Custom Search
Results 1 to 12 of 12

Thread: Replacing inductor coils

  1. #1

    Default Replacing inductor coils

    Has anyone out there replaced their ML inductor coils? I remember reading somewhere that someone replaced them with Alphacores. I am interested in doing this, because I think it may improve bass performance. BTW--I've already re-lined the cabinets with deflex and expert roadkill.

  2. #2


    I am in the process of doing several internal upgrades to my Clarities. Replaced a couple key caps (as indicated by Jim Powers) with some high voltage PIOs. Upgraded the PS 'lytics with better 'lytics (including Rubycons). Am now replacing the XO resistors with Duelund XO resistors and the big inductor with a Duelund inductor. I also removed unnecessary wiring (the LED and the NAC) and really deadened the cheap plastic base. I also upgraded certain connection points to direct-soldered with 4% silver solder. Would like to find a nice tranny upgrade (maybe Hammond) but I haven't yet. Since this isn't done yet, I can't give you a report on the results but I will let you know when I can.

  3. #3


    I would love to see pics of the improvements you are making and furthermore-can you be very specific about the internal upgrades recommended by Mr. Powers. Not Austin-but Jim!

    I would like to consider these myself.


  4. #4
    Senior Member
    Join Date
    Jul 2006
    Chatsworth, Ca


    Quote Originally Posted by zatoichi View Post
    Has anyone out there replaced their ML inductor coils? I remember reading somewhere that someone replaced them with Alphacores.
    I've had good results with Alphacore inductors in the past. They're clean and they're fast. One of these days I'm going to re-finish my Sequel cabinets, and when that happens, I'm going to upgrade the crossovers, and new panels, and possibly new 8" drivers too. Should make a good improvement! I'd also like to hear from any ML owners who've tried Alphas in their speakers.

  5. #5

    Default What Jim Powers told me

    I asked him if I could get a schematic of the XO and he replied that because the Clarity is currently in production, he could do that but he did give me the following guidance for upgrading:

    I see two caps that are of some importance. One is a 10uf 100 volt. The other is a 20uf also 100 volt. Getting to them is something akin to large animal veterinary medicine.
    I hope that helps.
    Happy listening!

  6. #6

    Default Capacitor replacement & ferrite clamp

    I replaced the polypropelene capacitors and one of the electrolytics (100 uf) and got a pretty big improvement in panel performance. Other things that help improve panel performance:

    1. ferrite clamp on the stator wires

    2. marigo dots on the panels

    On the other hand, the woofer been harder to tackle, which is why I'm contemplating replacing the inductor coils. My question is what impact does an inductor coil replacement have?

  7. #7


    Good idea on the ferrite - where is it on the stator wires? I assume inside the cabinet... is that correct?

  8. #8


    Yes, it is. Just loop the wires from the panels to the x-over thru twice.

    BTW--I don't know if you've tried David Magnan's ac filter ideas, but they make a huge difference, bigger than any component upgrade!

  9. #9


    No - I am not familiar with that tweak. Where can I find info? THanks

  10. #10

    Default Magnan AC filtering--Use at your own risk

    A Do-it yourself approach to AC line filtering

    This is only for the EXPERIENCED HOBBYIST who is familiar with a soldering iron and basic house electrical wiring practices. [Please note that Positive Feedback assumes no responsibility for injury, damage, or loss sustained by the DIYer the reader proceeds AT HIS OR HER OWN RISK.] Inexpensive and simple AC filter adapters can be made using large-value metallized polypropylene film capacitors. There are no commercially available units equivalent to the designs suggested here. If correctly utilized, such hand-made plug-in filters have a huge, almost unbelievable effect in improving the sound of digital, an order of magnitude more than the commercially available units mentioned previously. Multiple plug-in capacitors are required for best performance improvement. About half of them should be connected from AC line to neutral, and the other half connected from neutral to earth ground. The more the total capacitance, the better the sound. The 120 VAC line to neutral capacitor adapters should of course be carefully insulated using tape and/or shrink tubing to thoroughly insulate the caps and wiring to the 2-prong plugs.

