Problem w/ my new amp (XPA)

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acsubie
acsubie Posts: 773
edited March 2008 in Electronics
1st off let me start off by saying that i had an LPA-1 before with the same exact setup and it gave me zero problems

i am using an 805 with my XPA, seems like every time i change the source(cable to dvd, fast forward/skip chapter etc) my XPA shut downs and the leds blink, any interruption to what is currently playing causes this

never had this problem with the same exact gear i was using with my LPA, what i have noticed is that the channels that the LED light up to are the ones that im using silver ICs with, but like i mentioned earlier it never gave me a problem on the LPA..i made sure the signal arrow on the IC is correct(arrow from 805 to XPA)...cant figure it out, even tried plugging the power cord directly to the wall,

can anyone chime in and give any feedback on this issue...for sure its weird and im sure i will get it worked out in no time
Post edited by acsubie on
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  • apphd
    apphd Posts: 1,514
    edited March 2008
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    acsubie, not familiar with both (but would like to hear more about the XP5) but are you using a trigger from the 805 to turn on the XP5? Just a SWAG here but maybe when you change sources, some type of noise or something is going on there. If the trigger on the XP5 is more sensitive than the LPA1 you see it there but not on the latter. Like I said this is a SWAG since I do not know how the trigger feature works. Is it a steady voltage that needs to be present or a pulse that when seen by the amp will change the on/off status?
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    not using a trigger...switched to some cheapo ICs(stock red/white/yellow) and now i have no problems what so ever...has to be the characteristics of the silver ICs i got from ben, i'll have him chime in when he returns

    but ticks me off that i didnt have this problem with LPA and the silver ICs...got some signal silvers this week from the site so i'll see if the problem happens with them

    but even with the cheapo ICs the XPA throws out tunes with authority!
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  • apphd
    apphd Posts: 1,514
    edited March 2008
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    Good news to hear you are back in business and enjoying the new amp. Is pretty strange though. After you have a little time to put it through a good audition how about an update on what you think?
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  • WilliamM2
    WilliamM2 Posts: 4,811
    edited March 2008
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    Grab a multi-meter and check the cable. It may be shorting out, to check, connect the meter to the center pin and the outer ring, wiggle the cable around and see if you get continuity. You shouldn't. Try it at both ends.
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  • Early B.
    Early B. Posts: 7,900
    edited March 2008
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    It appears that a couple of other folks on the Emo forum have run into this issue with the XPA-5 and had to change out cables to get it working. The amp must have some sort of sensitivity to certain kinds of cables.
    HT/2-channel Rig: Sony 50” LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub

    "God grooves with tubes."
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  • WilliamM2
    WilliamM2 Posts: 4,811
    edited March 2008
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    I've heard of amps having problems with cable of really high impedance or inductance, can't remember which. Ben's cable are straight wire though, so I wouldn't think they would be a problem, unless one is shorting.
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  • Poee7R
    Poee7R Posts: 906
    edited March 2008
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    Sounds like a grounding issue to me.

    Any which way you shouldn't have to suffer with lesser rca's, so why dont ya just pack it up and send it to me and Ill do the suffering for ya. :D


    Dave
    Once again we meet at last.
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
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    Double check with a multi meter as mentioned above. One of the draw backs with solid wire is they are more likely to break at the connection. I have changed the way I build the cables so they are more resilient to breakage, but I run mine like the old style(straight braid with no sheathing). If the pin is shorted to the shell then you will have issues. If they are broken I'll repair them free of coarse. As for capacitance, or inductance these wires are extremely low on both counts(no problems). These types of issues are usually related to speaker wire, not IC's.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    thanks for chiming in ben, im pretty sure there is no break in the connection, how can i find out of the pin is shorted to the shell?
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
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    You need a multi meter, and check for continuity between the pin, and the outer connector. If there is continuity between the two then the cable is touching some where. Also test from center pin to center pin from one end to the other. Have you tried them between you CD, or DVD, and your receiver to see if there is a problem with them? Bill has described the process accurately.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    no problem when i used them on my cd player, just the XPA..ill have to get a multi meter then
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  • mmadden28
    mmadden28 Posts: 4,283
    edited March 2008
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    I just read something a couple days ago on the Emotiva site about this known issue specific to the XPA-5-I think it was mentioned that the cables were the cause, but the actual reason was unknown thus far. Of course I can't find it right now.
    ____________________
    This post is a natural product. The slight variations in spelling and grammar enhance its individual character and beauty and in no way are to be considered flaws or defects.

