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  • #61
    Yeah being able to 'see' whats happening on a scope is (imho) step one. Really makes things clear...
    Regards,

    Erik
    http://solypsa.com
    North American distributor for:
    Sensitive Sound MC Cartridges
    STST Turntables + Tonearms


    Available for in home setup and calibration of fine turntable systems

    Comment


    • #62
      Your tech should have a scope. You'll be able to see the issue if its the B+ filtering or layout .. On the heaters. For the most part, they should be DC on the input and splitter stage on a modern amp. For fun try a EH 7025 in the first position. They have low filiment to cathode interaction for situations like this and they are cheap.

      There is always a way to mod but it will not be original anymore. You will have to weigh your options if you plan to alter any thing as re sale will be affected-- or treat it as an experiment and mod away and a sunk cost.

      Front end: Aesthetix Io Eclipse with 2 Power Supplies and Volume controls
      Brinkmann La Grange & RonT Tube Power supply with Kuzma 4-point ,FR64S, Brinkmann 12.1 , .Koetsu Jade Platinum,Koetsu Rosewood Signature Platinum, Lyra Atlas, Lyra Etna SL Goldfinger Statement, KLAUDIO RCM, HRSM3X
      Amps: Wyetech Topaz, Futterman H3 Quad II,Citation II, Marantz 8b, 5 ,2
      Pre-Amps:Marantz 7, Marantz Model 1 Consolette Pair
      Speakers: Quad ESL 57, Beveridge Model 3 DD amps, REL S/2 x 2
      Otari 5050BXII, DeHavilland 222

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      • #63
        Rex you have some very experienced and smart people knowing in building modding amps. Pic a path and walk down it.
        reg modding if it’s done in a way to be able to put back do that.
        lastly I have said in the past sell these by a SS amp Perhaps an Aragon 4004 MKII.
        change caps all of them. Get bigger ones for the main psu. This is still all in under 2k and I’ll make a bet it blows up all amps you have tried so far. do you have the imp curve and 1 watt dB rating of your speakers. now what I’m asking is not published specs but a real graph done under correct conditions
        this is needed for anyone to pick a good amp speaker match. The Aragon is an good entry level into Hifi and when modded is near ultra Hifi. It is very stable down to 1.5 ohms and is a true dual mono. It plays my monsters and is silent. It bested a gryphon I did a recap mod on.
        amd don’t be confused with a 8008 it’s dog compared I had both.
        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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        • #64
          You don't need DC filaments for the amp to be quiet on horns. If removing the 12AX7 shuts it up there can be a variety of issues.

          One technique for running AC filaments is to bias the filaments at a positive voltage such that secondary emission from the filaments is vastly reduced. This is usually a fairly simple thing to do. Usually the bias voltage need not be more than about 60-80 volts.

          OTOH the hum/buzz might be from a ground loop in the 12AX7 circuit. Another common issue is if the designer failed to make the grounds for the grid and cathode resistors be the same thing, allowing noise on one ground to be audible since it isn't common mode to both. A third issue might be that the amp has its audio circuit ground and chassis as the same thing- which can result in a ground loop if the power cord grounds the chassis into the wall.

          Comment


          • #65
            There you go a man who builds ty.
            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

            Comment


            • #66
              Well, I feel a little relieved, but also pissed. I bought my amps because they were suppose to be dead quiet. I was told no problem operating with a high efficiency speaker. I was told I could climb down the throat of a horn and hear nothing. Heck, the maker also markets a horn speaker.

              I think some here thought I was crazy. That Rex the electrician knows so little about wiring he messed his house up and that's the problem. Ampa dont hum on their own. Every amp is created equal. Right.

              Well, I did enough testing to believe the issue was the amp. I looked around for some solutions and got decent suggestions. I then took one of my amps back to my local tech. I asked, do you hear the hum. If so try dc to the anode of the 12ax7 and try grounding the cinimag input transformer. My tech wrote back yesterday and said he sure heard the 60 cycle hum but nothing worked to shut it down. I then went to a reliable source with intimate knowledge of these amps. Not Ampsandsound. I complained to Justin the owner of Ampsandsound about the noise and that the amps had failed for a second time in a year and a half. This time a bios cap failed. The power tubes were walking away. One amp unusable. I did not want to spend $600 to ship them to have a $1 cap replaced so I had a local guy replace the cap like in kind. Justin then told me sorry your amp does not perform to your satisfaction but never send it to me again. Ampsandsound won't touch it. Not it's no longer covered by warranty. Justins response to a bad design and unhappy customer is to wash his hands, turn his back, walk away. Good for you Justin. Don't buy gear from Ampsandsound. Justin is not a good guy to deal with. Sorry Steve. I know you have a relationship with him.

