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Vintage threads from the first ten years

previous: M.Romasco Does anyboby know how the five posi... -- 1/28/1998 5:39 AM

Re: Tone Switch

2/2/1998 5:17 PM
Mike B	Re: Tone Switch I've never seen a schematic for the DC/30 but my guess is that the tone switch selects different coupling caps between the EF86 preamp tube plate and the volume control for that channel. It probably looks a lot like an AC30/4 EF86 preamp modded with a selector switch and multiple coupling caps. This would have the effect of rolling off more of the low end as smaller values of caps were switched in. This seems to be what happens on DC/30's I've tried. Maybe it's more complicated than that but it doesn't seem so. I experimented with this scheme on a Spitfire clone that I built. I used a six position switch to select the caps prior to the volume control. I honestly was not that impressed - simple bass and treble controls provide a lot more flexibility and tonal range. Mike B

2/2/1998 5:17 PM

Mike B

Re: Tone Switch

I've never seen a schematic for
the DC/30 but my guess is that
the tone switch selects different
coupling caps between the EF86
preamp tube plate and the volume
control for that channel. It
probably looks a lot like an
AC30/4 EF86 preamp modded with
a selector switch and multiple
coupling caps. This would have
the effect of rolling off more of
the low end as smaller values of
caps were switched in. This
seems to be what happens on
DC/30's I've tried. Maybe it's
more complicated than that but
it doesn't seem so.

I experimented with this scheme
on a Spitfire clone that I built.
I used a six position switch
to select the caps prior to the
volume control. I honestly was
not that impressed - simple bass
and treble controls provide a lot
more flexibility and tonal range.

Mike B