50/50 low end distortion problem

[jrostrom]

Hi - I just bought a 50/50 blue light -- I am getting really bad distortion on the low end -- unusable. I am hoping someone knows where to start troubleshooting. I have an SMS Classic Pre into a JBL E120 hempcone from tone tubby.

Thx

Jon

 

[Markedman]

Replace the tubes. This is kind of mandatory when getting a new tube amp, even if you were told that the tubes were just replaced. Got to do it.

 

[jrostrom]

I replaced all of the tubes with matched JJ tubes -- 6L6 and 12AX7...tone is killer but farting on the low "A" -- not every low note -- for instance low G is fine -- it is only at medium volumes and above. I don't get it -- brand new hemp cone JBL E120 in tone tubby cab, brand new preamp from SMS and the 50/50 -- thoughts anyone? I tried various speakers -- same result.

Thx

Jon

 

[stokes]

At medium volumes and above the bass tone control should be set at about 2-3.If that doesnt fix it,it is time for new filter caps.

 

[jrostrom]

50/50 only has a presence control -- are you referring to the SMS preamp? Thx.

 

[stokes]

Yes,the bass control is in the pre-amp.