The A/V Thread

Discussion in '-off topic-' started by Madmoiselle_Silk, Apr 17, 2018.

  1. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Fri May 27, 2022 8:28 am

    cardy wrote:
    I think it kind of lines up with today's prices actually - a broken junk Dragon will run $1500-2000 and an actual tested working one is $4000-infinity.

    cardy wrote:
    I got it on Ebay from a new 0-feedback seller who had a low BIN on it - I think they didn't know quite what they had.
    A huge gamble obviously, but the price was right. And if I can't fix it I'll flip it right back onto the junk market ::cred::
    The serial number is somewhat low but not in the "unserviceable/defective" range, and the previous servicer noted it as a "high mileage" unit. We'll see how it turns out.
     
  2. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Fri May 27, 2022 10:38 am

    flowersofnight wrote:
    I made a similar risk when I bought the Nakamichi DR-1 off a seller on ebay Germany.
    It was 100s less than the average price but the seller had perfect feedback and more importantly wasn't a typical electronics flipper who just sell anything that turns on as 'working'.


    I didn't know about Dragons being unserviceable or defective....I have to keep that in mind if I ever decide to look for one.
     
  3. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Fri May 27, 2022 11:13 am

    cardy wrote:
    All the Nakamichis seem to have "particularities" as they got revised over the years. The first Dragons (serial # less than 4000 or so) had all kinds of defects and had to be modified by hand at the factory before going out, or something like that. None of the servicers will touch one that old.
    Between 4000 and 8000 I think are "weird" in various ways and difficult but not impossible to service. The newest ones are in the 30000s.
    Mine is in the low 10000s, so it's old but out of the danger zone at least.

    The CR-70 is another model I have my eye on. It got revised twice, once to change the EQ circuitry and then again to switch from a tire idler (like the accursed one in the Dragon) to a gear idler. You want one with a serial number over 10000.
     
  4. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Thu Jun 2, 2022 10:59 pm

    I am now reaching the point of deep distrust in Dragons.

    Cheap DR-2 (calibrated by me) playing a 3kHz W&F test tape:

    upload_2022-6-2_22-49-58.png

    Dragon playing the same tape (at a higher volume):

    upload_2022-6-2_22-49-23.png

    It seems like the NAAC (auto azimuth control) is out of whack, despite seeming to operate. Phase is all over the place and beats are audible.
    But when I turn the unit on its side to access the NAAC control potentiometers, it refuses to play. It only plays lying flat in the ordinary position, and reverse-play doesn't work at all in any orientation.
    I suspect there are some tension/back-tension issues but you need a special test tape to even begin to troubleshoot that. I might try getting one, but I can't say I have much faith in this unit to get calibrated and stay calibrated.

    On the plus side, wow and flutter measurements are excellent, better than the DR-2 by about as much as you'd expect it to be. (0.05% for DR-2 vs 0.035% for Dragon)
     
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  5. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Mon Jun 6, 2022 12:45 am

    More on mysterious 15.7kHz noise, this time on VHS.

    From best to worst:

    1: A Pearl Jam music video tape that I just bought new in shrinkwrap specifically to test this. A faint ghost of the 15kHz line, frequency content all the way up to the limit (all these samples are recorded at 48k for a maximum frequency of 24kHz)
    pearljam-15khz.png

    2: Malice Mizer's "shinwa". A major-label release, I obtained it secondhand. A slightly stronger 15kHz line, good frequency response.

    shinwa-15khz.png


    3: Pride of mind's live video. A total indies release, from 1994 and probably played any number of times before I got it. Strong line at 15kHz, musical content over 14kHz seems minimal.

    pomrelease-15khz.png


    4: The review (?) copy of that same Pride of mind video, dubbed by an unknown party onto S-VHS along with some live clips. Absolutely ghastly 15kHz noise during the first part (the live performance), then a fainter line in the clips section.

    pomsvhs-15khz.png

    5: Zooming in on the "transition" area of the review tape.

    pomsvhs-15khz-transfer.png

    The heavy line stops at the end of the first dub, then after that we see a fainter line that persists through the nonsense junk in between clips, a blank spot, and then the live clips. It never quite disappears entirely though.

