The Dude Posted March 21, 2016 Share Posted March 21, 2016 I know this can be fairly common issue, along with being tackled many ways. But I thought I would check here first, doing so always saves me money. Like the title says, when I turn on my receiver Integra DTR 40.2 I have the 12 volt trigger line out to a Niles APC-3 trigger. I used this with my McIntosh MC2100 with no problems. Now with the Bryston 2b's, I get a very loud pop/thump when powering on and off. I will note I am running a 2 way active system, using MINIdsp for the crossover. I get this thump on both the mid/hi horn as well as the bass bin. One of the ideas is to solder a cap across the mains at the switch. But I have no idea what kind or value of cap to do. Another idea is a delay box/gadget/do hicky of some sort. Could a different pro crossover take care of this? So what do you guys do that have this issue? Thanks Quote Link to comment Share on other sites More sharing options...
Zim. Posted March 21, 2016 Share Posted March 21, 2016 x 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 21, 2016 Share Posted March 21, 2016 I think you need to send them to me... ;-) Bruce 2 Quote Link to comment Share on other sites More sharing options...
Paducah Home Theater Posted March 21, 2016 Share Posted March 21, 2016 Google "SurgeX ICE", or the sequencers. The ICE stuff may fix the turn on problem. http://www.surgex.com/pdf/surgex10004_ICE.pdf Although, are you sure it's not the MiniDSP when turning off? They are apparently notorious for causing big pops like this when turned off. I've heard that some people just leave them on all the time to avoid this. Quote Link to comment Share on other sites More sharing options...
Fjd Posted March 21, 2016 Share Posted March 21, 2016 (edited) I know this can be fairly common issue, along with being tackled many ways. But I thought I would check here first, doing so always saves me money. Like the title says, when I turn on my receiver Integra DTR 40.2 I have the 12 volt trigger line out to a Niles APC-3 trigger. I used this with my McIntosh MC2100 with no problems. Now with the Bryston 2b's, I get a very loud pop/thump when powering on and off. I will note I am running a 2 way active system, using MINIdsp for the crossover. I get this thump on both the mid/hi horn as well as the bass bin. One of the ideas is to solder a cap across the mains at the switch. But I have no idea what kind or value of cap to do. Another idea is a delay box/gadget/do hicky of some sort. Could a different pro crossover take care of this? So what do you guys do that have this issue? Thanks I’m aware of the following potential causes for the loud thumps. 1. Spark or brief electric arc caused by main power on/off switch of power amplifier. Each time the amplifier is switch on or off, a spark jumps across the gap. It can get pretty loud, especially if you are not expecting it. 2. Inrush current surges where there is an instantaneous input current draw by the transformer when the amplifier is first turned on. When an E-core transformer is first energized, the transient current can increase up to 15 times larger than the rated transformer running current. Toroid transformers can have up to 60 times inrush to running current. 3. DC offset at the output of your power amplifier, which is typically not nearly as loud of a thump (much more mild) as the spark/electric arc thump. If you have DC Offset voltage issues, the addition of an output relay with a delay will eliminate the thump sound on power up. However, this only removes the “sound” and does not solve any potential amp issues if the DC Offset is actually too high at the output. In relation to the spark/electric arc and inrush current surge issues, you will notice in the pictures below that the First Watt clones use CL-60 negative temperature coefficient (NTC) thermistors as in-rush limiters and X1/Y2 safety capacitors to suppress the spark or electric arc at the amplifier on/off switch. One CL-60 thermistor is wired in series between each of the AC mains from the IEC switch and connecting with each of the two transformer primary windings. The X1/Y2 safety capacitor wired in parallel to the main input, along with the switch and fuse. I believe many of the builders use the X2, which is fine; however, I have been using the following X1/Y2 safety class Murata ceramic disc capacitor (3300pF 250Vrms) in my amplifiers. http://www.mouser.com/ProductDetail/Murata-Electronics/DE2E3KY332MN2AM01F/?qs=sGAEpiMZZMsh%252b1woXyUXj%252bDtK1GHZzSD30dvJh7rnkA%3d This link has a section regarding the various classes of safety capacitors and how they are used. http://www.justradios.com/safetytips.html . Edited March 21, 2016 by Fjd Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 21, 2016 Author Share Posted March 21, 2016 Although, are you sure it's not the MiniDSP when turning off? They are apparently notorious for causing big pops like this when turned off. I've heard that some people just leave them on all the time to avoid this. I leave mine on all the time as well. Thanks for the link. I think you need to send them to me You don't want these, they sound horrible . But if you chose to damage your hearing by this horrible sound, I just so happened to stumble across one here locally. http://omaha.craigslist.org/ele/5482356587.html I don't know what this guy is smoking, but I haven't seen one go for $2150 anywhere (well except new). Plus he is using other photos, his add smells fishy. All the early 2B did this. The one I owned suffered the same condition. At one time, if you sent them back to Bryston they would modify them to eliminate the thump free of charge. Can't help with a home remedy but it probably isn't too difficult to cure. The problem lies with the amp, not the other components in your system. I think this will be my first step, to call Bryston and see what they recommend. Fjd, thanks for the info, if Bryston has no solution I will look into what you posted. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 21, 2016 Share Posted March 21, 2016 I found a couple of the 2B LP models at a reasonable price, but I would be smoking something myself if I thought I could buy one right now, even at the lower prices... Bruce 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 21, 2016 Author Share Posted March 21, 2016 I spoke with Mike over at Bryston. He informed me that if the units are still under warranty, that all I have to do is send them to them and they will update them. However there was no guarantee that this would eliminate the sound all together. I will call him with the serial number tomorrow and see what he says. If they are out, I will look into installing a cap like what FJD is referring to. I found a couple of the 2B LP models at a reasonable price, but I would be smoking something myself if I thought I could buy one right now, even at the lower prices... Its crazy what these things go for, even crazier if you knew the deal I got on them. Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 22, 2016 Author Share Posted March 22, 2016 If I delay turning on the amps. This time I turned on the receiver, then waited about 20 secs (maybe) before turning on the amps. At this time I heard not thump or pop. Could it be just a delay is needed to keep from thumping/popping? Are amps for home theater designed with this in mind? Or should these not do it at all? Hmmm, again if it cost me little to ship them and have them checked over, what could it hurt? Quote Link to comment Share on other sites More sharing options...
