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What's The Strangest Thing You've Observed in High-End Audio?

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  • What's The Strangest Thing You've Observed in High-End Audio?

    Here's one for the books!

    An audiobuddy many years ago had a system that included an ARC D250Rev amplifier (a darn good sounding amplifier in its day too!) and an ARC SP8 preamplifier. He had a lamp over directly over his preamplifier and you'd get hum in the system if you waved your hand between the preamplifier and the lamp. No, not touching the preamplifier; just placing it between the lamp and electronics. Go figure.
    Myles B. Astor, PhD, Administrator
    Senior Editor, Positive-Feedback.com
    ________________________________________

    -Zellaton Plural Evo speakers
    -Goldmund Telos 300 stereo amp
    -Goldmund Mimesis 37S Nextgen preamplifier
    -Doshi EVO and Goldmund PH3.8 phonostage
    -VPI Vanquish direct-drive turntable
    -VPI 12-inch 3D Fat Boy dual pivot tonearm, VPI 12-inch 3D Fat Boy gimballed and SAT LM-12 arm
    -Lyra Atlas SL Lambda, Fuuga Mk. 2, vdh Colibri Master Signature, MutechHayabusa, MOFI Master Tracker, Sumiko Songbird cartridges
    -Technics RS1506 with Flux Magnetic heads, Doshi V3.0 tape stage (balanced)
    -Assorted cables including Transparent XL Gen. 6, Skogrand, Viero, Kubala-Sosna, Audience Au24SX, Genesis Advanced Technologies and Ensemble Power Cords
    -Accessories including Stillpoint Aperture panels, Cathedral Sound panels, Furutech NCF Nano AC receptacles; Silver Circle Tchaik 6 PLC, Symposium ISIS and SRA Craz 3 racks, Audiodharma Cable Cooker, Symposium Ultra and assorted SRA OHIO Class 2.1+ platforms.

  • #2
    photosensitive?
    Magnepan 1.6 QR Loudspeakers, Amherst A-2000 MOSFET 150 WPC Amp, Conrad Johnson PV-10A Modded Tube Line & Phono Stage, Electrocompaniet MC II Class A Head Amp, Audio Technica AT-OC9XML Cart (Stereo) , Graham Engineering 2.2 Tonearm (Stereo) , VPI Aries-1 Turntable (Stereo) , VPI Clamp, Denon DL-102 Cart, (Mono) , Luxman Tonearm (Mono) , Kenwood KD-500 Turntable (Mono) , Michell Clamp, Marantz 20B Analog FM Tuner, Pioneer SACD, Onkyo DX-6800 CD Transport, DIY 24B/192K DAC, Sennheiser HD-650 Headphones, Headroom Max Balanced Headphone Amp, DIY Silver Interconnects

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    • #3
      Originally posted by MylesBAstor View Post
      Here's one for the books!

      An audiobuddy many years ago had a system that included an ARC D250Rev amplifier (a darn good sounding amplifier in its day too!) and an ARC SP8 preamplifier. He had a lamp over directly over his preamplifier and you'd get hum in the system if you waved your hand between the preamplifier and the lamp. No, not touching the preamplifier; just placing it between the lamp and electronics. Go figure.
      Did the lamp have any influence at all? I've seen a number of preamps that would do that (no lamp involved)- particularly if the cover wasn't properly secured.

      Comment


      • #4
        While at the Nyc audio show a few years back tgey had these huge 5 way horn setup. My expectations were high. once I went inside things quickly hit the floor. I kindly walked over to the man running the room and said.
        this looks great when will you have it fixed and ready to hear
        there were two men one Asian and one American
        the American snapped back at me and it’s fine
        I then turned to him and said are you kidding ?
        he said no it’s fine and left in a huff. The Asian man said I’m sorry yes it’s broken he blamed it on the cd prayer lol.
        he then showed me a spot taped on the floor and said stand here. It was to one side. it got a tiny bit better at times during music passages. i meant no harm or to insult but if you look at me and say it’s great I’m sorry I can’t lol
        analog stuff.
        otari mtr 10 2 track 1/4 made new by soren
        otari mtr 10 2 track 1/4 1/2 combo made new by soren
        sota sapphire used eminent tech ver 2 arm
        new sota nova table has magnetic levitation platter and full speed control and latest motor same arm as above
        thorens td124 sme ver 2 arm
        thorens td125 sme ver 2 arm
        kenwood direct drive sme ver 2 arm
        phono preamp Ml no 25 all re capped
        speakers cust infinity IRS V , new caps and LPS , magnets etc.
        mark levivson pre no 26 amps no 33
        digital three cust servers , win ser 2016 , AO
        Dacs lampi various

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        • #5
          Strangest thing??? Yes, in my system, figured it out just a couple of months ago, after your visit Myles... ever so slight hum in my phono with the preamp volume at or around max, much louder when I attempted to connect phono ground to preamp or DAC chassis.

          I run XLR from the arm to RCA phono stage with XLR-to-XLR cables plus XLR-to-RCA adapters (pin1 connected to signal negative) at the phono, plus additional ground wires from the XLR-to-RCA adapters' bodies to phono ground, a short 3 inch distance. Measuring for continuity, phono ground to RCA negative at the phono stage shows they are connected with a 0.1ohm resistance, so no harm with those wires, right???

          Wrong was I... apparently that 0.1 resistance is enough for all these troubles... remove those wires and all hum is gone. Goes to show that whatever small ground leak there was before, if amplified some 100dB it can be audible. It also shows that even tiny wire impedance variations can create ever so small ground leaks - reason I use the exact same length, brand and model power cords, and even that may not be enough.

