Korg Forums

[ShoNuff]

hi,
just getting round to doing outputs on the Beats (bit late, i know ..)
not *quite* as easy as implied it's hardly plug+play.

having tried the fit of a DIN and midi cable, i decided to do the
MIDI out on a stereo minijack, to avoid having to use force to
insert/remove - seemed a bit tight and stiff.

how are you getting on with regular DINs fitted either to the top
or the back? aren't they destroying the Beats?

also had some trouble fitting minijack sockets in the bottom of the
case -plastic enclosed type- so i had to dremel the case a bit, and
trim down the plastic around the jacks. (used those because i wanted
to be sure there was no accidental contact to the pcb)

wondering what could be done with these pink/white noise and ring
outputs? can these be fed back in somewhere?

snare mod: poked around with a capacitor to the points indicated
but didn't get a worthwhile result (or it's the wrong cap) so i've
left that out. (+ fear of destroying something i can hardly see)

re: alternative tap points: Kick by itself is shown on Instructables
as coming ?directly from a pot? - can this be done with other voices?

---
ok, so that's for the Beats... what about Keys ? what are people doing
with those waveform outputs? can you feed them back in somewhere?
any ideas for this?

and Bass: how about osc sync? what are people doing with the hack
points on this one? does anyone have a diagram for how to do
individual VCA levels?

these mods have dropped from view these days, so i thought i'd
give it a bump.

[roblabs]

I'm interested in the v bass osc sync mod...
_________________
www.soundcloud.com/rob-labs

[ShoNuff]

service manual:

https://elektrotanya.com/cgi-bin/download2.cgi?fid=322893&file=korg_volca_bass_sm.pdf

topic:
https://www.gearslutz.com/board/electronic-music-instruments-and-electronic-music-production/1183015-who-can-read-schems.html

"it looks like injecting a signal into the bases of Q1, Q3 and Q5 will get oscillator sync"

[LM]

[ShoNuff]

i had a good look at the Beats board last night - wasn't sure where
these traces are that you have to break. there seem to be tab-like
solder connections - as mentioned at 9,6,3 o'clock, but i can't see
them all on mine: only a couple are visible, and i can't see any
traces embedded in the PCB going from those points.

[LM]

Yes, those tiny little traces are in different orientations on each Volca and you might need help from a magnifying lens and a bright light to properly see them, but once they are carefully removed I can assure you that the mod works perfectly. You can use a sharp pointed blade in order to kinda dig a little moat on the space around each pad, to find and remove the traces (just don't go too deep).

You can check the proper removal of the traces by testing for continuity between each the pins and ground. Once the connection is interrupted you are good to go. I've done it on the Beats, Bass and Keys already.

[ShoNuff]

ok, thanks - confirms suspicion that it's not the same as the FM.
you say 'a little moat' - so you went all the way round? can you
recall how many you had to cut on each side for the Beats?

is it safe to scratch the (?epoxy coating?) to have a better look
at what i'm cutting? not sure how deep i can go (would hate to
lose MIDI, or something else...)

have not looked at the Bass + Keys yet.

-haven't done the Snare C78 mod: i held the cap in the
position indicated and just got a longer white noise trail,
less snap. maybe it isn't actually a 104. i can live with the
snare as it is for now - thinking of doing that output from
the lower *tiny* spot indicated on Instructables, among
that cluster of little holes. not sure what the best combination
of outputs will be really. have now 7 minijack holes at the
back(ring/pink+white noise?)

[LM]

It is safe to scratch the coating around the tabs, as long as you don't go into the surrounding traces nearby. But the whole idea is to do some controlled damage around the solder pads, in order to break the connections.

The number of connections per pad is the same for all the models, it's just the orientation that differs between them.

The Beats was indeed the hardest one for some reason, while I found the Bass to be the easiest, even though the procedure is basically the same for all of them.

For the snare mod, I soldered an 100 nF cap (104) to the vacant pads on the circuit board. Start by cutting the cap's terminals short and bend them into a tiny "Z" shape, so the the cap lies flat a little above the board, while the ends of the terminals touch the pads. Put a tiny bit of solder on each pad, and do the same at the end of the terminals. Use tweezers to hold the cap in place so that the terminals touch the pads and quickly touch each connection with the soldering iron, just long enough to make it stay in place. Does that make sense?

When done right, the result is a snare that sounds less metallic and more like a proper vintage analog drum machine. If you get a lot of white noise with long decay (even with the pot all the way to the left) then it means that you are touching something else, instead of the correct contact points.

I haven't tried any of the individual output mods, I don't feel like drilling holes in the case.

[ShoNuff]

i might have been sent any old cap, it doesn't have any print
on it - but i just found a clearly labelled 104 on an old pcb, so
i'll extract that and have another go. am actually thinking of
just soldering wires to those pads, and having the cap a little
bit off that location (maybe add a switch?) - currently sounds
more like the vid where the guy tries a 106 ie: just sounds
like white noise when i touch those spots.

drilling the holes is not too perilous but the choice of minijack
sockets is important, as standard plastic case ones are a bit too
high and you can't close the case. i had to dremel the base of the
case and trim down the plastic, to get them to fit. *and then saw
'gilledj''s version, with rca connections, which seemed like a
good idea, since you'd want fullsize jacks at the mixer end
anyway..

if you put a piece of masking tape on the outside of the case,
- mark first with a horizontal line, to get a nice straight row -
you can plan where to drill, and it protects from scratching, and
picks up a lot of the debris. watch out for that middle post, you
want to avoid that (i didn't, had to remove it) - and then you drill
a small pilot hole, 2.5mm bit, where you want the centres, after
which you can drill with 6?mm wood bit - check the size against
the minijack(or RCA), and then i drilled gently. have to make sure
the height is right: not too close to the base (or won't fit) or to the
top (won't close), and maybe just plan to have the metal open type,
- those do fit -
and isolate those after soldering with some heatshrink.
after drilling, you can use the drillbit by itself to gently clean up the
hole, then get a bigger bit to clean up/bevel the edge a bit.

i don't really know how many indiv outs are really needed tbh.
probably got too many here now - i'm wondering what the
ring/pink+white noise points can be for. maybe injecting some
of that onto a pot?

i've taken a photo of the Beats MIDI socket, i'll post it later.

[LM]

With so many extra outputs, it might be an interesting idea to remove just the front panel along with the ribbon and put it all in a bigger custom case, just like some folks have done with modded Monotrons. Maybe even enough space inside for a more decent speaker.

I read some comments from people who had done the snare mod with a switch and the verdict was that it was pretty much useless, because there was no reason for getting back to the old snare, after getting used to the modded one. I tend to agree, as I never really liked the original one anyway.

[megamarkd]

[LM]

[ShoNuff]

finally got round to uploading the photo of the volca Beats
MIDI connections. here we go. as you see, hard to see
connections/'traces' at 9,3 and 6 o'clock:

[LM]

3/6/9 on the left one, but it doesn't seem to be the same on the right one (notice the lines running alongside the 3/4/5 o'clock positions). It could be 6/9/12 on that one. It's been a while since I did it, so I don't exactly remember all the details.

[ShoNuff]

does a bit more contrast help see better?



thinking that yellow is the 'ground plane'.
hard to see what happens on the inside.

(note the blue tags for the other pins - all have a test point)

so: did you scratch back the epoxy first, or did you go
straight for the cut? !!