Archive of the former Yahoo!Groups mailing list: MOTM

I spent some time listening to (and recording and looking at) the outputs of
the various VCAs in my modular, which are two 110s, one 190, and a Blacet
quad VCA/mixer. I arrived at the conclusion that the clicking I have
perceived is indeed the result of the waveform being chopped at places other
than the zero crossing, and not a function of the VCA itself per se (or
rather, not a defect of the VCA). My 800 EGs have non-stock timing
capacitors, which I installed at Paul's suggestion to alter the
characteristics of the Attack controls somewhat. The difference was not
dramatic but it did make the controls "feel better" at least in my
perception.

This led me to think about the issue of synthesizing "punchy" bass sounds
without clicks in their attack. Sadly I sold my only other pure-analog
synthesizer, an ARP Odyssey, over 20 years ago, so I cannot compare the
behavior of my MOTM to other synthesizers directly--aside from a number of
digital synths, and that's not a fair comparison for the reasons that have
been cited previously.

So, unable to make comparisons directly, I turned to literature on the
topic. I happen to have an old book, "Synthesizer Technique", which is a
collection of excerpts from Keyboard magazine published in the early 1980s.
There are several articles about creating bass sounds on analog synths,
written by Roger Powell (now a MOTM user, as we know). He specifically
mentions setting the attack controls of EGs driving VCAs to zero, and does
not say anything about clicks. So perhaps we can conclude that Mr. Powell at
the time owned a synthesizer whose EGs had sluggish attacks and/or whose
VCAs were filtered in the manner that Jurgen described. On the other hand,
in an article about synthesizing plucked-string timbres by Patrick Gleeson
(I think), it was specifically mentioned that attack times of less than
around 5msec will cause "thumps" (his term).

Then I remembered that I have read somewhere (not sure where) that the Mini
Moog's famous capability for creating "punchy" bass is in part attributable
to a flattening of the peak of the attack phase of its EGs. There is a short
flat spot in the envelope's output between the upward slope of the attack
phase and the downward slope of the decay phase. It seems a little odd that
this flat spot actually lasts long enough to contain a cycle or two of a
bass-frequency wave, but Mini Moogs were a little odd in several other
respects so it's certainly plausible. I guess one could emulate this by
building an adjustable voltage clipper to limit the output of the EG to
slightly less than its full scale, thus clipping off its attack peak and
creating a flat spot.

Hence I arrived at the conclusion that the ability of a synthesizer to
create "punchy" bass sounds is as much a function of quirks in its
particular implementation of VCAs and EGs (etc.) as it is the operator's
understanding of the synthesizer and its operation. In other words, some
synthesizers are punchy and some aren't, and there's not much that you can
do about it. I sold my Oberheim Xpander in part because its envelopes were
so sluggish that it was very difficult to use it to create sounds with good
punch, snap, click, and/or pluck.

A further consideration is that most bass sounds we hear on recordings are
probably run through a DI box and/or a compressor, which would obviously add
punch to the raw output of a synthesizer.

--Adam

--
Adam Schabtach
www.studionebula.com