              Anyhow, a reliable source very intimate with the amp said I had tried all I could. In reading between the lines, it is what it is. It's no going to change.

              Alrainbow suggested a cap on the power supply. I have not rulled out cutting the top and putting one in. But, my conversations with my reliable tech lead me to believe he may has tried it and found it did not work. He cited quite a few reasons it would fail.

              So now I need a new amp if I want a quiet amp. God I wish I was done with this phase of my journey. I thought I was finalizing my setup with sources now. I thought my foundation was complete, only to find a keystone has a big crack.

              I will most likly live with the problem for a while. Nancy (my wife) and I were witnessing a wonderful couple with 2 small kids being crushed by recent events. We decided to gift them $5,000. I don't want to see a hard working small business owner put out in street due to no fault of their own. I should not be crying about noisy amps and spending money on myself when other are loosing their lives, occupations and homes. Replacing my noisy amp has no comparison to what some kindness and generosity to others can mean.
              PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI Paramount preamp,
              Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
              Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects. ADDPower Symphony and Electraclear.

              Comment


              • #67
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                PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI Paramount preamp,
                Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
                Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects. ADDPower Symphony and Electraclear.

                Comment


                • Rob
                  Rob commented
                  Editing a comment
                  it's always comforting to see "diy Tube" silkscreened on the PCB. Built from a kit? You don't think...no, no legit co. would do that
                  Last edited by Rob; 03-22-2020, 03:53 PM.

              • #68
                The amp hum will be soon be solved. Nice work looking at the bigger (human) picture...
                Regards,

                Erik
                http://solypsa.com
                North American distributor for:
                Sensitive Sound MC Cartridges
                STST Turntables + Tonearms


                Available for in home setup and calibration of fine turntable systems

                Comment


                • #69
                  My tech tried an assortment of fix. Some did nothing, others made it worse. Its actually a 120 hertz hum according to him. After a couple days he gave it back and said there was nothing he can do.

                  I put it back into my system. It was shockingly annoying how a bunch of buzzing can really ruin the relaxation i seek when listening. I'm constantly agitated when these amps play. The little Allo Volt plus d I use as a stand in is so quiet, its refreshing, just for the silence.

                  Super bummed I wasted close to $5,000 on boat anchor's. And was also treaded so poor as a customer. Time to move on.

                  Worst part. I have always loved the sound of tubes. Now I have developed a bit of a phobia. I'm sure its unfounded. I bet a lot of people ha e quiet tube gear.
                  PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI Paramount preamp,
                  Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
                  Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects. ADDPower Symphony and Electraclear.

                  Comment


                  • #70
                    KIingrex, that happens. I had a gorgeously made amp and the bass was just too much on my system and I could not tame it. Why I have no idea. Got another amp in and bass was perfect. I know this isn't a hum issue as you had, but sometimes you get a singular anomoly with a piece of gear. I had to reluctantly sell the bass heavy amp. Yet others do not report the same fault with the amp. In your case, I don' think tubes are the problem. Just the design versus your system/electrical environment. Hopefully, you can sell the humming amp.
                    JLH

                    Comment


                    • #71
                      Originally posted by Kingrex View Post
                      My tech tried an assortment of fix. Some did nothing, others made it worse. Its actually a 120 hertz hum according to him. After a couple days he gave it back and said there was nothing he can do.

                      I put it back into my system. It was shockingly annoying how a bunch of buzzing can really ruin the relaxation i seek when listening. I'm constantly agitated when these amps play. The little Allo Volt plus d I use as a stand in is so quiet, its refreshing, just for the silence.

                      Super bummed I wasted close to $5,000 on boat anchor's. And was also treaded so poor as a customer. Time to move on.

                      Worst part. I have always loved the sound of tubes. Now I have developed a bit of a phobia. I'm sure its unfounded. I bet a lot of people ha e quiet tube gear.
                      This is nothing to do with tubes and everything to do about design! Looking at the photos its hard to imagine how this was supposed to be quiet. For starters I wouldn't have used cheap rectifiers like that- they and the transformer too easily cause noise. That really long connection from the transformer? When you put a long distance like that between the transformer and the rectifiers, you can induce something called 'swept resonance' which is a capacitive (in the junctions of the rectifiers) aspect interacting with the inductance of the transformer. This manifests as a buzz.

                      The box is unshielded- single-ended circuits aren't good about rejecting hum fields. Not sure I would have employed an input transformer for unless to isolate grounding to prevent ground loops. With all the unshielded wires flying around preventing noise could be problematic. For starters I would have placed the input closer to the tubes with which it was to be used...

