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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Tue Dec 08, 2009 3:37 am Post subject:
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2nd batch is in. await emails/PMs soon. _________________
cheers,
matthias
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Big Boss at fonitronik
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Tue Dec 08, 2009 5:33 am Post subject:
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That's a perfect timing for me, i just received two LPG pcb after one month of wait and now i see the expantion boards are ready!
Thanks Fonik for making another run!
I 've just sent the payment for two of those with paypal and I specified my nickname and shipping adress as you pointed out on PM.
Cheers _________________ http://soundcloud.com/mister-vommi
http://tideofsound.net |
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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scriptstyle
Joined: Jan 22, 2008 Posts: 250 Location: nj
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Posted: Tue Dec 15, 2009 11:35 am Post subject:
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received mine yesterday.
thanks |
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Wed Dec 16, 2009 2:39 am Post subject:
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I just finished building and testing 2 LPGs+expantions.
One of the two expantions wasn't working at all... it was a cd4053 mounted backwards... fried! But i changed with a new one and it's ok now.
I made another mistake, i thought the pushbuttons were momentary and i founded some beautiful momentary switch with led on the inside, just like the ones of Fonik's video. Now i think that later i'll have to find some toggle switch with encapsulated led, but with mounting hole of 8mm...
But the silliest thing is that it seems that the exp board switches only two states of the LPG: With gate A low and gate B hi it turns to GATE mode. Same with both gates hi.
With all the other combinations i always have lopass, because the resonance is always active, and i recall that when in both mode resonance should be off.
I already have installed the jumper on the board, so i can't figure out what is causing that behaviour...
Any ideas?
Thanks, tommi _________________ http://soundcloud.com/mister-vommi
http://tideofsound.net |
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
Audio files: 23
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Posted: Wed Dec 16, 2009 2:52 am Post subject:
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tommi wrote: | Now i think that later i'll have to find some toggle switch with encapsulated led, but with mounting hole of 8mm... |
the ones you see in the video are schurter toggles with integrated LED.
Quote: | But the silliest thing is that it seems that the exp board switches only two states of the LPG: With gate A low and gate B hi it turns to GATE mode. Same with both gates hi.
With all the other combinations i always have lopass, because the resonance is always active, and i recall that when in both mode resonance should be off. |
mmmh...
just a wild guess: may the SW1 connector be in backwards? _________________
cheers,
matthias
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Big Boss at fonitronik
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Wed Dec 16, 2009 3:05 am Post subject:
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Quote: | mmmh...
just a wild guess: may the SW1 connector be in backwards?
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I used momentary normally open switch for those and they close when i push them. When i push them the leds turns on (aslong as i push, being momentary), so i think that this is the proof that they're connected the right way? _________________ http://soundcloud.com/mister-vommi
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Wed Dec 16, 2009 4:08 am Post subject:
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sorry, my fault! i meant the mode switch!
tommi wrote: | Quote: | mmmh...
just a wild guess: may the SW1 connector be in backwards?
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I used momentary normally open switch for those and they close when i push them. When i push them the leds turns on (aslong as i push, being momentary), so i think that this is the proof that they're connected the right way? |
_________________
cheers,
matthias
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Big Boss at fonitronik
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Wed Dec 16, 2009 4:08 am Post subject:
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tommi wrote: | I forgot to say that my modular is powered by +/-12V.
Dunno if it could make a difference... |
no. _________________
cheers,
matthias
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Wed Dec 16, 2009 4:38 am Post subject:
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Quote: | sorry, my fault! i meant the mode switch! |
You mean the connector? No, it's pin to pin so is very easy. To be sure i 've just tested the pins of the headers and they are good.
This could be a problem of the lpg board too..
If i leave the mode sw connector unconnected this should give me both modes. _________________ http://soundcloud.com/mister-vommi
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Thu Dec 17, 2009 4:29 pm Post subject:
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I am making some more testing with a dmm and my ears.
