smackos
Gepokt en gemazeld
tmt welke serienummer is die eerste serie MS20?
de eerste de beste?
- Thread starter dennisb
- Start date
vinnieq
Lidl
- Lid sinds
- 11 juli 2004
- Berichten
- 11.134
Ik heb wel een 45 pagina studie naar de MS filters als pdf. PB me maar of Google op:
A Study of the Korg
MS10 & MS20 Filters
Timothy E. Stinchcombe
30 August 2006
Introductie:
This paper contains a reasonably thorough analysis of the filters used in the Korg
MS10 and MS20, concentrating for the most part on the low-pass variants of those
filters. The filters have a reputation for having lots of ‘character’, and if we attempt
to attribute this to some facet of the filters’ topology, we immediately run into much
confusion: filters in the MS10 and early MS20s were built around a Korg-proprietary,
resin-sealed device, the ‘Korg35’; in later MS20s, the filter was re-designed around
the LM13600 operational transconductance amplifier (OTA). Korg finally divulged the
circuitry inside the Korg35 in 2000, confirming that the filters’ topology was indeed
one of the standard Sallen-Key types, as had been suspected for some time; the later
OTA-based filter however is basically two cascaded, buffered first-order sections, which
whilst still being a second-order filter, does not share the same Sallen-Key topology of
the original.
There are several purposes to my study. Firstly there is the mechanism by which
the transistors in the Korg35 chip are used to provide voltage-control of the filter cut-off
frequency: barring simple substitution of vactrols for resistors, adding voltage-control
to a standard filter topology such as the Sallen-Key types may require a good deal
of ingenuity. Korg have demonstrated such ingenuity by biasing two transistors in the
Korg35 in the reverse saturation mode, thus essentially using them as current-controlled
resistors, and I was keen to better understand how on earth this works.
Secondly, when mention is made of the MS20 filter and its “legendary sound”, it
is often unclear just which of the two filter types is being referred to: do they have
such similar aural characteristics that it is immaterial which one is actually meant?
It will be shown in this paper that, analytically at least, the two filter designs have
similarities, but there are also differences, and these are shown too.
A Study of the Korg
MS10 & MS20 Filters
Timothy E. Stinchcombe
30 August 2006
Introductie:
This paper contains a reasonably thorough analysis of the filters used in the Korg
MS10 and MS20, concentrating for the most part on the low-pass variants of those
filters. The filters have a reputation for having lots of ‘character’, and if we attempt
to attribute this to some facet of the filters’ topology, we immediately run into much
confusion: filters in the MS10 and early MS20s were built around a Korg-proprietary,
resin-sealed device, the ‘Korg35’; in later MS20s, the filter was re-designed around
the LM13600 operational transconductance amplifier (OTA). Korg finally divulged the
circuitry inside the Korg35 in 2000, confirming that the filters’ topology was indeed
one of the standard Sallen-Key types, as had been suspected for some time; the later
OTA-based filter however is basically two cascaded, buffered first-order sections, which
whilst still being a second-order filter, does not share the same Sallen-Key topology of
the original.
There are several purposes to my study. Firstly there is the mechanism by which
the transistors in the Korg35 chip are used to provide voltage-control of the filter cut-off
frequency: barring simple substitution of vactrols for resistors, adding voltage-control
to a standard filter topology such as the Sallen-Key types may require a good deal
of ingenuity. Korg have demonstrated such ingenuity by biasing two transistors in the
Korg35 in the reverse saturation mode, thus essentially using them as current-controlled
resistors, and I was keen to better understand how on earth this works.
Secondly, when mention is made of the MS20 filter and its “legendary sound”, it
is often unclear just which of the two filter types is being referred to: do they have
such similar aural characteristics that it is immaterial which one is actually meant?
It will be shown in this paper that, analytically at least, the two filter designs have
similarities, but there are also differences, and these are shown too.
chilistein
Junior member
ik neem aan dat je het "eerste" type had ?
