What is it?
The V’Amp is a combined voltage-controlled amplifier (VCA) and ring
modulator (A.K.A. ring “mod”), with a little bit extra. The effect of a VCA is known
as amplitude modulation (AM), while a ring mod is a frequency mixer, an effect
known as heterodyning.
Heterodyning takes two frequencies –– traditionally known as the “carrier”
and the “modulator” –– and mixes them, producing the frequencies that are sum
and difference of these two at the output, i.e., if the carrier is 220Hz and the input
is 400Hz, the sum frequency will be 620Hz and the difference frequency will
be 180Hz. Ring modulation is used to generate non-harmonic (not an integer
multiple of the base frequency –– 2x, 3s, etc.) frequencies, which are necessary
for, say, metallic sounds like cymbals. A perfect heterodyning will have neither the
carrier nor the modulator present in the output. While achievable on paper, this
is extremely difficult to accomplish in reality, so some bleedthrough of one or the
other (or both) is often present to some small degree.
While typical ring mod devices are designed specifically for frequency
mixing, the V’Amp allows you to not only change the degree of the mixing and
the level of the bleedthrough, but can also be used as a VCA at the same time.
The mixing can be varied from VCA (carrier only), into ring mod, then out of ring
mod into inverting VCA (inverted carrier).
Mod1 is the modulator. Envelope and Mod2 should be thought of as VCA
(AM) inputs, but separate. Envelope is a straight VCA control voltage (CV) input,
while Mod2 is an attenuated/variable CV input.
The morphing of the Mod1 function is not fully controllable by CV and
must be varied using the knob to access the full range of variation. However,
experimentation has shown that a control voltage applied to the second Mod1
input can be used to voltage-control a small range of the function morphing.
The two 7-pin headers on the back of the module are there for testing
and in case it turns out that there are other features that can be brought out in an
expansion module later in time.
As with all f(h) products, the V’Amp was engineered towards maximizing
functionality while keeping cost as low as possible. If some aspects of the unit
seem awkward, it is most likely due to this. The goal is to make unique, useful,
enjoyable, and affordable instruments, not just hoover
1
out your bank account, so
each module requires a little patience and experimentation before their secrets
become apparent.
And remember: every instrument has its quirks and unexpected aspects,
so RTFM
2
all the way through! Specific quirks are mentioned in the description of
the particular feature they apply to, so please read this through before emailing!
1) Hoover is a company that manufactures vacuum cleaners.
2) RTFM = Read The F*cking Manual!
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