Capture setup:
-ATI AIW9600XT capturing raw YUY2 to
HuffYUV AVI
-AV Toolbox AVT-8710 TBC
-JVC HR-S7500U
-JVC HR-S7800U
-All equipment was interconnected to the VCR via S-Video cables to avoid comb filters.
Both VCRs have Video Calibration and Digital R3 OFF and the TBC/DNR switched ON.
Please note, I may not have selected the EXACT same frame for every screenshot
The norm7800 files are from the HR-S7800U with Picture Control set to "NORM"
The norm7500 files are from the HR-S7500U with Dub Mode set to "OFF"
The 7500 does not have a NORM/SOFT/SHARP/EDIT Picture Control option like the newer JVC units, only the Dub Mode setting. See below for an explanation.
The edit7800 files are from the HR-S7800U with Picture Control set to "EDIT"
The edit7500 files are from the HR-S7500U with Dub Mode set to "ON"
According to the respective sections of the two VCR's manuals, enabling Dub Mode on the 7500 is equivalent to EDIT Mode on the 7800. Both manuals say to set the VCRs to this picture mode to minimize picture degradation when copying tapes. These functions disable picture filtering circuits in the VCR.
From what I can see from a quick analysis, the HR-S7500U/9500U does indeed have a similar picture filtering system to what is found in the later JVC HR-S7600/9600/7800/9800/etc. This is evident by looking at the PNG file sizes. The EDIT versions with more noise are nearly 75k larger! The primary difference is that it is NOT adjustable like the later models. The Picture Control function on the later JVCs appears to primarily be a sharpness control.
Perhaps the pros will weigh in on this better then I can. My initial opinion is the JVC HR-S7500U/9500U are perfectly fine for VHS restoration work. The only trade off is that you lose minor control over the picture filtering.