Forums Music Sound Equipment repairing a cheap Behringer mixer

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  • #1057491
    General Lighting
    Moderator

      These mixers are sold under loads of different brand names (often on special offer at CPC). This one was intermittent on one channel; it worked if you tap the top of the case.

      This is what it looks like inside (had to remove a shit ton of screws and nuts)

      14897263173_7925795e1c_h.jpg

      mostly SMD components; not easy to work with

      14874343401_adbbdffb1e_h.jpg

      could not see any obvious breaks on the tracks ; but at the top right hand corner next to the two horizontal chips (probably output stage chips) are the solder contacts for the two switches for the 2-track to control room / mix feeds. I reflowed and resoldered these connections (they looked like dry joints; the increasing use of the politically correct lead free solder makes these worse) – and it all works

      Managed to get it back together without dropping any small screws / bolts raaa
      14897251253_11d39f409a_h.jpg

      #1278121
      DaftFader
      Participant

        Here’s the tool you need …

        [ATTACH=CONFIG]86327[/ATTACH]

        You’re welcome. 😛

        #1278119
        sinner69
        Participant

          lol

          #1278118
          General Lighting
          Moderator

            the initial temporary fix was indeed to thump it hard until the channel cut back in (it was becoming a bit more than a “short tap”).

            Although Behringer gets a bad name and I wouldn’t use much of their earlier kit it for a mobile installation a lot of the bad stuff is from a time when the whole world was swamped with particularly bad electrolytic capacitors due to a Taiwanese “entrepreneur” stealing a fomula for the electrolyte from his former Japanese employers; these elcos got into everything made from around 1999 to 2012. Some US computer companies have had to pay out billions in lawsuits because of them.

            If you wire it (and the rest of your stuff) up correctly (avoiding looped pin one shields on XLRs and other misconnections that contaminate a balanced audio feed) and pay attention to where protective/frame earth [earth ground] and signal earth [signal ground] are ending up, it actually sounds decent.

            They aren’t lying when they say “British EQ”‘; as what it is is a modern reworking of 1970s era British studio consoles; although with better EMC blocking (as I’ve got that old GSM terminal running full tilt in the studio and don’t hear it on the mixer when I make a phone call).

            At least with their small signal kit when the elcos do bulge out you can replace them with decent vishays or panasonics or even the contents of a German Kemo lucky bag and it often works again.

            My only complaint is the use of SMD components everywhere; rather than TL071s or other decent man sized components (it wouldn’t have made the mixer too much bigger).

            The giant hairdryer thing is cheaper these days and I could put a old webcam on a bamboo pole and feed it to the Philips CRT TV to inspect things I cannot see with the naked eye; working with SMD devices for hobby electronics (or even maintenance at work) is to me like BDSM; I understand some folks get pleasure and enjoyment from it but for me its too much hassle and pain.

            I have seen at least 3-5 different brand names selling mixers with what appears to be this exact same layout at the same price point – wouldn’t be surprised if Behringers factories are subcontracting to make them for other brands.

            the (separate) power unit is reasonable (safety wise); unlike that cheap charger confiscated at work; that did get the hammer to it. (I got an optoisolator and a high brightness LED from it; which I wanted for detecting a ringing telephone line, I wouldn’t trust any of those components on 230V

            Its usually the PSU on cheap equipment that gives up the ghost first; especially if connected to rough mains from gensets/power in industrial areas and regularly switched on and off. Switchmodes are more susceptible to this failure than linear PSUs (and are more commonly found in any power amp that doesn’t weigh loads and/or is only 1U with strong power).

            I leave small signal kit like mixers switched on 24/7 on the “red” 230V supplies which are monitored and filtered via the UPS that supplies the router and telephone exchange.

            this mixer is used as a “telephone hybrid” (these are about £250 or more otherwise) and the 2-track stage as a headphone amplifier (it can do both at the same time as these are different circuits). I hope to start the live shows again soon (would have done so earlier had there not been two more major projects at work; although recently I’ve been getting more AV-related projects instead of the usual admin/finance IT ones)

            Channel 1 is the talkback feed from the main console, 2 is the cleanfeed (desk output minus phone/comms channel) and 3 is the main microphone after the compressor/limiter but before the “Dutch pirate” FX unit. Output goes via the other channel of the compressor/limiter (to keep out the worst of the harsh “click” noise as the talkback switches in and out)

            The mixer output goes to a very crude balanced to unbalanced converter and attenuator into the VOIP soundcard on my main desktop PC (its in the keyboard, which I think is a type used for computer games but I got it as it lights up in the dark with different colours), and this soundcard output goes the other way back into the console comms channel.

            14701238988_dfa1880888_k.jpg

            Its first test was to make a VOIP call to Good Energy due to some bank error leading to my direct debit being cancelled; and sort out my billing as they were using estimates and [not surprisingly] underestimated the electricity usage in my house; not everyone has a whole telephone exchange in their roofspace as well as the sound and networking equipment.

            It wasn’t a large increase and cheaper in cost (and effort) than replacing defect power supply units/components and the sound quality was good; though the call centre operator must have wondered what on earth I was speaking to her on as it would have sounded like a 1970s radiotelephone/intercom with the background sound cutting in and out.

            At least I didn’t accidentally activate the test oscillator and send üüü down the line or even ØØØ (it can do 100 Hz) at +9dbU or play piratenhits down the line :laugh_at:

            #1278120
            cheeseweasel
            Participant

              @General Lighting 562833 wrote:

              Although Behringer gets a bad name and I wouldn’t use much of their earlier kit it for a mobile installation a lot of the bad stuff is from a time when the whole world was swamped with particularly bad electrolytic capacitors due to a Taiwanese “entrepreneur” stealing a fomula for the electrolyte from his former Japanese employers; these elcos got into everything made from around 1999 to 2012. Some US computer companies have had to pay out billions in lawsuits because of them.

              That’s interesting to know.

              People can poo-poo these mixers, but they do find their way around; I was using one a few weeks ago on the front end of an interpretation system that was relaying audio to George Osbourne, the Chinese Premier, several hundred delegates and the BBC for live broadcast. The job only called for a mixer with a single mono input, and the production company clearly had no issue with using the Behringer. It worked fine (although not the most satisfying job I’ve ever done! :wink:).

              Behringer kit is becoming much more accepted than it was a few years ago when they were just producing bad rip-offs of other companies’ designs. And some of the newer stuff is excellent – it seems like every hire company in the country now owns an X32 – been tempted to buy one myself, but can’t really justify owning a desk at the moment.

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            Forums Music Sound Equipment repairing a cheap Behringer mixer