Future Cadet Modules?
Category: Unknown · Tags: cadet · Posts: 51
#1 — jnoble · 2018-08-20
I ran across these elseweb and got kind of excited. Are there any plans to produce these or anything else in the Cadet line?
Cadet XI Noise Generator
Cadet XII Wavefolder/Freq Doubler
Cadet XIII 3-Input Mixer
Cadet XIV Gamma Shaper
#2 — reverselandfill · 2018-08-20
I also hope these get life… especially the noise, wavefolder & gamma shaper.
@creatorlars …hint …hint… hit… just as schematic would be cool too! (if this saves time and effort…)
#3 — brendanleespengler · 2018-08-21
You guys got your thumbs in a lot of pies! But also, sign me up for all 4.
#4 — creatorlars · 2018-08-21
I’d love to at some point! But not anytime in the near future – too many other obligations, not the least of which is finally getting down to formal video documentation of all this stuff. I’d encourage all of you to keep your explorations going though, there’s a lot out there to explore. I can be here to help answer questions and solve problems.
#5 — jnoble · 2018-08-21
Totally understandable.
Another run of Sandin Function Generator PCBs (just the PCBs to keep it simple) would be
though 
#6 — JunkRhythm · 2018-08-21
Yes to this! More Sandin PCBs would be sweet.
#7 — creatorlars · 2018-08-21
I have the PCBs and will go ahead and get them up on the site soon. Was planning to do a run of white faceplates for them but … too many projects going on!
#8 — jnoble · 2018-08-21
Oh, this is great news!!! These will fit wonderfully in an Intellijel format tile.
#9 — microtonal · 2018-08-22
For a video mixer you can take most audio mixers and swap TL072 op amps with LM6172. I’ve done that on an Erica Synths DIY 3 channel Mixer II. The parts are through hole and I used a socket for the dual op amp. An LM6172 swapped right in and I do not see any noise or rolloff from the circuit.
The same board with a TL072 passes high frequencies but adds some ringing and distortion for the higher frequencies, even in the higher audio range.
#10 — jnoble · 2018-08-31
creatorlars wrote:
I have the PCBs and will go ahead and get them up on the site soon. Was planning to do a run of white faceplates for them but … too many projects going on!
I’m being the squeaky wheel.
#11 — creatorlars · 2018-09-01
How about I donate the Sandin PCBs to a single community member willing to distribute them to anyone who wants one?
#12 — reverselandfill · 2018-09-01
I’m willing to do that. contact me!
#13 — jnoble · 2018-09-01
I think we have it handled? Stay tuned!
#14 — jnoble · 2018-09-01
Details to follow, but I’ll just say for now that Lars is amazing.
#15 — pbalj · 2018-09-01
waaaaaaaaaaaannnnnnnnnnnttttttttt someeee
#16 — LauLindqvist · 2018-09-05
Love the Sandin PCB giveaway! But searching around on the interwebs i found mention af another Sandin module about to launch from LZX back in 2011: the Amplitude Classifier… did this module ended up becoming one of the expedition series modules in a slightly different vrsion? Or did it just not happen then? See mention that it would be to complex for most DIYers, but curious anyway!
#17 — creatorlars · 2018-09-05
The Amplitude Classifier module turned out to be outside the realm of a clone since I had re-engineered and added so many features to it – it was released as the 8 Stage Quantizer & Sequencer in Visionary series. I think we only made 50. It would be worth doing a DIY clone, but would be quite a large build!
#18 — reverselandfill · 2018-09-05
I’d would love to build it!!
If you are willing to share the schematics…
#19 — creatorlars · 2018-09-05
It is unfortunately a very parts heavy surface mount build that uses a CPLD at its logic core, and has a ton of fine pitch dual transistor packages. I’d love to document the schematic for a DIY version of the true Sandin architecture at some point though!
#20 — reverselandfill · 2018-09-05
would it be do-able with a SMD oven?
#21 — creatorlars · 2018-09-05
I’m afraid the 8 Stage Quantizer & Sequencer production module would be outside the scope of a DIY project (which is why I didn’t make it one in the beginning.) But the core Amplitude Classifier design is worth doing. Maybe we can talk @pbalj into doing it.
#22 — JonasBers · 2018-09-11
WHOA, this is all coming back to me – I remember checking out the gamma circuit in the old Linear Technology Video Circuits document. Would the Gamma Shaper have been based on the LT1230, like in the notes? I think I might even have a few of those around here somewhere.
#23 — JonasBers · 2018-09-11
The pre-cadet world was truly the dark-ages of DIY video. I can’t thank you enough, really. I was trying to make all this stuff on proto-board and failing.
