oscillators

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antispatula

antispatula

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I've been looking in my manual and it says to adjust my input and vu meter levels, I need an oscillator that can read -18db. I'm not all too familiar with oscillators, do all or most of them have a knob that I can use to find the specific db that I need it to be at? Any suggestions? Thanks!
 
Are you sure it's not a typo that's supposed to read -10db??

.......................;)
 
To try & answer your question,...

Oscillators come in many different configurations. Some have knobs, some have buttons, and some come at fixed frequencies with neither. Rule of thumb, is that the better & more expensive oscillators have knobs & switches, the lower end oscillators probably have buttons. The cheapie-cheap oscillators have neither.;) It kinda spans the range.

SEE: Fostex TT-15, ~$50
 

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See:...

Hewlett Packard 202C Oscillator:....
 

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See:...

HP 200CD Oscillator...........;)
 

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hey thanks dave

MAN those old hps are huge. For the output, it doesn't even read in db though.....

I DOUBT it's a typo, the only typo I've found in the manual is "OUTPAUT" :D

And another reason I doubt it's a typo is because I've read that for Mx 5050's of all marks, when you're adjusting the Input/ VU meters, you want to have the 1kh signal be 10 db below what the inputs take, which on my machine is -8 db, which I don't get, since I thought unbalanced equipment were set at -10. This whole calibration thing makes no sense, I'll proabibly just start recording with it even though I can't fully calibrate it, I mean, it sounds great as it is. But don't think that doesn't mean I may not need your help in a few weeks! ;) I don't know what I'm going to do about all these calibration mysteries, I'm waaaaay to braindead today to think sanely at the moment :D
 
There are a number of programs that will turn your PC audio card into a signal generator. It will be more than good enough to calibrate your tape deck.

You will be able to set the specified frequency and adjust the output to get the voltage you need.

Tascam line levels at 0VU are -10 dB as referenced to 1Volt. This equates to a 0.316 volt signal.

OH, they are free too.

Google for BIP Sine wave generator or NCH tone generator. Then just use an adaptor plug from your audio out to RCA jacks.
 
Okay,...

but how do you know the output of your soundcard is the correct/calibrated level?

Anti,... the Fostex is modern & small, and those HP's are huge dinosaurs. There's that & e'thing in between.

If your deck has an oscillator, then it should be used. ;)

I really don't get all the numbers you're referencing. I'd have to view the spec sheet & manual text. Somethin's goofy. :eek: ;)
 
A Reel Person said:
but how do you know the output of your soundcard is the correct/calibrated level?
Click to expand...

could a voltage meter check this?
 
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You measure it to verify the correct voltage level. You still have to measure the output of your hardware signal generator unless it has a calibrated output and is in cal. (of course you meter may be off too....)

Just like ou decks have to be calibrated to a known source (MRL tape) out instruments have to calibrated (ar at least referenced) to a known source.

In this case we assume that the voltage meter is accurate.

By the way, I alwayse liked the big dial on those old HP signal generators.
 
evm1024 said:
You measure it to verify the correct voltage level. You still have to measure the output of your hardware signal generator unless it has a calibrated output and is in cal. (of course you meter may be off too....)
....
In this case we assume that the voltage meter is accurate.
Click to expand...

if you have measured the signal and it is the correct voltage level; why would you still have to measure this output? I am so lost by this...

..Am I wrong in thinking that if we couldn't make this assumption then nothing would be possible at all?
 
Mighty big oscillator pics on this thread. Here's another.
 

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The Otari recorder is unbalanced +4.

Hope that helps to shed some light on this.
 
Today when you see unbalanced, yes that will mean -10.

But this is from the 80's, which means things were different like this.
 
I use the Fostex TT-15. It's not much bigger than a deck of cards... really is pocket size. It can be switched to 0, -10 or -30 dB. I see them on eBay now and then.


:)
 

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Another one to look for is the TEAC TO-122A. It has the same frequencies and settings as the Fostex.

:)
 

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my recorder says it needs to be at a -18db level though....I found one for free download actually. It has everything I need. I just don't know how I'm going to hook it up to my recorder. The recorder take an unbalanced 1/4" for the osc. and how would I hook it up from the comp? Are the 1/8" out on my soundcard balanced? And wouldn't going from my computer to my recorder change the level? Crap, I think I'm not even to try and do any of this.
 
antispatula said:
my recorder says it needs to be at a -18db level though....I found one for free download actually. It has everything I need. I just don't know how I'm going to hook it up to my recorder. The recorder take an unbalanced 1/4" for the osc. and how would I hook it up from the comp? Are the 1/8" out on my soundcard balanced? And wouldn't going from my computer to my recorder change the level? Crap, I think I'm not even to try and do any of this.
Click to expand...

That -18 dB is a new one on me.
 
the 1/8" output on your soundcard is unbalanced stereo. you could make a cable. this keeps getting more stressful for you dude. I would maybe make a goal for yourself to get it calibrated a month from now or something, so that you can take your time with it.
 
antispatula said:
my recorder says it needs to be at a -18db level though....I found one for free download actually. It has everything I need. I just don't know how I'm going to hook it up to my recorder. The recorder take an unbalanced 1/4" for the osc. and how would I hook it up from the comp? Are the 1/8" out on my soundcard balanced? And wouldn't going from my computer to my recorder change the level? Crap, I think I'm not even to try and do any of this.
Click to expand...

The soundcard is unbalanced sterio. You can buy a 1/8" sterio to dual RCA cable from radioshack. If it has the typical 3 pin balanced type connectors onthe deck you can build a cable.

Don't sweat it.
 
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