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Multi Space Filter

Started by StephenGiles, October 05, 2005, 04:44:36 PM

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frequencycentral

#40
March 02, 2009, 04:14:05 PM
Stephen, I've been following this thread and am really interested in it - don't despair!
http://www.frequencycentral.co.uk/

Questo è il fiore del partigiano morto per la libertà!

StephenGiles

#41
March 02, 2009, 04:37:19 PM
Quote from: frequencycentral on March 02, 2009, 04:14:05 PM
Stephen, I've been following this thread and am really interested in it - don't despair!

Great, I'm currently trying to fathom out the pulse generator. I'm having difficulty finding one elsewhere using a 13600, which I assume U3 is.
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

liquids

#42
March 02, 2009, 09:51:20 PM
Quote from: StephenGiles on March 02, 2009, 04:07:45 PM
judging by the overwhelming enthusiasm I have seen - perhaps fear even that it won't fuzz for this I am not too hopeful that it will find it's way to anyone else's breadboard!!

Man...even if my workbench were out, and I weren't fairly new to building, and even if I could get all of the parts needed, let alone the understanding of OTAs, and the skill needed to breadboard that without needing to do a months worth of debugging, then I might get to work on this and put every other project I have on hold, but it just doesnt work like that.  Fear not, there seem to be a fair amount of people interested not only in dirt boxes, other than yourself.  A little patience tempered with encouragement goes a long way  :icon_rolleyes:  And you know what they say...if you want it done right... 
Breadboard it!

StephenGiles

#43
March 03, 2009, 02:59:06 AM
Do you think I can find any 10k resistors? :icon_sad:
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#44
March 03, 2009, 08:10:02 AM
I think the trigger/one shot or whatever is a non starter. I think I'll refer to Uncle Robert Penfold's trigger circuits!
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#45
March 05, 2009, 02:55:07 AM
Quote from: StephenGiles on March 03, 2009, 08:10:02 AM
I think the trigger/one shot or whatever is a non starter. I think I'll refer to Uncle Robert Penfold's trigger circuits!

.......when I can find them!
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#46
March 05, 2009, 04:00:11 PM
So what we seem to be after - well, myself anyway :icon_biggrin: is a trigger circuit capable of presenting a negative pulse, in order to momentarily turn on the 2N 3819, which we all now know thanks to Bajaman is the alternative to the illusive FET in the ADA Flanger. And I'm buggered if I can find one, so I need some help please:icon_wink:
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

GREEN FUZ

#47
March 05, 2009, 05:11:28 PM
p.m me your address and I`ll send you a couple.

kvb

#48
March 05, 2009, 06:24:42 PM
also, if you look at the MFOS 16 step sequencer scheme the are some  edge triggered pulse generator circuits there which might be useful.
the way his are drawn, they are connected to a switch - but they can also be triggered by an inverter that is being toggled

you could use an op amp to do the math that would make a pulse negative

hope that helps

StephenGiles

#49
March 06, 2009, 06:32:46 AM
Quote from: kvb on March 05, 2009, 06:24:42 PM
also, if you look at the MFOS 16 step sequencer scheme the are some  edge triggered pulse generator circuits there which might be useful.
the way his are drawn, they are connected to a switch - but they can also be triggered by an inverter that is being toggled

you could use an op amp to do the math that would make a pulse negative

hope that helps

Thanks for that, I'd forgotten about the 40106 which has plenty of tricks available!
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#50
March 08, 2009, 09:12:25 AM
Might it be possible, I wonder, to produce just a positive trigger pulse voltage proportional to the strength of the note struck, which could be fed to the top connection of the Start Frequency pot? It would need to be held at 9v with the unit at rest - and then return to 9v at the end of each trigger.My thinking is that a sample & hold would then not be necessary.
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#51
March 15, 2009, 03:43:09 PM
Newsflash - just breadboarded the sweep generator section og the Adaptive Space Filter, and this "seems" to be working in that I am getting sweeps and reverse sweeps by having the start and stop frequency pots in different settings, and what is more it seems to be pluck sensitive looking at my Avometer. More anon.....
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#52
March 16, 2009, 05:43:25 AM
I can't make up my mind on the type of filter to use - opamps and optos, LM13600 or to be really flash - SSM2164. Perhaps facilities for all 3 :icon_biggrin:
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

liquids

#53
March 17, 2009, 08:23:39 AM
Okay, this week it is my goal to get one half of the circuit breadboarded (that is, if I can get my taxes done!).  Problem is I'm a noob with this kind of thing, especially OTAs, but I'm going to give it a go...

