8 RCA? Maybe more space available above the upper pcb, not sure. 13 mm heigth, 19 depth in the A-E potentiometer area (on the left).
Maybe enough deph for 4x 6.35 jacks on the Master Volume area (on the right). Probably tricky to put back the upper pcb after.
Anyway I think the best is to unmount it to check what’s the best for you.
getting my tools of my parents today. Going to do the mod on Wednesday when I am back. I am definitely going for 3,5 mm jacks as cables are easy to obtain and well it is way more easy to drill.
Mine is modded with multiple outs that essentially duplicate each track sound without the fx. It was done by our own @slicetwo and a buddy.
This modded unit sold recently:
Elektron Analog Four MKI with Individual Out Mod, CV cables https://reverb.com/item/27590732-elektron-analog-four-mki-with-individual-out-mod-cv-cables
I think it was listed here too, you might find more info searching the marketplace here.
Oh wow. That looks glorious. How far out to those MIDI cables stick? I’m building a new box and may need to get some.
Less than an inch. One Control cables.
Just did mine. It is very easy and working great. The effects sound fine when panned hardly. So this whole thing gabe me 4 seperate outs plus 2 effects. I can say goodbye to overbridge which always seemed to cause slight shifts in timing etc. Thanks to everybody for sharing their knowledge.
Congrats!
Your outputs are stereo?
Why do you have to pan hardly?
If it’s stereo, what about using only one output without hard panning?
The sound are going out from the main output regardless what you are doing but if you üan them hard you can grab the sound on the new outputs (they are mono anyway and if I wantd panmod I could add this later) and if the effects are panned to the other side you can use the regular in and out of the a4 as an fx unit. So I send aux 5 to a4 in L and aux 6 to a4 in R. Left goes to reverb, right goes to delay, both are panned hard. I take the either left or right main out (depending where you panned obviously) and feed it into a return of my mixer and set this return to mono. It does sound good. So I have 2 independent fx units and 4 analog synths. Just played a bit. Havin 4 outs is a completely different thing. Finally the a4 can be used for bass, kicks are punchy, percussion isnt muddy etc. I havent even used dynamics yet. If you had enough free mixer channels you could utilize 8 channels. For each synth of the a4 p lock sounds hard left or hard right so you could mix on 8 channels but lose the fx. For me 4 channels are enough as I have other stuff as well but I suppose you should be able to do a fairly complete song to track and just add fx transitions etc later on if you can live without samples (I can’t). So the mod in my eyes made the synth what I always wanted it to be but it never was as Overbridge just sucks. I experienced unstable timing with overbridge on several systems, os x as well as win, synced to overbridge, synced to erm multiclock etc nothing was relieable. Syncing to external clocck and using tve analogue signal however is extremely relieable but was useless due to missing single outs. Tracking straight away isnt an option for me so I didnt use the a4 for ages. Really pleased now 
Thanks for clarifying.
I’m curious about about how you plugged you individual outputs?
Stero Mini jack > 2 jacks cable, using left only?
You can disable tracks 1-4 Main /FX routing
AFAIK you can hard pan inputs, not fx.
For example input left hard pannned with reverb, the reverb is heard on both Main outputs, same for delay. And you can’t set dry / wet, nor inputs routing*, they go to Main anyway (routing choice possible for tracks 1-4).
So I wouldn’t say 2 independent fx.
*Theoretically you have to use PRE aux sends, fader down, otherwise you double the dry signal with potential phase issues.
When looking at the 8 holes in the pcb i used upper left tip upper right second bit on the trs and gnd from tve board.
For my cables i used stereo trs but just connected the tip so I can just use 4 mono.
What confused me was that the order on tve pcb up to down doesnt seem to be 1 - 4 or 4-1 as my jacks are not in order which isnt a big problen, labeled those.
No you cant pan the effects. I just use one of the 2 outputs as on the other one the signal of the other sounds is heard. I didnt try to be honest but I read that there isnt a way to gram the dry sounds and make them not go to the stereo out. I will try later but I suppose the point where you pull the sounds on the pcb is after the point where the a4 switches “sound to main” on or off so I guess that when disabling the sounds to the stereo out you wont get a signal on the new outputs either. As for the effects - well obviously pingpong is out of question and the reverb probably wont give you a 3d feeling. I usually use a very short reverb to give “room” and other more artificial sounding verbs for glueing and sounddesign. I can say the reverb pulled just on one line of a stereo signal sounds nice and is absolutely fine for what I need it to do. Same goes for the reverb. I create on hardware for that i need a couple of fx but I am tracking dry to mix in a daw where I can add highend algorithms if I want to, if not I can still track just the fx signal. Even my very basic Mackie CR1604 allows switching the return channels to mono so I get a crippled half of my stereo fx but make it pseudo stereo. It sounds great and I will definitely make use of it. Thinking of just a standard delay (i think the a4 dekay does sound quite nice by the way) and a reverb to do tails on snares or give just a tiny bit to vocals so they dont stand out too much. I am making electronic music and I think it should please my and others ears. Half of a reverb is anything but natural sounding but looking at the parameters of the algorithm I doubt natural sounding was what they had in their minds.
So no phasing issues as long as every sound is panned to the same site.
Thanks again for feedback. 
I’m really tempted to solder soon, but I need jacks sockets.
Seems a good solution.
I may use 2 minijacks and 2 jacks if possible…
On AR, it doesn’t cut the outputs…
Must be written somewhere here.
Personally I’d keep fx stereo. 
Just checking regarding the phasing.
As soon as i disable routing to main I dont get a signal on the new outputs
Not sure if I am making a mistake but you might be right. It seems that the fx also contains tve main signal so no 100% wet.
Using one of the synth channels with ext in in the oscillator settings might work but would mean I had to sacrifice one channel. Hmm.
Am I wrong in thinking so?
Yes. A4 inputs fx sends are post fader.
Bummer
What for? For fx? What can be the benefits compare to inputs with EXT IN settings (appart from env/filters etc).
Somehow I need to get the input signal into the fx and the 100 wet signal out of the main outputs.
From there I would grab the channel without the sounds of tve synths and feed back into my mixer.
I am a bit in a hurry but I think you were right saying that there isnt just a 100% wet signal available but I am really confused at the moment. Have to check tomorrow.
Hey - I’m considering modding my MK1… is there any view on sound quality of individual outs vs through main, particularly polyphonically? I’m thinking of sending to euro via a +6db preamp for each voice.
(My suspicion is there’s not much headroom in the internal mixer since things go to mush with poly patches…)
I don’t know about poly as I never use this feature. The sound seems spot on to me (it is pulled straight off the pcb) and using it with eurorack works nicely for me also without a preamp however if you need more volume just use a vca for that.
