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infinite melody question

infinite melody question

2003-12-12 by data2action

all,

i'm unclear about the function & use of the "bit disable" switches on
outputs 4&5 of the infinite melody schematic... and then the
associated mix ins. Are those ins optional? and if you decide to
omit them, should the disable switches be closed or open? And and,
what effects do they have on the final outputs?

while i'm at it, does anybody have panel layouts for this module they
could send pictures of? i'm on a mac, so i cant read shaefer files.
but would be interested to see any approaches.

thanks!

lbd
rdrake@...

Re: infinite melody question

2003-12-12 by sasami@hotkey.net.au

>i'm unclear about the function & use of the "bit disable" switches on
>outputs 4&5 of the infinite melody schematic...

Bit Disable switches are to limit the range of the melody. with 4 bits
running, you get a 16 semintone range. 5 bits, a 32 semintone range and 6
bits a 64 semintone range out of the fixed outputs.


>and then the associated mix ins. Are those ins optional?

Those are for the 4th channel that is fed via pots instead of the fixed
networks. You can wire as many or few of the bits to pots as you wish. If
the switches are included, they will effect the bit 5 and 6 outputs to the
pots. On the other hand, you can simply install only 4 pots (or 3 etc) on
the lower bits.


>and if you decide to omit them, should the disable switches be closed or
open? >And and, what effects do they have on the final outputs?

If you omit the mix ins totally (i.e., dont use any pots) simply don't wire
them up. The bit 5 and 6 switches are still needed for the fixed networks.
If you don't use the switches you will need to short out their positions if
you want to permanently reduce the number of bits. Leave them open if you
want the full range.

I hope that's not too confusing!

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: infinite melody question

2003-12-12 by Richard Brewster

Do NOT omit the bit disable switches! I labelled mine "Enable" instead
of disable. These optionally add the two more significant bits into the
three fixed outputs. What this means is that the fifth bit doubles the
range of the outputs and the sixth doubles it again. This is very
useful. As Ken pointed out, with 4 bits you have 16 semitones, 5 bits
32, and 6 bits 64. So it is not just the range, but the number of
possible discrete values on the output. You need those switches. You
will use them a lot.

I have the 4-pot mixer on the fourth output. I find that I don't use
this feature as much as the 3 fixed outputs, partly because I like the
fact that the fixed outputs are similarly weighted and I can use them to
drive serveral oscillators in a similar manner. On the mixed output I
have to dial up the weighting. This is very flexible, but also hard to
get right. If you want to save panel space, I'd suggest omitting the 4
mixing pots and hard wire the mix output to have some fixed weighting.
You could include all six bits in the 4th output if you did that.

I do not use output level pots, as shown on the schematic. I just put
100K resistors there to get the maximum output level. I took a lesson
from Bernie Hutchins (Electronotes) that attenuation is best done on
inputs. This also saves panel space.

-Richard Brewster

sasami@... wrote:
Show quoted textHide quoted text
>>i'm unclear about the function & use of the "bit disable" switches on
>>outputs 4&5 of the infinite melody schematic...
>>
>>
>
>Bit Disable switches are to limit the range of the melody. with 4 bits
>running, you get a 16 semintone range. 5 bits, a 32 semintone range and 6
>bits a 64 semintone range out of the fixed outputs.
>
>
>
>
>>and then the associated mix ins. Are those ins optional?
>>
>>
>
>Those are for the 4th channel that is fed via pots instead of the fixed
>networks. You can wire as many or few of the bits to pots as you wish. If
>the switches are included, they will effect the bit 5 and 6 outputs to the
>pots. On the other hand, you can simply install only 4 pots (or 3 etc) on
>the lower bits.
>
>
>
>
>>and if you decide to omit them, should the disable switches be closed or
>>
>>
>open? >And and, what effects do they have on the final outputs?
>
>If you omit the mix ins totally (i.e., dont use any pots) simply don't wire
>them up. The bit 5 and 6 switches are still needed for the fixed networks.
>If you don't use the switches you will need to short out their positions if
>you want to permanently reduce the number of bits. Leave them open if you
>want the full range.
>
>I hope that's not too confusing!
>
>Ken
>_______________________________________________________________________
>Ken Stone sasami@...
>Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
>Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>
>
>
>

infinite melody question

2006-10-29 by Jason Proctor

for those of you who have built infinite melodies - do you use the
analogue CV outs, or do you just use the digital outs to drive
diatonic converters etc?

i'm putting mine together right now and i'm thinking that as i might
not need the analogue outs, i could leave off the resistor ladders
and wire up the tl072s on the board as buffers for 4 digital outs.

good hack? what does the panel think?

tx

Re: infinite melody question

2006-10-29 by Richard Brewster

I think the three fixed D/A ladders are well worth having. They only
take three jacks on the panel. I use them a lot. It is also worthwhile
to add the two 'disable' switches for bits 4 and 5, so you can vary the
range of these outputs. Some people like the 4-input mixer with pots on
bits 0-3 and the mix output. I find I don't use that as much, partly
because I like having at least 32 levels in the output (which requires
bit 4, i.e. a fifth pot for the mixer).

I don't have Ken's diatonic converters, but I think they would be a nice
addition. If I were to do it over again, I think I would make separate
diatonic converters that had all the inputs available on panel jacks,
and also make the 6 bits out of the Infinite Melody available on the
panel (possibly with normalized connections to the diatonic converter(s)
inputs. That way I could mix up any combination of outputs using an
external CV mixer.

Richard Brewster
http://www.pugix.com

Jason Proctor wrote:
Show quoted textHide quoted text
> for those of you who have built infinite melodies - do you use the
> analogue CV outs, or do you just use the digital outs to drive
> diatonic converters etc?
>
> i'm putting mine together right now and i'm thinking that as i might
> not need the analogue outs, i could leave off the resistor ladders
> and wire up the tl072s on the board as buffers for 4 digital outs.
>
> good hack? what does the panel think?
>
> tx
>
>
>
> The CGS Modular Synth home page: http://www.cgs.synth.net/
>
> Yahoo! Groups Links
>
>
>
>
>
>

Re: infinite melody question

2006-10-29 by Jason Proctor

thanks for the response.

i'm making this particular IM a kinda minimal configuration, just 4
bits and no shift register, mainly because it is primarily for DC use
and i wanted to fit it in 1U.

but in any case i thought about it a bit more and decided to do both
ladders and digital outs, cascading a cgs56 board for buffers.

j
Show quoted textHide quoted text
>I think the three fixed D/A ladders are well worth having. They only
>take three jacks on the panel. I use them a lot. It is also worthwhile
>to add the two 'disable' switches for bits 4 and 5, so you can vary the
>range of these outputs. Some people like the 4-input mixer with pots on
>bits 0-3 and the mix output. I find I don't use that as much, partly
>because I like having at least 32 levels in the output (which requires
>bit 4, i.e. a fifth pot for the mixer).
>
>I don't have Ken's diatonic converters, but I think they would be a nice
>addition. If I were to do it over again, I think I would make separate
>diatonic converters that had all the inputs available on panel jacks,
>and also make the 6 bits out of the Infinite Melody available on the
>panel (possibly with normalized connections to the diatonic converter(s)
>inputs. That way I could mix up any combination of outputs using an
>external CV mixer.
>
>Richard Brewster
>http://www.pugix.com

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