    HT:Onkyo 805, Emotiva XPA-5, Mitsu 52" 1080p DLP / polkaudio RTi12, CSIa6, FXi3, uPro4K
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    From Lonnie over at Emotiva

    Even though the topology of the XPA series is based on the LPA design, there are some differences which give it a vastly improved frequency response. So much so that it could become an AM transmitter. The design and parts used in the XPA series give it a huge band width. To that end we incorporated bandwidth filters to limit the top end of the spectrum to about 100K give or take a little. This is one of the reasons the XPA series has such an open, non-compressed sound stage (not that the LPA is a slouch in anyway). Even with the filters the amp stage itself is still capable of reproducing ultra high frequencies that you could not hear, nor would your tweeters even hope to play. None the less the energy from those high frequecies could easily roast your tweeters and you wouldn't even know what happened. Thus the protect circuit monitors the frequencies as well as the power supply, inputs, outputs, amp stage and even your speakers.

    So it is my guess that your cables are picking up some super high frequency noise. It could be a cell phone tower, a micro-wave repeater beaming across your house, who knows for sure. But it is a safe bet that what is happening is the cables are picking it up, feeding it into the amp, possibly causing a beat note effect and the protect circuit is shutting down the amp to protect your speakers. Without having a cable here to test, I honestly can't say what it is about them that makes them more suseptable to high frequencies, but a fair guess would be the lower reactance of the cable (i.e lower resistance and capacitance) which would attenuate the band at much higher frequencies and allow more noise to be introduced. Beleive it or not, but having a certain amount of reactance in the cables is a good thing. When you are dealing with low frequencies (like the audio bandwidth) a small amount of reactance will prevent or really limit out of band noise. The easy solution would be to change the cables. However, if you really want to use those cables give me a call on Monday and let's discuss options.

    BTW. I just got back from China and I am working off a 14 hour time difference, so if some of my ramblings don't make since, please be kind. ;D
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
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    Emotiva XPA fans aren't going to like this, but it sounds like a design flaw to me from what Emotiva is describing. Nearly all good amps have negative feedback loops to kill any sort of feedback, or oscillation. I don't have any experience with Emotiva, but it seems like an isolated issue. You could try twisting the cables around each other about one turn every 2 inches, and I would be interested what they want you to try. Also be careful when routing them. I have never had any noise issues, and only had one customer complain of this, but he was using a transformer on a turntable that did not play nice with those cables.
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    the braid trick did not help :(

    ben do you make non-silver ICs
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
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    acsubie wrote: »
    the braid trick did not help :(

    ben do you make non-silver ICs

    Nope. There are hoards of them out there, and the issue is not the material, or design of the IC's; its the equipment. They have worked fine in every case except for the one I mentioned above, and all your other equipment. A manufacturer telling you your cables are built to good for that amp is crazy. They should just come out and say "please use cheap cables with our amp because we f'ed up the design, and it would cost more to revise something simple than make it work right for the smaller percentage of customers who use good cables". As far as switching to a high quality copper the inductance, and capacitance of copper is nearly identical to silver. I don't remember how many IC's you bought from me, but I can work with you if you really want to keep that amp. Sorry man. I hope you aren't reading this a insulting you, or harsh to you in any way. I just get pissed when companies put stuff out without catching something like that. Hopefully they take care of their customers, and have a solution that doesn't involve having to use high inductance/capacitance cables. Please let me know what they say.
    Thanks
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • ben62670
    ben62670 Posts: 15,969
    edited March 2008
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    ....
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
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  • acsubie
    acsubie Posts: 773
    edited March 2008
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    no insult taken ben...i bought a set of 5, its definitely an issue with the amp because mine is not an isolated issue...well see what they say
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