JCM 2000 DSL50 Troubleshooting

dannylerch

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Hey guys,

I recently upgraded my 4x12 cabinet to x2 WGS British leads and X2 WGS retro 30s.

I wired them in parallel 8 ohm fashion because I only have two lead connectors on my cab(I have a vintage style cab). A friend said I could wire them the same as my old 8 ohm speakers. These new ones are 16 ohms. I had my speaker cable coming out of my 16ohm jack from the head. Should I of had it in the 8ohm jack?

swd4by8ps8.jpg


My speakers are wired like that^^^

After looking at another diagram, is looks like I should have had a second jumper.

attachment.php



^^
After looking at another diagram, is looks like I should have had a second jumper.

Could this be my problem?

Well the amp sounded great for two practices til tonight. I was playing at a volume of around 7oclock, and my volume started dropping and my tone started breaking up. I immediately shut off the amp, took off the back plate, and turned the amp back on. My tubes are all lit up, I noticed a little blue in my first power tube. But they are getting power. Noticed just a slight electrical burn smell when i put my face in the back of the amp, but nothing too crazy.

Basically I'm trying to see if I overloaded my tubes with the speaker load, did I blow something else like a transformer, resistor, etc?
 

Dogs of Doom

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If your speakers are all 16 ohm, & you wired them in series parallel (like the diagram above), then you need to be plugged into the 16 ohm jack...
 

dannylerch

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They are currently wired like the picture of the 8ohm speakers not the lower 16ohm speaker diagram. Again, my mistake for taking a guys word for it if it is wrong.

What i'm asking is, did I blow my power tubes, something else?
 

Dogs of Doom

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I only see 1 diagram posted (the 8ohm).

It's hard to say what's going on. I'm not a tech though.

(edit) it showed up now - that's another way to get the same resistance...
 

dannylerch

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Gotcha, suppose it is time to take it to a tech. Sigh...

Its probably the power tubes from playing at high volumes. I'm sure the speakers changing and the tubes going aren't related. I had been pushing the head pretty hard the last few weeks, and I bought the head used so I have no idea when the previous owner re tubed and biased the amp last, if he ever did. Usually I do it every 9 months to a year anyway.
 
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Micky

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Sounds like you wired the speakers correct. Series parallel for 16 ohms.
Your amp problem is probably unrelated to the speaker load, as it appears as though you were set correctly at 16-ohms.

I would have your tech check the power tubes, and possibly install and bias a new set, but I think you have already figured that out by now.
 

dannylerch

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Yeah I checked the jackplate leads with a multimeter, read 12.5ohms so the wiring was not the issue at all. Took it to a local tech today, $65 for labor if it is just the tubes, maybe more if the transformer or something else went. Not bad considering, hopefully it was just my power tubes. The faint melty electric smell worries me though.
 

dannylerch

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Just a little update. Blown output transformer, blown resistor, melted cable, all the tubes need replaced. 320 bucks including labor. bummer!
 

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