As it is time to replace the heads on one of my reel to reels, I thought I should try experimenting with a magnetoresistive (MR) playback head. As way of background MR heads are commonly used in hard drives and represent a relatively new class. In MR heads a special material slightly changes its resistance in the presence of a magnetic field (as opposed to inducing a current with changes in such field, as in traditional inductive heads).
I see at least 2 benefits from its application in reading analog tapes and was told of a third one: (1) Since the head directly reads the field, it generates an electrical copy rather than a mathematical derivative. This eliminates any need for phase correction, the usual -6dB/octave slope, etc. In theory it should read down to DC (2) Since inductance is not used, matters such as LF "head bumps" and other resonance peaks should be eliminated.(3) Finally, I am told, azimuth is less of an issue.
There are some problems nevertheless, I read. MR heads are not linear in the frequency domain, need magnetic biasing to be mad more linear, etc. My early 1990s Philips DCC cassette player uses an MR head for both digital and analog and seems to work great.
Question is where do I find an MR head for this purpose? A few years ago I had read that at least one firm was starting manufacture of 4, 8 and 16 track MR heads but have not been able to find it.
I see at least 2 benefits from its application in reading analog tapes and was told of a third one: (1) Since the head directly reads the field, it generates an electrical copy rather than a mathematical derivative. This eliminates any need for phase correction, the usual -6dB/octave slope, etc. In theory it should read down to DC (2) Since inductance is not used, matters such as LF "head bumps" and other resonance peaks should be eliminated.(3) Finally, I am told, azimuth is less of an issue.
There are some problems nevertheless, I read. MR heads are not linear in the frequency domain, need magnetic biasing to be mad more linear, etc. My early 1990s Philips DCC cassette player uses an MR head for both digital and analog and seems to work great.
Question is where do I find an MR head for this purpose? A few years ago I had read that at least one firm was starting manufacture of 4, 8 and 16 track MR heads but have not been able to find it.
