sound device 302 setting

[Pete Cofrancesco]

Can anyone explain the Meter Ref Level setting. The manual says its set to 0vu=0dbu which is optimal for digital recording and suggests using 4dbu for analog. I'm feeding my video camera. Does this constitute analog? In layman terms what does this setting do? Does it effect the level or just what is displayed?

Also is there any control of the line level out? Can you increase it so the camera use less of its amplifier.

[Steve House]

Originally Posted by Pete Cofrancesco

Can anyone explain the Meter Ref Level setting. The manual says its set to 0vu=0dbu which is optimal for digital recording and suggests using 4dbu for analog. I'm feeding my video camera. Does this constitute analog? In layman terms what does this setting do? Does it effect the level or just what is displayed?

Also is there any control of the line level out? Can you increase it so the camera use less of its amplifier.

You're looking at the meter calibration here. 0dBVU=0dBU means that when the meter reads 0VU the mixer is putting out a signal that is 0dBU. Remember the "dBU" indicate a particular signal level referenced to a standard "0dBU" level of 0.775 volts while dBVU are purely relative. So when the meter reads 0VU the mixer is sending a 0.775 volt signal. It's almost as if the term "0VU" meant "norrmal design operating level" and it can be almost any voltage that the device designer wanted it to be.Changing to the suggested analog setting in the setup menu does not change the actual output level, it just changes how the meter lines up to it so that when the mixer is outputting a 0dBU signal, the meter reads -4dBVU or viewed another way, when the meter reads 0VU the mixer is outputting +4dBU. You camera is a digital recording device so SDs default setting is appropriate. Leave 0dBVU=0dBU and calibrate the camera audio input setting so the camera's meter reads -18dBFS or -20dBFS when fed a 0VU tone signal from the 302.

No way to increase the line level output from the mixer, though there is an attenuation setting in the setup menu that can pad down the outputs to decrease the nominal output level to make it easier to match mic level inputs, -10dBV consumer devices, or instrument level inputs.

[Pete Cofrancesco]

Thx for in depth answer, I'll keep the defaults. Btw, it's a great mixer. The sound quality, features and design live up to SD's great reputation. Finally had the resource to upgrade. My only complaint, the power supply wasn't included and was almost $100.

[Richard Crowley]

You did not identify your video camera, but it seems highly unlikely that it is analog unless it is a working antique.

The switch you are referring to sets the meter reading vs. the output signal level. Actually the "+4" setting will output a hotter signal (by 4db) for any given meter indication.

However, if you are sending line-level to your (unidentified) camera, you are already using "less of its amplifier", and increasing the line level won't be of any significant value.

Sound Devices is about as good as it gets. Little (if any) audio equipment is better.

Professional equipment like your SD 302 are designed to operate from a variety of power sources. There is nothing magic about a power supply from Sound Devices. Power is power (within reason). The only magic involved is the 4-pin Hirose power connector (available from SD and other places) if you want to use a cheap power supply from Radio Shack, etc.

[James Kuhn]

Pete...I use a Switronix 14.8 VDC battery distributed through a Remote-Audio Battery Distribution System (BDS). I also power my PMD-661 digital recorder from the same battery. I mention this as a portable alternative to AC power. This is not a cheap modification, though.

Regards,

J.

[Pete Cofrancesco]

I'm just complaining that a mixer of this cost should have included it. Since I didn't realize it wasn't included I had to put a special order for it that will take a couple of weeks to arrive. I decided not to cut corners on the psu because I've had generics fail. A electronic device is only reliable as its weakest link. Btw, I need ac because depos i do can go for 7hrs

[Allan Black]

Pete, don't leave any AA batteries installed in your 302 and forget 'em, when you run on AC.
7 hrs huh .. watch out for dirty power in old venues, maybe carry a small AC smoothing device.

You won't find any better limiters on any gear either, the best since the Nagra 4S.

Cheers.

[Pete Cofrancesco]

Originally Posted by Allan Black

watch out for dirty power in old venues, maybe carry a small AC smoothing device.

any recommendations where would you find these on B&H if they sell them?