    Found a few references online about this and it looks like even the pros just let this CRT noise slip in:
    https://forums.stevehoffman.tv/threads/15-6khz-interference.592609/
    https://www.reddit.com/r/audioengin...s_up_with_this_spike_at_around_157khz_on_the/

    The most obvious test which I didn't think to try: just get a brand-new blank tape.
     
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  6. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Wed Jun 8, 2022 6:49 pm

    flowersofnight wrote:
    I was away for a good week and now I'm reading everything and trying to unpack it all. I never quite figured out these test tapes.
    I've always just been judging my transfers by ear and twiddling the azimuth knob and either keeping it at the default or turning it up a bit.

    I probably should look into these testing tapes but I'm sure that'll send me down another rabbit hole.

    flowersofnight wrote:

    I haven't read through the links you provided yet but just at a glance and I'm somewhat shocked I never knew of this issue before. This will definitely haunt me and I'll be looking at it everywhere. I already opened a few official VHS tapes and see that line. It isn't audible but it's there.

    I just happened to open a file today of a record I transferred that was released in 1984 and the whole 20 minute B-side has that 15.7khz line. I'm trying to figure out how that happened. Was there a CRT monitor in the recording studio while that song was being mastered!?

    I need to start opening up transfers of copied VHS tapes with unknown generations to see if that dreaded line exists and if it actually has an audible effect when it's more visually pronounced.
     
  7. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Wed Jun 8, 2022 7:13 pm

    cardy wrote:
    For ordinary calibration, I got these which seem to be just fine:
    https://www.ebay.com/itm/284796150534

    For extraordinary calibration, I think I might need this:
    https://www.ebay.com/itm/185445644869
    But the seller hasn't accepted any of my best offers. Why have a best offer button if you're not going to give me a break already? ::cred::

    cardy wrote:
    Well that's kind of the thiiiing, most people can't hear that frequency at all, especially not people old enough to remember what a VHS is XD I expect nobody working on the mastering of these things was able to hear it either. If they were even listening back through equipment that could reproduce that frequency.

    When I was a little kid I could sort of hear the 15.7kHz noise on poorly maintained TVs, there was one in a local McDonalds that would give me a headache. It wasn't even a sound really, just a kind of... something.
     
  8. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Fri Jun 10, 2022 6:59 pm

    I might have to get that first set of tapes to see how my Nak is doing.
    Part of me is afraid though that my deck might be off which will surely send me down that spiral of "I need to transfer everything all over again!"

    I used to hear that frequency coming from CRTs. I could almost immediately notice it walking into a house / store / place that a television was on even if I couldn't see where it was or even hear it. And now that I think about it, I vaguely remember shopping malls having lots of CRTs in store windows without sound playing and there was always a constant hum.
    I was never sure if I stopped hearing it because I got older and my ears became less sensitive or if it was because mostly all CRTs disappeared by the mid 00's never to be seen again. Funny how they've become sought after in the old-school gamer world.
     
    Last edited: Jun 10, 2022
  9. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Fri Jun 10, 2022 7:35 pm

    cardy wrote:
    My DR-2 also needed the output levels adjusted, the right/left weren't even the same.
    To really get the most out of those tapes you'll need to get some banana-plug-to-RCA cables and use a multimeter to examine each channel's output.
     
  10. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Thu Jun 16, 2022 10:18 pm

    Today in A/V Horrification: stroboscopic analysis indicates that my old turntable ran too fast. Way too fast.

    strobe.gif

    If the speed was correct, those "33" numbers would be holding completely still.

    Battery-powered 60Hz strobe here: https://elusivedisc.com/kab-speedstrobe-turntable-speed-tester-strobe-disc-test-light/
    Alternatively, you can save some money if you get a strobe light that plugs into the wall and print out a paper disc.
     
