Maths - tips en trucs!

[ProgHead]

Voor het vervolg zijn onderstaande citaten uit de Manual van belang:

MATHS is laid out top to bottom, with symmetrical features between CH. 1 and 4. The signal inputs are at the top, followed by the panel controls and control signal inputs at the middle. The signal outputs are at the bottom of the module. LEDs are placed near the signal they are indicating.

Channels 1 and 4 are able to scale, invert or integrate an incoming signal. With no signal applied, these Channels may be made to generate a variety of linear, logarithmic, or exponential functions upon the reception of a trigger, or continuously when the Cycle is engaged. One small difference between CH. 1 and 4 is in their respective Pulse Outputs; CH.1 having End of Rise and CH. 4 having End of Cycle. This was done to facilitate the creation of complex functions utilizing both CH. 1 and 4. Channels 2 and 3 are able to scale, amplify and invert an incoming signal. With no external signal applied, these Channels generate DC offsets. The only difference between CH. 2 and 3 is that CH. 2 generates a +/-10V oset while Ch. 3 generates a +/-5V offset.

All 4 Channels have outputs (called Variable Outputs) which are normalized to a SUM, Inverted SUM, and OR bus so that addition, subtraction, inversion and analog logic OR manipulations may be achieved. Inserting a plug to these Variable Output sockets removes the associated signal from the SUM and OR bus (Channels 1 and 4 have unity outputs, which are NOT normalized to the SUM and OR bus). These outputs are controlled by the 4 Attenuverters at the center of the module.

There are many different signal outputs on the MATHS. All of them are situated at the bottom of the module.
Many of them have LEDs situated nearby for visual indication of the signals.
The Variable Outs
These outputs are labeled 1, 2, 3 and 4 and are associated with the four Attenuverter controls in the center of the module. These outputs are all determined by the settings of their associated controls, esp. the CH. 1 through 4 Attenuverter controls. All of these jacks are normalled to the SUM and OR Bus. With nothing patched to these outputs, the associated signal is injected into the SUM and OR Bus. When you patch a cable into any one of these output jacks, the associated signal is removed from the SUM and OR Bus. These outputs are useful when you have a modulation destination where there is no attenuation or inversion available (the CV inputs on the MATHS or FUNCTION modules for example). They are also useful when you want to create a variation of signal that is at a different amplitude or phase.
EOR OUT
This is the End Of Rise Output for CH. 1. This is an event signal. It is either at 0V or 10V and nothing between.
It defaults to 0V, or Low when there is no activity. The event in this case is when the associated Channel reaches the highest voltage to which it travels. This is a good signal to choose for Clocking or Pulse shaped LFO. It is also useful for Pulse Delay and clock division since the Rise sets the amount of time it takes for this output to go High.
EOC OUT
This is the End Of Cycle output for CH. 4. This is an event signal. It is either at 0V or 10V and nothing between.
It defaults to +10V, or High, when there is no activity. The event in this case is when the associated Channel reaches the lowest voltage to which it travels. The associated LED is on when nothing is happening. This is a good signal to choose for Clocking or Pulse shaped LFO.
Unity Signal Outs (CH. 1 and 4)
These outputs are tapped directly of the core of the associated Channel. They are not affected by the Channel's Attenuverter. Patching into this output does NOT remove the signal from the SUM and OR Buses. This is a good output to use when you do not require attenuation or inversion or when you want to use the signal both independently and within the SUM/OR Bus.
OR OUT
This is the output from the analog OR circuit. The inputs are CH. 1, 2, 3, and the 4 Variable Outputs. It always outputs the highest voltage out of all the voltages applied to the inputs. Some people call this a Maximum Voltage selector circuit! The attenuators allow for weighting the signals. It does not respond to negative voltages, therefore it could also be used to rectify a signal. Useful for creating variations on a modulation or sending CV to inputs that only respond to positive voltages (e.g. Organize CV Input on the PHONOGENE).
SUM OUT
This is the output from the analog SUM circuit. The inputs are CH. 1, 2, 3, and 4 Variable Outputs. Depending upon how the Attenuverters are set, you could add, invert or subtract voltages from each other using this circuit. This is a good output to use for combining several control signals in order to generate more complex modulations.
INV OUT
This is the inverted version of the SUM Output. It allows you to modulate backwards!

 

[MstrFX]

Persoonlijk zou ik een math’s mk2 wel interessant vinden maar dan de componenten thermisch gekoppeld en 20 stepped potentiometers of zoals de Melbourne Nina potentiometers.

Zou een commerciële hit worden denk ik

 

[ProgHead]

Hoezo - vanwege de precisie?

 

[MstrFX]

Ja en het herroepen van instellingen

 

[ProgHead]

Dat zou wel een groot verschil maken ja. Hoewel er ook mensen zijn die juist de analoge variatie en eenmaligheid waarderen. Wie weet komt er ooit nog eens een dergelijke door jou voorgestelde precies instelbare hybride versie.

