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Power tube flash

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Greg Williams (gwmn)
Username: gwmn

Registered: 08-2013
Posted on Tuesday, September 10, 2013 - 10:24 am:   

I started getting a slight blue tube flash on V2, (I think it's V2 - closest to the end), when I switch from standby. I get speaker crackle at the same time on both high and low power, just less on low power. I'm going to replace the tube sockets but I can't make out the schematic on which parts to replace along with the new sockets. .001/2000v caps, 1.5k's and a couple of black transistors?
Mike Kaus (mm210)
Username: mm210

Registered: 05-2006
Posted on Tuesday, September 10, 2013 - 04:24 pm:   

Black tansistors? Are you talking about the diodes? There are a couple of diodes strapped across there. I think they are something like 3kv diodes.
Greg Williams (gwmn)
Username: gwmn

Registered: 08-2013
Posted on Tuesday, September 10, 2013 - 05:08 pm:   

Sorry about my lack of knowledge. Yes the diodes. Are they heat sensitive beyond the norm for de-soldering and re-soldering?
Mike Kaus (mm210)
Username: mm210

Registered: 05-2006
Posted on Wednesday, September 11, 2013 - 07:42 am:   

No. They are pretty tough. I USUALLY replace them and let the leads stay a little longer and the same with any resistors on the sockets to get them up away from the socket heat. I also usually put the resistors on the OUTSIDE of the socket rather than right over the top so that the heat doesn't come straight up and hit the componenents, if there is room. Also, the resistors should be metal oxide, if you can get them. They hold up to the heat better. Might be e little tough finding the 2 or 3 kv diodes. If you can't find them, put the old ones back in. Mike.
Bill Moore (bill_moore)
Username: bill_moore

Registered: 03-2013
Posted on Wednesday, September 11, 2013 - 10:19 am:   

Mike, I never found the 5KV diodes for my RD100, but 3KV, as used by Fender, and 2KV, as used by Peavey, are easy to find.
Mike Kaus (mm210)
Username: mm210

Registered: 05-2006
Posted on Wednesday, September 11, 2013 - 12:16 pm:   

I haven't looked for them honestly, because I've never had to replace any! I'm sure Mouser or somebaody has to have them. Glad the 2 and 3k are available. They are plent. Leo probably just got a deal a hot truckload. Mike.