AC 30 topboost ( rear )

[hansaustria]

To my question now. If I turn the treble and the bass knob ( rear panel ) anti-clockwise to zero - no topboost effect on the amp!
Does the amp work like a treble model with a tone pot on the mainpanel?

Hans

[des mcneill]

Hi Hans,
I'm not too clear what you mean by "no top boost". The cut control on the main panel should still work on the top boost channel,as on the others. Are you saying the top boost channel does not work with the tone controls in the full anti- clockwise position?
Des.

[hansaustria]

How does the treble pot on the mainpanel work If you turn the treble pot and the the bass pot ( rearpanel ) to zero ( anti-clockwise )?
What happens?
Is it working like the usual treble pot on the AC 30 treble model ? Treble model AC 30`s have only a tonepot.

I was told that the treble pot at the mainpanel is working like the CUT - if treble and bass ( rear ) are full clockwise ( full bass and treble )!


Hans

[roger bayliss]

If you are referring to the 'Cut' control... then that works by cutting the high frequency presence and is a common feature on most Vox amps usually affecting all channels as its part of the power stage as I understand it. As to whether it sounds loke an AC30 treble amp I dunno but with the bass and treble off on my AC30 Heritage the top Boost sounds very much like the ef86 channel and has been mentioned by others previously.

[JimN]

How does the treble pot on the mainpanel work If you turn the treble pot and the the bass pot ( rearpanel ) to zero ( anti-clockwise )? What happens? Is it working like the usual treble pot on the AC 30 treble model ? Treble model AC 30`s have only a tonepot. I was told that the treble pot at the mainpanel is working like the CUT - if treble and bass ( rear ) are full clockwise ( full bass and treble )!
Hans

It is the Tone control on an AC30 Normal, Bass or Treble which is re-labelled Cut on a Top Boost model. But it's the same control and works on all three channels. Unusually, it produces its most trebly sound when rotated anti-clockwise (and vice-versa).

The extra bass and treble control only work on the Brilliant channel.

So if you use the Brilliant channel, and turn the bass and treble controls fully anti-clockwise, you will lose the extra bass and treble boost, but the Cut control will still work.

HTH,

JN

[bazmusicman]

Hi Hans and everybody,
I have a 50th. Anniversary AC30 top boost with the the Bass and Treble on the rear. When I turn the Bass fully clockwise the Bass is off, when I turn it anti clockwise the Bass is on!
Does this mean that the Bass control is wired the wrong way round? The Treble control works normally i.e. clockwise increases the treble.

Best regards,
Baz.

[hansaustria]

I have a 50 anniversary too. It`s the same way my amp works. Therefore my questions here.

Hans

[bazmusicman]

Hi Hans,
I think they are wired like that because the Bass and Treble are interactive with each other.

Best regards,
Baz.

[SteveG]

The bass control does work backwards on the Music Ground amps. I'm not sure if there were ever any original add-on top boosts with this arrangement, or why the MG engineer responsible for the TB unit's design elected to do it that way. I did once ask him, but didn't get a definitive answer.

Steve

[rogera]

On the original top-boost units both the bass and treble controls worked in the normal way ie turn them clockwise to increase.