phase linear 400

Good job Gene, ya done good. You may be able to just add the bias transistors and adjust bias and recheck DC offset without taking it back down. I don't see why not. See what Joe says.
Nice job!
 
Naw, solder them correct. Mock them up, tack solder them, check alignment and fit, finish solder them, and reassemble. You don't want doubt about quality of the job nagging you. It's good practice and you've got plenty of time to tear it down and build it back up. You'll be able to pass this amp onto your son and it'll last and last.
But you know, if some repair guy was replacing a bias transistor, he'd probably just cut it, extract the leads, and solder the new one in. Don't be that guy.
Just use the same care and follow the PDF precisely again. It'll be easier the second time. Just don't get over confident. Hope you've got 16 new silpads and maybe a nice accurate Fluke multimeter from Amazon or wherever. Later! Sitting at home listening to Pete Namlooks' Air 1 and Air 2 digital files on the system. Just amazing.
 
When I get time I'll hook my good digital scope up to the outputs of a 400 WOPL and see exactly what's going on there. Should be able to get some very accurate voltage measurements and see what the DC is doing in regards to + and -. Never thought about trying that until today. I'll post a photo so you can see.
 
George S. said:
Naw, solder them correct. Mock them up, tack solder them, check alignment and fit, finish solder them, and reassemble. You don't want doubt about quality of the job nagging you. It's good practice and you've got plenty of time to tear it down and build it back up. You'll be able to pass this amp onto your son and it'll last and last.
But you know, if some repair guy was replacing a bias transistor, he'd probably just cut it, extract the leads, and solder the new one in. Don't be that guy.
Just use the same care and follow the PDF precisely again. It'll be easier the second time. Just don't get over confident. Hope you've got 16 new silpads and maybe a nice accurate Fluke multimeter from Amazon or wherever. Later! Sitting at home listening to Pete Namlooks' Air 1 and Air 2 digital files on the system. Just amazing.
Click to expand...
yes sir...
been a long road...be kinda dumb to stop a few steps short...i have more sil pads...
 
George S. said:
When I get time I'll hook my good digital scope up to the outputs of a 400 WOPL and see exactly what's going on there. Should be able to get some very accurate voltage measurements and see what the DC is doing in regards to + and -. Never thought about trying that until today. I'll post a photo so you can see.
Click to expand...
inquiring minds want to know...
 
I just snug them until the edge starts to curl or wrinkle, then stop, no tighter. I wear a magnifying headset and look as close as I can as I snug them. Used ones on close inspection usually have a marked area so I replace them because they are cheap,
 
George S. said:
Naw, solder them correct. Mock them up, tack solder them, check alignment and fit, finish solder them, and reassemble. You don't want doubt about quality of the job nagging you. It's good practice and you've got plenty of time to tear it down and build it back up. You'll be able to pass this amp onto your son and it'll last and last.
But you know, if some repair guy was replacing a bias transistor, he'd probably just cut it, extract the leads, and solder the new one in. Don't be that guy.
Just use the same care and follow the PDF precisely again. It'll be easier the second time. Just don't get over confident. Hope you've got 16 new silpads and maybe a nice accurate Fluke multimeter from Amazon or wherever. Later! Sitting at home listening to Pete Namlooks' Air 1 and Air 2 digital files on the system. Just amazing.
Click to expand...
of course i had to look up pete...i never was introduced to his music...i will put him on the 8 fin tomorrow!!! sounds interesting on my phone!!!
 
George S. said:
I just snug them until the edge starts to curl or wrinkle, then stop, no tighter. I wear a magnifying headset and look as close as I can as I snug them. Used ones on close inspection usually have a marked area so I replace them because they are cheap,
Click to expand...