jason str Posted March 22, 2016 Share Posted March 22, 2016 My Adcom GFA 5500 thumps on and off, done this since new. Dims the lights in the whole house when turned on as well. Never had a problem with it. 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted March 22, 2016 Share Posted March 22, 2016 My Adcom GFA 5500 thumps on and off, done this since new. Dims the lights in the whole house when turned on as well. Never had a problem with it. Unless all of the lights in your whole house are on the same circuit as your amp, you need to see if you are getting adequate power to your main service. Right off the bat, I would check AC voltage on both legs. I found mine to be low, and the power company replaced my transformer free of charge. What I also learned from this experience is that low voltage can hurt appliances. I also learned that connections can get loose in the breaker box where the main service comes in. I think that about covers it. There's probably more, but it's been a long time since I had this problem, and it was when the A/C came on. Quote Link to comment Share on other sites More sharing options...
jason str Posted March 22, 2016 Share Posted March 22, 2016 My Adcom GFA 5500 thumps on and off, done this since new. Dims the lights in the whole house when turned on as well. Never had a problem with it. Unless all of the lights in your whole house are on the same circuit as your amp, you need to see if you are getting adequate power to your main service. Right off the bat, I would check AC voltage on both legs. I found mine to be low, and the power company replaced my transformer free of charge. What I also learned from this experience is that low voltage can hurt appliances. I also learned that connections can get loose in the breaker box where the main service comes in. I think that about covers it. There's probably more, but it's been a long time since I had this problem, and it was when the A/C came on. No problem with the wiring, this amplifier has been used in many different residences over the years and every one had the same thing happen. Just powering up those big capacitors at startup. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted March 22, 2016 Share Posted March 22, 2016 My Adcom GFA 5500 thumps on and off, done this since new. Dims the lights in the whole house when turned on as well. Never had a problem with it. Unless all of the lights in your whole house are on the same circuit as your amp, you need to see if you are getting adequate power to your main service. Right off the bat, I would check AC voltage on both legs. I found mine to be low, and the power company replaced my transformer free of charge. What I also learned from this experience is that low voltage can hurt appliances. I also learned that connections can get loose in the breaker box where the main service comes in. I think that about covers it. There's probably more, but it's been a long time since I had this problem, and it was when the A/C came on. No problem with the wiring, this amplifier has been used in many different residences over the years and every one had the same thing happen. Just powering up those big capacitors at startup. OK... Big *** amp with big *** caps. That there is what I call a man-sized amp. Quote Link to comment Share on other sites More sharing options...
jason str Posted March 22, 2016 Share Posted March 22, 2016 I wonder if the newer Nelson Pass designs do this as well ? Quote Link to comment Share on other sites More sharing options...
Zim. Posted March 22, 2016 Share Posted March 22, 2016 x 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted March 22, 2016 Share Posted March 22, 2016 I don't know if there is a design flaw in these amps or not, Bryston should and they should 'fess up and fix for you if so IMHO. But as a general rule in systems with with separate preamps, processors, mixers etc... and power amps: Power amps are turned ON LAST and turned OFF FIRST. 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 22, 2016 Author Share Posted March 22, 2016 I don't know if there is a design flaw in these amps or not, Bryston should and they should 'fess up and fix for you if so IMHO. But as a general rule in systems with with separate preamps, processors, mixers etc... and power amps: Power amps are turned ON LAST and turned OFF FIRST.That is the sequence i follow. However when i turn off the power amp first i get a thump/pop. Sent from my SM-N920P using Tapatalk Quote Link to comment Share on other sites More sharing options...
babadono Posted March 22, 2016 Share Posted March 22, 2016 Ok, then it sounds like there is a design flaw in the amp as "Zim" stated. Like you need a relay on the amp outputs that you turn on after the amp has stabilized and turn off before you turn off the amp. That would suck. IMHO. Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 22, 2016 Author Share Posted March 22, 2016 One of the amps is under warranty still. So i will send that one in, to see what happens. If the update takes care of the problem, they quoted around 85 to fix the other. Sent from my SM-N920P using Tapatalk Quote Link to comment Share on other sites More sharing options...
babadono Posted March 22, 2016 Share Posted March 22, 2016 Cool-- If the first one does get fixed this way I would still press the point that it appears to be a design flaw that THEY should cover. I mean it is not like you damaged the amp. It has always done this. But I'm a d%$k about this kind of stuff. 1 Quote Link to comment Share on other sites More sharing options...
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