has anyone compared side by side m90c to m90jw or comparable

i'm curious how much of a difference there is, and in sound quality, etc, and why is there more power for canadian models, very strange imo

i have seen various models but they are the same inside speakers , boards tranformers the only differeance i found one time was the newer had a change on the power switch ,, the older had 3 plugs and the newer had only 2 but it was just rerouted but technicly they were the same ,, could there be a slight change in voltage japan 100volts us 115 to 130 canada not sure but i belive that were some confusion as to ac power ratings give the impression of more louder sound,, like i said before all the m90 that i have seen are all the same i have 2 one is a 61 watt jw the other is 71 watt w they both sound basicly the same one is almost in great condition my other one is the beater which sounds just as good as my good one

with ramon --i have heard m90s with about every label --and in every very beat up --
to extreme new condition --
and the ALL SOUND GREAT !!

yup with the honorble guys above... I have had over 15 m90's all the same power untill i mod them

Think it may have had something to do with the electronics standards in each country-"ULC" standards in the US, "CSA" standards in Canada , and others around the world. I believe the output wattage of 7.5 watts rms per channel in the 70 series was somewhat under rated, would like to know if any members here have actually bench tested them to measure it? .Even though the "C" consumed more power, the output was marginally noticeable as being much louder than the JW. I also own 2 PC-550s, one is a JW with selectable world voltage, the other a "C" with fixed power. Here is a copy/paste from another site in regards to the letter designation for JVC:MODEL LINEUP:
The PC-55 was the first model in the series to be introduced. It came in silver finish. A black version occurs in some advertising, but has never been seen commercially.
PC-55: US model. 120/110v
PC-55b (need info)
PC-55c Canadian model. 120/110v or 220/240v
PC-55d (need info)
PC-55jw Japanese model. Switchable 110/120 to 220/240v
PC-55l (need info)
PC-55w World Edition. Switchable 110/120 to 220/240v
The PC-550 was produced later. It came in black finish. There were overseas versions that came in silver, they are amongst the rareset of boomboxes.
PC-550 American model. 120/110v
PC-550c Canadian model. 120/110v or 220/240v
PC-550d (need info)
PC-550j (need info)
PC-550l (need info)
PC-550w World Edition. Switchable 110/120 to 220/240v
PC-550wh (need info)

I don't know about M90's but I have had M50c's and M70c's and they are noticeably louder than their "jw" counterparts. The sound quality is the same but the power comes on much earlier. That doesn't change the THD though so the usable volume is the same....