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Adjusting the audio output on Beta SP UVW1800

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jay agoglia
Adjusting the audio output on Beta SP UVW1800
on Jun 17, 2011 at 4:15:21 pm

Hello,

I would like to know how to adjust the audio output on a Sony UVW 1800 Beta SP VTR.

I figured the best way is to dub a bars and tone test signal onto tape at 0vu and then calibrate the VTRs when playing back the tape to 0vu.

any direction is very much appreciated.

thank you!

-Jason A


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Chuck Pullen
Re: Adjusting the audio output on Beta SP UVW1800
on Jun 17, 2011 at 4:31:18 pm

That works, but if you need to continually adjust audio on tapes, you will have to run it through a mini-mixer… Or you can drill holes in the front and attach sticks to the pots like an engineer did to our MC decks at my old station.

Chuck


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Bob Zelin
Re: Adjusting the audio output on Beta SP UVW1800
on Jun 19, 2011 at 3:46:19 pm

Hi Jay -
you are not going to accomplish what you want. This is called a critical audio calibration, and it will not happen on the UVW series of Beta VTR's. The previous suggestion of using an external mixer is the only way to accomplish what you want.

Back in the stone age of the BVW series Beta machines, these were professional machines. Not only did they have both playback and record knobs on the front of the VTR, but if you lifted up the top cover of the VTR, there were small white potentiometers, that allowed you to calibrate the PRESETS (when you would push the play and record knobs in), so you could have a perfectly calibrated machine.

Then they released the cheaper PVW-2800 Beta VTR series. This machine did not have the presets that you could tweek under the front cover, and you had to adjust the boards to get a critical record and playback calibration - so that 0VU in matched 0VU out.

I believe this is what chuck is refering to, drilling holes in the machine to get easy access to the tweeks - the PVW series, not the UVW series.

When the UVW series came out, it was considered a piece of junk, and the BVW and the PVW were both still being sold. The UVW was made as an "industrial/educational" player recorder, but of course, everyone wanted the cheaper machine, and people stopped buying the more expensive BVW and PVW Beta VTRs.

The UVW had no ability to even adjust the playback level on the front of the machine, AND the analog averaging meters on the front panel of the machine were extremely inaccurate, driving people nuts when they would look at the LED VU's, and say "my audio level is so low when it plays back" - when in fact is was fairly accurate - you could only see accurate levels with 1K tone, not with average audio level from actual playback.

So the direct answer to your question is YOU ARE NEVER GOING TO BE ABLE TO CALIBRATE the UVW-1800 to have the audio levels match for playback and record. Chuck accurately said that you should be using an external mixer, to adjust your levels into your analog source.

AND - in 2011, why on earth are you using a Beta VTR, and worrying about analog audio calibration. All modern VTR's are barely used, and the MODERN ones have embedded audio into the SDI stream.

I have been doing this for a long time, and at a certain point (like now), you just have to let go of the old crap. Even when the UVW-1800 was a brand new machine, you could never perfectly calibrate this VTR (I own an analog dBm meter, so I know exactly what was going on back then). And most people today import files from cameras, and are not even using SDI VTR's.

You will find the same thing applies to inexpensive audio mixers. At one time there were wonderful, expensive analog audio mixers, that could be calibrated. When the Mackie was introduced, which then led to the parade of crap that was released on the market from Behringer, Soundcraft, Yamaha, Tascam, etc. all for under $1000 (and now $129), people said "hey, how come my meters don't match on all my machines (like a UVW-1800 and a Behringer 2442FX mixer). BECAUSE ITS ALL CRAP CHEAP EQUIPMENT. You want the good stuff, you buy the good stuff, that you can calibrate.

But alas, all of this is moot, as almost no one is working with older analog gear. Today, with embedded audio, you dont' have to worry about all this stuff. I have not used my analog dBm meter to do an audio calibration in LONG time.

