SVT4Pro Frequency Switch Issue

[paulorr]

I have an Ampeg SVT4Pro head. Lately I noticed when I turn the 5 position Frequency rotor, it seems to make no difference to tone shaping.

Is there possible a tube that blew out that controls this dial?

Any ideas much appreciated.

Paul

 

[asad137]

Do you have the Mid knob (not the Mid Frequency switch) turned up or down? I noticed on my SVT3 (that has a very similar, if not identical, EQ section) that the Mid Frequency switch doesn't have any audible impact unless the Mid knob is boosted or cut.

Makes sense, actually -- if the Mid knob is set flat, it's not doing anything, so it doesn't matter what frequency the Mid Frequency switch is set to.

If you want to hear what it actually does, then turn up or down the Mid knob first, THEN play with the frequency switch.

Ok, I just realized you said "lately" -- so maybe you can ignore what I just said.

Asad

 

[improvpwnd]

Do you have the Mid knob (not the Mid Frequency switch) turned up or down? I noticed on my SVT3 (that has a very similar, if not identical, EQ section) that the Mid Frequency switch doesn't have any audible impact unless the Mid knob is boosted or cut.

Makes sense, actually -- if the Mid knob is set flat, it's not doing anything, so it doesn't matter what frequency the Mid Frequency switch is set to.

If you want to hear what it actually does, then turn up or down the Mid knob first, THEN play with the frequency switch.

Ok, I just realized you said "lately" -- so maybe you can ignore what I just said.

Asad

Yup, and check out the manual--it'll tell you which frequency each notch corresponds to.

It is ±15 db @ Freq Selected (220, 450, 800, 1.6k, or 3kHz)

The ±15 comes from the Midrange knob.

 

[paulorr]

Ahhhh you are right. I recently set all the controls to flat line ... so I need to up or down the mid range to have an effect. I snagged an Am Dlx jazz and wanted to readjust from my p bass ...

Thanks!

Paul