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  11. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Wed Jun 22, 2022 6:38 am

    flowersofnight wrote:
    My DR-1 has a slight volume difference between the left and right channels. It's about 1db or so and I simply just raise the volume in post.
    Not sure if that's cheating or if it should really be matched when outputting from the hardware.

    I still need to look into those calibration tapes. I want to get them but I'm afraid of starting another project when I haven't finished so many.

    Just in the last day or two, I decided to transfer these 8mm tapes again of a Japanese band called 'False Love'. The lead singer graciously sent me her master video tapes with the intention of digitizing them. The quality is amazing for what is analog video from 1991 to 1993. It probably helps that I have the original masters and that they weren't probably played that much. There's literally no funny playback issues at all which goes to show what a good master tape can bring you.

    I already transferred these tapes once last year and used the fabled DataVideo TBC-1000 but then I realized that device actually darkens the signal and posterizes the shadows a bit. For most bright scenes it doesn't matter but most of these tapes are shot in dark clubs so I realized I lost precious detail / signal.
    So now I'm transferring all 13 tapes without the device just to be safe as I plan to send back the tapes when I'm done.

    That deck between the camcorder and USB capture card is a Panasonic ES10 DVD recorder which functions as a quasi TBC on analog signals. It can actually help minimize or get rid of tracking issues on VHS tapes that the DataVideo TBC-1000 can't.

    20220622_122642.jpg


    flowersofnight wrote:
    My old cheapo record player from 15 years ago which I got as a gift was a DJ style model which had this pitch shifting slider which adjusted the speed. It would have been fun if I was into that sort of thing but in terms of accurate playback, it was always off despite having the slider set in the default / off position.

    When I finally upgraded my player last year, I bought this Rega Neo PSU which supposedly provides cleaner power and helps with the speed playback.
    I was comfortable thinking that it could accurately play 33 1/3rd or 45 rpms with a press of a button but now I just looked at their website and found out they too have Strobe kit' which they describe as:

    "Designed as the perfect partner for the speed adjustable Rega Neo PSU."

    I'm sure it's still pretty accurate but it's potentially yet another project for this hobby which consumes too much off my time already :)
     
    Last edited: Jun 22, 2022
  12. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Wed Jun 22, 2022 12:07 pm

    cardy wrote:
    I assume it's fine, if you know exactly how much to change the levels by, but how do you know it's not just the original tape that's "lopsided"? (All the Malice Mizer "Sans Logique" tapes out there seem to be genuinely unbalanced, for example - maybe because they're all copies made through 20 generations of lopsided Nakamichis ::meev::)
    I think to figure out the correct % to raise the volume you'd have to use a calibration tape anyway, and if you're going that far you might as well just calibrate it.
    The output level is the easiest hardware adjustment of them all, all you have to do is take the lid off and use a + screwdriver to adjust the pots.
    By the way, in case anyone here doesn't already know about free service manuals: https://webspareparts.com/collections/free-service-manuals
    I've been printing out the relevant ones and putting them in a 3-ring binder.

    cardy wrote:
    Previously I had just been using the line TBC on my Mitsubishi deck but the new (old) Sony SVP5600 I got has a full-frame TBC built in. Seems to work well, though I haven't given it a genuinely challenging tape yet. The only downside is that it won't play anything that's not SP.
    I'm kind of shocked that the TBC-1000 isn't transparent when it comes to video quality. Wasn't this supposed to have been professional gear? I wonder if it needs recapping or something.

    cardy wrote:
    I'm guessing it's fine unless you did a lot of customizations and swapped in some 5kg platter or something. My new thing here is a Fluance RT82 which is about as cheap as you can get in the "audiophile" segment, and its speed was dead-on for 33s without any adjustments needed. (45s seem very slightly off) I think they calibrate it at the factory if they expect anyone might actually check, whereas with the consumer stuff (like in my picture above) they just let it go out the door with a +/- 10% tolerance or whatever.
     
