MB MK IV PROBLEMS (cont.)

[pjrhd28]

Mb Mk Iv Problems
I have messed around more and the hissing/ticking sound from my MB MK IV occurs when I switch from Simulclass to Class A in the switch in the back

Does this seem like a pre amp tube problem???

Thanks

 

[Grandor]

Please keep the same topic in the same thread next time.

- Do you use one of those external M/B classA/Simulclass switches or are you switching on the rear of the amp?

 

[pjrhd28]

I will keep the topic in the thread- thanks for the hint.

Its the switch in the back of the amp, not any kind of external switch.

Might that make a difference in the diagnosis?

Thanks for your help.

 

[Boogiebabies]

The switch only lifts or engages the ground on pin 8 of the inner 6L6's.
That is all it does. Try some new power tubes and call me in the morning.

welcome to tubeville.

 

[ned]

PJ-

I would call MB (contact a mesaboogie.com) on Monday morning and see what they say about this issue. If you get the recording leave a message the will call back.

Ned

 

[markiivi]

i live on a farm in the uk. we have livestock. in order to keep them in their respective fields we use electric fences. the electric fences pulse at the rate of 50 cycles and induce a hiss + pop at the same time in my boogie mk iv. i have many other sound-reproducing dvices on site whch exhibit the same problem in lesser degree. it might be worth checking to see if you have a similar scenario happening locally.