NC400 anyone bridging it yet?

ted_b · « **Reply #40 on:** 12 Jun 2012, 03:11 pm »

Quote from: zybar on 12 Jun 2012, 03:03 pm

Understood.

Of course, I have the luxury of the having the built in subs and not asking the amps to handle below ~100 hz.

George

Good point, but don't the amps see it anyway, or is the crossover before the amps?

rklein · « **Reply #41 on:** 12 Jun 2012, 03:44 pm »

This may be a naive question. However...

Ted:

Is there any way that you could have a pair of NCores amping the tranmission line section of your Revelations and another pair for the top section? Or would that totally disconbumerate those beautiful crossovers I saw when listening to your system a couple of weeks ago.

In any case, I should have my NCores up and running this coming weekend and will be happy to let you "live" with them for some more time to see if you really need the extra ooomph that bridging would offer.

Regards,

Randy

Don_S · « **Reply #42 on:** 12 Jun 2012, 04:07 pm »

When the NC400s are bridged do any specs change besides power? When some amps are bridged the noise floor decreases significantly. That can contribute to a sense of increased dynamics.

ted_b · « **Reply #43 on:** 12 Jun 2012, 04:14 pm »

Randy, yes horizontal biamping would be an option, but it doesn't produce any more real voltage to the speaker as a whole (like bridging would, as each amp is still driven full-range i.e before the crossover). If I thought my tweeters were clipping I'd say biamping would help give them more headroom. May be bad logic though...

roscoeiii · « **Reply #44 on:** 12 Jun 2012, 04:18 pm »

Quote from: Don_S on 12 Jun 2012, 04:07 pm

When the NC400s are bridged do any specs change besides power? When some amps are bridged the noise floor decreases significantly. That can contribute to a sense of increased dynamics.

Bridging can lower the noise floor? My understanding was that a downside of bridging was a somewhat higher noise floor. Of course with the ncore specs, discussion of noise floor may be moot since they could be extremely low in either case.

Emile · « **Reply #45 on:** 13 Jun 2012, 08:10 pm »

my room opens into an L-shaped area about twice the size of the room but hey every room is/sounds different.. Impedance drops to ~2 ohms somewhere but its not that bad. They really have plenty power for most people, its just that I come from bridged spectrons with 10 times more power.. I know how plenty powerreserve sounds

But it doesnt matter, I'm buying 2 more pairs and am switching to active which in my case will around triple headroom from dropping coils/resistors and halving power draw.

Quote from: zybar on 12 Jun 2012, 11:56 am

Interesting...

My speakers are also a 4ohm load (Vandy 5A's) and even less efficient at 86 or 87 db's. My room is 29x17x8 and opens up into the kitchen and a 2 story entrance foyer. I played music so that it hit over 100 db peaks from 15-17' away and I never heard the amps clip, get hard or glassy.

Is that 4 ohm load a nominal 4 ohms with dips much lower?

Just goes to show...careful system matching is always required.

George

serengetiplains · « **Reply #46 on:** 18 Jun 2012, 01:17 am »

Re bridging, and depending on the topology of the amp in question, bridging can reduce power supply noise by summing output noise anomalies. Imagine a +going noise spike on the output of amp 1. All other things being equal (they never are, but bear with me), the same (or similar) +going spike will appear on the output of amp 2. These spikes will represent zero (or a small) voltage difference between + and – sides of the voice coil and thus will not actuate movement in the driver to the extent they are the same voltage spike. Noise reduction results.

Bridging an Ncore should provide this benefit---particularly, I would think, if the two bridged amps are driven from the same supply.

serengetiplains · « **Reply #47 on:** 18 Jun 2012, 07:03 pm »

Btw, I found this note on bridging from a manual for a UcD amp:

Because Ncore inputs float, I don't think ground connection is stipulated for unbalanced input.

One other point, Bruno suggests the capacitor probably should be a bit higher for Ncore bridging, like 150nF.

playntheblues · « **Reply #48 on:** 23 Jul 2012, 11:07 am »

Ok guys, I have ordered four NC400's and 4 SMPS600's. Uriah Dailey is putting together my bridged mono's. I am waiting to hear from Hypex as to the ship date as I get the information I will post it on a new thread. Also I will ask Uriah to post pictures as the build starts. YAHOOOoooOOooOo

playntheblues · « **Reply #49 on:** 25 Jul 2012, 01:54 pm »

OK they shipped my 4 NC400's and 4 SMPS600's on Monday the 23rd, whew, now they are out and won't be shipping again until 9/3/2012. Case's ordered from Robert. We are moving in the right direction.

dan92075 · « **Reply #50 on:** 21 Aug 2012, 11:38 pm »

I would agree with prior posters that the Spectron in stereo mode is descent but bridged (mono) mode takes it to a whole new level.

