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Author: Earplug Subject: Outboard DC protection for speakers? Posted: 01 October 2026 at 4:04pm fudge22 wrote: In most of the amps I've seen recently, especially the plate amps, the SMPS is what goes bang, so no DC ever even gets to the output. That could be the solution. Just replace that heavy transformer, etc. with some cheap SMPS!! From the original post. I still run a matrix ukp2100X (smps) for my live band rig. Ok, yes. I've never seen a Matrix amp - not at all common down here, so couldn't comment, but like I said " especially the plate amps". I still stand by that. Also, I have had a few Yamaha P5/7000's for repair & the fault has never traveled from the SMPS to the actual amp. That Matrix must have something odd with it if the relay fail has happened on others & the designer recommended twin relays, etc.

Author: shaun1264 Subject: Outboard DC protection for speakers? Posted: 01 October 2026 at 3:25pm Earplug wrote: "In an amplifier with a dual rail power supply, the current could be in either direction, so there is a 50% chance that the magnet you glued to the relay is the wrong polarity because the “wrong” output devices shorted." Funnily enough, the proliferation of Class D & SMPS has most probably made the problem of blown O/P devices a bit less common. In most of the amps I've seen recently, especially the plate amps, the SMPS is what goes bang, so no DC ever even gets to the output. That could be the solution. Just replace that heavy transformer, etc. with some cheap SMPS!! You are right in that regard.. Class D amplifiers, Switched mode power supply blowing up. With linear amplifiers I also found it interesting how the VI circuit is implemented and the type. (single slope or twin) how it is modelled against the SOA at a given temp of output transistors and the amount of output transistors. Edited by shaun1264 - 3 hours 6 minutes ago at 3:26pm

Author: fudge22 Subject: Outboard DC protection for speakers? Posted: 01 October 2026 at 1:34pm In most of the amps I've seen recently, especially the plate amps, the SMPS is what goes bang, so no DC ever even gets to the output. That could be the solution. Just replace that heavy transformer, etc. with some cheap SMPS!! From the original post. I still run a matrix ukp2100X (smps) for my live band rig.

Author: fatfreddiescat Subject: ev dc one in bootloader mode/bricked Posted: 01 October 2026 at 8:12am This^^ a PC with a with a built in serial port running XP. Failing that it may be a case of finding another and copying the firmware off of the eeprom using a chip reader onto another, if it is a removable chip.

Author: coolboarder Subject: ev dc one in bootloader mode/bricked Posted: 30 September 2026 at 8:45pm Had the same once. Xp compatibility mode didn’t work from various PCs. Got an old real XP laptop from eBay and could recover the dc one immedialty. Was worth the 20 bucks. Since then, only xp laptops or manual control. Cheers Fabian

Author: Sypa Subject: Best budget 4/8 LMS for Approx £500 Posted: 30 September 2026 at 6:30pm One in the XTA DPA 100 .

Author: delapoer Subject: Best budget 4/8 LMS for Approx £500 Posted: 30 September 2026 at 5:27pm Which XTA are you using?

Author: levyte357- Subject: Ideal HOG driver? Posted: 30 September 2026 at 4:35pm paulus wrote: i know a crew who made switch from 1850s to sw115 in hogs ( k20 ) and he says he has never looked back for reliability and shear air , but also said misses the certain "tone" of the 1850s , I my self if I had hogs would change as the b n cs are such a strong driver having ran them for over 2 years myself the amount of silly low eq you can give them is next level !!!! saying that i have just gone full circle and gone back to 1850s for a bit but once I get 1 casualty it will be an 18 sound driver for me for some testing , Nothing like actual feedback When I had '9601's in my Scoops, I was amazed at how sensitive they were for such a hefty driver, 5.3" VC !! 1x per channel of a QSC RMX 5050 made plenty of noise, just like an 1850, even though well under powered. Edited by levyte357- - 3 hours 11 minutes ago at 4:36pm

Author: Lucasdude Subject: Subwoofer with adjustable mass Posted: 30 September 2026 at 3:17pm https://www.audiotec-fischer.de/en/helix/subwoofers/iq-w12-dvc2 In a nutshell, you pop off the dust cover and either add or remove disc weights to raise or lower the moving mass thereby adjusting the drivers fs. New one on me!

Author: Earplug Subject: Outboard DC protection for speakers? Posted: 30 September 2026 at 12:50pm "In an amplifier with a dual rail power supply, the current could be in either direction, so there is a 50% chance that the magnet you glued to the relay is the wrong polarity because the “wrong” output devices shorted." Funnily enough, the proliferation of Class D & SMPS has most probably made the problem of blown O/P devices a bit less common. In most of the amps I've seen recently, especially the plate amps, the SMPS is what goes bang, so no DC ever even gets to the output. That could be the solution. Just replace that heavy transformer, etc. with some cheap SMPS!!

Author: kedwardsleisure Subject: Outboard DC protection for speakers? Posted: 30 September 2026 at 12:27pm I am very sceptical that they work. you'll have to take that up with the manufacturers who see fit to use them.

Author: fudge22 Subject: Outboard DC protection for speakers? Posted: 30 September 2026 at 10:45am The magnet pulls the arc to one side and makes it harder to maintain. Cloud used them, I think some crests, alot of the magnets ended up stuck to the side of the enclosure over time. Quite a few amp manufacturers down here, like DAS used them, as well as a few more, like Ecler (IIRC). If these are just a small magnet glued on to the side of a standard relay, I am very sceptical that they work. I’m not saying that the concept is unsound. There are commercial relays available that have magnets built in to them for this very purpose. However, it might be worth noting that the arc deflection is polarity dependent. Relays with inbuilt magnets are designed for applications where a DC current is in a single known direction. In an amplifier with a dual rail power supply, the current could be in either direction, so there is a 50% chance that the magnet you glued to the relay is the wrong polarity because the “wrong” output devices shorted. If you are experimenting, perhaps a snubber circuit across the contacts might be a simpler way to go. They can be quite effective. Another alternative to the crowbar circuit, I mentioned previously, is creating a hybrid relay. A couple of MOSFETs can be wired across the relay contacts. The mechanical relay has inertia, so in electronic terms, the contacts move slowly. The MOSFET drive circuit can be designed to turn on before the relay and turn off af