Testing the legendary DPS-375SP digital timebase corrector

[@TomHansonKNVPStudios]

Another gotcha when using a VTR as a converter whilst testing analog signals through it, would be ensure that the proc-amp on the VTR itself is all in UNITY or PRESET, so that you are not inadvertently making additional adjustments through the VTR (proc-amp is found by pulling the front faceplate on the DVW-A500 out, and the encoders are along the top)

[@video99couk]

Good point. They are all set to PRESET rather than MANUAL on both of the DigiBeta machines used in this video.

[@andydelle4509]

One thing about tantalum capacitors is they are either perfectly good or shorted. They don't lose capacitance with age like electrolytics do. Unfortunately they are most often used as power supply bypass capacitors and when they do short out with higher current power supplies they can do a lot of PC board damage. And it's possible to start a fire as well. I have two Ampex 1982 VPR2s that are full of them. No failures to date.

[@video99couk]

I remember back in the 1980s when I worked in an electronic manufacturing company, they would never decouple a supply with a tantalum unless there was an inrush protection resistance. But it seems that policy was not universally applied.

[@nonsuch]

So, I ended up with a piece of gear called a "VIDEOTEK VSG-204D 601 Digital Sync Generator". I have no idea what it is or what it does but, for some strange reason, I bet you do! 😁. I'm assuming it syncs audio and video being that it has a total of 14 BNC connectors and 4 male XLR sockets. The BNCs are labeled: REF. IN 1-2, BLACK 1-4, 48KHz, 27MHz, TEST SIGNAL 1-2, DIG. BLACK 1-2, and ABS/EBU 1-2 3-4. The XLR male sockets are labeled: AES/EBU 1-2 3-4, and ANALOG 1-2 3-4. It's looks identical in dimensions to the DPS-375SP you're showing. No relevance why I'm mentioning it, it just seems like a piece of gear right up your alley. If I was close by, I'd give it to you. Cheers! 🥂

[@wdavem]

Wow synchronicity, Im fixing a 475 and am setting up processing for an archive and am looking into this thing kind of sort known as SC - RF but not really. You might want to connect a BVT800p to the right deck, if you don't mind 8 bit... just a hint!!! I'm looking into some mods that are just barely over my head at this moment, might be a while but I'll possibly cook up some secrets for applying umatic processing to vhs. Research in progress. If I've got some secrets in the future I should probably share them. No promises, part of it's a steep climb for me.

[@bjarneanthony1363]

Hey Collin i clean a DVD combi the DVD stop meny times i lay Some fat were the laser linz run now its run fine its a Lumatron year 2004 :)

[@scott7305]

This may be quite a hard question to answer, but what would you say is the most reliable tape format? I own a nice Betacam Sp camera and deck and I haven’t had any problems, this technology really is quite remarkable for being 30+ years old.

[@video99couk]

For professional use, both BetacamSP and Digital Betacam machines are very well made and reliable. Panasonic professional machines (MII, DVCPRO) are horrible.

[@tekvax01]

If memory serves; the white chip on the DPS full frame colour bars is 77% IRE and not 100% IRE. So there is the difference between the two bar generators.

[@tekvax01]

You can assemble your own dub cables, you only need to buy the appropriate Hirose connectors. Digikey sells them. RM12BPE-7S(71) / HR1740-ND/1125541 and RM12BPE-7PH(71) / HR1734-ND / 1125535

[@TTVEaGMXde]

Do you know what the "glorious" parcel company from the USA is called ?

[@video99couk]

Fedex lost it, apparently.

[@MichaelWesseling-dd4uf]

What a shame to hear, they are so hard to find.

[@cbehr91]

American here. The only package I've ever had lost was courtesy FedEx as well.

[@wdavem]

Great VIdeo!

[@SPINNINGMYWHEELS777]

when you took the lid off wow a serious piece of kit !!! can it not be done on a local chip board in 2023 ? all those components look discreet ! :) Sweet deal .

[@Capturing-Memories]

Now the special delivery moment is very predictable, Need some changes to keep it interesting. Just kidding, still love it.

[@rsuryase]

I have a DPS 295 NTSC and the output picture has a greenish tint. Changing the chroma, luminance and hue level doesn't fix the problem. I read it's because the capacitors are bad.

[@video99couk]

Quite possible. But there are a lot of capacitors so you will need a bit of help to locate the correct area. If it's no longer of use to you, let me know because I would love to play with it.

[@bjarneanthony1363]

After meny years i think the fat dry out so if you have Some DVD combi just put Some fat were the laser linz run and your combi run fine.

[@bobsbits5357]

hi you know them plugs i see alot of them the man i got the video's of had looms with them on i forgot to ask him about the dubb leads i was in a hurry at the time hell alot of heavy gear we have around

[@tekvax01]

The stop button lamp is flashing on the VTR. This means you don't have a good black reference signal present.

[@video99couk]

Fixed that at 14:47 onwards.

[@tekvax01]

@@video99coukI saw that after I posted the comment... :)

[@SFtheGreat]

I could use a Dub out...

[@bobsbits5357]

hi ask phil at the cinema museum london he come's in to things like this time to time he deals with old video dubbing studio buy outs got to high vhs from him as parts

[@tekvax01]

From an Operational and Engineering point of view, these DPS TBCs were beyond annoying to time, and adjust. The coincident H and SC course and fine controls meant you could always get the timing close, but never exact, as the timing moved lock step together when adjusting it; forget having the SC/h phase correct, without several attempts, always needing to split the difference, from close, to almost close enough. There were much better TBCs around that did dub cables as well. We e-wasted dozens of these old-style DPS-x75s because you could never get schematics, or parts to repair them. Horrid units...

[@video99couk]

They are worth a mint now! Not many TBCs do Dub, there were some For-A units but they have their own problems.

[@tekvax01]

@@video99couk if only I hadn't listened to my boss and tossed them out! :)