no sound in this amp

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gurusimran
Posts: 14
(3/17/04 1:06 pm)
 no sound in this amp
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 I turned on this plexi with no ground connection.
it did a sound for 1 second then nothing more.
Then I tried again but there´s no sound.
Only a little bit when I turned the volume a 9.
How can I fix it?
 
GroundhogKen
Forum Moderator
Posts: 2324
(3/17/04 1:12 pm)
 Re: no sound in this amp
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 Any blown fuses?

Do any tube plates get red?

Do the heaters glow and tubes get warm in standby?

No hiss, no hum, no static, nothing?

Any sign of burned components?

Can you post the tube voltages?
Preamp tube pins 1,2,3,6,7,8
Power tube pins 1,3,4,5,6,8

Ken
 
wayneosdias
Senior tube assistant
Posts: 269
(3/17/04 4:55 pm)
 Re: no sound in this amp
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 Ken
your too nice.
 
gurusimran
Posts: 15
(3/18/04 4:30 pm)
 no sound in this amp
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The heaters works fine.
The plates are normal.
No hiss, no hum, no static nothing.
Only the guitar sound at around 9 on volume but extremely quiet.
The pins votages are
v1: pin1 131v, pin2 0v, pin 3 843mv, pin6 147v, pin7 0v, pin 8 2.4v
v2:pin1 1.65v, pin2 3.4v, pin3 2.12v, pin6 269v, pin7 9.4v, pin8 12.5v
v3:pin1 202v, pin2 1v, pin3 36v, pin6 196v, pin7 12v pin8 36v
v4:pin1 1.3mv, pin3 440v, pin4 400v, pin5 -40v, pin6 452v, pin8 1.5 mv
v5: pin1 1.4mv, pin3 455v, pin4 454v, pin5 -40v, pin6 454v, pin8 1.4mv
 
GroundhogKen
Forum Moderator
Posts: 2329
(3/18/04 4:44 pm)
 Re: no sound in this amp
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Check your components and connections.

V2 pin 1 should exactly equal V2 pin 7 because the pins are wired together.

Go back and check your work carefully.

As you find errors, fix them and re-post the new pin voltages.


Ken


 
gurusimran
Posts: 16
(3/18/04 11:02 pm)
 no sound in this amp
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 v2: pin1 9.4v, pin7 9.4v
I'll check the components and conections now.
 
6bq5
Junior tube assistant
Posts: 15
(3/20/04 9:51 pm)
 Re: no sound in this amp
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 hello there, if those voltages for v2 pins 1 and 7 are correct, you probably have a bad 100k plate resistor--the one mounted on the v2 socket. change it out and see what you get. hope this helps. rh
 
 
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