Preliminary JVC HR-S7500U vs. HR-S7800U comparison
 

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.

Very cool! I didn't get to look through them too closely yet, but both seem to do a good job. The 7800 looks a bit nosier in a few, but the 7500 seems to render small details better, at least in some of the shots -- although the fact that some are not exactly the same frame does make both of those questionable observations. The 7500 definitely runs a little bit hot in some of the shots -- you can see it losing a little bit of the fine line details because of it, but the 7800 doesn't seem to render them as well to begin with (although this may be due to movements in not-exactly the same frame).

You have to wonder too how many of these types of comparisons of similar models are valid for the line at large and how many of them really only apply to those specific in ones possession. Still though, you can tell both do a solid job.

I'd like to do one of these too -- HR-7800U vs SR-V101US vs SR-W5U.

I don't see the SR-V101US being all that different from the 7800. Its pretty much the same VCR inside. The W5U would be nice to see. I'd say the differences between the 7500 and 7800 are "splitting hairs". Any difference is well within the normal variation between decks. 99% of the improvement in picture quality on these machines comes from the TBC/DNR circuit anyway.

if you look on Videohelp there is a SR-W5U comparo
i have a SR-W7U and it is a great machine.

Yeah my own anecdotal observations are that the V101 and 7800 look just about the same as you'd expect.

That's my deck actually -- compared against a V101US. I should redo it though as I had a few issues, or at least update it with some video clips.

the non DD decks 7800 7900 V10 and V101 are all going to be the same.
the transports ,TBC's and filters are all the same.
ive owned all 4 and there is no difference

the real comparo on the 7500 vs 7800 is DD vs no DD and VC vs no VC

Yup, sounds about right. Based on my own observations, the 7600 performs about the same as the V101US as well. Much less sturdy of course, but basically the same performance, I didn't find that it had any appreciable differences.

the 7600 has the DD and VC
it is the very best of the 7000 series.
it is essentially a 9600 minus the ghost reduction tuner and with 2mb instead of 4mb

Yup, it is a very nice deck, I owned one for quite a long time. As I said though, performance wise I found my deck to be identical with the 7800 and V101US. Certainly a better build quality though.

Just out of curiosity, did you get this idea from me comparing the 9600 and 9800?

Not at all. It was mostly out of curiosity since people were saying the 7600/9600 and newer models were better picture quality-wise over the 7500/9500. FWIW, the 9600 and 9800 are identical inside except that the 9800 removed the Commercial Advance and Movie Advance features.