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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Tue Jan 21, 2014 10:43 am Post subject:
pt2399 and Lunetta |
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this chip is driving me crazy.
I already add pt2399 delays to a siren... i used a Rebote without any oamps. (like: http://guitarwork.ru/electronic/Other/Rebote_Delay/ )
but iam trying the last 3 evenings trying to get a simpler pt2399 work with my lunetta.
I tried the circuits from Phobos (moon base explorer and Pitch shift thingie). No success.
I read mutch about faked pt2399, and not starting oscillating circuits. I triple checked everything. (chips work in a rebote delay)
(why iam posting this in Lunetta forum?) I added two 4040 to the clock out (my scope is over 30 years old, up to 10mhz only). and i get a nice squarewave. (will use this as osc in the lunetta, and some extra blinking). so the osc will start.
the circuits dont work for me with or without a 4040 aded. so wats is the trick?
at the moment i have exact this on my Breadboard (2nd simplifieyd circuit, using 47n as c4 + c9, tried difrent values for c13 (1, 4.7, 10, 47u)) -> http://circuit-diagram.hqew.net/Digital-Delay-Unit-For-Surround-Sound$2c-Reverb-$26-Echo_13932.html ).
I run it from my Lunetta power suply a 7805, some caps. and i build a dedicatet (running from 12v adapter..). When i connect a 4093 osc to the input the sound disapear when i power the 2399... (tested diffrent input levels 50k pot)
what means " It is essential that the 5V supply has a low impedance," ?
the output i connect to a simple passiv mixer. |
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Wed Jan 22, 2014 3:55 am Post subject:
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okäääääyy - now iam confused.
found 8x pt2399 - 4 working in this circuit and 4 are not working. (all work in my Rebotedelay). And some sounds a bit difredifferent.
missed here a groundconnection.
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Wed Jan 22, 2014 4:12 am Post subject:
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i uploadet a small test:
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Wed Jan 22, 2014 9:42 am Post subject:
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hey - thanks Phobos,
in my case the 4040 shud work. the datasheet of the 2399 say 10,5k resistor == 4,5 Mhz. the 4040 can handle 7Mhz (at 5V) so the 4040 shud work for evrybody who uses delays longer than 97ms (5,8k resistor) i think. (was try to figure out why its working the last 15min ... )
in your circuit i dont get realy what the diodes doing there. (they keep the output high, but why?)
i using Q12 and Q7 == 19 stages (Q5 is only for some optical fx )
your schematic uses Q10 and Q10 == 20 Stages - or do the diods somthing with the dividing? (i think my 19 Stages exact on the repeat of the echo, i testet with a short "ding sound" and watch the LED)
i googled pt2399 and 4040 after thinking about the divider and found this:
http://www.aronnelson.com/gallery/main.php/v/cathexis/Veroboard+Layouts/Magnus+Modulus/PT2399+Tempo+Indicator.jpg.html?g2_imageViewsIndex=1
thats the same like you posted (but i dont understand it)
(originally my hope was find a way to feed the clock in the chip)
btw - what program is this u use for the schematics phobos? (like the look and iam not realy happy with tinycad) |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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Posted: Thu Jan 23, 2014 4:47 am Post subject:
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yeah I think you're correct, as long as you don't make the delay times to short it should work with a regular 4040. I know when I made the indicator
years ago it didn't work very well, untill I replaced the 4040 with 74HC4040's.
The diodes + pullup resistor function as a AND gate and are there to reset the counter once it has reached a specific number. As long as one of those
outputs is low the reset pin will be held low, only when all of those outputs are high the reset pin will be made high.
For the first counter it's 2^4 + 2^6 + 2^7 + 2^8 + 2^9 + 2^10 = 2000.
For the second counter it's 2^3 + 2^4 + 2^6 + 2^8 +2^10 = 1368
which makes the total count 2000 x 1368 = 2736000.
now if you look at the datasheet there is a table with the delay time and VCO frequency. I't not really linear so with a fixed divider it won't be exact
but it comes close. For a delay of 342mS the CLK out is 2MHz. 342mS -> 2.92Hz so the LED should flash at this rate. 2000000 / 2736000 = 0.73Hz
which seems too slow but 0.73Hz is exactly 2.92Hz / 4, so either it flashes at 1/4 of the actual delay rate or my calculations are off
It would make sense to divide it by 4 since it would flash rather fast if you didn't.
The software I use to draw schematics is ExpressSCH _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Thu Jan 23, 2014 6:49 am Post subject:
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thanks phobos for the explanation.
(cost me about one hour to get it and test a bit the ExpressSCH, but cant find a just empty dip16 chip. looks like i have to make some custom parts - phew... )
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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Posted: Thu Jan 23, 2014 9:11 am Post subject:
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yeah, you'll probably have to make custom parts quite often. Even the ones in the library aren't always useful. But you can select the component, then
go to "Component" > "Ungroup component", change it and then choose "Group to make component" which can save some time compared to drawing
it from scratch. And you can save it as custom component for future use. Also if you connect lines to eachother (cross or T) it doesn't always connect
them and then it doesn't show a dot on the connection when you export the schematic. _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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Cynosure
Site Admin
Joined: Dec 11, 2010 Posts: 966 Location: Toronto, Ontario - Canada
Audio files: 82
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Posted: Thu Jan 23, 2014 7:47 pm Post subject:
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Try increasing the resistor on pin 6. The oscillator sometimes doesn't work if the resistance is too low. You can then lower it after the circuit is powered on and oscillating. |
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Fri Jan 24, 2014 6:47 pm Post subject:
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mhm the osscilator is starting (i checked that with scope and the two 4040) i use a 12k resistor and a 50k pot. (other ppl use 2,2k and get starting problems with the osc.)
i dont investigate this any more ... it must be the PT2399... not me and not the circuit. (i change one from the not working to my rebote delay and still got 4 working here.... thats enouth echo for the next days )
maybe i shud work on a springdelay but cant find a usefull spring... |
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DUBmatze
Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Wed Feb 19, 2014 9:49 pm Post subject:
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i just paintet a few circuits from my black book (playing with expressSCH). This is what i made with my PT2399 notes... :
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