balanced/unbalanced/+4/0/-10 SOUP

[brooksy]

ok...I have a chance to get an MCI machine. Here is the problem. I currently am using a tascam msr-16s and 2 tascam 300 series boards. The 300 series have 4 balanced +4 outs each. does this mean I can only record 8 tracks simultaneously with the mci? Currently I use the line out on each channel and can record up to 16 tracks at once. Could i use the line out with the mci as well, would I be able to hit the tape hard enough or would the mixer electronics clip? I know there are converters but Im not going to spend more on converters that the machine so...any ideas? ghost?

 

[ofajen]

ok...I have a chance to get an MCI machine. Here is the problem. I currently am using a tascam msr-16s and 2 tascam 300 series boards. The 300 series have 4 balanced +4 outs each. does this mean I can only record 8 tracks simultaneously with the mci? Currently I use the line out on each channel and can record up to 16 tracks at once. Could i use the line out with the mci as well, would I be able to hit the tape hard enough or would the mixer electronics clip? I know there are converters but Im not going to spend more on converters that the machine so...any ideas? ghost?

Should be no problem! Just set the MCI recorder gain on each channel so that a more modest input level produces reference fluxivity on the recorder. That's easy to do when you're calibrating the machine. This was my standard practice when using my little Mackie 1604 mixer's unbalanced preamp outputs to feed the inputs on the various 3M and Ampex machines around here. I turned the gain up somewhere around 8 dB so that a -4 dBu input level produced reference fluxivity, just to give myself more headroom. I also tend to use a 355 nWb/m reference fluxivity, even on a high output tape like 3M 996 so that I have more headroom on the tape, which makes that gain adjustment all the more essential. Now that I'm feeding the machines from beefier, balanced outputs from stand alone preamps, I could turn the gain back down, but I prefer the extra headroom on the electronics (and I'm lazy), so I haven't.

Cheers,

Otto

 

[brooksy]

thanks otto. thats good news that its workable. i don't understand the term "reference fluxivity". could you please elaborate?
thanks again!

 

[ofajen]

thanks otto. thats good news that its workable. i don't understand the term "reference fluxivity". could you please elaborate?
thanks again!

That's just the fancy term for the reference level you record at, based upon setting your reproducer (playback) gain using your calibration tape. Based upon confusion and incorrect information posted in some recent threads, this idea seems to be something that several folks here could use a brief explanation of.

For example, I usually use a reference fluxivity of 355 nW/m at 1 KHz, and all I do is set my reproducer gain to show 0 VU on the meter when I play the 1 KHz tone on my MRL calibration tape (which is a 355 nW/m tape). Bear in mind that you often see the number 370 nWb/m, which is actually the same tape. 370 is a throwback to the days of the old Ampex reference level of 185 nWb/m at 700 Hz, and the equivalent fluxivity at 1 KHz is 355 nWb/m. I'm assuming most people calibrate their reference level at 1 KHz these days.

Then there's the details of aligning the reproducer settings for flat response according to an EQ standard and then using that calibrated reproducer (playback) system to calibrate the record settings so that, in the end, a signal showing 0 VU on input shows up as 0 VU when you record and then plays back at 0 VU. When you calibrate the record settings, you set the recorder gain and you input a 1 KHZ test tone, say, at a known level (you measure its RMS voltage value) and adjust that signal to the level you want to produce a 0VU signal (the reference fluxivity).

If you want a +4 dBu signal to record at 0 VU, you input a 1.25V RMS signal (+4 dB relative to a reference voltage of 0.775 V). OTOH, if you wanted to take it easy on your mixer electronics and set a - 4 dB signal to record at 0 VU, you input a 0.489V RMS signal at 1K and adjust recorder gain to record at 0 VU. And of course, there are the details of the other record settings to achieve flat respnose, low distortion, noise, etc.

Sorry, that was a lot of info. I hope that helps explain this a little better.

Cheers,

Otto

 

[brooksy]

thanks again! that makes a little more sense, but i'm gonna hold off on any more questions until i get the thing in front of me and try to get it rolling.