redbenjoe said:
thats very surprising --
so --the big news is --that a :super: capped box is the only way to go
norm --did you agree with melly re this comparo ?
Here ya go:
My (2) M-X920. Melly left the nicer/mintier one for you richer guys.
Here is Melly playing with and giving the Sanyos a good thorough evaluation. He was here for hours testing them. I would say if there were sound differences between them, he has discovered them all.
Here are a few boxes given the comparo. A second M9998 is on the left not visible from the screen. There was also a Sharp GF-800H there for Melly to play with.
Ira: I've always said in previous threads where we've discussed this before -- and got my ass kicked each time so what the hay.
Here is what I can know for sure. There were (2) M-X920's there. There were (2) Sanyo M9998's there. Both 920's sounded similar and both 9998's sounded similar. There were minor variations in sound quality as you can expect from unit to unit but the characteristics between the models were clearly similar.
THE COMPETITORS:
The M-X920's is a very very high quality boombox. M90 quality or better on many fronts, in my opinion (not speaking sound, loudness or whatever). I'm just referring to build quality and component selection although I believe that the M90, while often buggy, has a more robust tape deck. Both 920's were re-capped to an extent. The nicer one was re-capped completely and the power amp module was upgraded to 6600uf worth of capacitors. The second M-X920: when I received it, had very poor sound quality, low output, one channel working initially, then turned very scratchy and staticy. You are thinking deoxit to the rescue on the controls, right? Nope. Melly can attest that on the completed boombox, the controls have zero static on them and I did not touch those at all. The amp module was suspect and the amp was removed for re-capping and in the process, I replaced both amp modules too (they had to come out because a substantial number of capacitors remain under the heatsink, which boxes them in). This amp has tons of connectors tethered to it, and the amount of work required to remove it was not worth doing twice so everything was redone just in case. The amp chips had to be desoldered anyhow so they were both replaced at that time. The completed results was a night/day difference. Because a large number of capacitors resided below the heatsink and completely boxed in, they are subject to all the heat generated by the amp module. I believe that the M-X920 is a prime candidate for re-capping.
The 9998's. Both are pretty much original. The interior configuration is very very tight. One thing on these M9998's. It appears that the tuner is a poor design. Both of these have dead AM and I have a third Sanyo (M9990) with the dead AM so this appears to be a common problem on these. I did not recap these and the amps were performing as you would expect so I never contemplated a re-capping. Also, the boards are tethered with wires every which way to timbuktu so without audio quality symptoms, I was never motivated to touch that.
Bass is clearly better on the M-X920, both at low and high volumes. The highs are crystal clear and wide separation is typical sanyo -- terrific. (The RC-838 is the worst, in my opinion). Input sensitivity is higher than the M9998 and the M-X920 also gets louder -- the type of sound you would expect from a significantly larger chassis enclosure. Now, that doesn't mean that the 9998 is a slouch. By itself, it's a pretty good sounding boombox and can hold it's own. But here, we have them (4) all in the same room and the results is clear. Maybe our impression was colored somewhat by the prism of vanity since the muted 9998 certainly doesn't have the size and flash of the M-X920 and it's not unusual to vote in line with the more visually attractive offering, regardless if boomboxes or members of the opposite sex
. But if the M-X920's were not there, side by side, the impression might've been different. To me, it wasn't like 920 - 100points, 9998 - 50 point type of thing. Rather, if the 920 was a 100, then the 9998 might've been a 92 or so.
All right, so this is one man's opinion (maybe melly might be the second) so take this with a grain of salt. Is the 920 a better boombox or were they unfairly advantaged from a re-capping restoration? I dunno.
Get both! 
Plus, the black body and that green tuner light is gorgeous. 
