#1 2009-03-21 15:43:37
555 filter LFO for Synthcart!
Hey Peeps,
This morning I've built a little Lfo inside my breadbin for use with Cynthcart, Since It's not an option on the Cynthcart controls...
A simple 555 timer circuit with a waveform shaper from sine to square, I'm still figuring some stuff out but it works and is cool!
I used this schematic (http://www.mikmo.dk/cblfo.html) as a starting point and added a pot to control the shape of your LFo waveform...
If somebody's interested I'll post a Sample...
Last edited by PIGSNOOT (2009-03-22 14:21:28)
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#2 2009-03-21 22:13:49
- firebrandboy
- Centipede
- From: glasgow, scotland, uk
- Registered: 2006-11-11
- Posts: 148
- Website
Re: 555 filter LFO for Synthcart!
more info, samples.
all of the above.
yes, please!
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#3 2009-03-22 11:41:49
Re: 555 filter LFO for Synthcart!
hey I can't seem to post embedded pics and stuff here, I'm a nitwit in HTML shit...
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#5 2009-03-22 12:03:56
- Flemming
- The Last Ninja
- Registered: 2008-11-27
- Posts: 291
Re: 555 filter LFO for Synthcart!
Wow!!!
Where does the circuit get it's power from?? ..and where/how did you connect it in the C64 to make it work ??
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#6 2009-03-22 12:10:18
Re: 555 filter LFO for Synthcart!
Ok I used this board layout from Mikmo
And added the last bit with the waveshaper en depth from Casper electronics Speak & Spell Lfo 
I connected the Third unused Pot lug from the c64 filter pot To left pot lug of depth pot and middle lug of filter to right lug of depth,
You have to tweak the filter knob together with the Shape and Depth Pots to get different styles of LFO, from Sine to Triangle , Sawtooth and Eventually Square ...
I'll post a Sample, but my Filtercaps of my 6581 are busted I think cuz When you play Polyphonic stuff it gets really crackly and distorted,
Anyway gonna throw a Sid2sid in there for Fun and replacement of caps
It's really a nice add on for live tweakability of Synthcart, you could use it also with Mssiah, but since Mssiah has a lot of options regarding Filter Lfo's It's not that needed
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#7 2009-03-22 12:12:59
Re: 555 filter LFO for Synthcart!
Oh yeah, The 555 ic is very adaptive you can give it juice Starting from 3V to 12V ,
I found a 5v Output somewhere in the upper section of the board and just used that...
Get your multimeter and Poke around...
Be sure to connect the other end to ground 
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#8 2009-03-22 12:25:52
Re: 555 filter LFO for Synthcart!
Can I post a video here? or audio?
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#9 2009-03-22 12:29:38
- firebrandboy
- Centipede
- From: glasgow, scotland, uk
- Registered: 2006-11-11
- Posts: 148
- Website
Re: 555 filter LFO for Synthcart!
you can upload up to 6mb here.
http://www.prophet64-forum.com/uploads.php?uploadit=
for video, i suggest vimeo.com. good quality sound and video!
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#10 2009-03-22 12:39:00
Re: 555 filter LFO for Synthcart!
Ok cool i'm uploading a video for you guys...
The filter caps are really a little screwed I think, crackling and shit...
Or is this a bug of Cynthcart? Naaa
I replaced the potmeter twice because I thought it was a faulty one, but no success...
Anyway video coming up!
Last edited by PIGSNOOT (2009-03-22 14:22:15)
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#11 2009-03-22 13:36:09
- firebrandboy
- Centipede
- From: glasgow, scotland, uk
- Registered: 2006-11-11
- Posts: 148
- Website
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#12 2009-03-22 13:39:35
Re: 555 filter LFO for Synthcart!
Video is online! Great quality indeed on Vimeo!
http://www.vimeo.com/3799818
Last edited by PIGSNOOT (2009-03-22 14:35:38)
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#13 2009-03-22 15:54:58
- Flemming
- The Last Ninja
- Registered: 2008-11-27
- Posts: 291
Re: 555 filter LFO for Synthcart!
That's just lovely nice video i must say, and cool mod.. i hoped to see the insides too though!!
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#14 2009-03-22 16:24:44
Re: 555 filter LFO for Synthcart!
Insides are a big mess .. but I'll post them soon, gotta record and make Hit records right now!
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#15 2014-01-13 09:37:42
- wax+wire
- GI-Joe
- Registered: 2007-04-25
- Posts: 10
Re: 555 filter LFO for Synthcart!
I hadn't seen this thread when I built my 555 LFO. - I built it for Cynth Cart as I don't own Mssiah
I based mine on the casper electronics circuit also, but didn't put in the trimpot or the last 10K resistor. I did put a switch in right at the end of the LFO so I can send the LFO to either paddle 1 or 2.
It works well, though the shape doesn't seem quite right (perhaps the 10K pot is too much, as I feel only the first half of the turn does much)
I also added normal Pots in series with the LFO so that you have a control for the base and the LFO is voltage on top if that makes sense, and then used a basic 5V regulator before going back to the paddle port/ADC so there was a safety incase it fried the SID chip with greater than 5Vs.
I'll do a video of mine too soon when my internet is back up to full speed
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#16 2014-02-25 02:09:52
- electriclifeform
- Bub
- From: United Kingdom (London)
- Registered: 2006-08-03
- Posts: 158
- Website
Re: 555 filter LFO for Synthcart!
just seen this post... shame the vimeo video is no longer available ;-(
www.handbakedarcade.co.uk <-- arcade :-)
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