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Old 4th May 2019, 2:57 am   #10
TIMTAPE
Octode
 
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,963
Default Re: Different Dolby B / C Calibration Standards

Quote:
Originally Posted by paulsherwin View Post
Ted:

The problem is the differing sensitivity of the different tape stock. BASF chrome has very low noise levels but also low MOLs. A correctly recorded BASF chrome cassette will play back 3-6dB lower than a good pseudochrome. It's quite easy to see this effect when playing back commercial cassettes recorded on different stock. There is no practical way for tape duplicators to counteract this effect. The playback machine can be Dolby calibrated for high or low MOLs but not both.
I'm not sure I go along with this, Paul. For a tape with sensitivity 3 db below reference we simply increase record gain by 3db. Whereas MOL is the maximum level a tape is capable of, or for a given level of distortion. Since Dolby B and C only kick in at the low levels, MOL shouldnt affect their performance, unless the MOL is very low. That's my understanding anyway.
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