Who has experience with the MX99 Multiplex adapter?

[GordonW]

(BTW: First actual substantive thread in the new Eico Place subforum )

I've had one of these MX99s for years, along with an HFT92 AM-FM tuner. I bought it, as I never could find a TX97 tuner- and this looked to be just about the same thing, functionally...

To now, I've never even gotten around to re-capping it or the HFT92, much less using them frequently. Just too many interruptions.

Anyone had any experience with these? How does it actually compare to the TX97???

Thanks!

Regards,
Gordon.

 

[ferninando]

Gold star for Gordon.
1st REAL thread in Eico Place.

 

[Darkover]

I have one and use it with a Fisher TA-600

 

[Trnsfmr]

Hi Gordon,
I have been obsessed with the ST97 and MX99 off and on for years. They are unique, in my opinion, in the whole world of Stereo FM Multiplex. There are many other people who, like me, think that when one of these is restored with audio grade capacitors and properly aligned, that it is the best sounding FM Stereo tuner ever made. I have many threads here on Audiokarma and on the old Yahoo eico group about them.

I'm a sucker for an MX99 discussion. I know the thread is a couple months old, but can I help with your MX99?

 

[Rbradio]

I have an mx 99 myself but one of the IF cans keeps sliding out of alignment. Has anybody else ever encountered this issue?

 

[backmd]

Hi Gordon,
I have been obsessed with the ST97 and MX99 off and on for years. They are unique, in my opinion, in the whole world of Stereo FM Multiplex. There are many other people who, like me, think that when one of these is restored with audio grade capacitors and properly aligned, that it is the best sounding FM Stereo tuner ever made. I have many threads here on Audiokarma and on the old Yahoo eico group about them.

I'm a sucker for an MX99 discussion. I know the thread is a couple months old, but can I help with your MX99?

Aha, but comparing the MPX schematic of the Eico ST97 and the Dynaco FM3, they are BOTH diode matrix decoders, where they both have four diodes with respective resistors. One pair of outputs from the four diode circle is connected to the 38Khz oscillator, and another pair of outputs is connected to the L and R channnels.

 

[backmd]

Aha, but comparing the MPX schematic of the Eico ST97 and the Dynaco FM3, they are BOTH diode matrix decoders, where they both have four diodes with respective resistors. One pair of outputs from the four diode circle is connected to the 38Khz oscillator, and another pair of outputs is connected to the L and R channnels.

Also the Sansui TU555 has the diode matrix decoder and the LC transformers in the IF section. So it has the good stuff that the Eico ST97 and Dynaco FM3 have.

 

[backmd]

After comparing the schematics of the Dynaco FM3, Eico ST97, Mcintosh MR67, and Marantz 10B specifically on the MPX section, they both use the matrix MPX decoders, which are like a circle of diodes with their respective resistors. These then feed the 38Khz oscillator circuit and also feed the L and R channels. So that is four matrix MPX decoders that I know of.

 

[backmd]

Wow even the lowly Pioneer SX300 has both the LC IF transformers and the diode matrix MPX decoder

 

[s-petersen]

I used the ST-97 for years, and it was a great tuner. I have the MX-99, and never used it, as I didn't buy too many mono tuners.
I bought it in case I needed parts for a 97.