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Total Votes : 43 |
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davebr

Joined: Jun 09, 2007 Posts: 198 Location: portland, or
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Posted: Tue Aug 18, 2009 9:02 pm Post subject:
Variable Slope Filter / Phaser Subject description: Demo |
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I thought I would try and make a quick demo tonight. Sheesh. I kept hitting the mic stand, forgetting what I was trying to show, turning the wrong knob, forgetting to speak ... but it's made. It isn't pretty but it shows some of the characteristics. It's a saw wave into the varislope with a single ADSR. The more I play with this module the more I appreciate it. There are very subtle changes with the various switches and the feedback can get real gritty.
Mp3 demo on my website about 1/3 down the page http://modularsynthesis.com/jhaible/varislope/varislope.htm
Dave |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Wed Aug 19, 2009 1:57 am Post subject:
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Thanks for the demo Dave! |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Wed Aug 19, 2009 7:17 am Post subject:
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Nice demo! I just got all of the on-board components soldered last night. Now just waiting for my panel (which I based on yours, Dave - thanks!). Also have my Living VCOs board all stuffed and waiting on that panel (based on Dave's largest panel design there as well). These will be the first JH projects I've actually managed to start and finish in the same year that they materialized  |
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The Bad Producer

Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Posted: Wed Aug 19, 2009 12:56 pm Post subject:
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numbertalk wrote: | These will be the first JH projects I've actually managed to start and finish in the same year that they materialized  |
I know that feeling!  |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Wed Aug 19, 2009 9:19 pm Post subject:
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damn,this filter sounds realy good. |
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vtl5c3
Joined: Sep 08, 2006 Posts: 425 Location: PDX
Audio files: 13
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Posted: Thu Aug 20, 2009 9:16 am Post subject:
DG419 Q |
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Dumb question, but should the DG419s be treated as highly static sensitive, like I would CD4XXX series ICs? |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Thu Aug 20, 2009 9:35 am Post subject:
Re: DG419 Q |
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vtl5c3 wrote: | Dumb question, but should the DG419s be treated as highly static sensitive, like I would CD4XXX series ICs? |
Everything should be treated as static sensitive. Myself, I don't treat anything as *highly* sensitive - I store in conductive foam, I discharge myself to the radiator (earth ground) before handling an IC, but I don't wear a wristband or conductive shoes.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Thu Aug 20, 2009 10:39 am Post subject:
Re: DG419 Q |
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jhaible wrote: | I discharge myself to the radiator (earth ground) before handling an IC,JH. |
So none of your radiators are paint?  |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Thu Aug 20, 2009 1:57 pm Post subject:
Re: DG419 Q |
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TekniK wrote: | jhaible wrote: | I discharge myself to the radiator (earth ground) before handling an IC,JH. |
So none of your radiators are paint?  |
Not the union nut that holds the thermostat ...
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Thu Aug 20, 2009 2:07 pm Post subject:
Re: DG419 Q |
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jhaible wrote: | TekniK wrote: | jhaible wrote: | I discharge myself to the radiator (earth ground) before handling an IC,JH. |
So none of your radiators are paint?  |
Not the union nut that holds the thermostat ...
JH. |
oh!,your r smart
comap i guess then |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Fri Sep 04, 2009 7:58 am Post subject:
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I'm trying to trim the 6 voltage trimmers while I'm waiting on a few pots I was missing to come today and am having a little trouble. The voltage at the test points does not seem to want to hold - it wanders a lot, even if in a consistent direction (depending on if I had last turned it "up" or "down" it continues wandering in that direction). Am I doing something wrong? It sounds like I do want to get at least trimmer 3 set correctly so I'd rather not just give up and set them all to centered.
Thanks. |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Fri Sep 04, 2009 9:30 am Post subject:
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numbertalk wrote: | I'm trying to trim the 6 voltage trimmers while I'm waiting on a few pots I was missing to come today and am having a little trouble. The voltage at the test points does not seem to want to hold - it wanders a lot, even if in a consistent direction (depending on if I had last turned it "up" or "down" it continues wandering in that direction). Am I doing something wrong? It sounds like I do want to get at least trimmer 3 set correctly so I'd rather not just give up and set them all to centered.
