Simple but good dual vca

Ok, the first batch arrived today (faster than expected), and my first impression is that they’re recycled. But I can live with that. Now I’m just waiting for the PCBs to show up…

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Ok, got the second eBay batch today, and it looks a lot less recycled. Maybe they pulled them from sockets this time :slight_smile:

(now I just have to figure out which seller sent me what package…)

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There are some things Man was not meant to know

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Work in progress…

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Ready for testing.

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Single board stripboard by @Dud here:

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but not yet tested :slightly_smiling_face:

have you tested yours ?

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I did some smoke tests IIRC but don’t recall if I did any more functional testing (my build discipline isn’t what it’s supposed to be :confused:)

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What’s that power supply module?

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An USB plug ?

btw i havn’t seen the title :rofl:

Sans titre

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It’s an industry standard SIP DC/DC converter. Nice for testing, since they’re well protected against shorts/overload.

IIRC the one in the picture is a MEAN WELL DPAN02E-12 but they’re available from a bunch of manufacturers, and for different input voltages (5 V USB in this case) and power requirements.

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I edited my stripboard layout
I saw that i wrote 100k for all pot :roll_eyes:
it’s allways not yet tested but it’s now the good values for pots :slight_smile:
I still have 2 of these modules to build, maybe tomorrow …

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@fredrik , i have a question about this build

What does means the note on the build info on N Ronnberg site, about the red square
“Note the red square which indicates that you need to bend that connection.”

i allways connect it in pin 9 (like all others connections between the “2 board”)

also do you know what exactely adjust the trimpot please

thx

Isn’t the red square comment just pointing out that the connections are not aligned, so if you use a header you need to bend it one step:

The 100k trimpot adjusts the input offset. Set it somewhere in the middle (no offset) if you don’t have a reason to put it somewhere else.

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Thank you :+1:

(more ch…)

When testing my 2 new VCAs, they don’t react like the others I had done in the past.
I check my old one, and i see that i put 4 x 560K resistors (2 instead of the 2 cap optional 33pf).

Sans titre

on my old build, with the Initial level pot i can have all the input signal without “cv fx”, even if the cv level is on.

on my new one that increase the initial level, but with allways the “cv fx”.

both are different and interresting, and i keep that like this.

an interesting error in fact

btw i need to change it on my stripboard layout to make it like the original schem :slight_smile:

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Well another Dual VCA, the 5th and another coming soon :slight_smile:
which allowed me to check my stripboard layout, which is good !

i add this for the indicator led (to have an indication mix from CV 1 & 2

vca indicator led - sound bender

A little patch with it

And the VERIFIED stripboard here

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No it’s not the same pics that is just above :rofl: (you can play to find difference )

Another build of this module (the 6th)

and a little patch

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I had to stop playing this game, as my hand was hurting from scrolling up and down the tread too many times, but I do have an answer!!!

The lower standoff is in a different location?

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:grin: Yes !!! :medal_sports:
but i think there is a more big evidence … :face_with_monocle:

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