Weird voltages..got some issues. Could use some eyes please?

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Big Mike
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Weird voltages..got some issues. Could use some eyes please?

Post by Big Mike » Thu Feb 21, 2013 6:43 pm

anyone eyeball anything that looks wrong?
Working the startup test...

4.7 volts before the recto tube.
only 33V on v1 pin 1 so i Stopped.

Thanks for any help! Much appreciated.

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Metroamp kit JMP50 - CM OT
Metroamp JTM45 turned JMP50 w/Classictone OT
Marshall 2550 Jubilee
Powered by Thorn and Kauer guitars
Scumback Speakers

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neikeel
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Re: Weird voltages..got some issues. Could use some eyes ple

Post by neikeel » Fri Feb 22, 2013 11:28 am

Sorry Mike need better pics with better light of the rectifier socket, PT wiring and switches.

What I can see even magged up looks ok......
Neil

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Big Mike
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Re: Weird voltages..got some issues. Could use some eyes ple

Post by Big Mike » Fri Feb 22, 2013 1:22 pm

thanks I'll get some better ones.

weird stuff.

4.7 volts between 2&8 of recto
120V at the wall
610 Volts on standbye off...on it drops to 406

Nothing on pin 5 of V4 and V5 (Should be -45DC)

heaters are good.

when I went (farther than I should have) yesterday with preamp tubes in, ( no power) only got 33V on pin 1 of V1.
Metroamp kit JMP50 - CM OT
Metroamp JTM45 turned JMP50 w/Classictone OT
Marshall 2550 Jubilee
Powered by Thorn and Kauer guitars
Scumback Speakers

User avatar
Big Mike
Senior Member
Posts: 796
Joined: Tue Oct 31, 2006 12:42 am
Just the numbers in order: 7
Location: East Bay California - Raider Nation

Re: Weird voltages..got some issues. Could use some eyes ple

Post by Big Mike » Fri Feb 22, 2013 1:34 pm

Recto tube readings for pins 4 and 6

standbye off. tube in.

Pin 6 347VDC
Pin 4 422 VDC

Standbye on

pin 6 36VDC
pin 4 50 VDC
Metroamp kit JMP50 - CM OT
Metroamp JTM45 turned JMP50 w/Classictone OT
Marshall 2550 Jubilee
Powered by Thorn and Kauer guitars
Scumback Speakers

User avatar
Big Mike
Senior Member
Posts: 796
Joined: Tue Oct 31, 2006 12:42 am
Just the numbers in order: 7
Location: East Bay California - Raider Nation

Re: Weird voltages..got some issues. Could use some eyes ple

Post by Big Mike » Tue Feb 26, 2013 12:52 am

Foiled by a bad HT fuse.

Everything dropped right in line...though the recto was a bit under 5V.
Sounds great though.
Metroamp kit JMP50 - CM OT
Metroamp JTM45 turned JMP50 w/Classictone OT
Marshall 2550 Jubilee
Powered by Thorn and Kauer guitars
Scumback Speakers

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