#24 — creatorlars · 2018-09-11
My gamma circuit (as implemented in Shapechanger) uses two LT1256. One as a power of 2 multiplier (expo curve), and the other to crossfade between expo and log curves. Log curve is created by subtracting the expo curve from the input signal at a gain of 2X (using an opamp.) This design allows for a mathematically accurate sweep (with video rate CV) between expo, linear, and log curves. This architecture would likely fit into a Cadet module, but there are other ways to do it as well.
#25 — JonasBers · 2018-09-11
Those chips are endlessly useful.
#26 — creatorlars · 2018-09-11
Yes, and especially for DIY/through hole designs, make multipliers and VCAs very low parts count!
#27 — LauLindqvist · 2018-09-27
A question for anyone in the know about adapting audio mixers and other stuff, related directly to:
microtonal wrote:
For a video mixer you can take most audio mixers and swap TL072 op amps with LM6172. I’ve done that on an Erica Synths DIY 3 channel Mixer II. The parts are through hole and I used a socket for the dual op amp. An LM6172 swapped right in and I do not see any noise or rolloff from the circuit.
But assuming i do this, I will still not have 0-1v clipping of incoming frequencies, and hence the mosule will sometimes output voltages in excess of the 0-1v used in the lzx ecosystem, right? So if i wanted a proper lzx 0-1v, i would have to adapt the whole circuit? Or is that overkill for just a simple mixer? This is most definately out of my competence in the near future …
But just swapping a few components could certainly be done.
#28 — reverselandfill · 2018-09-27
there is also a schematic of the summing mixer in the LZX archive.
4ch video mixer. (for LZX format signals)
if you are into DIY build one. I’ve some pcb’s left if you want the easy route.
#29 — LauLindqvist · 2018-09-27
reverselandfill wrote:
there is also a schematic of the summing mixer in the LZX archive.>>>> 4ch video mixer. (for LZX format signals)>>>> if you are into DIY build one. I’ve some pcb’s left if you want the easy route.
Yup, im embarking on that route, the summing mixer, VCA and Crossfader (and some other audio rate DIY stuff, to be used for the audio into video synth routing, attenuation, switching, Some LFOs, perhaps a Quadrature LFO, perhaps the OScilloscope graphics artist) are on my to do list. Have plans for getting into designing the PCBs for those together with a friend, af first steps into the design your own PCBs, but If you have spare PCBs or perhaps just files that can be used for ordering PCBs for some of those, im interested, will send a personal message. Thanks!
#30 — JonasBers · 2018-09-27
If anyone is in the same boat but doesn’t want to design the PCBs: The cadet crossfader is basically the same circuit. Also, the BSO QVAM is very similar to the summing mixer but with some improvements. As far as I know, Nick (BSO) is open to selling unpopulated PCBs for it.
#31 — joem · 2018-09-28
For the most part, it doesn’t matter if a mixer with swapped op amps is clipping signals at 1V or not, since whatever LZX gear you plug it into most likely will clip it to 1V anyway, since the inputs are usually (or always?) designed so that higher voltages plugged in won’t damage them.
#32 — windspirit · 2018-09-28
Just FYI my company Mystic Circuits is working on some new LZX compatible video modules and my goal is 100% to have them have through hole/ DIY/ open source options to expand the DIY video landscape.
#33 — Tan_Sat · 2018-09-29
windspirit wrote:
Mystic Circuits
Love y’all’s work! 0hp series is a brilliant idea!
#34 — reverselandfill · 2018-09-30
you are awesome! This attitude for open source is so great for the community.
I am so glad that it is now possible for non-rich persons to build and play live with these modular video synths.
cool
#35 — wednesdayayay · 2018-09-30
oooh nice I’m really feeling the DIY gods pulling me their way
I want to start with something very simple
all I’ve done soldering/electronics wise is fixed banana jacks and made passive switches
I’d love to know more
#36 — MoireMotion · 2019-02-11
Has anyone explored lars’ gamma circuit further as a DIY?
#37 — reverselandfill · 2019-02-11
not yet. but I was planning a extended VCO. (with more waveshapes)
This might be a good addition
#38 — luix · 2019-02-11
Lars mentioned at some point some noise module for the Cadets, I guess is just matter of time since the Oompa Loompas @ LZX are very busy.
#39 — transistorcat · 2019-02-11
Don’t hold your collective breaths waiting for my project backlog to clear, but i’m also kicking around the idea of doing some cadet/castle-format modules.
My current short list is:
- A tri->sine shaper
- A “Scan generator”: an adjustable linear-> trapezoid function.
With faders, crossfade across multiple video sources.
Three of these will make a voltage-> hue function.
