400 S1, I added same pot/attenuator that the S2 uses, kinda hard to see under the meter light bar pcb. If I can find a photo of my twin built S2 today, I'll post it. Have to run now for work.IMG_20200517_100604.jpg
 
Here you go, the S2, really no difference. Not a piece of the original wiring in either build other than the wiring that's integral with the transformer. All PTFE/teflon silver plated mil spec.
Don't rush your build. I incorporated some of the original wiring and wasn't happy, so tore them back down. I had a bias wire burn thru and wasn't happy so I tore them back down a second time and added Phoenix connectors on both boards for all the small AWG wires. Take your time and do it right and you'll have a amp you can pass on to your kids. These are dead silent with the volume turned up, no hum, no hiss.
Building a set of WOA meters this weekend if I find the time. Will post photos and what I think of them as a sperate thread. PXL_20201108_005837952.jpg
 
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Joe makes it possible with his wire length cutting guide, just spot on accurate. I wasn't prepared for needing additional wire and tried to use what I had on hand, but it wasn't close in quality to his wire kit! Wow! What great wire, never saw silver plated teflon insulated wire before. The Belden coax is whatever Joe recommended in a old post, saying he uses it for his automotive products, don't have that # right now.
I think NAVLinear may have a eBay store selling PTFE/teflon wire, but I got mine including the 14 AWG I later used for the IEC power socket conversion from a seller in New Jersey. The coax was purchased as a cheap remnant spool.
The bias wire burning thru was totally my fault, probably knicked the strands when stripping. Then with all the flexing from cleaning the boards, assembly, reassembly, etc, there just wasn't enough left intact to handle the load. Too many broken strands. So I'm a firm believer in using Phoenix connectors for all those fine wires. Little additional cost compared to total, and besides, every wire hole on those boards are sized for the connectors anyway. May even be a good idea for us hobbyist non-engineers to go up a wire size on the bias wires. Have fun!!!!¡!
 
Having rebuilt and re-wired my first WOPL 400-II, still nearing completion, I have a new appreciation for the meticulous level of detail you have put into these systems, George. I also found the teflon insulated wire to be of incredible durability, albeit a chore to hold on to while stripping, as it is so slippery. I finally found a use for the spring loaded "clamp&strip" tool that I bought for a couple dollars at a yard sale! It is perfect for the 22ga wire.

Anybody who attempts a WO upgrade on a PL system should seriously consider adding the small charge for Joe's teflon wire package (if you don't already have an inventory of that wire). There was plenty of leftover wire, after cutting the lengths he provides for the main interconnections, to replace every strand of factory wire that connected the Cylon meters and other enhancements, such as Don's DCP board.

I don't have the nice teflon/tinned coax cable you used for the RCA jacks to pots to control boards, but a friend who used to make up custom interconnects for home audio systems and studios gave me a spool of this cable when I mentioned the rebuild project to him. It is copper and PVC jacket ... I'm thinking while not the ultimate solution, it should be better than the 2-conductor cable PL used.

Also re-capped the original Cylon meters. Inching closer to the finish line every day.
Al
 

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Good while back Perry stated in a post that the variable attenuators(pots) have no effect on signal quality. Being that they can be bypassed completely like a original S1 that doesn't have them, or left in circuit like a S2. He said he tested both ways, got same results. I believe him even after he said he hires a Wino to do his builds! Hope he isn't getting over run from the border being open.
Al, however, what markings are on that black coax your using? Someone more knowledgeable than me can confirm it's appropriate as there are various impedances and types.
The original coax should be Belden branded and I've read it's good enough to reuse in a WOPL.
 
George S. said:
Good while back Perry stated in a post that the variable attenuators(pots) have no effect on signal quality. Being that they can be bypassed completely like a original S1 that doesn't have them, or left in circuit like a S2. He said he tested both ways, got same results. I believe him even after he said he hires a Wino to do his builds! Hope he isn't getting over run from the border being open.
Al, however, what markings are on that black coax your using? Someone more knowledgeable than me can confirm it's appropriate as there are various impedances and types.
The original coax should be Belden branded and I've read it's good enough to reuse in a WOPL.
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The original coax used by PL is actually shielded twisted pair and not coax. It is made by Belden. It is horrible to work with because it suffers melt back with the application of any heat. I always replace with high quality RG316 type teflon coax. Smaller diameter also makes it dress more nicely.
 
I looked closely at this cable and see no markings...I think that's odd as well. My friend will go to his storage shed and see if he can locate the original spool, but he assures me it is a high quality, low loss cable that he has used for years with high end equipment.

But the bottom line is that I got it all together this afternoon - and powered up! Aja NEVER sounded this GOOD ! I have been holding back from taking the volume up too high just yet, but I will get there soon enough!

Question for Joe ... how hot will those .33ohm emitter resistors get during high-demand volume levels? I have one of the coax cables routed where it is close to one of them.

MANY, MANY thanks to this awesome community! From the onset when I posted my introduction, the welcomes and helpful advice have been amazing. Joe has developed the most amazing product line for these old PL boxes. I have a local friend with a 400-II that is going to be very impressed with this reborn system.

Next project might be a P3600 pre-amp that was given to me. Immediate problem is that ridiculous ribbon cable between boards; it is delaminated in several spots. Not sure if it is worth the time investment...but it is a project and folks out here seem to like the phono pre-amp section ( I searched !)
Pics attached:
Al
 

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YEAH! You can always open it back up for upgrades in the future. And to think you bought it new. I don't think many of us can say that! Enjoy!
 
Oh - and Mark, I took your advice and removed that input jack plate, directly grounded the jack rings to the WO PL14_20 pin #2, as you recommended. Thank you!
 
e30m3mon said:
I looked closely at this cable and see no markings...I think that's odd as well. My friend will go to his storage shed and see if he can locate the original spool, but he assures me it is a high quality, low loss cable that he has used for years with high end equipment.

But the bottom line is that I got it all together this afternoon - and powered up! Aja NEVER sounded this GOOD ! I have been holding back from taking the volume up too high just yet, but I will get there soon enough!

Question for Joe ... how hot will those .33ohm emitter resistors get during high-demand volume levels? I have one of the coax cables routed where it is close to one of them.

MANY, MANY thanks to this awesome community! From the onset when I posted my introduction, the welcomes and helpful advice have been amazing. Joe has developed the most amazing product line for these old PL boxes. I have a local friend with a 400-II that is going to be very impressed with this reborn system.

Next project might be a P3600 pre-amp that was given to me. Immediate problem is that ridiculous ribbon cable between boards; it is delaminated in several spots. Not sure if it is worth the time investment...but it is a project and folks out here seem to like the phono pre-amp section ( I searched !)
Pics attached:
Al
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At 200W per channel into 8 ohms, each 3W 0.33 ohm emitter resistor will be dissipating 0.9W each, in other words, cruising...
 
That's a beautiful, classic amp, the wood side panels make it even more interesting.
 
Gepetto said:
I always replace with high quality RG316 type teflon coax.
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This is very high quality coaxial cable perfect for the input signal wires for Phase Linear amplifiers.
However, avoid the wire from China because their QA is not as good as ours. If you can find USA-made wire from a reputable source in the USA, such as Thermax or ITT Surprenant, buy it. Better yet is the Mil-spec version, M17/113-RG316, a little more expensive, but really nice. I have some that was left over from a Raytheon government contract; good stuff. You will know it if it has continuous marking on the cable, the government requires it to be so marked. Right, WOPL Sniffer?
 
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