Clair Bros Amp

Northwinds

Northwinds

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The kids blew up one of my Kenwood amps using an iPod to drive it at a summer party this year. I don't own one myself and don't know shit about them but I tell you what, no iPod will ever be connected to my good equipment
 
WOPL Sniffer

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Lee, have you or can you use the GBPC3504 Bridge rectifier? It's 400V 35Amps instead of the 600V 50 amp one (KBPC5006)? Just asking because I have a couple and will use them if possible. Thanks

P
 
WOPL Sniffer

WOPL Sniffer

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Northwinds said:
The kids blew up one of my Kenwood amps using an iPod to drive it at a summer party this year. I don't own one myself and don't know shit about them but I tell you what, no iPod will ever be connected to my good equipment
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I'm what you call a professional..... Watch this kids.....
 
Gepetto

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TheWOPLwhiffer said:
Had a hell of a time trying to troubleshoot a Clair amp a guy bought from me. I sold it for "Parts Only" since I didn't have time to dick with it but he talked me into getting it up and running before I shipped it. Anyway, The right channel would not work no matter how many times I kicked it, so After probing around, I thought I found an issue with Q206 (one of the transistors with the big square heat sink) which is in the right channel on the PL-36 board. So, I went to remove it and the collector lead came out, it was broken and you couldn't see the leads since they are hidden under the heat sink. It rocks the house now. I rebuilt the PL-36 board so he wouldn't have any issues with it for a long time. I gotta tell you, the workmanship of some of these boards coming out of PL is something else. The left gobs of flux all over the place which takes a jackhammer to get loose after all these years, the wires look like they were stripped with a chainsaw etc.... I think I found one of the guys from third shifts glass eye stuck under the widget by the high speed bumper bolts... JEEEZE

P
Click to expand...
The 40412 transistors were not properly shock mounted to the board by PL during assembly. What you saw was a fairly common failure mode. The mass of the heat sink was only suspended by the 3 tiny wires of the TO-5 transistor within it and those 3 leads were not enough mechanical support. The rough handling that these Clair amps saw would bring this out. What you ended up with is a fractured glass bond at the bottom of the TO-5 transistor. At best this produced an intermittent, heat sensitive connection to the bonding wire. At worst it made for an open connection. I have had a couple of 700Bs with the intermittent connection problem. They should have glued the heat sink to the PCB but that never happened.

Yes, unfortunately the Series 2 were low quality builds. The PL36 board was the cost reduced version of the earlier PL20 board after the bean counters got their way at PL.
 
grapplesaw

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laatsch55 said:
Yep....except for the complementary version...
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All the large heat sinks on my boards are held with two heavy solder points on the long width. They have not been any trouble for me. The next one I rebuild I will use these Thermalloy type screwed and glued. Have a look Perry before you discard the Pl36 board as may be able to reuse them with a little work. I have some 2N3440 to use with heat sinks. I may need to trim a little material on the bottom side along the narrow widths

http://www.aavid.com/products/standard/2212b-5assyg

TO-5 TO-39 Anodized Aluminum Heat Sinks.

Thermally part number 2212-B-5 1.

1.08" OD x 0.375" H.

Mounting holes are threaded for 4-40 screws and measure 0.925" center to center.

Teflon inserts in lead holes isolate leads from case.






s-l1600.jpg
 

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laatsch55

laatsch55

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The 3440 would do well in a board used in a 400 , but you really should use the 3439 in a 700 board. The 3439 is a much more robust part.
 
WOPL Sniffer

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Just buttoning up the Clair I just wopl'd. It is sweet. I'll get some pics posted. Gonna get it good and warm and do another bias adjustment and put the face on it. It had a FU right meter so I put another in. Now I got 2 meters to repair. Have not messed with one yet but I need to now.
 
Gepetto

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TheWOPLwhiffer said:
Just buttoning up the Clair I just wopl'd. It is sweet. I'll get some pics posted. Gonna get it good and warm and do another bias adjustment and put the face on it. It had a FU right meter so I put another in. Now I got 2 meters to repair. Have not messed with one yet but I need to now.
Click to expand...
Nice, is this the one you are listing on the Bay right now?
 
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