  13. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Tue Jun 28, 2022 9:59 am

    flowersofnight wrote:
    When I had the Nakamichi DR-3 I transferred a few tapes and then transferred them again when I got the DR-1.
    All of those tapes are consistently lower in one channel with the DR-1. So I chalk it up to being the player.

    I downloaded the service manual for the DR-1 and the exploded views of the inside scare me and I feel like if I ever attempted to open mine, I'd never be able to put it back in working order.
    For now, I just bump up that right channel 1db or so.

    flowersofnight wrote:
    I just assume whenever there is signal alteration / modulation, the output will always differ slightly from the input. So I'm not sure if this slight darkening is normal or a defect now.
    It really is not that horrible and to most eyes probably wouldn't be a big deal I think. I have to pick and choose my battles. For tapes that need more help, I'll keep the TBC1000 in the chain, with the case of these master tapes, they weren't played back much and are very stable so I can play them without the TBC. Here's a quick screen capture showing two versions of this capture. The video is being shown at 200% scale. The darker frames are the ones which used the TBC1000.

    https://mega.nz/file/9RxRXZIB#gAQVBNym2NYulRImDRZewzFMkDrfnK06fSYeDm-nxws

    If I remember correctly, the TBC-1000 was one of the cheapest entry level full frame TBCs and was consumer-grade. It was $300 or so when I bought it in 2003 and I think more professional level ones were much more expensive and even rack-based pieces of hardware.


    flowersofnight wrote:

    I didn't customize it much besides the needle being added to it which required the arm to have more weights to be added. So far most of my recordings sound pretty good. I'll have to A-B check one day to find out. So far...when I've compared against specific songs or albums that appeared in CD form, my track lengths are pretty spot on. I'll keep telling myself that for now as I don't want to find out otherwise! The ol' head in the sand technique :)
     
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  14. flowersofnight -moderator- -moderator-

    flowersofnight
    Joined: 04 Aug 2004
    Posts: 13284
    Location: Vintage Live House, 1994
    Posted: Tue Jun 28, 2022 11:53 am

    cardy wrote:
    If the DR-1 is anything like the DR-2 you don't actually have to touch any of that stuff or disassemble the whole mechanism, all the adjustable pots are bright orange and right out in the open, apart from the one inside the motor. Between that and the adjustment gears under the tape heads you can get a lot done. It certainly helps that I don't care about the record or erase heads so I can skip all those calibrations XD
    The Dragon, on the other hand, really is that miserable. I haven't gone back for another try at it yet or bought any torque gauges.

    cardy wrote:
    You had me convinced at the very first "flip". :shock:

    cardy wrote:
    And now it's worth $4000 ::cred::
     
  15. cardy -member- -member-

    cardy
    Joined: 03 Nov 2004
    Posts: 328
    Posted: Fri Jul 1, 2022 5:35 am

    flowersofnight wrote:
    Adjustable pots doesn't sound so intimidating. I'll have to crack it open one day.

    Have you thought about bringing the Dragon to an hi-fi shop to get officially repaired? Or is the price for repairs just too much to get it in working order?


    flowersofnight wrote:
    I haven't seen it go for that much....last time I checked they go for $1500-2000 on ebay.
    Still crazy but I guess the rules of supply & demand dictate the price.

    It reminds me of when I worked at ad agency in the late 00's. The video dubbing room had tons of old rack-based video equipment, VHS, Beta, probably TBCs, that hadn't been used in years at that point since mastering to DVDs was the way to deliver. They eventually just got rid of all that gear. At the time, my VHS capturing days were in hibernation mode and I didn't even attempt to grab anything. Ah, the regrets in life!

    And if anyone reading this is ever looking for video gear, the forums of digitalfaq.com is a great place to find things. Of course, those TBC's get snapped up quickly and aren't that much cheaper than ebay prices but what you do get is knowing the hardware's history and its usage.
    http://www.digitalfaq.com/forum/marketplace/