3trinsRGB+1c to LZX Adapter PCB

Or if enough people would like to purchase someone could get 5 to 10 pcbs made…

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If there’s sufficient interest, I’d be up for laying this out with a few additions to make it a 4HP module (I have my 3trins racked). I was able to snag one of the expander PCBs back when they were available but added a few other simple mods to my 3trins to fill out a 4HP panel.

  • Three gate inputs (using LM339/CD4066) tied to the RGB vertical / horizontal range latching buttons

EDIT: oops, forgot I also tied the 4th switch to the vertical adjustment button. Personally don’t use this much since you can’t control the speed or direction of the scrolling but you can get a Diver-ish H/V scrolling of external input video with this

  • CV control over brightness

It would be nice to have them all on one proper PCB instead of on bits of stripboard. It would still require a little bit of soldering wires to points on the 3trins’ PCB.

That reminds me I need to try adding a S-Video output to mine at some point. The 3trins uses the same encoder IC as Cadet II (AD724) which just requires a 220uF cap and 75r resistor in series to both the Chroma and Luma pins which are broken out. I added this to my Cadet II and it works great.

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I would definitely pick one or two up if someone made some pcbs !

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I would also be interested in one.

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I’m interested in one if anyone builds it!

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Someone recently did this:

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OSH Park is the most expensive way to do this though. $17.50 for a board that would cost under $1 elsewhere if someone ordered a few.

I might do a run. is an eurorack version preferred or is just a pcb fine?

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I mean, a mountable PCB with an eurorack panel and some kind of cable to the 3trins. (MTA or so)

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basic setup:


the original pcb has a few DNP resistors connected to +5v
what was the purpose of these? Why did they got cancelled I mean

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I remember something about the output from 3trins being different for each device. Some output 5v, some 4.2v, etc.
Don’t know if the resistors had to do with that though

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I remember not installing those resistors. my device is at my other home, 1100km away :slight_smile:
my trins outputs 3.3v

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Just checked mine, R1, 5, 6, 10, 11 and 15 are not placed

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are the opamps OPA340?
I seem to recall that they are different opamps. maybe I am mistaken

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Yep!

If you rig up a Eurorack power connector, you could run the 3trins off of the +12V rail and then route the +/-12V rails to this expander so you could use LM6172s instead. I’ve run my 3trins off of a Eurorack supply for years and it’s been fine.

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Basic idea. some space on the panel, so maybe something can be added.
like mentioned above.

the things @rempesm posted sound useful, but I don’t have my 3trins here, so I can’t test this now.
in about a month I’m back in NL, so then I do some tests.

the connections to the Trins can be MTA with this pinout header. maybe I move it a bit

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I’m a fan of the mods I listed above but if this is wired up to the header by the AD724 on the 3trins, I wonder if it would make more sense to include the S-Video output and a second buffered composite output. Less clunky wiring, you get one cleaner output and an easy way to have one composite output for a preview monitor and save the one on the 3trins for easy feedback with a super short RCA cable.

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If you’re using OPA340’s, I think your positive and negative power pins are swapped.

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I’ll check this, thanks!

you were correct. I am so used to separate power pins that this threw me off.
the power pins rotated as I mirrored the part

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