I know that technical review. I've written many times to Jack to share some measurements I've taken on some recorders but I never got a reply.
This is my little contribution consisting in frequency response measurements performed on some 1/4" studio recorders (two track DIN or NAB head layout) after being refurbished and running at 15 IPS with CCIR eq and 320nWb/m flux with SM900 or GP9 tape:
I know that technical review. I've written many times to Jack to share some measurements I've taken on some recorders but I never got a reply.
This is my little contribution consisting in frequency response measurements performed on some 1/4" studio recorders (two track DIN or NAB head layout) after being refurbished and running at 15 IPS with CCIR eq and 320nWb/m flux with SM900 or GP9 tape:
Obviously someone didn't bother to read John Curl's paper and the meaningless of THD and IMD. Maybe we could also get a graph of the harmonic spray too.
Unfortunately I didn't take pictures of all the measured parameters. The recorders are gone now, together with their technical sheets.
Anyway I've those pictures related to a sweep of the THD+N (way higher than THD alone) of a Studer A812 MkII taken without and with HX Pro in the recording chain:
There is a model which is really incredible for its playback linearity...
In this video it's playing back a CCIR calibration tape made for 7.5 IPS at 15 IPS. Upper limit of 20 KHz becomes 40 KHz. Note the level.
Obviously someone didn't bother to read John Curl's paper and the meaningless of THD and IMD. Maybe we could also get a graph of the harmonic spray too.