Bob Zelin
ps - if you wind up trying it yourself anyway (which will require a UVW-1800 service manual), you will find that there is more than playback and record calibration. You put in a calibration tape with bars and tone (which I am sure you dont' have) to aligh your playback. Then you put in a 0VU (+4dBv) audio tone signal into each channel, and align the E/E level coming into the machine. THEN you pop in a blank tape, and align the CONFIDENCE LEVEL, because one you hit the play and record buttons on the SONY VTR, you will see that the audio level changes (thus - the confidence record adjustment). THEN, once that it done, you play back your tone signal, and THEN adjust your playback level to read 0VU. AND THEN, if you monitor the output of the VTR, even though the meter shows 0VU, the output may not be putting out a +4dBu signal. On the rear of the machines (only on the BVW, PVW, 1" VTR's, etc, not the UVW), there is a line driver amplifier for the XLR connector that can be tweeked, to perfectly match the output to +4dBu, so that when you go into another calibrated product, it too will show 0VU.

A pain in the ass - huh ? But it kept me employed for a lot of years doing that !

Bob Zelin



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Bob Zelin
Re: Adjusting the audio output on Beta SP UVW1800
on Jun 19, 2011 at 3:56:24 pm

by the way, to do this test (once you get a Beta VTR or other stable source), you can take the COMPOSITE VIDEO OUT of the Beta VTR, and feed this into the Reference Input of the Blackmagic card. This will do the same thing as a Black Gen, as all it's looking for is a stable sync signal. When you put in a Black Gen, all it's doing is stripping off the sync signal from the Black - so you can stick anything in there - BUT NOT YOUR VHS MACHINE (or 3/4" machine) video ! You MUST have a STABLE rock solid reference, and VHS, Betamax, Hi8 or 3/4" WILL NOT DO. If you work with sources like this on a daily basis, you MUST have a frame synchronizer to accomplish your work - anything from a cheap DataVideo to a wonderful AJA FS1

Bob Zelin



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Chuck Pullen
Re: Adjusting the audio output on Beta SP UVW1800
on Jun 19, 2011 at 6:23:28 pm

I believe you are correct Bob it must have been a PVW series, but that was in jest Jay...Please don't drill holes in your deck!

As always Bob is 110% correct, and I completely agree with everything he has told you.

Depending on your setup, I always had a 1RU 4 channel audio mixer that we would always mount in the rack with the 1800's, I think they are around $100.

Chuck


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jay agoglia
Re: Adjusting the audio output on Beta SP UVW1800
on Jun 20, 2011 at 7:03:45 pm

Thank You Bob and Chuck for all the info. ,

I wanted to calibrate these machines as a learning process and felt it was something that should be done (0vu IN = 0vu OUT) and could be done easily. I guess I was wrong!

We never output from the beta decks or digitize from beta tapes anyway. We dub spots onto beta tapes and ship them out to TV stations across the country.

Yes they are pieces of junk that are far to old. while we focus on digital delivery we still have a couple of hundred stations that take beta sp tapes.

I will certainly focus my attention elsewhere. But a raising concern is that the VU meters on the front of the UVW1800 are extremely unreliable. As we are starting to adhere to the CALM act ..this is an issue.

Right now i am using the VU meter on the 1800 series in combination with the digital peak meters on the DIGI beta deck to monitor the audio on our commercial spots (the spots being adjusted from the flip factory first).

I guess will have to add a dependable VU meter to this equation.

Chuck I will not drill holes and no desire to!.

thanks guys!!

-jay


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mohammad chaudhry
Re: Adjusting the audio output on Beta SP UVW1800
on Sep 1, 2012 at 3:19:58 pm

I have problem with channel 1 audio crash on play back on beta sp uvw1800.I record with colour bars both levels good ballance on uv meters. But when i play back audio on 1 channel goes too high (crashing) and audio on 2 channel remains good. When i play any old recorded tape audio on both channels show good level. Any idea what can cause this? Previously this machine had been recording good. This happened just recently. Does the head needs to be cleaned or something else. anybody's help will be appreciated.

Mohammad


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Bruce Little
Re: Adjusting the audio output on Beta SP UVW1800
on Oct 7, 2012 at 1:43:10 am

Agreed that the UVW's are/were pretty crappy, but I am also curious if there is a way, even taking the top off to adjust the output levels of the 1800/1600 series VTR's? I had to drag out an old deck from the storage room and have noticed that the levels coming out of the deck are too hot, channel 1 is clipping the input of my mixer, and it's trimmed all the way down.
Any thoughts?
thanks
Bruce


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