                      Put another way, people have been using tubes with horns since before the advent of the transistor. If tubes were all that buzzy we'd have known about it for decades- obviously its not a thing. Just find an amplifier that is properly built and you will be OK.

                      Comment


                      • Kingrex
                        Kingrex commented
                        Editing a comment
                        I discovered today if you wrap your hands around the bell ends of the transformers, the hum reduces. Looks like shielding is part of the issue.

                    • #72
                      I discovered today if you wrap your hands around the bell ends of the transformers, the hum reduces. Looks like shielding is part of the issue.
                      Hm. Is it a mechanical sound coming from the amp itself or do you hear this effect in the loudspeakers?

                      Comment


                      • #73
                        You have to figure out how the hum is being picked up. Is it via the power lines or via EMR? To figure this out you will need an EMR meter to be able to hunt down and identify where the hum field is being generated from. You can figure it out other ways but a good meter can be a time saver.

                        I bought a Tri-FIeld meter some years ago and it has been a time saver for me on multiple occasions. A meter like that will also help in identifying the best location for your system.

                        What I am suggesting may be a bit backwards because this should have been done at the beginning but many people, even the best installers, omit this kind of check.

                        If you have a phono based front end with LOMC cartridge(s) the necessary gain will make your system one hell of an antenna capable of picking up lots of different kinds of interference. Even the best cables can be susceptible to EMR/Radio pickup. If you do some quick math, the gain on a typical LOMC front end, will make it capable of picking up some of the lowest level interference sources.

                        A little movement of your system can fix some of the worst problems. The best place I ever had for any of my systems was on the basement floor due to the concrete slab and the low level of the location. The higher you raise your gear the better the chance of picking up something.

                        Anyone here who lives close to a broadcast station (Radio/TV/etc) can attest to the problems these kind of installs can encounter.

                        A map of your EMR/Radio interference can be very helpful in locating your system. Unfortunately there is one decent location in my condo and it is directly adjacent to an AC hum field. My neighbor can make things worse or better depending on whatever they switch on/off.

                        Noisy refrigerators, dishwashers, air handlers or anything with a motor can be a mini broadcast station of its own noise pollution.

                        The Tri-FIeld meter that I own was bought some years ago and it's an old analog meter. There are many new models on the market capable of hunting down AC, Radio and many other sources that radiate in your listening space. I believe I spent a little over $100 on my Tri-Field meter and I consider it a good investment.

                        If you are interested I recommend Googling around for different models and the reviews of those models. The meter you choose should be able to pickup AC power fields, magnetic fields and Radio fields. The capabilities for different frequencies and sensitivity will set the price of the unit.

                        I expect there is someone around here who knows more about this that I do. I found just a little experimenting was very helpful.

                        Ed
                        Life is analog...digital is just samples thereof
                        https://www.edsstuff.org

                        Analog: VPI Prime TT w/Walnut Plinth, HRX Pulley + 3 Belt Drive + ADS Speed Ctrl, 3D Dual Pivot Assy, Tru Lift, HW-40 Feet
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                        Comment


                        • Kingrex
                          Kingrex commented
                          Editing a comment
                          Can you measure around inside an amp with the meter. I was thinking of shortening that super long choke cable. Then the input location and cable.

                        • EdAInWestOC
                          EdAInWestOC commented
                          Editing a comment
                          I can move it around the components on my stands and I can see where the hum field is its strongest. I am not sure how selective it would be but it will tell you how much the gear is radiating.

                      • #74
                        I general I am eyeing new amps. Kind of thinking SET style, but I am beginning to believe 20+ watts is needed to make my 2 x 15" plus horn speakers work best. Also considering a Blade by Scott with Found Music. I want good tone, but i expensive readily available tubes is a plus.

                        Since adding my second circuit, general humming is maintaining a low level. Its still heard at the chair. But it is no longer so loud your hearing it during quiet passages in a song.
                        PAP Trio 10/Voxativ & PAP Trio 15 Horn speakers, Ampsandsound Casablanca monoblocks, First Sound Audio Mark 3SI Paramount preamp,
                        Mojo Audio Deja Vu server, Mojo Audio Mystique V3 DAC, The Linear Solution Ethernet Switch, Blue Jeans Ethernet cablling,
                        Akiko Corelli, Custom power strip direct wired to panel with OFC copper wire. Inakustik Ref Air 2404 Speaker cable. Genesis and Inakustik NF2404 Air Interconnects. ADDPower Symphony and Electraclear.

                        Comment


                        • #75
                          Depends on the noise level. If it is not strong and does not disturb you, you can correct the noise reduction.

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