At 01:27 PM 8/29/2014, Tom Fine wrote:
>Hi Jamie:
>Regarding your point about super-hi-rez transfer to capture bias, doesn't 
>that work only with your special heads and electronics? If you played a 
>tape on a stock ATR-100 or Studer A-80 and captured at 192 or 384, would 
>anything usable to Plangent be recovered?

Well, probably not an A-80.  Its repro electronics are deliberately rolled 
off fairly steeply above 20 kHz.

With other machines, yes, a usable signal can often be recovered if the 
bias is below 90 kHz, or there's some other stable signal recorded on the 
tape below 90 kHz.  Helps if the azimuth has been adjusted for maximum 
recovered bias level.

Spectrum analysis of the output of a machine with digital electronics will 
often show noise spikes that didn't come off the tape, e.g. A-820's have 
noise at 76 kHz from the switching power supply regulator, and ATR's have 
noise spikes generated by the reel motor drivers.  If the bias signal 
happens to be right on top of one of these noise spikes, that's not 
good.  If the bias is far enough away from the noise spikes, s/n is often 
good enough for speed correction and a useful level of wow and flutter 
reduction.  Of course, Plangent heads and electronics will give bettter 
s/n, which will allow more complete removal of wow and flutter.

-- John Chester