Does your guy know why the VCA level may drop depending on the chosen gate source ?
Bit cheeky tagging Scot like this, possibly not an original 2600 thing either, but then again, it has its own quirks and often there’s a good reason …
here’s my mind bender
i have a very very simple vanilla patch on the blue marvin, just about as simple as it gets …
one osc into the filter
quickish ADSR envelope opening the closed filter
longer AR env on VCA
i was revisiting CV triggering of that voice which is where the ARP has one of its interesting quirks wrt gating
i noticed something odd when using my Korg SQ64 and it manifested as a quieter signal by a noticeable margin, probably less than 3db but no need to measure, it’s plainly lower
well that’s weird, the only thing i vary across comparisons is the gate - nothing else is changed !!
so i compare the following
Manual trigger (via button)
S/H ‘auto’ gating (via switch)
vco 2 square (mono-polar 0v > 10v)
S/H manual gating (via internal clock out) (mono-polar 0v > 10v)
also A4 CV out set to gate 0v > 10v
all of teh above behave the same, they all fire the envelopes when i send a feed of the gate multed or via Y splitter - and they all sound the same level wise
the outlier was the original device selected which inexplicably sounded quieter than the manual trigger method - this was the SQ set to V-Trig 10v !
I also fired up the square LFO from the Brother32, presumably bi-polar circa 5V +/- (i didn’t measure) and it delivers the same lowered output - again, i am just changing the gate source … the envelopes are clearly firing, but for some reason they outcome is a lower overall volume … wut ?? … i can’t get my head around this
wondering if this is something that affects the og or if anyone has any leads (no pun intended)
what i started to imagine, albeit that to me it made no sense, was that maybe the gate was a bit lightweight from the Korg, far from it, it’s pumping out an 11v gate on the 10v setting and it is actually higher than other gates - the max on A4 is ten so i can’t test 11 on that
does it make any sense that a gate input (sole source split/mult … triggering the gate/trig simultaneously) in excess of 10 could manifest in some biasing of the VCA or some other thing which drops the volume
i may see if there’s a calibration on the Korg or a way to adjust that in due course
but for now i’m flummoxed - ftr, just using a regular voltmeter, nothing fancy, but the stead state part of the gates is easy to verify and is as mentioned
i need to review the Behringer documentation and maybe google the quirks given that the circuit should be broadly cloned
Otherwise looking for any confirmation of the B2600 observation and any credible ideas about what could trigger this - i can’t imagine there’s anything being overlooked, but i’d be happy to have my understanding straightened out
The one thing i didn’t test was teh SQ powered by DC, but the 5v usb device charging it is good for plenty more amps than required and it’s kicking out 11v anyway
@anybody what gives … ?