I think the benefit of bridging has to do with cancellation of distortion though and not noise as a prior reviewer explained. Any class D amp I have ever tried already had no hiss even if I put my ear up to the tweeter. But just because they have low levels of noise by no means meant they all sounded good. In contrast I have owned Class A/AB amps that sound phenomenal which however have an audible hiss if you put your ears next to the speaker.

So again, I think its pretty much a distortion cancellation phenomena.

For Spectron when you bridge - one way to think about it is you are cancelling distortion. The other way to think about it is your effectively taking the 500kHz sampling rate and doubling it to 1 Mhz. So what you notice is not only less distortion in midrange but also extended treble.

Mark Levinson in their 53 and did a full 2 MHz - so I would expect this Class D amp does not have any high frequency issues (although I have never heard it). Effectively what they did is bridged 4 amps each switching at 500kHz (and also did so in a syncronized fashion)

So in any case one of the key benefits of bridging the NC400s (if done properly) should be less distortion and better high frequency performance I would expect?

serengetiplains · « **Reply #51 on:** 22 Aug 2012, 01:32 am »

Dan, if you're referring to me, by noise I meant distortion. Anything emerging from the output terminals of the amp that is not an amplified replication of the input signal is noise, or distortion. That noise may be modulated by the signal, but it's noise all the same.

dan92075 · « **Reply #52 on:** 22 Aug 2012, 04:57 am »

I am a comm engineer and for us the terms distortion and noise mean different things, but now I see you are using them in a loose way
So I think then we are on the same page. . .

Anyways, I am curious now to hear what the results are from the bridging!

playntheblues · « **Reply #53 on:** 22 Aug 2012, 12:11 pm »

Ok guys the bridged mono's are being assembled, I will have pictures either tomorrow or Friday. Uriah is actually putting a board in that has mosfets tied to a switch that will allow stereo, dual parallel or bridged mono. Hoping this covers all options.

GS · « **Reply #54 on:** 3 Sep 2012, 12:04 pm »

Serengetiplains
Waiting for the explosion.....
Is there any news about the bridging "master"piece
Jerry

playntheblues · « **Reply #55 on:** 3 Sep 2012, 01:24 pm »

Well I don't know about master piece but it is done and going through the final testing. We decided against the the mosfet board for switching and just made it a straight forward bridged mono. If I need dual parrell or a stereo amp I will just have to rewire. I should have it in the system next week and I will report back and post some pictures.
Guy

GS · « **Reply #56 on:** 3 Sep 2012, 06:45 pm »

Guy

thanks for the update. When its ready then its ready.
Interested if it not only deliver mass of watts but also is it stable and how about the quality.
Take your time.
Jerry

playntheblues · « **Reply #57 on:** 10 Sep 2012, 05:02 pm »

Well my bridged monos ship today from Houston to Dallas so they should be here in a couple of days. I have not heard so many good things about an amp (from people who are not fans of class D no less) in a long long time. The guy that built my amps is not a big fan of class D, when he first got all four modules in the chassis he tested each of them to make sure all was well. He did this by going of to a friends who has a balanced pre, a well known Class D designer. He told me their mouths dropped and they could not believe how good the NCOREs sounded. Last night they repeated this process with the amps bridged, using Revel speakers the model just under the top of the line. Both thought the improvement by bridging them was out of this world. My guy told me it was one of the best amps he has every heard, this is from a tube guy. So I asked, well does that put them in the top 5 or top 10? He responded one of the top three amps he has every heard! No I didn't ask what the other two amps were as it didn't matter, he said the highs where the best he ever heard. I can't take it, can't wait till they get here. More to come.
Guy

GS · « **Reply #58 on:** 10 Sep 2012, 07:47 pm »

Quote from: playntheblues on 10 Sep 2012, 05:02 pm

Well my bridged monos ship today from Houston to Dallas so they should be her in a couple of days. I have not heard so many good things about an amp (from people who are not fans of class D no less) in a long long time. The guy that built my amps is not a big fan of class D, when he first got all four modules in the chassis he tested each of them to make sure all was well. He did this by going of to a friends, a well known Class D designer. He told me their mouths dropped and they could not believe how good the NCOREs sounded. Last night they repeated this process with the amps bridged, using Revel speakers the model just under the top of the line. Both thought the improvement by bridging them was out of this world. My guy told me it was one of the best amps he has every heard, this is from a tube guy. So I asked, well does that put them in the top 5 or top 10? He responded one of the top three amps he has every heard! No I didn't ask what the other two amps were as it didn't matter, he said the highs where the best he every heard. I can't take it, can't wait till they get here. More to come.
Guy

Oh Yes, that's we were anxious waiting for...
"Sounds" good looks like an understatement.
Jerry

Rclark · « **Reply #59 on:** 10 Sep 2012, 07:58 pm »

Wow!!! : "Both thought the improvement by bridging them was out of this world."