X101B, Hi-FREQ(10KHz) Phono Squeal, Volume Dependent

Discussion in 'Fisher' started by larryderouin, Sep 10, 2016.

  1. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    Location:
    Ball Ground, GA
    For what it's worth, the 12AX7LPS tubes I've checked when using RCA operating conditions show a Gm of about 2100 on average, versus the 1600 published standard. That may be part of it, but it would also be interesting to know what the impedance is of the offending cartridge. It may just be that it represents too high of an impedance to keep the input of the X-101B stable. Question -- with nothing plugged into the phono inputs -- no cables or shorting plugs at all -- is the unit stable in that mode with the treble and volume turned up when phono is selected?

    Dave
     
  2. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Dave;

    It currently has ALL Sylvania OLD STOCK Yellow lettering 12ax7's, none of the sections are more than 100mhos apart per my Philco 9100 (533a rebadge). And all are btwn 1400 and 1600mhos, with a 90 or better on emissions.

    With the source unplugged and the jacks open, everything is normal will all controls maxxed out in phono. A little bit of hum/hiss (bass influenced) that is adjustable by way of tone controls, but that is normal. Shorting plugs reduce this to negligible.

    The Shure V-15-III cart I used on the PL-A45D (Problem TT) is the same cart on the same headshell I use on the SL-1200. I have an identical V-15-III mounted on the sled for the Zero 100, and the M91 on a twistlock headshell has a twin also mounted on a Garrard sled. So I can compare relative performance without spending an hour or so changing 2 carts on shells and sleds. Both V-15-III's have new elliptical Jico stylus, as do the M-91's. (I WISH I could afford shibata's but none of my records are what would be considered in very good condition. A lot of them were my parents stuff, and are older than I am. ) I run the V-15-III's @ 1.0gram mostly and the M91's @ 1.5gr. The PIONEER PC-30 is the original cart for the PL-A45D and has a Brand new Jico Conical and I run it between 3.0 and 4.5gr depending on how bad the record is warped (I use this for my worst records on TT's that have twistlock headshells.)

    V15 III HE

    [​IMG] [​IMG]

    [​IMG]
    rate/review

    1973 $130


    Type moving magnet
    Output Voltage 3.5mV
    Frequency Response 10Hz - 25kHz
    Tracking Force 0.75 - 1.25g
    Mass 6.4g
    Channel Separation 25dB
    Channel Balance 1dB
    Load Impedance 47k ohms
    Output Impedance 1350 ohms
    Stylus VN35HE
    Stylus Tip Hyperelliptical 5 x 38u (0.2 x 1.5mil)
    Cantilever Aluminium
    Dynamic Compliance
    Static Compliance
    Notes

    Alternate stylus VN35MR (Micro�ridge (1.5 x 3mils, 0.75�1.5gm VTF). Suggested replacement cartridge M97xE.

    M-91E SHURE
    Shure
    M-91 E

    [​IMG] [​IMG]

    [​IMG]
    rate/review

    1973

    Type moving magnet
    Output Voltage 5.0mV
    Frequency Response 20Hz - 20kHz
    Tracking Force 0.75 - 1.5g
    Mass 5.6g
    Channel Separation 25dB
    Channel Balance 2dB
    Load Impedance 47k ohms
    Output Impedance 630 ohms
    Stylus N91E
    Stylus Tip elliptical 0.2 x 0.7mil
    Cantilever
    Dynamic Compliance
    Static Compliance
    Notes


    No notes available for the PIONEER PC-30 (Original cart for the PL-A45D).

    Pickering 500v.3
    Stanton
    500 V3

    [​IMG] [​IMG]

    [​IMG]
    rate/review

    2006

    Type moving magnet
    Output Voltage 4.6 mV
    Frequency Response 20Hz - 17kHz
    Tracking Force 2.0 - 5.0g
    Mass 5.5g
    Channel Separation 28dB
    Channel Balance 2dB
    Load Impedance 47k ohms
    Output Impedance 535 ohms
    Stylus N 500
    Stylus Tip spherical 0.7mil
    Cantilever
    Dynamic Compliance
    Static Compliance


    No MATTER WHICH cartridge is on the PL-A45D with it connected to the X-101-B it squeeals. I'm thinking it may be a grounding issue with the RCA's, or an undersized RCA Center probe, or oversized outer clamp on the plug, or internally in the cables or turntable. It's probably due for a re-wire, as it has all it's original cables and RCA's. I wonder if the Japanese cable RCA PLUGS are dimensionally different from the US or Brit cables just slightly. No calipers so I can't check. One more thing is the rca jack placement on the X-101-B. One channel is on top while the other is on the side. This imparts a large curve in the RCA Cable and more strain on the cable and the jack from the cable hanging down. Possibility the one channel's cable is starting to get thin in the separation btwn the inner and shield of the cables. A 3" or 4" spring type strain relief may be needed on the cables? OR a 90* female to male plug adapter maybe??

    As soon as the 400 on the bench is done, I plan on installing NEW RCA JACKS on the PHONO, TAPE, & AUX inputs. Plus NEW Hardboard for them all. If I got some lexan in 1/8" I could mount them on the outside, slightly oversized and use the label maker with a clear tape and black lettering, then trim the labels right up to the lettering. Hmmm, that sounds like an interesting idea. If that works, then do the rest of the chassis markings.
     
    Last edited: May 13, 2017
  3. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    Ah! OK. So it's an issue with the TT. What happens if you remove the head shell and leave the arm without anything installed, but the TT is connected to the Fisher. Will it squeal then?
     
  4. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    HUMS like crazy from open ended RCA's until you move the tonearm over the platter. The PL-A45D doesn't connect the cartridge until the arm is over the platter. Doesn't matter if off or on, cartridge in or out, as long as it's connected to the 101-B it squeeals with the arm over the platter. Pull it back to storage position it stops, which means the cartridge wiring in the tonearm is probably bad, or the terminal strip joints are crappy OR the contact points for the tonearm wiring are out of sorts and touching maybe. Gonna have to open this one up eventually and go over it.

    BUT THE X-101-B IS NOT at fault.
     
  5. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

    Messages:
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    Location:
    Glen Burnie Md.
    The problem is in the Turntable not the X-101-B as shown below. I spent two whole days swapping cartridges around on turntables and couldn't get it to squeeal except with the PL-A45D.

    I've hooked up the SL-1200, 2 different Zero 100's, a LAB 80, ELAC Miracord 50-H, A PIONEER PL-115D, a PL-518, and 2 different FISHER (BSR's) from the late 60's to Early 70's. I used the V15-III, M-91, an Empire 2000E, and the FISHER's had ATE family Pickerings. None of the combinations of Turntable, and cartridge produced a squeeal in the X-101-B. But connect the PL-A45D in any configuration and the X-101-B Squeeals like the proverbial pig. I've got some heavy duty cables on an old DUAL that I can put on the PL-A45D hardwired internally with a strain relief. The inner covering is larger than the outer shield of the old RCA Cables. And the shield is woven like a chinese finger trap. 4ft long with less than 3ohms on either lead. So these will go on the PL-a45d with new tonearm wires from Gary @ voice of music which I have in stock. Clean up the mute contacts or remove them. It's in line with the other stuff behind the 400.
     

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