Searching a simple VCA DIY project

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Hales
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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 10:45 am

no, but as said before, continuity test are ok.

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cackland
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Re: Searching a simple VCA DIY project

Post by cackland » Tue Jan 14, 2020 10:47 am

How are you powering the module?

Hales
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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 10:56 am

Module is not powered yet! :hihi: I posted a photo before that shows where I am, there are only electronic parts soldered for now. I re-post this photo.
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cackland
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Re: Searching a simple VCA DIY project

Post by cackland » Tue Jan 14, 2020 11:01 am

ok well you need to power the module if you want to test the voltage through the circuit

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 11:30 am

Yes, but I wanted to do some tests with the multimeter to know if at the stage where I am, everything works.
You can read in previous posts that Veils fails at continuity test on positive VCC with ICs. I don't have a sacrificial power supply yet and I think it's better to check if everything is ok at this stage before soldering mechanical parts… maybe I'm wrong(?)
However we were telling ourselves that there is a problem with positive on Veils…

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 11:53 am

I would like to have test instructions to determine if D2 is dead.
The last tests I did are these:
"So far I have been testing continuity in continuity mode on my multimeter, I have now tested the diodes on diode test mode. I have the same results on Ripples and Veils: multimeter show around 130/135 with black probe on cathode, multimeter show 1 with red probe on cathode."
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adam
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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 12:41 pm

i think it's going to be easiest to plug it in and see, you can always just power on for a very short time to see if smoke comes out, there is not a huge amount you can do without powering the module.

you can test for shorts without power however, if you measure the resistance between 12v and gnd (and -12 & gnd)

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cackland
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Re: Searching a simple VCA DIY project

Post by cackland » Tue Jan 14, 2020 12:45 pm

You can test for voltage throughout your circuit without having to solder mechanical parts (pots, jacks etc). Agree with Adam, power it up check for magic smoke and test...

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 12:48 pm

OK, and what to do with continuity test that fails with Veils? it's not significant?

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 12:53 pm

measure the resistance between 12v and gnd (and -12 & gnd)?
Is it another test than continuity ? Do you select resistance like testing a resistor?

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Re: Searching a simple VCA DIY project

Post by cackland » Tue Jan 14, 2020 1:06 pm

You are wanting to test the voltage through your circuit, no? Measuring what voltage in reference to gnd.

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 1:20 pm

I did continuity tests with Ripples that look good (look at the previous posts)
Same test with Veils are not good as I don't have continuity between +12 V power pin and positive pins of all the ICs, so the question remains open:
is this normal or is there a problem? if it's a problem at this point there's no point trying to power it… I think(?)

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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 2:11 pm

if you power it you can find out if it works or not...

if you check the resistance between the 12v and gnd pins you can give yourself an idea if there are any short circuits, you can do this before powering the module, if the resistance is very low, you might have a short (or several), this will be a few ohms, this won't damage anything if the module isn't powered

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 2:21 pm

With "20k" settings on the multimeter, Veils show 14.53. Ripples show 12.56.

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 3:05 pm

I thought continuity test on the power pins helped to know if there is shorts, isn't it?

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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 4:07 pm

Hales wrote:
Tue Jan 14, 2020 2:21 pm
With "20k" settings on the multimeter, Veils show 14.53. Ripples show 12.56.
if that kOhms then it's fine, if it's ohms you might have a problem

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 4:15 pm

Yes, that's kOhms, multimeter at 2000/200 ohms setting displays no results.
What about the continuity test with +12V power pin and positive pins on ICs that fail?

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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 4:21 pm

i'm not sure, easiest is going to be powering it on and checking it out with some live voltages

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 4:34 pm

OK, as said before, I need a sacrificial power supply, unless you think that I run no risk in connecting it to the power supply of my system, I could try by disconnecting the other modules and using the 0-coast+koma field kit FX which are in there original box for testing things…
About the sacrificial power supply I wondered if it was possible to use the original box of the Behringer Neutron? Maybe there should be topics about that in the forum, I will search.

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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 5:36 pm

any psu will do, if it doesn't have other modules attached they won't get damaged, you could perhaps watch for smoke and hold your hand over the pcb to detect heat, if it gets really hot, switch power off immediately

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Re: Searching a simple VCA DIY project

Post by Hales » Tue Jan 14, 2020 5:59 pm

OK, so I can plug the 2 modules without finish to solder mechanical parts?
I imagine it's better to do like this for testing things with multimeter and if I’m going to have to SMD rework it will be more easy.
Or do you think I have to go on and finish the assembly?

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Re: Searching a simple VCA DIY project

Post by adam » Tue Jan 14, 2020 6:48 pm

these are both analogue modules so you won't necessarily need to solder jacks but you might need to solder the pots

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Re: Searching a simple VCA DIY project

Post by cackland » Tue Jan 14, 2020 6:49 pm

If you are worried about soldering the mechanical components and it not working, then don't. The potentiometers on that schematic don't link to any voltage references.

Simply power it on without those and test away.

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Re: Searching a simple VCA DIY project

Post by Hales » Wed Jan 15, 2020 6:20 am

So… finally, I solder the pots or not?

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Re: Searching a simple VCA DIY project

Post by adam » Wed Jan 15, 2020 6:35 am

try without first, but if you find any strange results take a look at the schematic and see if the missing voltage you're trying to measure goes through a pot or not

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