From Brian Willoughby Sent Sun, Apr 21st 2019, 17:56
From Brian Willoughby Sent Sun, Apr 21st 2019, 17:56
Hi James, Can you explain exactly what is supposed to be the benefit of combining = two AX60 synths? What would the resulting voice architecture look like? What you=E2=80=99ve described so far sounds like an apples versus = oranges comparison. The Akai samplers are 6-voice and lack filter resonance. The Akai synths = are 6-voice and lack sampling. Combining the two types gives you a = 6-voice keyboard with both sampling and resonant filtering. The voice = architecture ends up being very similar to most other subtractive synth = architectures where there is an =E2=80=9Cexternal=E2=80=9D channel in = the mixer at the filter input. The advantage is that the external = samples can be synchronized, although this relies heavily on MIDI, which = is available for non-Akai models. By combining dissimilar products, you = obtain something unique with features of both. If you were to combine two AX60 synths, I don=E2=80=99t see how it would = be a benefit, since you=E2=80=99d still only have 6 voices. Consider that the Akai samplers always output their 6 voices onto the = 13-pin cable, and the Akai synths always take 6 voices as inputs on that = same cable. You do point out that one AX60 will be a =E2=80=9Cmaster=E2=80= =9D and one will be a =E2=80=9Cslave.=E2=80=9D But it=E2=80=99s worth = pointing out that turning an AX60 into a master means that you can=E2=80=99= t use any of the existing circuitry that=E2=80=99s used for the 13-pin = cable as an input. Your =E2=80=9Cmaster=E2=80=9D AX60 will need to = output 6 voices, and there=E2=80=99s no signal path in the synth for = that. At this point, your challenge is not actually any easier because = you have an AX60 - you could pick any 6-voice synth as your =E2=80=9Cmaste= r=E2=80=9D and the circuit modifications would be equally difficult. In = other words, I don=E2=80=99t see how choosing the AX60 as your master = makes anything easier. Another way to phrase the above is this: You cannot connect two inputs = together! (and the hidden problem is that converting the 13-pin input on an AX60 = into a 13-pin output would require extensive modifications) Even if you manage to pull this off, you=E2=80=99ll have the entire = VCO+VCF+VCA signal chain of the =E2=80=9Cmaster=E2=80=9D AX60 feeding = the mixer input of the VCF of the =E2=80=9Cslave=E2=80=9D AX60. This is = not a very common voice architecture. You might be able to get some = interesting filter sounds, but note that the filters will still be in = series, not in parallel. The only possibility would be like buying a = vintage Synton Syrinx only to find that the VCF RTNG knob is permanently = stuck in the anti-clockwise position, when arguably the most interesting = Syrinx patches use the other filter routing options. Anyway, if you can explain what you hope to accomplish, then maybe = I=E2=80=99ve missed an interesting combination that would make sense for = the AX60. Note that you won=E2=80=99t end up with a 12-voice synth. That would be = possible with an external MIDI processor that would sit between the = master and slave keyboard, and would not require any modifications. Brian Willoughby On Apr 21, 2019, at 9:41 AM, James Meagher <x.xxxxx.xxxxxxx@xxxxx.xxx> = wrote: > I=E2=80=99m looking for an EE/tech who will consult with me via email = in my attempt to connect a =E2=80=9Cslave=E2=80=9D Akai AX60 to a = =E2=80=9Cmaster=E2=80=9D AX60 in the same manner that you can run an = Akai Sampler (S612 or S700) into an AX60 to combine the sampler=E2=80=99s = voice with the AX60=E2=80=99s single osc pre-CEM3394 filtering. Of = course I=E2=80=99m happy to pay this person for their time.=20 >=20 > Of course previous knowledge of the AX60 and/or S612 would be a bonus, = but I don=E2=80=99t think it=E2=80=99s at all necessary for someone who = has the electronics understanding that I lack. I am able to follow = schematics (in a rudimentary, signal-path kinda way), find components on = a circuit board, and my soldering skills are decent. The two AX60=E2=80=99= s are recently refurbished (all key contacts and slider pots = disassembled and cleaned, all switches replaced and power supplies = outputting proper voltages), and are ready for coupling.=20 >=20 > I=E2=80=99ve gone over the AX60 schematics, the S612 schematics, and = the CEM3394 datasheet, and can see numerous places from which I access = the voices from the =E2=80=9Cslave=E2=80=9D AX60, and numerous points to = which I can introduce those voices into my =E2=80=9Cmaster=E2=80=9D = AX60, but I don=E2=80=99t have the EE understanding to make an informed = decision as to which option will make the most sense (or simply work). = I=E2=80=99ll save further details of my thoughts for my lucky = collaborator.=20 >=20 > Please let me know if you, or anyone you know, could be the right = person for the job. Feel free to share with any other group/list you = think might make sense - I=E2=80=99m no longer a member of sdiy or muffs = for precisely the same reason I need help with this project. ;) >=20 > Cheers, > James