I think they might also be useful as a sort of soft “window” key 3. Gamma shaper 4. Wave folder 5. Something along the lines of RGB <-> YUV 6. Noise 7. Resettable Monostable/bistable. Think trigger delay/ key latcher
I also want to look at an audio in + audio filter + envelope extraction module, but i’m not quite sure if it will fit in the form factor with what i want to achieve.
Gamma shaping (as Lars is hinting) is probably achievable with a processor and two faders (and some creative patching). I’ll probably spend some time playing with that before deciding whether to invest the time.
I’ll probably spend some time working through this list and abandon some of them on the way
(Especially if someone else beats me to the punch)
#40 — luix · 2019-02-11
transistorcat wrote:
Don’t hold your collective breaths waiting for my project backlog to clear, but i’m also kicking around the idea of doing some cadet/castle-format modules.
This is the purpose of cadets! To give us basic building blocks of other stuff so we can create and evolve our own modules… and perhaps new Video specific Eurorack Manufacturers?
A good video rate quadrature VCO would be nice…
#41 — transistorcat · 2019-02-11
I think™ you could probably make a workable quadrature shaper with the IX and some analog switches and a comparator. (You can split the triangle from the IX into four separate “zones” and then offset and invert as needed to stitch it back together) This works at audio rates, but the switching might be a problem at video rate.
#42 — transistorcat · 2019-02-11
Alternately, invert-chop the TRI into a SAW (Which can trivially be wavefolded back into a TRI), offset it (by a CV-able amount), and then fold it back. if the wavefolder is precise and fast enough, this would give you a new TRI with controllable phase offset. As with the other approach, this depends on speed and precision to work glitchlessly
#43 — reverselandfill · 2019-02-13
I tried that gamma trick, (triangle VCO to Multiplier CV & input) . it gives a very nice waveform.
This definitely goes into the next vco pcb!
how can you chop a saw from a triangle and get the full range? I patched it with a squarewave into the Fader, but that gives me a half saw (1/2 of the triangle)
I also did the pedestal mod , it has interesting effects on the shape and frequency.
#44 — transistorcat · 2019-02-13
Fade with the square between the TRI and an inverted and offset TRI. (flip the tri around on the down slope).
#45 — reverselandfill · 2019-02-13
would this be possible with patching, you think?
Vco (with squarewave mod), Fader & Processor / Multplier ?
#46 — transistorcat · 2019-02-13
I think so? mult the tri to fader A and processor, turn the processor amount fully ccw, plug processor output to B, SQW to fader in and adjust the bias on the processor until to get it matching (I think you want the bias to post and fully clockwise). Be aware that this gets you a 0->2V SAW, so either adjust the amplitude with another processor or adjust the input amount on the next module in chain accordingly
#47 — transistorcat · 2019-02-13
Note that if you’re redesigning/modding pcb’s, remember that you can swap the expensive/rare fader parts an analog switch if you’re not actually fading inbetween the extremes. (for example for the tri->saw)
#48 — reverselandfill · 2019-02-13
I may get back to you about that when I do the layout. Thanks!
#50 — sean · 2019-10-31
With the retirement of Cortex, how about something like this?
Want to get me some of that clean component output.
Put a NTSC/PAL dip switch on the backside, since most users probably set it just once? Add RCA sync?
Have been dragging my feet on a Cortex, since I already have a Vidiot. Now thinking TBC2 + Marble Index + Diver + this would be a perfect Cortex+ replacement.
(Also seems like this would take pressure off including component out on the upcoming Automata standalones.)
#51 — joem · 2019-11-02
That doesn’t seem like it’d be a very hard module to design. If you check out “Circuit Diagram 4 (RBG to YUV)” at the very bottom of this YUV to RGB page, it looks easy enough and is using pretty normal parts (no not-in-production ICs). It’s just some analog addition and subtraction, after all. The circuit on that page looks to me like it’d be pretty close to what you’d need. I think you could cut out the LM1881 entirely and just use the sync signals from the cadet 14-pin sync. Also, you’d want to replace the power bit with the power bit from a Cadet/Castle module. I’m not 100% sure about the inputs and 4053… The 4053 seems like it’d be a good idea, to ensure no stray inputs bleed into the sync portions, if I’m understanding it correctly.
#52 — sean · 2019-11-03
Wish that I had the skillset to make it happen (or the time to learn) but alas not at present. Fully admit that my hope was/is that it is an easy enough project that someone might take it on (if not LZX themselves). Never really thought there would be much interest in such a thing while VC was the standard base module, so hadn’t mentioned it before. In a post-Cortex world, perhaps such a module starts to make sense?