I got started Sunday night and hit a bump immediately regarding the op amps, the schematic, etc.

Anyone have more basic info on how to replace the op-amp IC1a-d in the schematic, with more common types?  I don't have any of the said types, and don't plan to put in an order anytime too soon since I don't need much in that regard otherwise....but I'd like to make it work unless it's impossible.  Can I just replace them with 

As a noob, here's the little I understand: from past use of op-amps, it seems I'd need a voltage divider (there's a few components going to Vb anyhow), and I would then need to put something to VBb off most of the inputs of each op-amp stage...but after that I'm lost.

Is this necessary if I use more standard dual op amps (TL072, Tl062, TL074 and the like)? 

Is this a quirk of the LM324 type, that it's not necessary to have stuff at the inputs seeing Vb?
Breadboard it!

StephenGiles

#54
March 17, 2009, 10:15:24 AM
From the data sheet:

The LM324 series are low-cost, quad operational amplifiers with true differential inputs. They have several distinct advantages over standard operational amplifier types in single supply applications. The quad amplifier can operate at supply voltages as low as 3.0 V or as high as 32 V with quiescent currents about one-fifth of those associated with the MC1741 (on a per amplifier basis). The common mode input range includes the negative supply, thereby eliminating the necessity for external biasing components in many applications. The output voltage range also includes the negative power supply voltage.

Perhaps someone could enlighten us what these "several distinct advantages are".
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

gez

#55
March 17, 2009, 07:27:20 PM
Don't know if it's an advantage in your circuit Stephen (haven't checked it over), but try doing the above list with a TL072 or other bog-standard amp.
"They always say there's nothing new under the sun.  I think that that's a big copout..."  Wayne Shorter

StephenGiles

#56
March 18, 2009, 06:54:41 AM
Quote from: gez on March 17, 2009, 07:27:20 PM
Don't know if it's an advantage in your circuit Stephen (haven't checked it over), but try doing the above list with a TL072 or other bog-standard amp.

Maybe I will, I used a 324 as in the Space Drum sweep generator, converted from using CA3094 to LM13600.

I am not having much success with an SSM 2164 VCF I tried.

My circuit is just an idea at present of course.
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

markusw

#57
March 18, 2009, 08:28:44 AM
Hey Stephen,

following this thread with great interest  :icon_cool:
Not much to contribute from my side unfortunately.

FWIW, the Craig Anderton pick/plug detector in one of the early "Device" issues on Mark Hammers site is fantastic. It triggers very reliably.
As far as I remember it triggers more or less at the peak of each note. Would be perfect in combination with a S/H for your plans....
Also works at 12V single supply.
Much more complex though than the Electrax trigger generator.....  :(

StephenGiles

#58
March 18, 2009, 08:54:21 AM
Quote from: markusw on March 18, 2009, 08:28:44 AM
Hey Stephen,

following this thread with great interest  :icon_cool:
Not much to contribute from my side unfortunately.

FWIW, the Craig Anderton pick/plug detector in one of the early "Device" issues on Mark Hammers site is fantastic. It triggers very reliably.
As far as I remember it triggers more or less at the peak of each note. Would be perfect in combination with a S/H for your plans....
Also works at 12V single supply.
Much more complex though than the Electrax trigger generator.....  :(

Thanks for the reminder, I had forgotten about that one. I must dig out my Device folder. What I'm finding is that having several deadlines on the go at the same time during the day results in very tired eyes in the evening - so plenty of scope for breadboading errors - roll on the weekend!
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".

StephenGiles

#59
March 19, 2009, 12:10:06 PM
I've given up  ::) on an SSM 2164 filter in this, after 6 separate breadboardings. I think back to basics - A CA3094 sweep generator and a Bifilter Follower filter. Funnily enough I don't recall any jitter in the Space Drum VCO sweep, I'd forgotten that - must be the "Statins" I take!!
"I want my meat burned, like St Joan. Bring me pickles and vicious mustards to pierce the tongue like Cardigan's Lancers.".
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