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Marantz CD-400 stopped working

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furui_suterioo

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Yes, screenshot was from the CD-400B manual, cd-4 test records are not all equal, I have the CD-4 45rpm test record for my Kenwood 9940 but I like the Fisher/Enoch Light 12in 33rpm CD-4 test record much better. I use the test record to adjust the carrier level pots(9940 has two) and to get the seperation pots in the neighborhood of where they are supposed to be, then use a music cd-4 to make final seperation pot adjustments. I allow a bit of leakage for smoother sound, I recommend take a photo of the seperation pots once you have a setting you like, the carrier adjustment is not as critical as seperation, if carrier pot is past 12o'clock and carrier test tone is steady then it should be fine.
 

par4ken

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Yes the direct switch should of been on the front, it's not so useful on the back.

Your set up sounds about right, with the pot cranked most of the way up.

You didn't say if your turntable has low capacitance cables, the stock cables likely aren't, the capacitance of the direct cable should not matter.

What cartridge are you using?

The IC's in the turntable are for the speed control of the turntable.
 

n8nagel

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Yes the direct switch should of been on the front, it's not so useful on the back.

Your set up sounds about right, with the pot cranked most of the way up.

You didn't say if your turntable has low capacitance cables, the stock cables likely aren't, the capacitance of the direct cable should not matter.

What cartridge are you using?

The IC's in the turntable are for the speed control of the turntable.
I've been told that Technics original cables are in fact low capacitance. At least the ones used on SL-1200 Mk2 and later. Not sure if the SL-1650 uses the same cables or not, but they're working. It sounds like the reason the radar light was not lighting was because as someone else pointed out the DIRECT OUT switch completely disconnects the TT signal from the demodulator. The extra 18" of Mogami doesn't noticeably degrade the sound, although my ears might be a bit tin.

Cartridge is an AT15Sa with a new JICO Shibata.

And sorry if I was using too much shorthand, I meant interconnect by IC not Integrated Circuit.
 

Doug G.

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My favorite record for CD-4 setup is the Harman Kardon setup/demonstration LP, pressed by RCA. It agrees best with real world conditions. It's the one with different colored squares on the front of the cover.

And yes, as I indicated earlier, there will be output from all four speakers under all conditions with almost all outboard demodulators. In 2 channel mode, there is no decoding going on at all. Matrix LPs will play as any regular stereo record. The only difference will be in the mixes, if there are any (there usually are) but there is NO quadraphonics going on in that mode. The demodulator acts as just a 2 channel preamp and outputs the same thing to both the front and back outputs/speakers.

The only place low capacitance cables are necessary is between the turntable and demodulator. Others can just be normal audio cables.

It's a bit strange having problems with many 2 channel records causing the radar to light up in auto mode. I use my SE-405 in that mode all the time with no problems. It switches into CD-4 mode with a CD-4 record on and sends the signals to the demodulators and switches to 2 channel mode with a 2 channel record on and bypasses the demodulators and sends the signals to all four outputs and thus to all four speakers.

I have come around to think, after all these years, that the carrier level adjustment is more critical than most think it is. Too low level and the demodulators will drop out of demodulation and cause sandpaper quad. Too high a level and there will be other types of distortion that sound similar to distortion with regular 2 channel play. Since I have adjusted my SE-405 "by the book", it is virtually trouble free.

Doug
 

kfbkfb

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surround.sound.enthusiast

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That given, I was able to find an instruction manual for a 4DD-5 and also rummaging through my as yet uncleaned/unfiled records the Marantz CD-4 calibration disc. Will it be obvious what I'm listening for with the 30 kHz adjustment? I will hook it back up later and report back... (don't want to do it now as everyone else is asleep and if I run the disc through the ultrasonic now I might be bludgeoned...)
Do make sure you clean the calibration disc though if you haven't already. Trying to set-up a demodulator with a poor reference source will likely only lead to frustration. You need to make sure that all of the years of "stuff" has been cleaned out of the grooves!

I use a JVC 4DD-5 and have had very good luck setting it up and adjusting it with it's supplied 45rpm disc. I also have a Marantz CD-400, but never got it integrated into the system. The only thing that caught my attention with the CD-400, was that the carrier signal knob has detented positions. The 4DD-5 does not, so it's "infinitely" adjustable. I've wondered whether the detented positions on the Marantz would hurt me rather than help me when I eventually go to set it up.
 

jefe1

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That makes me wonder why Marantz upped the CD-400 to the B model with auto carrier adjustment. They must have thought it was better.
 

n8nagel

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I did run the calibration disc through my ultrasonic. It has one scratch on one side and looks more worn than I'd like, but otherwise seems to play fine... except for the track with the chimes which sounds horrible!

And I have no idea about the CD-400B, although somewhere in the dark recesses of my memory I seem to recall reading that it was a completely different unit inside than the CD-400 which I do believe to be a 4DD-5 in a different case with an added "AUX" input.
 

Doug G.

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Theoretically, auto carrier level detection is better. You don't have to worry about adjusting anything to have the levels be correct for the demodulators. Like all things, however, it's a matter of execution.

Doug
 
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