Markbass TA 503 problems

[bassrad]

Just a little help needed.

I have the Markbass TA503, love the head, but...

The lower row of equilizers is not making any diference in the sound wher I turn them.

Could this be an tube issue, or not?

Thanks,

R.

[gillento]

The lower row sets the frequency of the row above.
Let's say you want to boost the 100hz low band: you turn the lower pot (1st one I suppose) to 100 hz. With the pot just above, you boost the 100hz you just selected with the lower button, by turning it clockwise.

So, in case the upper post are all at 12 o' clock (no boost or cut), none of the lower buttons show any result.
Hope this helps

[bassrad]

I will try it once I get home.

English is not my first lenguage and I couldn't understand the manual very well.

Thanks.

R.

[rodl2005]

For a try out,
boost one of the upper row controls, then, while playing an open string, move the lower control (that goes with the boosted upper control) back & forth.
You should be able to notice a difference & hear what they do.