Color shift when using U-MATIC DUB OUT with DPS-295

[digicube]

Is my DPS-295 defective? Bad caps? Here are the videos https://drive.google.com/drive/folders/1zBMwiN1RAM9qI74ksQe0gJqAO-ZaYVDW?usp=share_link
All DPS 295 chroma, luma, hue settings are at 0. I tried changing the hue but no where close to original color.
I'm using VO-9850.

[dellsam34]

Are you connecting both the DUB-Y and DUB-C ? What are the settings on the front panel?

[digicube]

Yes DUB-Y and DUB-C connected. Here is a pic of the front panel.

[U-Matic]

Any alternative products with dps-295? It looks that unit is out off stock and the keystrobe costs me to much. I also bought a bvu-950 NTSC Modell and search a way to capture via Dub out because I read that's the best signal method to capture it. Also my Bvu has no internal TBC card inside and I read that this TBC won't work for dub out so thats why I need DPS I might and connect this with my dps575? Hope some can help thanks

[aramkolt]

295's come up for sale occasionally, I saw one on ebay posted a few days ago on ebay, but it apparently sold already. The problem with the DPS units is that there are no service manuals for them and lots of adjustments inside.

As far as alternatives, the rest are just as rare, but I've got an I.Den IVT-9Plus that will accept U-Matic dub that I was planning to list for sale, though chroma still needs to be fed into it via composite - which is also the case for the DPS-295 (and even the keystrobe dub optimizer actually). Same issue with the I.Den though - no service manuals out there to fully adjust them ideally. Some adjustments are clearly labeled as to what they are, but the order of adjustments and patterns that should be used during the adjustments are unknown. I did do some minor recapping to mine some suspect caps that looked to be slightly out of spec, but wasn't anything majorly off that I could see in-circuit anyway and the unit does pass a stable image.

The more common IVT-7 can also accept U-Matic dub signals, but it looks like it originally had a custom cable that grabbed chroma from composite at the player end and likely just had chroma presented as composite on the chroma pin of the 7 pin connector to the TBC side, but I haven't tested that to know for sure if it'll work with a custom dub connector cable. It could be that the custom cable had a way to passively filter out the DC component (luma) out of composite - leaving just the AC chroma portion?

You do NOT want an IVT-7P as that is the PAL variant and that does not work with NTSC signals.

Have you tried a capture with just the DPS575 over the composite output? If so, I'd be curious to see a sample of the result posted. Might give a better idea how much improvement you could expect with DUB as I'm not sure how good the 575 is with composite signals.

[U-Matic]

295's come up for sale occasionally, I saw one on ebay posted a few days ago on ebay, but it apparently sold already. The problem with the DPS units is that there are no service manuals for them and lots of adjustments inside.

As far as alternatives, the rest are just as rare, but I've got an I.Den IVT-9Plus that will accept U-Matic dub that I was planning to list for sale, though chroma still needs to be fed into it via composite - which is also the case for the DPS-295 (and even the keystrobe dub optimizer actually). Same issue with the I.Den though - no service manuals out there to fully adjust them ideally. Some adjustments are clearly labeled as to what they are, but the order of adjustments and patterns that should be used during the adjustments are unknown. I did do some minor recapping to mine some suspect caps that looked to be slightly out of spec, but wasn't anything majorly off that I could see in-circuit anyway and the unit does pass a stable image.

The more common IVT-7 can also accept U-Matic dub signals, but it looks like it originally had a custom cable that grabbed chroma from composite at the player end and likely just had chroma presented as composite on the chroma pin of the 7 pin connector to the TBC side, but I haven't tested that to know for sure if it'll work with a custom dub connector cable. It could be that the custom cable had a way to passively filter out the DC component (luma) out of composite - leaving just the AC chroma portion?

You do NOT want an IVT-7P as that is the PAL variant and that does not work with NTSC signals.

Have you tried a capture with just the DPS575 over the composite output? If so, I'd be curious to see a sample of the result posted. Might give a better idea how much improvement you could expect with DUB as I'm not sure how good the 575 is with composite signals.

Thanks for your Answer, I didn't know that I need go via composite into the dps-295 too. Thanks for the tip! Sounds at all a bit complicated, im not a pro and got here 800 U-matic tapes to digitize them in the best quality way. So I read you can get 15-25% better image quality if you go out with 7pin Dub into a TBC and capture the signal. Yes I have seen the DPS in eBay but was a bit late. And I try composite out in my dps575 but it looks that unit have problems with Umatic signals also I tested with my other unit the vo-9600 just been waiting next week for my bvu-950. Maybe it's better I find an internal TBC card for my Bvu and capture the signal from there. Hmm maybe you need a Waveform and vectorscope to adjust your unit?

Regards ayhan

[aramkolt]

Most adjustments like luma and chroma you can adjust using the proc amp settings from the front panel on the 295, it'd just be nicer if the default "zero" values were correct, though not required I suppose.

Hard to say if the other adjustments inside of the 295 or the I.den devices would actually improve the picture quality or not since we don't really know what they do without the service manual.

[U-Matic]

Most adjustments like luma and chroma you can adjust using the proc amp settings from the front panel on the 295, it'd just be nicer if the default "zero" values were correct, though not required I suppose.



Hard to say if the other adjustments inside of the 295 or the I.den devices would actually improve the picture quality or not since we don't really know what they do without the service manual.

A friend told me that about:
You need to make sure the levels are correct on the dps using scopes, Ire level video level chroma etc.

I am not sure about the iden - how much will that unit costs? On a other post I read you have U-Matic music videos? Are these maybe Rap or 90s Hip Hop Videos?

I also collect rap videos ^^

[aramkolt]

Yeah, you would typically adjust the output levels of whatever TBC you are using with a vectorscope/waveform monitor if you've got one. Technically, if the capture card you use has good automatic gain control, it should scale down the waveform so that brights don't clip, but VS/WFM can get you into the technically correct levels which should not clip whites or crush blacks. The issue is that not all automatic gain controls work the same, so you ideally don't want to rely on them. Each tape will likely have different output levels due to a variety of factors, so you can't quite set it and forget it with the proc amp when capturing the 800 tapes you've got haha. Color usually doesn't need much adjusting, but if your tape has color bars at the front as U-Matic often does, you can adjust the chroma phase (hue) and saturation to match the color bar targets within the scope as well. The IDEN also has proc amp controls as does your DPS575, so kind of up to you as to where you want to make the adjustments. The 575 does have a known issue where if luma comes in too hot that it'll just clip regardless of if you adjust it down afterwords, so you'd probably be better off doing most of the adjustment on the IDEN or whatever DUB to S-Video device you end up using. I believe the 575 clips around 115IRE or so which isn't too hard to exceed even with VHS.

I've got probably around 30 music videos on U-Matic, just random ones collected off of ebay. The idea was to put them on YouTube eventually as most should be better quality than the official music videos posted there, though I'm finding there's all kinds of copyright issues you could run into. I just figured any revenue would just go to the copyright holder and the video would still be allowed to be posted, but looks like not in at least some cases. What I haven't looked into is whether the videos are higher quality than what Apple has on their store - I'm guessing not, but would be interesting if they were better quality somehow.