Scope issue Not getting cotton candy effects on Marantz 2500
- Thread starter PooPoo
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- 2500 cotton candy scope
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PooPoo
Active Member
Yes scope works but just a line it’s just isn’t doing the cotton candy effect.
You know, I'm not particularly a Marantz guy, and certainly not in the ranks that regularly deal with 'scoped Marantz gear - but my first question would be about whether any stereo separation is audible when the 'scope is showing a straight line. A straight line should be indicative of monophonic sound, no?
Apologies if I'm interloping,
chazix
Apologies if I'm interloping,
chazix
The trace pattern should alternate between, for example, a straight line when someone is speaking with NO music behind their voice and change to the "cotton candy" effect when complex info like music begins playing. However, this is only in the "Audio" setting.
PooPoo
Active Member
This could be the problem
jstang
Honey,I can't hear you...
As some one that has owned and trouble shot many Marantz scoped units .... Post a pic....
Great tidbit of what these days is esoterica! I see that Marantz uses that moniker (at least in the 2600 OM, the closest I found).
I really like "cotton candy", though! I can't remember ever having heard this usage before. (Maybe because I'm pretty much a stranger to audio gear with built-in 'scopes?) But I knew what it meant right away, while "Lissajou figure" would have made me think of single-frequency (or multiples thereof) phase comparison displays.
Cheers,
chazix
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PooPoo
Active Member
So, looks like FM is selected, but STEREO indicator is not lit. Perhaps the station is not broadcasting in stereo? (If this is in the U.S., that would not be unusual in the below-92MHz band, which is often dominated by mostly-talk-format NPR stations.)
If a known stereophonic source like a music CD is played, does the cotton candy appear?
Does the STEREO indicator ever light up when listening to FM?
If a known stereophonic source like a music CD is played, does the cotton candy appear?
Does the STEREO indicator ever light up when listening to FM?
Your scope circuitry is OK it's just showing mono in that picture. Since the display is at a 45 degree angle it shows that both channels are getting to the scope and are at equal levels just not in stereo. The Lissajous pattern will look like "cottoncandy" ONLY when there is a difference between left and right channels as in Stereo. I'm not familiar with this Marantz but does it show audio other than FM?
Craig
Craig
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