phase linear 400

ABebar

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Wait... maybe I’m speaker lubricated here but... did you install the second row with nothing but thermal paste? No mica or sil-pad? The case is the collector, that would be a dead short to ground no? Glad you had a good day for the motor scooter. I only had one so far here. Managed to find all my wiring gremlins on that ride too. Old ‘75 super glide in bad need of electrical work. The only
Electrical working in power to the ignition. TF she’s a kicker.
I'm using the sil-pads for all output transistors. I only used heat sink compound for the heat sink to chassis thermal transfer. Transistor to heat sink thermal transfer (and insulation) is via sil-pads.

I actually took an hour to pull the boards out last night and I think I found my problem. I trimmed the solder joints too close to the board on a few of the large (3 watt I think) resistors on the back plane board. A few of them are basically flush with the board and I believe when I added the second row and over torqued the thermal strap nuts, one of those two forces (or both) caused one or more of those now poorly soldered connections to fail. I'm going to take some time and touch up the solder work and I believe I'll be back in business. This time I'll actually use the magnifying glass/light that I bought for this exact purpose.
 

George S.

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I'm using the sil-pads for all output transistors. I only used heat sink compound for the heat sink to chassis thermal transfer. Transistor to heat sink thermal transfer (and insulation) is via sil-pads.

I actually took an hour to pull the boards out last night and I think I found my problem. I trimmed the solder joints too close to the board on a few of the large (3 watt I think) resistors on the back plane board. A few of them are basically flush with the board and I believe when I added the second row and over torqued the thermal strap nuts, one of those two forces (or both) caused one or more of those now poorly soldered connections to fail. I'm going to take some time and touch up the solder work and I believe I'll be back in business. This time I'll actually use the magnifying glass/light that I bought for this exact purpose.
Good deal, good lighting and magnification is a must when building these. I have LED strip lighting above the bench and additional small halogen desk lamps. At my age I wear reading glasses and a Optivisor headset anytime I'm doing any work. With the Optivisor I can watch the flux melt and wash over the joint followed by the solder .
Your methodical so you'll get this figured out. Good job.
 

ABebar

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Warrenville, IL
Either take the time to do it right, or find the time to do it twice. Apparently this time around I have selected the latter.

I spent my 20's as a bench technician and a field service tech working on dynamometers. I was fairly good at troubleshooting at one point. That feels like a long time ago. I have recapped about a dozen solid state receivers, integrated amps, and preamps, but this is the most ambitious project I've taken on in a while.
 

George S.

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Oh, and yes, those backplane components and wiring do need to be cut fairly flush, but those boards sit elevated on the stepped washers, so absolute flush isn't critical. I solder both sides of all my boards, being very careful with the heat. Also, be very gentle and precise snugging those outputs down. Over tighten them and you'll bend the transistor case and puncture the silpad. Those output cases are electrically hot, a punctured silpad is usually a sort to ground Snug until the silpad edge starts to curl or wrinkle, then stop. None of the output screws or bolts should be tight, just snugged while closely watching the silpad edge.
Listening to Bachman Turner Overdrive flac files on a 400 S1 WOPL , upgraded PL2000 S2, and Pioneer CS-99 vintage speakers.
 

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ABebar

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I had a set of Pioneer CS-99a's with the FB drivers in my garage setup at my last house. I had remodeled my kitchen and mounted all of the old cabinets in the garage with the Pioneers as the focal point. I rented the house out and left the garage setup as-is thinking that would be a good feature for a perspective renter. Well, the trash that ended up renting there ripped the cabinets out and installed home Depot racks throughout the garage and filled them with scrap metal. When I found out I asked about the speakers and he said he donated them. I know he was lying because the old Jensen 3-ways and the 90's era pioneer separates were still there. He knew those speakers had value and he sold them. It was ten years ago and I'm still angry.
 
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ABebar

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Warrenville, IL
I don't know what they are, but those speakers look awesome. That Phase Linear 200 is basically why I'm here in this forum now. When I was a kid, my dad had that 200 and a Harman Kardon Citation 11 preamp pushing some Infinity 12" 3-ways. The bass was so punchy and tight. It took me decades to understand damping and why I wasn't getting that same low end control over my speakers with 100+ watt receivers. I loved my Sansui 9090 and my Yamaha CR-1000, but nothing came close to matching that Phase Linear punch.

Unfortunately my mom threw away/donated that PL200 and the HK pre when she downsized homes as an empty nester. Wish I still had it.
 

gene french

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guayabo de bagaces, guanacaste, costa rica....
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thank you...those speakers are home made...all dayton audio drivers....used subbox to design the box...xsim for the crossovers....and a ton of reading to order the drivers for what i wanted....i knew i wanted front discharge vented....i am happy with them...
that is how i feel about the 400 i just bought....great memories from days gone by...i probably will recap the 200 later....when i finish up the 400...i am looking for a 400 or 700 to white oak...i have patience....i will find one....i will move the 200 to make room for the 400 on the entertainment center...
the guys here have been very generous with their advice and comments....very nice forum...i appreciate being accepted here!!!!
 

gene french

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guayabo de bagaces, guanacaste, costa rica....
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