new Formant book arrived

[Martin Czech]

When I saw the add for that book my stomach said:
"don't buy, cheap-quick-and-dirty approach"

Seems to be justified now ...


m.c.

:::From: jhaible at t-online.de (jh.)
:::To: "diy" <synth-diy at node12b53.a2000.nl>
:::Subject: new Formant book arrived
:::Date: Sat, 4 Nov 2000 18:59:55 +0100
:::X-Sender: 320011350262-0001 at t-dialin.net
:::
:::Got the new Formant book today.
:::
:::First impression brings up a couple of questions:
:::
:::TL081's as noninverting buffers after 3080's in VCF.
:::Should lock up due to phase reversal when heavily overdriven,
:::shouldn't it ?
:::
:::Heated transistor array for the VCOs. Adjustment by measuring
:::the voltage drop over a be junction and emitter resistor. They say
:::the voltage depends on the manufacturer of the chip - I'd
:::expect it to be different for each chip, not just for each manufactuer.
:::
:::Moog ladder with with single opamp buffer stage ... debatable.
:::But what's really bad about the Moog VCF article is the theory:
:::They show an unbuffered symmetrical RC filter and say the
:::transistors take the place of the resistors - way over-simplified.
:::
:::A lot of low current BiFet opamps (TL061) are used, mainly for the
:::output stages. Why use the low current version here, but TL081's
:::in the VCF's internal stages ?
:::
:::The nice old OTA-based 4pole VCF is gone. The tiny jacks remain.
:::
:::Still a lot of words about the quality a VCA should have - and still
:::3080's used.
:::
:::Nice little sequencers added.
:::
:::(Just a first impression.)
:::
:::JH.
:::
:::
:::