I had my elbow calibrated to precisely 6 inLb on a HP 29012 torque-master which was purged with oxygen free oxygen, and temperature controlled to a chilly 98.6 F

Now I just tighten until my fake shoulder pop's out of the socket preventing curling of said SilPad. Did I mention it was 5 years ago this week I had my Shoulder replaced? It works great as long as I don't use it :)
 
as a younger man after college i had a flooring contractor business for 15 years...spent my day moving furniture and handling 600 pound rolls of carpet...i tore up one of my shoulders...had surgery...after a year i was good to go...no more pain...worked out great until a few years ago...my son couldnt handle a new mother cow...so...i got me a rope too...that 1500 pound cow jerked us both across the pasture on our bellies...turned out i tore every tendon in both shoulders...went to have it fixed...then thought about the last surgery and the doctor complaining about how complex the shoulder is, i opted to live with it...maybe it would discourage future stupid behavior...septigenerians have no business roping angry cows...maria has to help comb my hair these days...working below shoulder level presents no problems...over head is another story...
i understand your pain sniff...getting older aint much fun...but sure beats the alternative!!!
a question sniff, if i may...you are the soldering guru...would you solder the bias transistors in from the top of the board, or would you disassemble and solder from the back???
joe??? your thoughts please...
asking for a friend!!!
 
gene french said:
as a younger man after college i had a flooring contractor business for 15 years...spent my day moving furniture and handling 600 pound rolls of carpet...i tore up one of my shoulders...had surgery...after a year i was good to go...no more pain...worked out great until a few years ago...my son couldnt handle a new mother cow...so...i got me a rope too...that 1500 pound cow jerked us both across the pasture on our bellies...turned out i tore every tendon in both shoulders...went to have it fixed...then thought about the last surgery and the doctor complaining about how complex the shoulder is, i opted to live with it...maybe it would discourage future stupid behavior...septigenerians have no business roping angry cows...maria has to help comb my hair these days...working below shoulder level presents no problems...over head is another story...
i understand your pain sniff...getting older aint much fun...but sure beats the alternative!!!
a question sniff, if i may...you are the soldering guru...would you solder the bias transistors in from the top of the board, or would you disassemble and solder from the back???
joe??? your thoughts please...
asking for a friend!!!
Click to expand...


I would put a heat sink on the leads to protect the component from heat degradation, and solder them from the top if it means tearing out the back planes to get at them risking God knows what and messing with a tidy wiring bundle.. I don't normally like to solder on the component side of the board but in this case, I would. Good reason to leave the project alone in the future until ALL components are installed. There was really no reason to install the Back Planes without having ALL components installed except you were in a hurry. I'm different, I never tape up wires and try to bring up the amp until everything is ready. There is no reason to. Time Saver? Not if you have to disassemble to finish the work you could have done already. Just my 2 cents worth. :)
 
thanks....i asked for your 2 cents worth...thanks for supplying it...you are, after all the premiere expert on soldering ....just wanted to know your thoughts...i have hemastats...they make excellent heat sinks...and i use them often...
i really dont think its that big of a chore...the pads on the back side are about the same size and will still have a wire in the hole...
i will consider...
 
gene french said:
thanks....i asked for your 2 cents worth...thanks for supplying it...you are, after all the premiere expert on soldering ....just wanted to know your thoughts...i have hemastats...they make excellent heat sinks...and i use them often...
i really dont think its that big of a chore...the pads on the back side are about the same size and will still have a wire in the hole...
i will consider...
Click to expand...


When you lower the bias transistor into the hole, you'll feel it hit the back wall, you can then mark the leads with a scratch awl or exacto, and raise it into position and not have to worry about the leads shorting during Bring Up.
 
WOPL Sniffer said:
I would put a heat sink on the leads to protect the component from heat degradation, and solder them from the top if it means tearing out the back planes to get at them risking God knows what and messing with a tidy wiring bundle.. I don't normally like to solder on the component side of the board but in this case, I would. Good reason to leave the project alone in the future until ALL components are installed. There was really no reason to install the Back Planes without having ALL components installed except you were in a hurry. I'm different, I never tape up wires and try to bring up the amp until everything is ready. There is no reason to. Time Saver? Not if you have to disassemble to finish the work you could have done already. Just my 2 cents worth. :)
Click to expand...
joe instructed me how to proceed...i would never know to jump c and e on the bias transistors...i think because of my situation , taking 3 weeks to get parts...he wanted us to find out if i blew something up...the parts could be sent earlier...and not lose 6 weeks...just mho...
i do appreciate the advice and assistance...
this is exactly what a forum should be like...
congrats lastsch!!!
kudoos to all administrators as well...
joe goes without saying....
 
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