Jupiter amp

Hello everybody

I'm working on a Jupiter mono tube amp
Problem is that the sound drops almost to zero
It is loud for about 2 sec. and then drops to almost zero and gets a bad sound
I changed all the tubes but no result
It is a amp with
2x EL84
3x ECC83

Who can help me?

Thank you

Hello

I I forgot to say
I have only 200 ohm on the primary coil of the output transformer
I believe this must be aprrox 7000 ohm
Can this be the problem?

Regard,

Tim

Hi Tim,

First of all: I am not a technician.

I checked our Jupiter Manuals, but they don't show any values for Output transformer LS16/7 B (?).
Electro Kicker intorduced a new Output transformer - LS19 7/842 which could be used for all tube amps with EL84, 6973, 6L6 and 7189. So for yours as well.

This output transformer shows primary an impedance of 7300 Ohm.

Next to this: Can't faulty capacitors cause such an error? If they loose their capacity?


Hildegard

Hi Hildegard

Thank you for your reaction
I found the the problem
It was a bad resistor on the el84 tube
I've replaced all the resistors,caps and tubes
The amp is working 100% again
Most people hate work on a Jupiter jukebox
But they are fun to work with
I've learned to solfe alle the problems and weak spots

Regards,
Tim

Hi Hildegard

Thank you for your reaction
I found the the problem
It was a bad resistor on the el84 tube
I've replaced all the resistors,caps and tubes
The amp is working 100% again
Most people hate work on a Jupiter jukebox
But they are fun to work with
I've learned to solfe alle the problems and weak spots

Regards,
Tim