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Post by leonski on Oct 17, 2015 3:18:53 GMT -5
moovtune, It would appear you have 4 kilowatts of 'd' amp. @8ohms. I trust you have 3 or 4 dedicated circuits for all that power? If NOT, you are either severely limiting max output (your house lights should flicker in time to the music) OR, more likely, you simply do not use nearly as much power as perhaps you think you need or actually USE. And I didn't even bother with an estimate of the REST of your extensive equipment list.
What led you to D-Sonic over some other 'd' amps? Bel Canto? PSAudio (used market) or maybe Spectron? and countless others using N-Core and B&O modules.
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Post by bolle on Oct 17, 2015 4:20:28 GMT -5
Of course you don´t use that much power...
In theory I also have 12x500W Class D and 2x900W Class AB with SMPS in my home Cinema on one 16A / 230V circuit. This is more about Impulse power available / not limiting your headroom.
Even just one 7-350 would be too much for a normal circuit here in Germany if you would listen to sine waves at full power.
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Post by leonski on Oct 17, 2015 15:52:20 GMT -5
many years ago I had a the Carver Cube called the M400t. It was only 200x2@8 and maybe 250x2@4. Amp had a Carver designed power supply and no capacitor larger than a 'c' battery. If THAT large. It also had 6 output devices per channel AND a 15 amp fuse on the mains input. When playing my panels (MG-1 Magnepan back than) at redline, it would flicker the lights in the house in TIME to the music. I'll guess NO higher than maybe 55% to 60% efficiency plug to speaker at full power. It ran fairly cool and only warmed when REALLY pushed. Right at the edge, it would blow the 1 1/2amp fuse for mid/tweet of the panel. 200 watts at 4ohms is only 28vac. And maybe 7 amps, which is probably what it would take to pop a 1.5amp fuse as 'peaks'.
All that is preface to the real power measure of 'd' amps. Nice of bolle to mention sine waves. That is of course the Non-Realistic test of all times. But that being said, some other informantion may help. Some works in FAVOR of such amps, like music has a 10db to 20db crest factor where the peak power is 10x or greater the RMS draw. This works in your favor. The 'dis' is that 'd' amps typically are TIME LIMITED at max power. Even the N-core with heat sink as part of the CASE, when mounted per spec, can only take so much full power / time before getting too warm. B&O modules list (for the ASP modules) either 30 seconds OR 60 seconds, depending on module. RMS (ftc method?) of the 250 watt module is not even HALF the 'rated' power AND in addition, there are frequency limits in high power use brought on by the OUTPUT ZOBEL.
Bolle? Isn't impulse power available sort of the same as NOT limitiing your headroom. I'll agree that headroom is a good thing!
I'd just say to be careful with 'd' amp power ratings. If in doubt, get a peak grab/hold true RMS meter and an SPL meter. To complete the kit, get a Kill-a-Watt power meter. Those, at least are fairly inexpensive.
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Post by bolle on Oct 18, 2015 3:19:19 GMT -5
The 'dis' is that 'd' amps typically are TIME LIMITED at max power. Even the N-core with heat sink as part of the CASE, when mounted per spec, can only take so much full power / time before getting too warm. B&O modules list (for the ASP modules) either 30 seconds OR 60 seconds, depending on module. RMS (ftc method?) of the 250 watt module is not even HALF the 'rated' power AND in addition, there are frequency limits in high power use brought on by the OUTPUT ZOBEL. Bolle? Isn't impulse power available sort of the same as NOT limitiing your headroom. I'll agree that headroom is a good thing! I'd just say to be careful with 'd' amp power ratings. If in doubt, get a peak grab/hold true RMS meter and an SPL meter. To complete the kit, get a Kill-a-Watt power meter. Those, at least are fairly inexpensive. That´s exactly what I meant regarding Impulse power and headroom. Perhaps I wasn´t so clear in my post. You are also right about power limiting. But even the 30 seconds mentioned would be enough - I can´t imagine any movie or Music with 30 seconds of continous full power... My Pascal S-Pro 2 digital amp modules, which are developed by ex B&O engineers, were measured with 2x506 watts at 4 ohm and Limit after 15 seconds to 2x342 watts when reproducing sine waves... The frequency spectrum goes from 6Hz to 44kHz with -3db each. No Problem imho with any real world material / Scenario.