I 've measured continuity between the pins of the mode sw of the Expansion board.
Here's what i found:
-When both gates are low and when gate A hi and gate B low: I see an open between pins 1 and 2 and between 3 and 4. I see close to 150 Ohm between 5 and 6 (lopass mode).
-When gate A low and gate B hi and when both are hi: 150 ohm between pins 1&2 and 3&4, pins 5&6 are open (gate mode).
I have also tried closing the pins as it would be if i had a mechanical 3PDT switch. When all pins are open i got both mode: gate and lopass with no resonance. When pins 5&6 are closed i am in lopass resonance mode and when i close pins 1&2 and 3&4 i got gate mode.
Fonik, in the picture on page 1 of this thread i 've noticed that Q1,Q2 and Q3 are mouted backwards. Is that because you 've used a different kind of trannie?
P.S.: My IC2 is a CD4053BE. Is it the problem maybe? _________________ http://soundcloud.com/mister-vommi
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Fri Dec 18, 2009 1:01 pm Post subject:
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Hello,
I am doing some more measuring (i 've also had a look at the CD4053 datasheet).
On my 4053 Vdd is +6V and Vee is -6V.
Looking at the 4053 datasheet, pin 6 is the INHIBIT input. When he sees a 'hi' voltage we should have all contacts open. Well, not in my case!
The voltage i measured on pin 6 when both gates are low is +3,33V and goes to +0,14V when i press the manual switch of gate A.
On pins 9, 10 and 11 wich are linked toghether on this PCB i see 0V when gate B is low and +5,33V when is hi.
Gate B have an effect even when gate A is low. This should not be possible looking at the truth table on the datasheet.
I am suspecting that the voltage i 've got on pin 6 is too low to be seen as 'hi' and it's always like i had gate A turned on. The only states of the Lopass Gate i can obtain are Lopass state and Gate state indeed!
But it's strange 'cause i 've got the same problem on two boards.
_________________ http://soundcloud.com/mister-vommi
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Fri Dec 18, 2009 2:45 pm Post subject:
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Maybe fixed!
I 've put a 1k resistor in parallel to R6. Then i 've just checked the pins of the mode switch. They now seems to be in line with the truth table. Tomorrow i 'll check the whole module's behaviour to see if i can confirm or not that i've fixed my problem... _________________ http://soundcloud.com/mister-vommi
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sat Dec 19, 2009 6:44 am Post subject:
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i confess i have not read your posts by now. is it fixed? R6 is 1k per schematic and BOM actually.
BTW what about R8? did you check the value? _________________
cheers,
matthias
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Big Boss at fonitronik
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Sat Dec 19, 2009 7:55 am Post subject:
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R8 is 47k. R6 is 1k, but now that i put in parallel of R6 another 1K resistor lowering the value of R6 (to 500 ohm?) my reading on pin 6 of ic2 (cd4053) is +4,21V (when both gates are 'low') wich now seems enough to be seen as 'hi' from the 4053 inhibit port.
I powered on the module for testing and now the expantion PCB works as it should (as written on the truth table). _________________ http://soundcloud.com/mister-vommi
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Sat Dec 19, 2009 9:22 am Post subject:
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Well... as it turns out i didn't solved the problem.
After hearing what it sounded like i noticed that even in 'both' mode the resonance pot have an effect: it adds distortion to the signal.
I thought i had some problem with the LPG, but as i disconnected the mode switch connector distortion disappeared totally.
So, again, i measured the resistance between pins 5 and 6 on the Expansion board. When both gates are low i readed a floating value, going from 5 Mohm to 14Mohm. On pins 1/2 and 3/4 my resistance measuring readed an open circuit (at least more than 20Mohm wich is maximum value on my dmm).
This test was done with a 1k resistor in parallel with R6.
Then i substituted the 4053 and leaved out the resistor in parallel, done another test, and, again, with both gates low i read a closed (150ohm) between pins 5/6.
