Members ToddAnisman Posted May 11, 2014 Members Share Posted May 11, 2014 Time for ChinoSound to Buy a pair of Amps, thinking IPR2 5000's to Run some JBL728 Subs. Little strong, but Like the ability to Run a pair on an Amp if necessary. Thoughts on the reliability of these at this point? I've been using tried & True QSC PLX3402's, but two of them are REALLY long in the tooth. They will be run of festival Power - diesel & Gas generators often. I remember the IPR's having issues with shutoff due to a grounding Issue, and Some problematic stuff, and poor service. These issue been remedied? Best Todd A. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted May 11, 2014 Members Share Posted May 11, 2014 Time for ChinoSound to Buy a pair of Amps' date=' thinking IPR2 5000's to Run some JBL728 Subs. Little strong, but Like the ability to Run a pair on an Amp if necessary.[/quote']I'd consider the 755 watts per driver that amp will supply to a pair of 728's quite OK without additional limiting as long as you have a proper HPF upstream . OTOH I'd not GAS out and buy them if I already had the PLX3402's - you only gain 1.4 dB (unless you buy into the "PLX suck on subs" thing). Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 11, 2014 Members Share Posted May 11, 2014 Todd, I may be interested in some aging 3402's... Link to comment Share on other sites More sharing options...
Members ToddAnisman Posted May 11, 2014 Author Members Share Posted May 11, 2014 RR - More of a "These amps have been ridden hard and put away Wet" kinda scenario, which is also why I'd not sell em - 7 Burns on em, hundreds of outdoor shows…. I think the 3402's are great on the 728's… but I also have 6 of them, 4 725's, and 2 722's… that come sot having 6 of them.. and I have only 4… use a borrowed QSC EX4000, and a PL1.8 on the 722's. SO thus the desire to have a few more amps. Todd Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted May 12, 2014 Members Share Posted May 12, 2014 I have 7 of the IPR's , 4-1600's and 3-3000's. I had an odd problem with two of the 3000's where they shut down and required repair. The issue was related to running my speakons adjacent to my snake for a distance. Something about the topography of those amps that makes that a bad thing to do. Peavey repaired them quickly and free even though they were past warranty. Link to comment Share on other sites More sharing options...
Members dboomer Posted May 12, 2014 Members Share Posted May 12, 2014 Sounds odd? Any more details about that? Link to comment Share on other sites More sharing options...
Members Pro Sound Guy Posted May 12, 2014 Members Share Posted May 12, 2014 That was the explanation Peavey had for the failures? Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 12, 2014 Members Share Posted May 12, 2014 An issue with class d amps in general is that the carrier leakage back into the input due to routing of an output close to the output over an extended length. The carrier residual couples into the input due to capacitive coupling so the inputs must be very very resistant to carrier residual. This means careful filtering and ground current routing to prevent contamination. One of class d's soft white under bellies. Link to comment Share on other sites More sharing options...
Members ToddAnisman Posted May 12, 2014 Author Members Share Posted May 12, 2014 Tomm - This is one of the issues i heard about - and I assume these are the Version 1 3000's? Aged - any reason to think this is a continued issue in the IPR2? whats your take? I could stick with a tried & True PLX,. don't think I would be worse for wear, hard to find softly used amps of those ilk these days. Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 12, 2014 Members Share Posted May 12, 2014 I wouldn't expect there to be any problems with the new IPRs Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted May 12, 2014 Members Share Posted May 12, 2014 Yes these were the original series IPR. I don't know if Peaveys repair addressed the issue or simply replaced bad parts to original specs. Regardless, other than that issue, I've put quite a few miles on them and like them. Just don't run the speaker cables alongside your snake!! Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 12, 2014 Members Share Posted May 12, 2014 Yes these were the original series IPR. I don't know if Peaveys repair addressed the issue or simply replaced bad parts to original specs. Regardless' date=' other than that issue, I've put quite a few miles on them and like them. Just don't run the speaker cables alongside your snake!![/quote'] Correct, running speaker lines parallel to mic lines over an extended distance is bad practice in general, worse in the case of class d due to the relative ease of carrier coupling and since the carrier contains some audio information the mic pres must have exceptional rfi filtering as rejection isn't happening at carrier frequencies. Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted May 12, 2014 Members Share Posted May 12, 2014 It seems that this condition is not widely known, I don't know when it was "discovered". It would be a good thing for it to be common knowledge at a basic level. I'm avoiding it regardless of amp class. Link to comment Share on other sites More sharing options...
Members ToddAnisman Posted May 12, 2014 Author Members Share Posted May 12, 2014 Correct' date=' running speaker lines parallel to mic lines over an extended distance is bad practice in general, worse in the case of class d due to the relative ease of carrier coupling and since the carrier contains some audio information the mic pres must have exceptional rfi filtering as rejection isn't happening at carrier frequencies.[/quote'] define "extended"? >25? 10? 50'?' Link to comment Share on other sites More sharing options...
Members Pro Sound Guy Posted May 12, 2014 Members Share Posted May 12, 2014 I found this on Wikipedias info on PWM amps [h=3]Electromagnetic interference[edit][/h] The switching power stage generates both high dV/dt and dI/dt, which give rise to radiated emission whenever any part of the circuit is large enough to act as an antenna. In practice, this means the connecting wires and cables will be the most efficient radiators so most effort should go into preventing high-frequency signals reaching those: Avoid capacitive coupling from switching signals into the wiring.Avoid inductive coupling from various current loops in the power stage into the wiring.Use one unbroken ground plane and group all connectors together, in order to have a common RF reference fordecoupling capacitorsInclude the equivalent series inductance of filter capacitors and the parasitic capacitance of filter inductors in the circuit model before selecting components.Wherever ringing is encountered, locate the inductive and capacitive parts of the resonant circuit that causes it, and use parallel RC or series RL snubbers to reduce the Q of the resonance.Do not make the MOSFETs switch any faster than needed to fulfil efficiency or distortion requirements. Distortion is more easily reduced using negative feedback than by speeding up switching. Link to comment Share on other sites More sharing options...
Members SoundMan Posted May 12, 2014 Members Share Posted May 12, 2014 Agedhorse nailed it. The problem has been addressed. I still wouldn't advise running an input in parallel with an output for very far. Just bad practice. Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 13, 2014 Members Share Posted May 13, 2014 Class d amps are a whole 'nuther animal when it comes to managing signal integrity. There are all kinds of coupling paths that are "hidden" when normal low frequency coupling mechanisms are assumed. At RF frequencies, insulators aren't insulators and grounds aren't grounds! Once that's understood, it makes more sense. Link to comment Share on other sites More sharing options...
Members Tomm Williams Posted May 13, 2014 Members Share Posted May 13, 2014 Just for the record, my cables and snake were adjacent for about 60 '. Don't know if a much shorter run would be safe but from now on they get seperated for any distance whatsoever. Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 13, 2014 Members Share Posted May 13, 2014 coupling is proportional to length. Link to comment Share on other sites More sharing options...
Members Two of Seven Posted May 13, 2014 Members Share Posted May 13, 2014 I have run into this idea a few times in various forums: "class d sensitive to the loudspeaker load due to their high output impedance" ...anything to it? Link to comment Share on other sites More sharing options...
Members agedhorse Posted May 13, 2014 Members Share Posted May 13, 2014 I have run into this idea a few times in various forums: "class d sensitive to the loudspeaker load due to their high output impedance" ...anything to it? Nope, total crap. Link to comment Share on other sites More sharing options...
Members race81 Posted May 13, 2014 Members Share Posted May 13, 2014 We are running two IPR 1600 (early version) that were sent in and repaired(modified). Worked great ever since. We are also running a IPR2 7500 with great results and no problems as of yet after running it for almost a year. Link to comment Share on other sites More sharing options...
Members Two of Seven Posted May 13, 2014 Members Share Posted May 13, 2014 We are running two IPR 1600 (early version) that were sent in and repaired(modified). Worked great ever since. We are also running a IPR2 7500 with great results and no problems as of yet after running it for almost a year. Care to share more on how you are using yours? I also have an IPR2 7500 and have had good luck with it. Even ran it 2 ohms dual mono a few times (carefully) to see how it behaved. Never broke a sweat. Actually getting ready to acquire another unit. Link to comment Share on other sites More sharing options...
Members Two of Seven Posted May 18, 2014 Members Share Posted May 18, 2014 Whoo-hoo, new IPR2 7500 arrived ! Whoo-hoo, D.O.A. ! Seriously questioning my karma........... Link to comment Share on other sites More sharing options...
Members ToddAnisman Posted May 20, 2014 Author Members Share Posted May 20, 2014 Seriously??? lord... Link to comment Share on other sites More sharing options...
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