@Randy:
hab ich in nem anderen Forum gefunden: (Du kannst doch bestimmt änglisch, oder?)
"Please be aware that the Fairchild 670 was widely (almost universally) used in mastering, expecially in the days of vinyl where the Lat/Vert mode allowed mastering engineers to control the factors affecting groove dimensions. So it was every bit a mastering device.
It is no less useful to us today for mastering digital media, but it is not the most intuitive device. A good deal of time is required to master the art of using this peice of gear. That is as true of the hardware version as of the software. The engineers who invested 30 grand in this thing did not expect it to run itself. They were tweakers to the max. They spent hours listening to the audible effects of changing parameters. Should we choose not to do so, we will get proportionately less usefulness from it.
For mastering a full mix with the 670, you will almost certainly need to use something other than the default settings or factory presets. You will probably want to start by backing off on the Bias setting to about 2-3 o'clock.
That will get you in the stadium. To find your row and seat, you'll probably want little (or no) Input [g=105]Gain[/g], and a low (or zero) Threshold. You'll probably want to use a Time Constant of something other than 1-3 (most likely one of the Program Dependent modes, 5 or 6, or occasionally 4, rarely 3). The ideal Time Constant setting will vary greatly with the above parameters and the source material. So it may be necessary to change this and go back to square one and start again if you don't like where you're heading.
You'll probably be most happy on a full mix when you see little or no activiy on the [g=105]Gain[/g] Reduction meters, even in loud passages. That may be counter-intuitive, but it works. You are trying to acheive a smoothing and sweetening effect, not a brute force taming of dynamics. Today, we have very good brickwall limiters to use after the 670, such as the L2, etc. (or the Precision Limiter) Use them.
Much experimentation is needed to familiarize yourself with the wide variety of possible outcomes. For example, did you know that tweaking the "[g=184]Balance[/g]" screw has a measurable and audible affect on the sound? Originally this would tweak the voltages across the 6386 tubes, which does not produce a straight-forward effect on stereo level when the two screws are set slightly differently.
Rather it causes low-level dynamic phase variations that can be quite euphonic. I find that on mono signals and some stereo mixes, it is best to have these two screws set exactly the same (with fine increments of the keyboard), preferably so that the little paint dot is at the 12 o'clock position. But for many mixes, I have preferred the sound of one screw set fully clockwise and the other fully counter-clockwise, or somewhere in between. Try it and see what you hear.
Again, I say that this is a complex and amazing piece of gear, and it will be some time before the user gains enough familiarity with it to know instinctively where to go to get the desired result. But for those of you who have not had much time to spend with the 670 on a full mix, I urge you to do so. I warn you though, that you may end up like me. I agree that for most material, it doesn't sound right any more until it's been through the Fairchild! And I've never had ANY piece of equipment, let alone software, about which I could say that!
The correct way to use the Fairchild when mastering or fine tuning stereo mixes is with the GR ([g=105]Gain[/g] Reduction) meters barely moving.
IOW, it is used to color and enrich, but not compress to the point of [g=105]gain[/g] reduction."
Gruß,
Christian