I really dont know what to do now... _________________ http://soundcloud.com/mister-vommi
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sun Dec 20, 2009 11:23 pm Post subject:
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i have not had the time to read carefully through your posts yet, tommi. i just wanted to let you know that i did not forget it. _________________
cheers,
matthias
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Mon Dec 28, 2009 5:26 am Post subject:
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tommi wrote: | The voltage i measured on pin 6 when both gates are low is +3,33V and goes to +0,14V when i press the manual switch of gate A. |
this is exactly what my spice model shows for +6V/-6v operation. if i understood the datasheet correctly, the 4053 would need just 30% of VDD do switch. so actually no problem here!?
that would mean that the gate circuit is working correct, but the 4053 is not.
what furthermore irritates me is the distortion you get.
you do not use a HC4053, don't you? these parts are for 5V operation only.
BTW if i wanted to increase the voltage level on pin6 i would increase R13/R15 to 4.7k. _________________
cheers,
matthias
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Sun Jan 03, 2010 3:22 am Post subject:
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Quote: | that would mean that the gate circuit is working correct, but the 4053 is not. |
Yep. This is certainly correct.
Quote: | you do not use a HC4053, don't you? |
No. All tests i've done refers to the CD4053BE.
I have also tried an HEF4053BE. This is working correctly with no need to rise the inhibit voltage for pin 6. With this ic i got a correct behaviour (as in the truth table), but i always have distortion.
So, i think this is good in some way, because it confirms that my problem lies in the type of ic.
This is the distortion's behaviour: i got it when i turn all way up any of my 3 input volumes and, in both mode, when i turn up the resonance pot any value that isn't zero (distortion rises with res pot's value obviously).
Sadly i got only this two types of 4053 to try so i can't tell wich result i can have with others.
Please tell me if you need some audio example i can record some mp3 to listen to the distortion.
Cheers,
tommi _________________ http://soundcloud.com/mister-vommi
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Sun Jan 03, 2010 3:36 pm Post subject:
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if i got it right you have distortion only when using the expansion board. so what is the peak to peak voltage of the audio? maybe it is just clipping? you may try to attenuate the signal then. _________________
cheers,
matthias
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Mon Jan 04, 2010 2:09 am Post subject:
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BTW it may be good in general to increase the value of R13 and R15 to 4.7k, this should avoid all issues with the threshold. _________________
cheers,
matthias
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tommi
Joined: Dec 05, 2007 Posts: 247 Location: Italy
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Posted: Mon Jan 04, 2010 2:53 am Post subject:
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Quote: | f i got it right you have distortion only when using the expansion board. |
Yes.
Quote: | so what is the peak to peak voltage of the audio? maybe it is just clipping? you may try to attenuate the signal then. |
My tests were all done feeding into the LPG waves from my mfos VCO and/or from my XR-VCO. Both this modules have a standard +/-5V output, so i didn't thought this was the matter. Plus, if i remember well, distortion appears even in BOTH mode (no contact of the switch should be closed in this mode) when i turn up the res pot. I thought this was an issue caused by the fact that the contacts aren't really open... they have a hi resistance, but not hi enough to be as an open circuit.
So, i tried measuring this resistance with multimeter. On the 20MOhm range i read an open, but after a while the reading begins to float, going to 10MOhm and then coming back to open. Well, dunno if this floating is an issue...
[/quote] _________________ http://soundcloud.com/mister-vommi
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fonik
Joined: Jun 07, 2006 Posts: 3950 Location: Germany
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Posted: Fri Jan 08, 2010 6:15 am Post subject:
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maybe it would be good if you could post a short soundclip. i wonder if the distortion is just clipping or maybe noise?
in the latter case you could try 100uF for C7/C8 and/or 1n in parallel to R2 and R4. this may reduce noise induced by the voltage divider/buffer set up. _________________
cheers,
matthias
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