          Eventually, that's when I got special XLR-to-RCA adapters with Pin1 floating but with a ground wire coming out of Pin1, which was then routed to phono ground. In other words, the problem was between the original common adapters' Pin1-to-Pin3 connection and that 0.1ohm resistive impedance
          Analog: VPI Aries 3, custom suspension + platter interface || Magnetically stabilized JMW 10.5i || Ortofon A90 || Modded & fully shielded Pass XP-25 || Last gen VPI SDS speed controller || Magnum Dynalab MD-90SE/105 Digital: Spectral 4000SV || Fully shielded Yggdrasil 2 Amplification: Spectral DMC-30SV || DMA-500AR Speakers: Heavily modded MartinLogan (custom Mundorf dual xover, cabling, woofers, xformer; structural mods) || Modded REL sub Cabling: Fully shielded MIT Oracle 50ic,MA-X,90.1 || Shunyata Alpha v2,Omega AES/EBU Power: Shunyata Denali 6000/S v2, Venom XC and NR cords, SR-Z1 outlets, PS10, Typhon. Tweaks: Isodamp, mumetal, 3M AB5100, Dynamat, Copper foil; Vishay diodes, resistors, Mundorf coils & capacitors

          Main System Link
          Second System Link

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          • #6
            Originally posted by atmasphere View Post

            Did the lamp have any influence at all? I've seen a number of preamps that would do that (no lamp involved)- particularly if the cover wasn't properly secured.
            Yes, the lamp had to be on. And the top of the SP8 was properly screwed down. But I know what you’re getting at. IIRC Enid (?) said ARC preamps sounded better with their tops off.
            Myles B. Astor, PhD, Administrator
            Senior Editor, Positive-Feedback.com
            ________________________________________

            -Zellaton Plural Evo speakers
            -Goldmund Telos 300 stereo amp
            -Goldmund Mimesis 37S Nextgen preamplifier
            -Doshi EVO and Goldmund PH3.8 phonostage
            -VPI Vanquish direct-drive turntable
            -VPI 12-inch 3D Fat Boy dual pivot tonearm, VPI 12-inch 3D Fat Boy gimballed and SAT LM-12 arm
            -Lyra Atlas SL Lambda, Fuuga Mk. 2, vdh Colibri Master Signature, MutechHayabusa, MOFI Master Tracker, Sumiko Songbird cartridges
            -Technics RS1506 with Flux Magnetic heads, Doshi V3.0 tape stage (balanced)
            -Assorted cables including Transparent XL Gen. 6, Skogrand, Viero, Kubala-Sosna, Audience Au24SX, Genesis Advanced Technologies and Ensemble Power Cords
            -Accessories including Stillpoint Aperture panels, Cathedral Sound panels, Furutech NCF Nano AC receptacles; Silver Circle Tchaik 6 PLC, Symposium ISIS and SRA Craz 3 racks, Audiodharma Cable Cooker, Symposium Ultra and assorted SRA OHIO Class 2.1+ platforms.

            Comment


            • #7
              That’s not a surprise to me. The vacuum Tubes in amps and preamps work like antennas that capture every kind of electrical noise. If I left a pair of cables connected only in one side and the other side free without being connected I get immediately noise in my tube amp or tube preamp. High sensitive…
              SEAS EXCEL DIY Speakers; CJ Premier 12; CJ Premier 14; CJ Premier EV1; Accuphase DP 85; MAC Airbook + Audionirvana plus+ Qobuz + Tidal; Micro Seiki RX 1500; Ikeda IT 407 12" + Ortofon MC A95; Thomas Schick 12" + Ortofon SPU 90th Anniversary; Fidelity Research FR64 FX 10" + Ortofon SPU Royal GM MKII; SME M2 12-R + Ortofon MC XPRESSION; Kenwood KD 7010 + Ortofon Jubilee; Revox B710; Revox A77; Revox PR99; Pure Silver DIY Cables; Sennheiser HD800; Sennheiser HDVD 800; Akai AT S-08 Tuner.

              Comment


              • #8
                The most unexpected experience I had,
                not necessarily strange happened recently.
                I changed all my rca connectors, rca sockets, binding posts, terminal posts, internal wire in all amps, preamps and the internal tonearm cable for WBT pure silver AG nextgen connectors and pure silver wire.
                In every signal pathway that I could I change for pure silver. The difference is indescritably!. Much, much better!!. I recall that the differences between my ortofon a95 and the ortofon spu Royal gm mkii were almost not perceptible ( both have the replicant stylus). But after these upgrades the A95 revealed so superior and in another league of its own. High end it’s all about electronics…
                SEAS EXCEL DIY Speakers; CJ Premier 12; CJ Premier 14; CJ Premier EV1; Accuphase DP 85; MAC Airbook + Audionirvana plus+ Qobuz + Tidal; Micro Seiki RX 1500; Ikeda IT 407 12" + Ortofon MC A95; Thomas Schick 12" + Ortofon SPU 90th Anniversary; Fidelity Research FR64 FX 10" + Ortofon SPU Royal GM MKII; SME M2 12-R + Ortofon MC XPRESSION; Kenwood KD 7010 + Ortofon Jubilee; Revox B710; Revox A77; Revox PR99; Pure Silver DIY Cables; Sennheiser HD800; Sennheiser HDVD 800; Akai AT S-08 Tuner.

                Comment


                • #9
                  Originally posted by MylesBAstor View Post

                  Yes, the lamp had to be on. And the top of the SP8 was properly screwed down. But I know what you’re getting at. IIRC Enid (?) said ARC preamps sounded better with their tops off.
                  If the panel was painted or anodized, and the screws didn't break through the insulation caused by either, the result would be as CJSPU suggests- the panel would become a noise source rather than shielding. There used to be certain zener diodes that were light sensitive back in the 1980s and 1990s. Its easy to imagine a florescent lamp giving a circuit with them installed a pretty hard time.

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