 

[ProgHead]

Voor de kolom van vier knoppen in het midden nemen we onderstaande schaalverdeling aan:

 

[ProgHead]

De Manual duidt erop dat:

[imath] \mathrm{U}_1(t) = \mathrm{Ctl}_1 \cdot \mathrm{US}_1(t) [/imath]

En dat wordt door mijn metingen bevestigd.

 

[ProgHead]

Uit de Manual lees ik ook dat Channel 1 en Channel 4 hetzelfde werken op de EOR en EOC output na. Omdat we Channel 1, de EOR output en de EOC output al bekeken hebben, hoef ik Channel 4 niet apart meer te onderzoeken.

 

[ProgHead]

Verder vind ik:

[imath] \mathrm{U}_2(t) = \left \{ \begin{array}{lc} \mathrm{Ctl}_2 \cdot \mathrm{In}_2(t) & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_2 \, \mathrm{bus} \\ \mathrm{Ctl}_2 \cdot 10 \mathrm{V} & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_2 \, \mathrm{bus} \end{array} \right. [/imath]

[imath] \mathrm{U}_3(t) = \left \{ \begin{array}{lc} \mathrm{Ctl}_3 \cdot \mathrm{In}_3(t) & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_3 \, \mathrm{bus} \\ \mathrm{Ctl}_3 \cdot 5 \mathrm{V} & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_3 \, \mathrm{bus} \end{array} \right. [/imath]

Om precies te zijn mat ik dat de maximale versterking (in positieve of negatieve richting) ietsjes groter is dan 1. Meten andere MATHS bezitters hier dat ook?

 

[ProgHead]

En ten slotte:

[imath] \mathrm{OR}(t) = \max(\mathrm{R}(\mathrm{W}_1(t)) , \mathrm{R}(\mathrm{W}_2(t)) , \mathrm{R}(\mathrm{W}_3(t)) , \mathrm{R}(\mathrm{W}_4(t)) ) [/imath]

[imath] \mathrm{SUM}(t) = \mathrm{W}_1(t) + \mathrm{W}_2(t) + \mathrm{W}_3(t) + \mathrm{W}_4(t) [/imath]

[imath] \mathrm{INV}(t) = - \mathrm{SUM}(t) [/imath]

Met:

[imath] \mathrm{R}(x) = \left \{ \begin{array}{lc} x & \mathrm{voor} \, x \geq 0 \\ 0 & \mathrm{voor} \, x < 0 \end{array} \right. [/imath]

[imath] \mathrm{W}_1(t) = \left \{ \begin{array}{lc} \mathrm{U}_1(t) & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_1 \, \mathrm{bus} \\ 0 & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_1 \, \mathrm{bus} \end{array} \right. [/imath]

[imath] \mathrm{W}_2(t) = \left \{ \begin{array}{lc} \mathrm{U}_2(t) & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_2 \, \mathrm{bus} \\ 0 & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_2 \, \mathrm{bus} \end{array} \right. [/imath]

[imath] \mathrm{W}_3(t) = \left \{ \begin{array}{lc} \mathrm{U}_3(t) & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_3 \, \mathrm{bus} \\ 0 & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_3 \, \mathrm{bus} \end{array} \right. [/imath]

[imath] \mathrm{W}_4(t) = \left \{ \begin{array}{lc} \mathrm{U}_4(t) & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_4 \, \mathrm{bus} \\ 0 & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{U}_4 \, \mathrm{bus} \end{array} \right. [/imath]

 

[EdwinSL]

Om precies te zijn mat ik dat de maximale versterking (in positieve of negatieve richting) ietsjes groter is dan 1. Meten andere MATHS bezitters hier dat ook?

Ja, als ik de knop op 9 of respectievelijk 3 uur zet krijg ik ongeveer dezelfde spanning. Dus dat is best een significante versterking (was me nooit opgevallen, heb dat ding al wat jaren)

 

[ProgHead]

Dan ga ik ervan uit dat dat ook de bedoeling is. Wat heb je dan als maximale versterking?

 

[EdwinSL]

20 tot 25% schat ik in

 

[ProgHead]

Zo ziet het er bij mij ook uit! De amplitude van de output is dus 3 bij een input amplitude van 2. Dus is versterking 3/2 = 1,5. Ik zal de betreffende formules aanpassen. Het moet zijn:

[imath] \mathrm{U}_2(t) = \left \{ \begin{array}{lc} 1,5 \, \mathrm{Ctl}_2 \cdot \mathrm{In}_2(t) & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_2 \, \mathrm{bus} \\ \mathrm{Ctl}_2 \cdot 10 \mathrm{V} & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_2 \, \mathrm{bus} \end{array} \right. [/imath]

[imath] \mathrm{U}_3(t) = \left \{ \begin{array}{lc} 1,5 \, \mathrm{Ctl}_3 \cdot \mathrm{In}_3(t) & \mathrm{met} \, \mathrm{een} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_3 \, \mathrm{bus} \\ \mathrm{Ctl}_3 \cdot 5 \mathrm{V} & \mathrm{zonder} \, \mathrm{jackplug} \, \mathrm{in} \, \mathrm{de} \, \mathrm{In}_3 \, \mathrm{bus} \end{array} \right. [/imath]