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    Can someone confirm these resistor values?

    Since nobody seems to notice they've gotten PM's on this forum I'm forced to create a thread. I want to rework the crossovers in a set of TEAC speakers I have, and was considering replacing the resistors with higher quality pieces as well as the capacitors with films. There's probably, no benefit to replacing the coils, but if I find out my Fluke 77 Series IV can read their value in millihenries? then perhaps I may humor copper foil inductors.

    But anyway, I read these resistors as 1 Ohm and 22 Ohm, is that correct?
    Attached Files
    Presonus Audiobox USB, Schiit Magni 3, Sony MDR-V700

    #2
    Re: Can someone confirm these resistor values?

    3W 1Ω Tolerance J
    3W 22Ω Tolerance J
    "The one who says it cannot be done should never interrupt the one who is doing it."

    Comment


      #3
      Re: Can someone confirm these resistor values?

      Thank you for the confirmation Per Hansson!

      I'll return with pics!
      Presonus Audiobox USB, Schiit Magni 3, Sony MDR-V700

      Comment


        #4
        Re: Can someone confirm these resistor values?

        They are also non-inductive resistors type.
        Never stop learning
        Basic LCD TV and Monitor troubleshooting guides.
        http://www.badcaps.net/forum/showthr...956#post305956

        Voltage Regulator (LDO) testing:
        http://www.badcaps.net/forum/showthr...999#post300999

        Inverter testing using old CFL:
        http://www.badcaps.net/forum/showthr...er+testing+cfl

        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
        http://s807.photobucket.com/user/budm/library/

        TV Factory reset codes listing:
        http://www.badcaps.net/forum/showthread.php?t=24809

        Comment


          #5
          Re: Can someone confirm these resistor values?

          Other than that they appear to be from a speaker crossover, what markings make it known they are non inductive?

          Comment


            #6
            Re: Can someone confirm these resistor values?

            Wire wound resistors for crossover need to be non indcuctive, cheap cross over may use regular wire wound resistors instead.
            https://forum.digikey.com/t/inductiv...e-resistors/62
            https://www.amazon.com/8-ohm-Non-ind.../dp/B0058E98R4
            Last edited by budm; 06-20-2020, 01:31 PM.
            Never stop learning
            Basic LCD TV and Monitor troubleshooting guides.
            http://www.badcaps.net/forum/showthr...956#post305956

            Voltage Regulator (LDO) testing:
            http://www.badcaps.net/forum/showthr...999#post300999

            Inverter testing using old CFL:
            http://www.badcaps.net/forum/showthr...er+testing+cfl

            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
            http://s807.photobucket.com/user/budm/library/

            TV Factory reset codes listing:
            http://www.badcaps.net/forum/showthread.php?t=24809

            Comment


              #7
              Re: Can someone confirm these resistor values?

              I figured as much, since there were no special markings that they were non inductive. I suspect for audio, antiparallel wound resistors would do, though this is a special case.

              Kind of funny, world would be a better place if there were no inductive resistors. Pretty much the only use for inductive resistors are DC voltage droppers, everything else (RF, terminators, etc.) needs "real^H^H^H^H^H"ideal" resistors.

              Comment


                #8
                Re: Can someone confirm these resistor values?

                Yes, as I stated they are for a crossover. I noticed while browsing Digi-Key there some, which additionally, are non-magnetic. I've never heard reference to this with speaker guys.
                Presonus Audiobox USB, Schiit Magni 3, Sony MDR-V700

                Comment


                  #9
                  Re: Can someone confirm these resistor values?

                  Non-magnetic resistor:
                  https://www.mouser.com/new/thinfilm/...PNM-Resistors/
                  Never stop learning
                  Basic LCD TV and Monitor troubleshooting guides.
                  http://www.badcaps.net/forum/showthr...956#post305956

                  Voltage Regulator (LDO) testing:
                  http://www.badcaps.net/forum/showthr...999#post300999

                  Inverter testing using old CFL:
                  http://www.badcaps.net/forum/showthr...er+testing+cfl

                  Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                  http://s807.photobucket.com/user/budm/library/

                  TV Factory reset codes listing:
                  http://www.badcaps.net/forum/showthread.php?t=24809

                  Comment


                    #10
                    Re: Can someone confirm these resistor values?

                    I've never seen non-inductive resistors used in a passive cross-over network.
                    The inductance of ordinary wirewound resistors is very low, at most a few uH which is so small compared to the inductors or the driver's voice coil reactance that it does not cause anything audible.

                    Putting a 3.3uF film cap in place of the BP electrolytic will make a huge sonic improvement. But if you must replace those resistors, I would use ordinary Yageo SQP 3W if the same size. The non-inductive NSP I have never seen for sale.

