Testing a Marantz CD-400B ( or any CD-4 decoder ) without a CD-4 turntable.

[tonyE]

Great. Have fun.

Doug

I just got the CD-400B. It looks really nice, powers up nicely and the "Quad mode" light comes on correctly.

Now i got to wait to see it that "seller" is alive and if he wants to sell his Ortofon step up transformer.

Slow sellers really piss me off. Either sell, reply or take the ad down... down waste my time!

 

[jaybird100]

I know Linda used, and I presume still uses, a moving coil cartridge with either pre-preamplification or step up successfully.

Doug

I've used a high output moving coil quite successfully, too; a Denon DL-160.

 

[tonyE]

I've used a high output moving coil quite successfully, too; a Denon DL-160.

That's 1.6 mV? What phono preamp were you using? What decoder were you driving?

My Grado only does 1.0 mV.

 

[audiomaster]

Thanks for the ideas...

(1) There are two versions of the Grado Master 2. I have the low output version, 1.0mV, which sounds better. I suppose I could take the output of the phono preamp (2V) and drive it into the input of the RIAA encoder/converter... hmm... I got two phono preamps of sufficient gain, but the one in tubed CJ might not have the bandwidth, for sure the the Grado preamp (solid state) does. I think.

(2) The guy on eBay believes his passive converter has the bandwidth. He also has an active one... I'm awaiting for his response.

If (1) and (2) above work, that ought to be kludgy but it will work.

(3) Those old vintage receivers only support MM cartridges with 47Kohm loading and gain for a 5mV cartridge.

(4) The step up transformers, as a rule of thumb, don't have the bandwidth, or so I'm finding out. That was my first attempt, to get a step up transformer for my Grado to drive the CD4 decoders. Mind you, that route ain't cheap!

(5) Hmm... maybe just driving a 30Khz carrier signal might trigger the "radar" detector... that ought to be easy to do. Just need some software to drive a 30Khz detector and drive that one of my DACs at 24/96 encoding (the DACs have sufficient bandwidth for this).

(6) I ought to note that I don't have a CD4 calibration LP... only a handful of CD4 LPs I got over the years... and a few QS/SQ as well. This is not meant to be a long term set up, just a test rig to ensure the hardware works. If i set up four Maggies for quad in my living room ( hey, I have the stuff to do it, I got a spare set of 12s and the amps to drive them: Aleph 2s in front, Aleph 5s in the rear and the Kimber 4TC cables to reach...) my wife will surely kill me.

Hasn't anybody else done this before?

Do you mean done things that could result in death by wifey? Yes, been there, done that, barely survived. For some reason, it concerned her that I wanted to install 13 speakers in the living room? Never understood why, but I had to pick another room for the system? Banned to the basement, but the sound is great!

Oh, you mean the quad thing? No never tried that. I have a Bose 4401 quad preamp with the optional CD-4 decoder board. I do have a JVC 4DE-205 CD-4 adjustment record. If you can't find one for sale, could probably loan it to you. You need a good cart with Shibata stylus and low tracking force to play it without damage.