Back to an earlier question about the output. I find that the input levels on my Sony Z1U camera need to be set very high to get a decent signal from the mixer 8+. I took a picture of the camera set at 10 and the mixer generated tone is still below 0db. Any idea what's going on?

http://i14.photobucket.com/albums/a3...ps7c4e9cb1.jpg

[Brian P. Reynolds]

From your pics ... The input level is way to hot on your camera, the '0' from your mixer should be '20' on the camera.
The '0' point on the camera is the clipping point hence the red indicator.
Depending on what you are shooting it is often good to set the right channel 1 bar lower than the left to give that channel just a little more headroom if you accidentally get a rogue sound spike.
(This would ONLY happen if you are recording the same signal to both channels... For true stereo shooting the should match)
Often people get hung up with dbv's dbu'ss dbs's etc and its often hard to explain...... all they want and need to know is where do I set the tone level to?

0 on the mixer = 20 on your camera

Edit... I have just had a look at the operational manual for the camera and what few instructions they have given for audio set up are very vague and quite confusing.

[Allan Black]

Originally Posted by Pete Cofrancesco

any recommendations where would you find these on B&H if they sell them?

Something like this APC jigger for your camera, lights, 302 etc, local model of course ..

SurgeArrest Performance - Product Information

Maybe one of these power back up units. Add this feature to your rate card especially to support your 7hr clients.
Total your current power requirements on location, then add at least 50% to find out which model you need ..

UPS Backup | B&H Photo Video

Cheers.

[Pete Cofrancesco]

Originally Posted by Brian P. Reynolds

From your pics ... The input level is way to hot on your camera, the '0' from your mixer should be '20' on the camera.
The '0' point on the camera is the clipping point hence the red indicator.
Depending on what you are shooting it is often good to set the right channel 1 bar lower than the left to give that channel just a little more headroom if you accidentally get a rogue sound spike.
(This would ONLY happen if you are recording the same signal to both channels... For true stereo shooting the should match)
Often people get hung up with dbv's dbu'ss dbs's etc and its often hard to explain...... all they want and need to know is where do I set the tone level to?

0 on the mixer = 20 on your camera

Edit... I have just had a look at the operational manual for the camera and what few instructions they have given for audio set up are very vague and quite confusing.

thx, I agree the manual is vague. Ok I'll sync it to 20 on the camera.

[Steve House]

Originally Posted by Pete Cofrancesco

thx, I agree the manual is vague. Ok I'll sync it to 20 on the camera.

Be sure to use the camera's input level controls to adjust the standard 0VU level tone coming from the mixer to -20dBFS on the camera's meters. Once you do, don't touch the camera's input level again - in fact, it's not a bad idea to use a little piece of gaffer's tape to make sure they don't accidentally get bumped. And when you have set the tone and switch to recording real signals, keep in mind that peak reading meters like those in the camera show different values for pure sine wave tones and complex waveforms with the same RMS level while averaging meters such as a a VU meter read the same for either waveform.. A sine wave tone with an RMS average level of 0dBu will read 0dBu on both an average and a peak reading meter. But a complex waveform such as pink noise (and real human speech) with an identical actual average RMS level of 0dBu that reads 0dBu on an average reading meter such as a VU meter will read about 8 to 10 dB higher on a peak-reading meter. So when you adjust the camera levels so the mixer's 0VU tone reads -20 in the camera and then switch over to speech with the mixer's inputs set to bounce between 0 and +4 or so VU on the mixer's meter, the camera meter will start reading around -12 or -10 dBFS. This is perfectly normal and does not mean the camera inputs need to be readjusted.

[Brian P. Reynolds]

Pete, How did you go with the level settings?

[Pete Cofrancesco]

Despite what was said I needed to set the camera level to 8 to get the necessary volume. I'm recording conversations so maybe that has some thing to do with it. Even though I think 8 is a lot, its line level, my previous mixer I output mic level to the camera even though the camera was set at 5 it was doing more amplification. Btw, I using AT-899 lav mics.

I'm just trusting my eyes and ears. Setting the mixer so the peaks are just below the red and then doing the same for the camera.

[Rick Reineke]

"Despite what was said I needed to set the camera level to 8 to get the necessary volume

--That is NOT normal, you are negating the benefits of the 302's premium preamps... so why even bother with it?
Confirm the 302's cal. tone is set to '0dB' or -2dB, and your camera is adjusted to -20dBFS. Your meter selection is set to 'Stereo Source' and you are not attenuating the output. (the orange LED on the output panel should NOT be illuminated) You may want to look into the FULL SCALE method of alignment. (see the manual)
Perhaps you're not interpreting the 302's meters correctly. In one of the 302's peak ballistics modes they should be hitting at least 0dB and above. Check your output limiter settings. For a full scale applications, set mine to +17dB, the factory pre-set I recall is +18dB.