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Post by leonski on Oct 18, 2015 3:37:35 GMT -5
One other 'fact' about 'd' amps. The high efficiency is largly an illusion. ALL 'd' amps efficiency numbers you see are rated at FULL POWER. As we agree, this is kind of a useless power, since if you are running at full power you have NO headroom. Also, few speakers are capable of sustaining such high powers for long. So, the result is that while many 'd' amps are 80% + from Plug to Speaker, that efficiency drops to conventional A/B range fairly quicly as power required drops.
Now, before anyone asks, YES. I HAVE owned 'd' amps. I owned the PSAudio take on the B&O ASP500 module. It was a fine, cool running piece of goods. But I could NOT live with the high frequency problems / interactions with my panels. That's when I starter investigating the facts and specs about them.
Also, IF it matters to you, and I'm NOT a spec hound, few 'd' amps will produce a proper square wave at 10khz.
If I had time, I'd link the B&O datasheet for ASP modules. You'll be surprised how their numbers match your Pascal's.
I read that the N-Core is 'load invariant'. This is NOT true of the B&O modules so they are doing something very different from each other. I suspect it may have somthing to do with the output Zobel. Also, when I spoke with Bruno P., he said his amps do well on square waves. I heard his stuff at some shows where we spoke and it IS very good indeed. I'd need it for a month with my setup to hear if what I heard at the show translates to my house.
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Post by bolle on Oct 18, 2015 5:50:48 GMT -5
There are at least 1 or 2 Generations of d-amps on the market newer than the B&O, much improved especially regarding different / complex loads and high frequency Response.
I tried the B&O Icepower myself, didn´t like them. Same goes for Hypex UCD.
I simply tried a lot of AB and D-amps in my System and compared, the specs are a nice Addendum but not the main Thing I care about... The specs of the B&O and the Pascal modules may be Close but the Pascal amps are sonically much improved to the older icepower - for me they are in the same class as the N-Core amps.
Regardless, I am looking forward to what Emotiva will use. I really don´t think it will be something entirely new but more a modification of an existing design.
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Post by leonski on Oct 18, 2015 14:37:17 GMT -5
Right: My experience was with the B&O ASP series. MUCH has been done since than. I don't have the money to try 'a lot of AB and D-amps in my System'. I think, based on my BRIEF listening experience with the N-Core 1200 or whatever at T.H.E.Newport that Bruno MAY have found the magic bullet. He also is a believer in LARGE amounts of NFB. Negative FeedBack is one of those 3rd rail issues that either elicits a Shrug or a Shriek. Bruno has found that LARGE amounts, like up to 60db is GOOD. I don't know, but I do know that the latest N-Core would appear to have little to no change in performance (except for power) as impedance changes. The usual Zobel interaction causes frequency response to begin the knee down at lower and lower frequencies as impedance drops. The Largest ASP Module was like 0.5db down at 20khz @4ohm. This causes HF PHASE SHIFT which what was apparently driving me NUTS with my panels.
And YES, for sure. A clean sheet design WITHOUT infringing on the various patents? Difficult, methinks. And the Lawsuits would be nutty. No, I think you're right. An adapted module or 'custom' would be the way to go. Now? On to price point. Don't expect it to be inexpensive.
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klinemj
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Honorary Emofest Scribe
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Post by klinemj on Oct 18, 2015 19:07:00 GMT -5
Once again....love my nCores...I think Bruno must be a genius.
Mark
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novisnick
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Post by novisnick on Oct 18, 2015 19:38:41 GMT -5
Hey Mark,,,,,,,,,,, Class A/B,,,,,,,,, class D whatever it takes!!!
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