Thanks. |
The filter is "living"!
(Only joking)
But seriously: The 7 transistors are not thermally coupled, so wandering is expected. It's a phaser, it's a filter, not a VCO.
If you can set these -7.5V to +/-1V (or even +/-2V), it's ok.
In my JH-3 module, I didn't have these trimmers at all. They are basically in there for the case that you have extremely mismatched transistors.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Fri Sep 04, 2009 9:36 am Post subject:
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Well that's perfect then that I'm building them to primarily use with the Living VCOs
Good to know - I'll get them as close as I can. Should I go by what my multimeter reads right after setting the trimmer, or should I let it "settle" for a few minutes (if so how long?) and come back and measure it later and go by that?
Thanks!
jhaible wrote: | numbertalk wrote: | I'm trying to trim the 6 voltage trimmers while I'm waiting on a few pots I was missing to come today and am having a little trouble. The voltage at the test points does not seem to want to hold - it wanders a lot, even if in a consistent direction (depending on if I had last turned it "up" or "down" it continues wandering in that direction). Am I doing something wrong? It sounds like I do want to get at least trimmer 3 set correctly so I'd rather not just give up and set them all to centered.
Thanks. |
The filter is "living"!
(Only joking)
But seriously: The 7 transistors are not thermally coupled, so wandering is expected. It's a phaser, it's a filter, not a VCO.
If you can set these -7.5V to +/-1V (or even +/-2V), it's ok.
In my JH-3 module, I didn't have these trimmers at all. They are basically in there for the case that you have extremely mismatched transistors.
JH. |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Tue Sep 08, 2009 8:41 pm Post subject:
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Finally got the pots I was missing and finished up this module tonight. I had 1 question - with resonance in normal mode the filter does self- oscillate but seemingly not even over an entire octave and even turned up high and with the feedback trimmer all the way up the resonance is quite mild sounding - not what I'd expected to hear. However in inverted mode the filter seems to oscillate over several octaves and I get a great strong sounding resonance from the filter. This is with all switches in lowpass mode of course. Is this the expected behavior? Also the slope pot is fully ccw so it should be in 6-pole mode. I triple checked the wiring on the normal/inverted toggles and it's definitely wired up correctly so I'm assuming its doing the right thing but just wanted to make sure since I'm not exactly sure if most LPFs I have experience with have inverted feedback. If so this is probably why that behavior is what seems "normal" to me.
Thanks! |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Tue Sep 08, 2009 11:05 pm Post subject:
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numbertalk wrote: | Finally got the pots I was missing and finished up this module tonight. I had 1 question - with resonance in normal mode the filter does self- oscillate but seemingly not even over an entire octave and even turned up high and with the feedback trimmer all the way up the resonance is quite mild sounding - not what I'd expected to hear. However in inverted mode the filter seems to oscillate over several octaves and I get a great strong sounding resonance from the filter. This is with all switches in lowpass mode of course. Is this the expected behavior? Also the slope pot is fully ccw so it should be in 6-pole mode. I triple checked the wiring on the normal/inverted toggles and it's definitely wired up correctly so I'm assuming its doing the right thing but just wanted to make sure since I'm not exactly sure if most LPFs I have experience with have inverted feedback. If so this is probably why that behavior is what seems "normal" to me.
Thanks! |
This module allows so many configurations that not every combination of parameters gives equally imressive results. Positive / negative feedback makes more sense in APF mode than in LPF mode for instance. It's quite likely that the module will jump from smooth filtering into screaming resonance, or even "motorboating", with just the flick of a switch, at certain settings. It's a rough, untamed beast.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Wed Sep 09, 2009 6:22 am Post subject:
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Glad to hear nothing I described seems to concern you. Have barely had a chance to play with it - just finished calibrating it late last night. Excited to dig into it more soon.
Thanks! |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Fri Sep 18, 2009 1:10 am Post subject:
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nice,are these NKK toggles?,i plan to order those NKK's with leds into it for this project. |
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numbertalk