    Care should be taken when removing one of the 120v AC line-connected capacitor plug-in units from the receptacle since the capacitors may be charged up to over 180 volts at the moment of removal. Always short out the plug prongs before handling. Alternatively, a 50,000 ohm 1/2 watt resistor can be soldered across the caps to automatically discharge the caps rapidly on removal from the receptacle.

    The capacitors connected from AC line to neutral should be plugged in as close to the CD player (or DAC and transport) IEC power inlet(s) as possible. The largest improvement in smoothness, transparency, depth of image and lowered noise level is obtained using an adapter allowing the AC line to neutral plug-in caps to be placed near the CD player (DAC/transport IEC input receptacle). This short adapter has a female IEC at one end, a box containing the caps or a multiple ungrounded (two wire) AC receptacle for the caps, then a male IEC connector for the power cord.

    In addition, more plug-in AC line to neutral-connected capacitors should be placed in the same or adjoining wall receptacle that the system is plugged into. These capacitors drastically improve the sound by greatly reducing digital timing jitter through their AC line noise reducing effect, and also supplement the CD player/DAC/transport power supply capacitors during the short rectifier diode conduction periods (120 times per second) by acting as supplementary instantaneous current sources derived from their stored electrical charge.

    The plug-in filter capacitors connected from neutral to earth ground reduce noise on neutral by bypassing or shunting it to earth ground, and improve the sound of digital even more than the AC line-to-neutral connected capacitors. The neutral to earth ground-connected capacitors must be wired to 3-prong AC plugs. For factory-terminated molded plugs, connection is from the white or blue wire (neutral) to green wire (earth ground).

    These plug-in filters should be inserted in wall AC receptacles wired to each of the AC lines in the house, except the line the stereo system is plugged into. This is necessary because large neutral to earth ground connected capacitors usually cause ground loop hum and buzz if plugged into the audio system AC line.

    Each of the non-audio system-connected power lines should have at least one capacitive filter on neutral because noise-induced on the neutral lines by appliances, digital, and RF devices in the house all sums at the common neutral tie point in the breaker box to be transferred to the audio system-connected lines. As many separate receptacles on each line as possible should have plug-in filters, for the best results.

    Recommended capacitor type and values for a single plug-in unit for wiring either as an AC line to neutral or neutral to ground adapter: One to four 4-10 microfarad 400-600 volts DC metallized polypropylene film caps, connected in parallel and bypassed by at least one .47 microfarad and one .01 microfarad 400-600 volts metallized polypropylene cap.

    Similarly to when connected directly in the audio signal path, the powerline capacitors have different sounds or sonic signatures when connected one way versus reversed. For the absolutely best results, the capacitor types used should be tested to determine the best sounding orientation or polarity, before wiring into the connectors.

    Recommended capacitor brands and sources (inexpensive and good-sounding):

    GE Series 41L, 10 microfarad/400VDC metallized polypropylene caps. Source: Madisound Speaker Components (608) 831-3433.

    Xicon .47 and .01/630V metallized polypropylene film capacitors. Source: Mouser (800) 346-6873, part numbers 1429-6474 (.47), 1429-6103 (.01)

    A number of other capacitor manufacturers also make as good or even better-sounding units in the same values, but at somewhat higher prices. Examples are Reliable and Axon. Reliable: (PPMF type) (562) 946-8577; Axon: recommend only the 20 microfarad/1200v: (602) 272-6696.

  11. #11

    Default Inductors

    You will benefit greatly if you change the inductors in your panels.
    Bass will be deeper and tighter, sound more natural.
    I'm currently working on a set of old Quest. The owner wants to take it all out.
    That translates to LARGE Mundorf SIO caps, HUGE Goertz inductors and rewireing of all cables.
    (Silver flat cables w/teflon insulation and something called "linolje" in Norwegian - ref. Duelunds theories)
    Problem is that the components are so large that they will not fit, so a special rebuild is required to make it alle go together.
    Estimated weight of upgrades are around 4 pounds each...

    Hopefully this will make a great upgrade when it finally is ready.
    Highly recommended!
    Last edited by Hifiasylet; 04-16-2007 at 08:46 AM.
    | | | | | |
    ( @ @ )

  12. #12


    Do you recommend a particular gauge?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts