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Post by leonski on Oct 3, 2014 3:16:40 GMT -5
Ncore and B&O modules would end up being a fairly expensive amp. A less expensive choice would be to go with International Rectifier modules. I have a developement module and it sounds fine to its limits. I used it with my Maggies and it worked fine with the 4ohm impedance and even played fairly loudly, until simply runningg out of power. I think I have the 125x2 module. I may not have an optimum (high limit voltage) PS, either. But to confirm that I'd have to dig into the amp again. www.mouser.com/new/International-Rectifier/IR-IR43xx-amplifiers/Something from the above list would be fine for low power applications:
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Post by Cogito on Oct 3, 2014 6:28:04 GMT -5
Ncore and B&O modules would end up being a fairly expensive amp. A less expensive choice would be to go with International Rectifier modules. I have a developement module and it sounds fine to its limits. I used it with my Maggies and it worked fine with the 4ohm impedance and even played fairly loudly, until simply runningg out of power. I think I have the 125x2 module. I may not have an optimum (high limit voltage) PS, either. But to confirm that I'd have to dig into the amp again. www.mouser.com/new/International-Rectifier/IR-IR43xx-amplifiers/Something from the above list would be fine for low power applications: Not sure about nCore, but ICEpower based amps can be very reasonable. One great example is Class D Audio's SDS-470C. At $695.00 for a 300/600W/ch 8 Ohm/4 Ohm stereo amp makes it a pretty good deal in my book. LOOK HERE
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Post by leonski on Oct 3, 2014 11:13:42 GMT -5
B&O makes a series of modules. For example, the ASP series Includes an on-board switching power supply. This means you just need to hook up mains power, an input and speaker. Do that 2x and you have a stereo amp. Other 'seriess' need power. Like whatever series is used in the SDS-470C, above. Photos of the interior show a torrid and capacitor board. IOW, a conventional, 'linear' supply. In a bi/tri amped system, you CAN draw power from another module. I'm not current, but here's a link to the B&O site and a listing of current modules, by series. www.icepower.bang-olufsen.com/en/downloads/You must be careful with 'D' power ratings. If anyone cares, I'll go into it or you can look into the REAL data yourself and tell ME!
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Post by Cogito on Oct 3, 2014 11:28:23 GMT -5
If given the choice, I would go linear over switching. Linear tends to be a lot quieter (RFI) and less problematic in design and reliability. The Class D Audio power supplies seem nicely over-engineered, much akin to Emotiva's designs.
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Post by leonski on Dec 29, 2014 3:56:25 GMT -5
Circuit layout for 'd' amps is a big deal, I'm told. Don't forget the high frequency, maybe 250khz to 450khz triangle wave that goes with the 'd' amp. AM radio starts at 550khz or so, which means the 2nd harmonic is IN range for an AM radio. Here is a good article from International Rectifier. I think these guys OEM for some 'lower' end stuff, but don't let that fool you. I've spoken with the designer at length, and have had good luck with an older 'reference design' 2-channel amp. www.irf.com/product-info/audio/classdtutorial606.pdfThe article claims a THEORETICAL 100% efficiency, but due to RDON, (device resistance in its ON condition) this'll never happen. And don't forget you have OTHER parts of the circuit, too. The B&O ASP modules run 80%+ at FULL POWER. Lower powers result in lower efficiency. I'm a linear guy, too. At least for the DIY guy, you can plug thru the calculations, use a few well tested 'rule of thumb' estimates and come up with a nice, working PS. I wouldn't know where to BEGIN if someone asked for help with a switcher.
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Post by bolle on Dec 31, 2014 9:50:43 GMT -5
I replaced my 7-350 with 2x IMG STA-2000D amplifiers. SMPS with 2 Pascal Audio S-Pro 2 Modules for each amp for 4x500W at 4 Ohm. Sonically they are a bit better than the 7-350 for my ears, especially more control at high volumes and better bass separation. Both may have to do with my difficult to handle speakers which dip under 3 Ohm - digital amplifiers tend to handle this better in my experience. Here a link to the datasheet of the OEM, Pascal Audio: www.pascal-audio.com/downloads/S-PRO2_Datasheet-1_20.pdfPerhaps another alternative to B&O or IR... Hypex UCD is clearly inferior in my ears (also in comparison to the 7-350 the UCD loses by a wide margin), to nCore I didn´t directly compare.
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Post by Gary Cook on Dec 31, 2014 12:51:50 GMT -5
Kinda oxymoronic isn't it? One of the claimed big advantages of Class D amps is their efficiency, not a lot of heat produce as the input power results in output not wasted. Yet the covers are left off to "optimise the cooling".
Happy New Year Gary
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Post by leonski on Jan 1, 2015 7:53:04 GMT -5
Must distinguish between 'plug to speaker' and output only. Since the output of a 'd' amp is either ON or OFF, it will be pretty efficient. Power supply? Input stage which COULD even be class 'a'? Not so much. The B&O callout for the ASP modules, which are power supply AND amp on a single compact board, is 80%+ AT FULL POWER. There is even a slight difference between 8ohms and 4ohms in that spec. I suspect the output stage ONLY could run 90%+, again at full power. But NOT for long. Time / Power limits for 'd' amps are another story for another thread.
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Post by arcticemotiva on Jan 3, 2015 1:01:32 GMT -5
Not been a poster here but here is a vote for an Emotiva Class D. Something to be said for smaller, lighter, and more efficient as long as equal or better sound can be had without breaking the wallet. Been looking at Wyred 4 Sound stuff... would love to see Emotiva shake up that market some.
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Post by leonski on Jan 4, 2015 23:48:41 GMT -5
Be ready for some potential tradeoffs. I OWNED a 'd' amp for several years and sold it in favor of a more conventional A-A/B amp. And while the power / time limits never interferred with my experience, the HIGHS were eventually a little grating. I more than suspect something to do with the high frequency (maybe 400khz) triangle wave which runs the whole thing. No matter what you do, you end up with phase shift in the highs and mediocre square wave response. Most 'd' amps are also sensitive to load impedance, with falling HF response with lower impedance.
There are many hurdles to overcome with perfecting 'd' amps, though I will admit that much progress has and IS being made. The N-Core stuff gets great reviews as do a few modules which start from B&O and are modified by the end users.
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Post by charlieeco on Oct 10, 2015 14:54:10 GMT -5
Hi Emotiva Fans It´s been quiet around this Thread for a while. I´m going to share my last experience with class D amps and Class A/B amps. Last week I visited an Audio Shop near by Miami, Fl. and it happens there were in store a pair of Bryston Monoblocks 7BSST paired with Magnepans 1.7 and sounded so good to everyone in the room (the amps cost 8k a pair) and there was some customer trying to convince the salesman to wire a D-sonic stereo clas D amplifier (he brought into the store under his arm, don´t know the model but he said it was a colosal 1000 watts pc into 4 ohms, off course nobody in the room belived to him) to the Magnepans, He finally convinced the salesman to do so, the results were spectacular, as pure and neutral as the Bryston sounded very very comparable to, the guy ended up buying the Magnepans, but everyone in the room were in shock when the guy told us he paid $1700 for the class D amplifier. Being Emo fan, I would be very interested in an Emotiva Class D amp in the very near future, please Emotiva people let us know when, I bet there´s a bunch o fans waiting for. Happy listenning
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Post by leonski on Oct 14, 2015 20:12:09 GMT -5
Bryston may NOT be the best match for Maggies. Try some ARC tube gear. Even Mc is not universially praised. Pass comes close to 100% but are pretty pricy. I went from 'd' to a traditional Parasound. Hurdles to make 'd' work for EMO? Buy a module or original design? Can you make the financial numbers work? If I was EMO, I'd consider a powered sub with an EMO 'd' amp making it work.
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klinemj
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Post by klinemj on Oct 14, 2015 20:18:49 GMT -5
Hi Emotiva Fans It´s been quiet around this Thread for a while. I´m going to share my last experience with class D amps and Class A/B amps. Last week I visited an Audio Shop near by Miami, Fl. and it happens there were in store a pair of Bryston Monoblocks 7BSST paired with Magnepans 1.7 and sounded so good to everyone in the room (the amps cost 8k a pair) and there was some customer trying to convince the salesman to wire a D-sonic stereo clas D amplifier (he brought into the store under his arm, don´t know the model but he said it was a colosal 1000 watts pc into 4 ohms, off course nobody in the room belived to him) to the Magnepans, He finally convinced the salesman to do so, the results were spectacular, as pure and neutral as the Bryston sounded very very comparable to, the guy ended up buying the Magnepans, but everyone in the room were in shock when the guy told us he paid $1700 for the class D amplifier. Being Emo fan, I would be very interested in an Emotiva Class D amp in the very near future, please Emotiva people let us know when, I bet there´s a bunch o fans waiting for. Happy listenning The 1.7's are a special speaker. I have no plans to get rid of mine. Mine did well with my XPA-2, but I really feel they went to a new level with my nCore Class D's (for $1500 for a pair of monoblocks!) Mark
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Post by GreenKiwi on Oct 15, 2015 2:04:48 GMT -5
Ditto for the nCores and 3.6s.
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Post by mgbpuff on Oct 15, 2015 8:42:06 GMT -5
I love my 3.6R's with XPA-1 (Gen 1) monoblock power.
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Post by leonski on Oct 15, 2015 13:19:08 GMT -5
I know it is tough but BIamping panels works wonders. A PAIR of the N-Cores per speaker? Nice. You'll need some speaker 'surgery' and a line-level crossover for best results. DSP may be the last system mod you'll ever make.
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Post by moovtune on Oct 15, 2015 14:11:34 GMT -5
I replaced all of my Emotiva amps with 3 D-Sonic Class D amps - a stereo with 600wpc, a 3 channel with 400wpc and a 4 channel with 400 wpc (all into an 8 ohm load- double that for 4 ohms). I've been very happy with them for over two years now and they're lighter and cooler too. The Emotiva's were great, but heavy and hot.
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Post by charlieeco on Oct 15, 2015 18:04:55 GMT -5
I replaced all of my Emotiva amps with 3 D-Sonic Class D amps - a stereo with 600wpc, a 3 channel with 400wpc and a 4 channel with 400 wpc (all into an 8 ohm load- double that for 4 ohms). I've been very happy with them for over two years now and they're lighter and cooler too. The Emotiva's were great, but heavy and hot. Hi moovtune, how do you feel about this class D amps? in terms of sound quality, what speakers are you using with them ?
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Post by knucklehead on Oct 15, 2015 18:13:26 GMT -5
I have a pair of Crown XLS-1000 amps and I'm planning on getting one more. Currently I have one driving the L/R song towers and the second one is driving the center channel speaker in bridged mono mode. For a paltry $169 its a no-brainer IMO. I may still own A/B amps but they'll be little ones - like the Emo Flex Amp I'm using to drive the zone II speakers. I will never have another amp that weighs anything close to or over my age.
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Post by moovtune on Oct 16, 2015 10:32:21 GMT -5
I replaced all of my Emotiva amps with 3 D-Sonic Class D amps - a stereo with 600wpc, a 3 channel with 400wpc and a 4 channel with 400 wpc (all into an 8 ohm load- double that for 4 ohms). I've been very happy with them for over two years now and they're lighter and cooler too. The Emotiva's were great, but heavy and hot. Hi moovtune, how do you feel about this class D amps? in terms of sound quality, what speakers are you using with them ? You can see my gear in the list below this posting. I've recently switched to Ascend mains and wides because of the great ribbon tweeter. I think if there were any issues with Class D amps for mid range and highs I'd have heard them by now with ribbon tweeters. I'm happy with the amps.
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