Joined: May 05, 2008 Posts: 992 Location: Austin, TX
Audio files: 5
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Posted: Fri Sep 18, 2009 5:25 am Post subject:
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TekniK wrote: | nice,are these NKK toggles?,i plan to order those NKK's with leds into it for this project. |
thanks. they're mountain switch actually - mouser carries them, haven't been able to find them anyway else. pricy but nice and solid, like the NKKs. |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Fri Sep 18, 2009 5:36 am Post subject:
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yes they looks hardcorerocking resistant |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Fri Nov 20, 2009 8:17 am Post subject:
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Juergen,for selecting APF/LPF u use 3 switches on your desktop model,i suppose u did used 3x DP switches,my question is can i use 3x single pole switches controlling each 2 of the switch ic's (its because of limited space i have on my frontpanel i just did designed,i would like to use nkk toggles with bipolar led into the handle,these are single pole but take the space of an double pole)?
Thanks for your attention
Regards
TekniK |
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jhaible

Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Fri Nov 20, 2009 10:04 am Post subject:
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TekniK wrote: | Juergen,for selecting APF/LPF u use 3 switches on your desktop model,i suppose u did used 3x DP switches,my question is can i use 3x single pole switches controlling each 2 of the switch ic's (its because of limited space i have on my frontpanel i just did designed,i would like to use nkk toggles with bipolar led into the handle,these are single pole but take the space of an double pole)?
Thanks for your attention
Regards
TekniK |
Yes - that's the benefit of electronic switching!
Just connect the "sw" pins together that you want to control from the same switch http://www.jhaible.de/varislope_filter_phaser/varislope_filter_phaser_sch1.pdf
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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TekniK

Joined: Aug 10, 2008 Posts: 1059
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Posted: Fri Nov 20, 2009 10:32 am Post subject:
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jhaible wrote: | TekniK wrote: | Juergen,for selecting APF/LPF u use 3 switches on your desktop model,i suppose u did used 3x DP switches,my question is can i use 3x single pole switches controlling each 2 of the switch ic's (its because of limited space i have on my frontpanel i just did designed,i would like to use nkk toggles with bipolar led into the handle,these are single pole but take the space of an double pole)?
Thanks for your attention
Regards
TekniK |
Yes - that's the benefit of electronic switching!
Just connect the "sw" pins together that you want to control from the same switch http://www.jhaible.de/varislope_filter_phaser/varislope_filter_phaser_sch1.pdf
JH. |
ok,Thank u very much for quick reply and help!
Best Regards
TekniK |
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johans121

Joined: Jun 19, 2007 Posts: 178 Location: Huntsville, AL (USA)
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Posted: Fri Dec 04, 2009 9:25 am Post subject:
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jhaible wrote: | Theoretically that HPF should come as MOTM module some day, so I was reluctant put a HPF mode into this PCB project.
But you can easily hack the circuit to get a HPF:
http://www.jhaible.de/varislope_filter_phaser/varislope_filter_phaser_sch1.pdf
(1) Remove R7, R15, R20, R26, R31, R36.
(2) Omit all DG419 chips and connect Pin1 to Pin2 on each DG419 footprint.
Not tested by me, but it should work!
(Please report back if you have tried it. )
JH. |
Has anyone tried the HPF mod, and if so do you have any recommendations/pointers? I'm probably going to start my build in the next month or so and I figured I'd ask....
Thanks,
Jim _________________ Don't feed me Indian, you WILL regret it!
-Jim |
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JoeMorris
Joined: Apr 26, 2009 Posts: 161 Location: Brighton
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Posted: Sun Jan 10, 2010 3:21 pm Post subject:
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Just finished this, sounds great.
One question...
My LFO seems to run quite fast, with a minimum speed of around 20hz...
Is this right?
Joe |
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