I Need a TBC and confused about SDI

Without this forum I’d be so lost.

Ok, I want to start getting more into glitch video but my Edirol can’t handle it when I’m going out into an LCD or projector. I get the intermittent blue screen, etc . . Do you guys know of a TBC that is available and won’t break the bank? I really want to be able to see the true and full glitch effect from, say a Fluxus Duo, on my LCD and Projector.

Lastly, and probably unrelated, I am confused about the difference between rca composite and SDI. I’m assuming that composite is analog and SDI is digital, right? So let’s say I have a composite rca cable and I want to go into a Blackmagic recorder that has SDI inputs, can I just use a passive rca to BNC manual converter or will the recorder not recognize an analog signal? If it won’t recognize the signal by using a passive converter, do they make an affordable rca composite to SDI converter? And is BNC analog just like RCA but just has a funny connector? Why do manufacturers put BNC inputs on their gear when RCA is so much more universally used?

Thank you guys so much for helping me out. It’s crazy but this question is not addressed on any websites I could find.

Oh, and THANK YOU LARS FOR THE NEW SERIES OF LZX MODULES :pray:t2:. I am so excited!

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You definitely need a Blackmagic composite to SDI converter and a cable specific to SDI signals to run from the converter to the capture device. From my understanding, using the wrong cables might very well fry your hardware because of different electrical impedances specific to the SDI cable. It’s the same concept as why you don’t use speaker cable to connect a guitar to an amplifier.

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Wow, thank you so much for the heads up :pray:t2:

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I don’t know any low cost TBC devices. I’ve used my Edirol mixer to do that, but it sounds like you have signals even that can’t handle.

SDI is the pro digital video standard. HDMI is the domestic video standard. So you’ll need a composite to SDI converter, or a composite to HDMI converter. A BMD Recorder card will accept SDI and HDMI inputs, so there’s a low cost option available. I’ve successfully used a similar HDMI->Composite converter, so I’d expect similar results going the other way.

BNC sockets have the advantage of locking, unlike HDMI. Many professionals prefer SDI over HDMI. My own experience is that HDMI cables can too easily be pulled out. Other advantages of SDI include alt inputs and zero frame loss. It’s easy to see why this would be valued.

Anyway, here’s a low cost RCA to HDMI,AV to HDMI Converter.

There are also low cost SDI<->HDMI “micro” converters from BMD.

All these low cost devices run from USB power, so its easy to power them all from a PSU with multiple USB sockets. Just make sure the PSU can supply enough current for them all. I use a 5-port Anker PSU for mine.

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The only real way that you can project glitch that looks the same as on a CRT is to point a camera at the screen and project the output of that.
Glitched signals are typically outside the spec of the PAL or NTSC signal. CRT’s try and interpret them one way, but digitral devices have a lot more trouble interpreting the mangled signals. This is whey you get the blue screens.
Even if you get a TBC, the way that it interprets the gliched video feed will not necessarily look like it does on a CRT.
This is what I’m not too keen on working with glitched signals. I can make a cool looking patch that looks totally different when I record it.

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Thank you soooooo much! :pray:t2::pray:t2::pray:t2::pray:t2:

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This makes a lot of sense. I guess I should find a flat screen Trinitron and just record that. Thank you so much :pray:t2:

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I don’t think this is much of a danger. Pretty sure impedance mismatches in video ~mostly~ just result in signal degradation/distortion (due to reflection), not broken equipment. Even then, ~generally~ negligible unless you have something complex like a patch bay or other situation where multiple impedance mismatches will start to add up (or are running super long cables where signal degradation is already an issue).

A much greater danger is simply using a glitch signal at all. Depending on the particular device, it may be sending out a signal WAY out of the voltage range expected by the receiving gear. In my experience, ~most~ devices can take it, but I have fried at least one piece of cheap gear by having it after a glitch device in a signal chain. But TVs can certainly handle the abuse and probably anything with a TBC will be fine too.

That being said, totally agree that I would avoid plugging ANY analog signal — especially a glitch one — into a device expecting a digital one, as such devices may be less robust in dealing with signals outside their comfort zone.

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Word, a pro photographer friend of mine recently purchased a new high-end camera that uses SDI and was explaining to me that, according to the manual, if he didn’t use an SDI specific cable into a capture device, it would fry the camera. Maybe that issue is specific to that camera. It’s definitely a good idea to double-check though, or else one might find themselves with an expensive paperweight.

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Yeah, I’ll admit my experience here is 95% in the analog world, so totally possible that digital gear is more susceptible to impedance mismatch (and signal reflection) damage than I am aware.

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For getting glitched video to not cause black/blue screen dropouts, I think you’d want something like @cyberboy666’s Sync-ope: Sync-ope : sync restoring circuit - next revision ideas - current projects - scanlines

It was pretty much made specifically for what you’re talking about. It’s definitely cheap, though it takes some DIYing. I think it might still be a work in progress so you might want to ask in that scanlines thread to see.

SDI should be 75 ohms at 800mV p-p, well within the range of analog video. You wont hurt analog gear by plugging SDI into it. However, an sdi RECEIVER may not necessarily handle analog signals over 1V gracefully.

Please beware that there are a few different flavors and rates of SDI. SD-SDI will only get you to 480p; HD-SDI to 720p/1080i; 3G-SDI to 1080p; 6G to 4K and so on. Dual link sdi varieties will give you higher frame rates and/or resolution than their single link counterparts. For example, Dual link HD-SDI will get you 1080p60 and dual link 6G-SDI can get you up to 4k60 (also achievable with 12G-SDI).

Some of the really cheap sdi converters are really picky about taking EITHER 29.97 or 30fps ONLY

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Hopping off the back of this thread about dropped frames from glitching, if I need to post elsewhere please tell me
I’m getting dropped frames, A LOT, when the Memory Palace is going full acid mode (both mirrors, reflect and tile modes turned on and zooming in/out). Signal flow is MemPal → Roland V440HD (SVideo) → BM Intensity Shuttle (Component)

The dropped frames are only in Media Express, so after the BMIS (it seems)

Any suggestions?

I have never heard of sdi impedance mismatch causing damage to an output or an input, in 20y. I’ve had it not work, sparkle or have noise.

All the utilities guys here say the same. Survey of 3 other engineers not here onsite all were met with very confused looks.

I have however read of unshielded power cables going to an accessory, causing electrical interference and frying outputs.

Service bulletin from arri here: https://www.arri.com/resource/blob/194752/26e7a4ca07e7a8f0ce038b23109b216c/download-technical-information-data.pdf

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Then that’s probably what my friend was talking about. I figured it had to do with an impedance mismatch because of my experience with high and low impedance cables and musical amplifier circuits. Really good to know that impedance is not the issue. Thank you for pointing that out.

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The v-4 mixer also has a menu setting titled “sync threshold”.

By default/preset sync threshold settings, nearly any glitches cause blue screen / dropped frames. Adjust the sync threshold (i believe to 20-30 range? Don’t quote me) and you might find the v4 handling glitches better.

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Another TBC tip for glitch stuff: get a panasonic ave5, the inbuild tbc handles glitches really well. I use it a lot with the syntonie glitch gear.

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Yeah, Panasonic MX12 mixer also handles glitches like a champ (though it pulls sync from one input, so you need a clean sync source going into one and then the other can be very glitchy no prob).

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