agree with Ingo.
i'd also be interested in a dual 48db lowpass filter module with simple features, for use with my A188 BBD modules.


Bakis Sirros - Parallel Worlds / Interconnected / Memory Geist

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--- On Wed, 12/15/10, selfoscillate < synaptic_music@... > wrote:

From: selfoscillate < synaptic_music@... >
Subject: 1 Re: Module requests: Simple 48 db filter and simple Hipass
To: Doepfer_a100@yahoogroups.com
Date: Wednesday, December 15, 2010, 11:25 PM







 











hello joachim,



> I would like to share two module suggestion that came to my mind

> while patching:

>

> 1. A simple and cheap dual 48 db filter to use with the BBD modules.

> Only 2 jacks (in/out) and 1 potentiometer (frequency) per filter.



in principle a good idea, but i'm not sure if it would be

really satisfying for using it with a bbd, at least for me.

without a cv input the filter cannot follow the clock of the bbd,

which means that you need to close the filter more than necessary,

when the delay time is modulated. the a188 has a cv output for

controlling a vcf, so you can dial in just as much filtering as

necessary, which is a great feature imho. this is of course not

valid if the delay time is not modulated, but isn't that a big

part of the fun on bbd delays often i also add a slight portion

of resonance on the vcf to emphasize the higher frequencies,

which reduces the dulling effect even more. i always use

the a108 for that, but somehow it is a bit of an overkill,

especially when you want to filter before and after the bbd

and therefore need two of them. so to make it cheaper without

omiting the useful things, i would prefer a very steep

dual vcf with reduced functions. only one cv input per channel

instead of 3, no resonance insert, no attenuators for the

audio input and a more neutral sounding and simpler filter

circuit (no need for selected transistor ladder stuff here).

it should have 48db steepness, or even 60db if possible.

i want such a module since the a188 is available and i would

buy it instantly. there was a switched capacitor dual filter in

the planning stage some years ago, for exactly this purpose,

but i believe that technical issues delayed the development

and i don't know if this project is still alive.



> 2. A simple and cheap (maybe passive) Hipass filter (80 Hz), maybe also

> dual:

> 2 jacks (in/out) + bypass switch.

> Useful for modules which generate too much low end signals.

> If it would be active and dual, one 80 Hz and one 40 Hz filter would

> make sense in my eyes. The latter could then be used for basses and

> bassdrums and cut those frequencies that almost no loudspeaker can

> handle and thus increase the headroom and help reduce some nasty

> unwanted distortion effects.



a passive dual highpass filter is not a bad idea,

i just don't know how many people would buy it,

as it is a very simple circuit.

maybe you should start a poll



best wishes



ingo

























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