50/50 Hum

[Ayin 0]

Since yesterday, I have a lot of hum on my 50/50. I use it with one cab now, and I turn the B side knobs to zero with no cable in the B output.
Even if nothing is connected to the input (A), there's this hum.
Strangest thing is, when I put my GForce in front of it, the hum is almost gone, anything else before it, and there's the hum again.

Any ideas?

thanks,

Jan

 

[Harsh]

Hi,

Have you been able to sort the hum out?

After hearing so many good things about the 50/50, I decided to buy one to go with my Triaxis. Since I've plugged it in, it's been humming and making noise. Even when there's nothing connected to the amp, it continues to make noise. It also seems to be picking up radio signals, which is really weird. The left channel also gives off a loud feedback-like noise when there's nothing even plugged into the amp.

I thought it might be old valves so I bought a whole set of JJ 6L6's and 12AX7's, and changed out all the valves, but this hasn't done anything. I'm really ticked off!

Can someone please help?

 

[marantz1300]

There is a ground switch on the back of the 50/50. Have you tried both positions on it? Also my 50/50 hums when the reverb is turned up above 5 on my Studio pre. So check your settings on what your feeding it with.

 

[rsanz]

Hello:

i am going through several problems with my 50/50 amp. One of the problems is that when i connect something in the B input it makes a huge hum noise even with the volume set to zero. When i try to open it with the amp still on it makes noises, this means that there is a ground wire with a bad connection. Next week if i have time i will look for it. I'm also into this http://forum.grailtone.com/viewtopic.php?f=5&t=32954 . You can try doing this (always with taking care) take some isolated pliers and move the cables from the input and output from the sleeve of the cable and force them gently, also force a little bit the input connectors to see if it takes a good ground from your jacks... let's see if it works

good luck

 

[crane]

When i try to open it with the amp still on it makes noises

Have you changed your preamp tubes ? One of them could be microphonics, and it's normal that when you open the chassis with the amp on it makes noise. Chassis act like a shield.

 

[rsanz]

thank you for your help. My problem deals with something arround the ground connections of the input B connectors.