Hi, Andrew, Yes there will be changes, but they are not huge and the slope is gentle (less so with AME). Look at www.mrltapes.com and look at the Choosing and Using a test tape document -- there are cross references between standards for applying a calibration tape of one standard to another. Cheers, Richard On 2011-01-29 3:23 AM, Andrew Hamilton wrote: > On Jan 28, 2011, at 10:12 PM, Richard L. Hess wrote: > >> ...One of my clients likes it that we can pitch the tapes for him in >> the analog domain. >> > > > Dear Mr. Hess, et al., > > I was wondering how much speed tolerance there is to a given > pre-/de-emphasis EQ, even if a vari-speed oscillator is available. > Say there is a 1 kHz tone at 990 Hz, and you know they had intended > the EQ to be NAB... Had the horse already left the barn (in terms of > the emphasis's efficacy) when they were signaling a 1k sine, but the > machine was turning a bit faster than 15 ips (say, 15.2 ips) and > turned the 1000 cycles per second into 990 cps when played back at the > intended record speed? Or, by speeding up the playback machine to > 15.2 ips - enough to make the intended 1k tone actually play 1000 cps > - does the vari-sped playback (at the original record speed) magically > de-emphasize the haunted pre-emphasis? What is the point at which an > alteration should be made to the pre- and/or de-emphasis EQ? > (Obviously, if the recorder is turning at 20 ips or higher, a > different emphasis eq has to be set, whence the custom curves - let > alone AES and AME.) > > > Thank you, > Andrew > -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX http://www.richardhess.com/tape/contact.htm Quality tape transfers -- even from hard-to-play tapes.