                    Comment


                      #11
                      Re: Can someone confirm these resistor values?

                      hmm...this is a strange crossover, looks like the resistors are a voltage divider across the tweeter. But I've always thought that even these resistors at audio frequencies would not affect it that much.

                      Well, I had to measure. I have this 50W 10Ω wirewound and measured 13µH. At 44KHz (well beyond audio range) it's 3.6 ohms. This actually would have some impact if it's really 13µH - because I measured -5µH on a 25W 25Ω wirewound which clearly is incorrect. So I will have to ask someone else to measure their wirewound resistors as my Sencore appears suspect. Nevertheless the 3W resistors with smaller cross sections should have lower inductance. And those surface mount resistors may have problems at 3W...

                      Comment


                        #12
                        Re: Can someone confirm these resistor values?

                        There are simple crossover and complex crossover.
                        https://www.parts-express.com/resour...ng-a-crossover
                        https://www.madisoundspeakerstore.com/xover-design
                        https://www.aperionaudio.com/blogs/a...ign-and-theory
                        https://www.calsci.com/audio/X-Overs1a.html
                        https://www.parts-express.com/resources

                        OP's speaker is not high end so it may not make much improvement, or it may have placebo effect after the modification, may be should do A/B blinded test. I can see changing that BP LYTICS cap though to film cap, it may have dried out now.
                        Last edited by budm; 06-22-2020, 03:20 AM.
                        Never stop learning
                        Basic LCD TV and Monitor troubleshooting guides.
                        http://www.badcaps.net/forum/showthr...956#post305956

                        Voltage Regulator (LDO) testing:
                        http://www.badcaps.net/forum/showthr...999#post300999

                        Inverter testing using old CFL:
                        http://www.badcaps.net/forum/showthr...er+testing+cfl

                        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                        http://s807.photobucket.com/user/budm/library/

                        TV Factory reset codes listing:
                        http://www.badcaps.net/forum/showthread.php?t=24809

                        Comment


                          #13
                          Re: Can someone confirm these resistor values?

                          A first-order 6dB/oct crossover like OP's, the resistors are only to pad the tweeter which might have say 100uH inductance so a few uH is not an issue.

                          My Amrel LCR meter will also give negative values for inductance measuring wound power resistors. I don't think it's your Sencore.
                          1R0 1W is -1.5uH, TRW
                          2R2 5W is -1.5uH, Yageo SPW500
                          6R8 25W is -97uH, ECG
                          8R2 3W -120uH, but metal oxide

                          Power resistors can have nichrome wire, steel end-caps and leads, so they are magnetic. "magnetic distortion" as Douglas Self calls it, is due to steel at high currents (power amplifiers) binding posts, relays etc causing non-linear inductance and is measurable. It shows up when you are at ppm levels of THD 0.001%

                          I've ordered a new LCR meter in March that uses a sine-wave and measures current+voltage+phase but it has not arrived. I haven't investigated why you would get -ve inductance values with some LCR meters on WW resistors.

                          Comment


                            #14
                            Re: Can someone confirm these resistor values?

                            Negative numbers doesn't make sense unless the capacitive nature of the windings is now dominant. The reading is faulty and does not indicate actual inductance.

                            I have a few others to test but getting negative numbers means it's probably not worth it. Might have to conjure up some other experiments to measure inductance with my other measurement tools...

                            BTW the 10Ω 50W is a Clarostat ceramic tube (measured 17µH with a VA) and the 25Ω 25W (measured 6µH) is a Ohmite Dividohm. Those two are notably helical and about ⅜" diameter cross section. I also tried a 15Ω 5W (unnamed) which got 1.3µH, and got 0.6µH from a 1Ω 10W (Dale, but could be a fake though it works fine!) -- these are all "square" ceramic and have much smaller cross sections (and lower wattage), which correspond nicely to the lower inductances.
                            Last edited by eccerr0r; 06-22-2020, 12:20 PM.

                            Comment


                              #15
                              Re: Can someone confirm these resistor values?

                              After said and done, you have to test the unit as the whole, meaning test the speaker system frequency response, Z chart, etc. to see the real affect of the difference type of component being used.
                              Last edited by budm; 06-22-2020, 01:24 PM.
                              Never stop learning
                              Basic LCD TV and Monitor troubleshooting guides.
                              http://www.badcaps.net/forum/showthr...956#post305956

                              Voltage Regulator (LDO) testing:
                              http://www.badcaps.net/forum/showthr...999#post300999

                              Inverter testing using old CFL:
                              http://www.badcaps.net/forum/showthr...er+testing+cfl

                              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                              http://s807.photobucket.com/user/budm/library/

                              TV Factory reset codes listing:
                              http://www.badcaps.net/forum/showthread.php?t=24809

                              Comment

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