Fisher FM stereo Multiplexer 12ax7

newbie308
newbie308 Posts: 773
edited September 2011 in Electronics
I have been tinkering with a 1959 Fisher 600 tube integrated AM/FM receiver for a few weeks. I have replaced all the capacitors and a few tubes, and now the unit is functional. 22 tubes all lit up looks soooooo cool in the dark! As my 7 year old daughter said, "Daddy it looks like Christmas!" I found a FM Stereo Multiplexer Fisher MPX-60 on Ebay that has no tubes, but requires three 12ax7's. My question is, "Will there be any audible difference between a new JJ tubes vs. a vintage NOS Siemens or RCA tube in this application?"

I know that this multiplexer was designed for a console stereo, and that it was supposed to draw it's power from the console stereo's amplifier power supply, but my intention is to build an external power supply for it using a Dynaco transformer.
Sources: Technics SL1200MKII | SME3009 Tonearm | Monster Alpha 1 MC cartridge | Oppo UDP203 disk player | Nikko NT-790 analog tuner | Musical Fidelity Trivista 21 DAC | Preamp: Threshold SL-10 | Amplifier: Threshold Stasis 2 | Speakers: Snell Acoustics C/V | Kimber 12-TC bi wire speakers | Analysis plus Oval 1 preamp to amp | Wireworld Eclipse 7 DAC to Preamp | Wireworld eclipse digital IC Oppo to DAC | Audioquest Quartz tuner to preamp |
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  • newbie308
    newbie308 Posts: 773
    edited September 2011
    Attachment not found.Here are some naked pics of the Fisher ta-600.
    Sources: Technics SL1200MKII | SME3009 Tonearm | Monster Alpha 1 MC cartridge | Oppo UDP203 disk player | Nikko NT-790 analog tuner | Musical Fidelity Trivista 21 DAC | Preamp: Threshold SL-10 | Amplifier: Threshold Stasis 2 | Speakers: Snell Acoustics C/V | Kimber 12-TC bi wire speakers | Analysis plus Oval 1 preamp to amp | Wireworld Eclipse 7 DAC to Preamp | Wireworld eclipse digital IC Oppo to DAC | Audioquest Quartz tuner to preamp |
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  • newbie308
    newbie308 Posts: 773
    edited September 2011
    Why aren't the pics showing? I tried loading them from my dektop, but nothing shows!
    Sources: Technics SL1200MKII | SME3009 Tonearm | Monster Alpha 1 MC cartridge | Oppo UDP203 disk player | Nikko NT-790 analog tuner | Musical Fidelity Trivista 21 DAC | Preamp: Threshold SL-10 | Amplifier: Threshold Stasis 2 | Speakers: Snell Acoustics C/V | Kimber 12-TC bi wire speakers | Analysis plus Oval 1 preamp to amp | Wireworld Eclipse 7 DAC to Preamp | Wireworld eclipse digital IC Oppo to DAC | Audioquest Quartz tuner to preamp |
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  • Joe08867
    Joe08867 Posts: 3,919
    edited September 2011
    I don't think that is a feature that is going to stay around.
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  • inspiredsports
    inspiredsports Posts: 5,501
    edited September 2011
    My early '60s Fisher KM-60 FM tuner has the "WX" multiplexer built in. It uses one 12AX7 and two 12AT7's in this particular multiplex module.

    I've found rolling all 3 of these tubes make noticeable differences, but I had the unit rebuilt/recapped and that made a bigger difference than tube rolling in the mpx section. The single 12AX7 in my mpx section seems to make the biggest difference of the 3.

    I've found the tubes on the output side have a bigger impact on sound quality, specifically the 6DJ8 in V1 and the 12AX7 in V7 (the KM-60 only has 11 tubes so I'm not sure the "V" positions are labelled the sames as yours).

    There are some other vintage Fisher owners here who may be able to chime in with something more specific to your exact model, but I believe most of the circuits from this era are very similar.

    Maybe some of my photos and links will be helpful . . .

    http://www.inspiredsports.com/images/Fisher-KM-60/
    VTL ST50 w/mods / RCA6L6GC / TlfnknECC801S
    Conrad Johnson PV-5 w/mods
    TT Conrad Johnson Sonographe SG3 Oak / Sumiko LMT / Grado Woodbody Platinum / Sumiko PIB2 / The Clamp
    Musical Fidelity A1 CDPro/ Bada DD-22 Tube CDP / Conrad Johnson SD-22 CDP
    Tuners w/mods Kenwood KT5020 / Fisher KM60
    MF x-DAC V8, HAInfo NG27
    Herbies Ti-9 / Vibrapods / MIT Shotgun AC1 IEC's / MIT Shotgun 2 IC's / MIT Shotgun 2 Speaker Cables
    PS Audio Cryo / PowerPort Premium Outlets / Exact Power EP15A Conditioner
    Walnut SDA 2B TL /Oak SDA SRS II TL (Sonicaps/Mills/Cardas/Custom SDA ICs / Dynamat Extreme / Larry's Rings/ FSB-2 Spikes
    NAD SS rigs w/mods
    GIK panels
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  • newbie308
    newbie308 Posts: 773
    edited September 2011
    Wow! Nice tuner insiredsports! Certainly a lot less going on in there than in the 600! The 600 has 22 tubes and two separate tuner sections. I need to find some 7v festoon lamps, or brighter 12v lamps because the ones I put in do not illuminate the face well. Maybe I will do something with white LED's if I can't find the proper lamp.
    Sources: Technics SL1200MKII | SME3009 Tonearm | Monster Alpha 1 MC cartridge | Oppo UDP203 disk player | Nikko NT-790 analog tuner | Musical Fidelity Trivista 21 DAC | Preamp: Threshold SL-10 | Amplifier: Threshold Stasis 2 | Speakers: Snell Acoustics C/V | Kimber 12-TC bi wire speakers | Analysis plus Oval 1 preamp to amp | Wireworld Eclipse 7 DAC to Preamp | Wireworld eclipse digital IC Oppo to DAC | Audioquest Quartz tuner to preamp |
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  • TNHNDYMAN
    TNHNDYMAN Posts: 2,145
    edited September 2011
    Fisher Philharmonic IV P-29 1964.JPGglowing tubes.JPGFisher Tube Layout.jpg
    IMG_0291.jpg
    IMG_0285.jpg
    Garrard AT-6.JPGIMG_9076.JPGNewbie-

    I've got a 1964 Fisher Console w/ the added multiplex board. It contains 3 12AX7 tubes made in West Germany, but Ihaven't pulled tubes to confirm if they are Telefunken's. I've tried to locate someone local to test the tubes to get values, but no luck. The console does work and I am considering parting out the tubes. If you might be interested let me know. I'm considering pulling the whole chassis out of the console and trying to use it w/ some KLH Model Six's I picked up but not sure how easy that would be to do w/ powercord in console not on the chassis itself.
    2-ch System: Parasound P/LD 2000 pre, Parasound HCA-1000 amp, Parasound T/DQ Tuner, Phase Technology PC-100 Tower speakers, Technics SL-1600 Turntable, Denon 2910 SACD/CD player, Peachtree DAC iT and X1asynchorus USB converter, HSU VTF-3 subwoofer.

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