NC400 anyone bridging it yet?

fsimms · « **Reply #80 on:** 13 Oct 2012, 02:45 pm »

Quote from: playntheblues on 18 Sep 2012, 12:33 pm

More to come when the balanced DAC/PRE arrives in about 10 days

Guy

playntheblues

Now that you have had the balanced DAC/PRE for a couple of weeks are you ready to comment?

Bob

jackman · « **Reply #81 on:** 13 Oct 2012, 04:06 pm »

Guy, what did you get?

playntheblues · « **Reply #82 on:** 14 Oct 2012, 09:54 pm »

Hey guys there has been a delay. Since I use my DAC (LampizatOr) as a pre I needed more gain. Lukasz is mailing me a more powerful DAC board on Monday.

Other than the power the system is sounding wonderful. However I am beginning to realize once again that changing two things at once is not such a good idea. If makes it really hard to pin point what changes are coming from where.

The big changes are...sound stage is much larger and pin point, clarity and musicality. As I get more familiar with the new gear I will share.

playntheblues · « **Reply #83 on:** 18 Oct 2012, 11:18 pm »

Ok guys a little more insight. The bridged NCORE amps are clean clean clean, very transparent, you miss nothing. I love detail so this great for me, but over the years I have grown to like some tube magic, liquidity, body to the music. You all know the age old argument.....Tube lovers think to much transparentce is thin sounding and harsh, while the SS lovers feel to much body is just distorsion.

So for me and my tastes in my room I have combined the Ncores with a balanced LampizatOr Level 4.5. This DAC/Pre has two output tubes ECC 82's and a tube rectifier 5Y3. I have changed the ECC 82's for some Brimmar ECC81 which I feel gives the music body. I also changed the plate resistors at the same time, all according to Lukasz's instructions.

I like this combination of tubes and class D. I am trying not to be over the top with these amps but man are they clean and transparent

. I have not heard them with a SS. Pre but in my system they are smooth. My last two amps, to give you some perspective were..Berning ZH 270 which was my favorite pre NCORE and before the Berning was Spectron monos maxed out.

I will write more as everything seatles in.

Stay thirsty my Friends

uob · « **Reply #84 on:** 2 Nov 2012, 08:35 pm »

I hope you have some pictures to post. A picture says more then........ and all that.

dan92075 · « **Reply #85 on:** 8 Nov 2012, 04:54 am »

Quote from: serengetiplains 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.

I have a Y-splitter and wondering if I could quickly try out bridging with my monoblocks?

Is it possible to bridge by instead using the same polarity on both inputs, and invert the outputs instead?
In other words, on Amp1 the red output goes to speaker red and the black output goes to ground,
and on Amp2 the black output goes to speaker black and the red output goes to ground.

High-level its the same concept, but perhaps there are some gotchas related to DC on the lines, or perhaps only the minus outputs can be grounded, etc?

Does anyone know?

udailey · « **Reply #86 on:** 8 Nov 2012, 04:28 pm »

That will work. I built a pair of amps using the configuration you quoted. Sounded very good.

udailey · « **Reply #87 on:** 8 Nov 2012, 04:30 pm »

NVM, I wasnt reading your post fully. You need to build it the way it is in the pic to be safe. Dont cheat it. Besided this isnt to hard to wire up and you can easily return to normal config.

dan92075 · « **Reply #88 on:** 9 Nov 2012, 05:26 am »

Appreciate the tip - I will follow the diagram then - thanks!

dan92075 · « **Reply #89 on:** 13 Nov 2012, 01:19 am »

Ok - so I bridged my stereo NC400 last night - I used a 150nF cap per recommendation for Ncore

I also have a mono NC400 so I was able to rapidly do an A/B (using only one speaker at a time and connecting the interconnect to amp under test)

Overall my initial impressions were I liked what I heard with bridged - - music was more engaging, partly I think because sounds were more defined.

Going from my Class AB amp to NC400 I had the exact same reaction - I didn't want to go back my Class AB after listening to NC400 mono.
Now after listening to bridged NC400 I did not want to go back to mono - its funny that I thought mono sounded so good until I listed to bridged

With one speaker at a time, I could not test sound stage, imaging, etc - although my guess is those would be improved too

Overall, the jump from my Class AB to mono ncore was the bigger jump, but bridged was definitely better

Rclark · « **Reply #90 on:** 15 Nov 2012, 03:04 am »

Very interesting... are you going to order another set? Keep us posted.

jackman · « **Reply #91 on:** 24 Dec 2012, 01:16 am »

Are you matching SPL's when making the comparison? It's funny but slightly higher SPL's will give you the false impression of more dynamics or more depth, etc., not to mention placebo affect. I've never tried a bridged ncore but I've tested various amps in bridged mode and they always sound better to me in non bridged mode.

JoshK · « **Reply #92 on:** 24 Dec 2012, 01:49 am »

Quote from: jackman on 24 Dec 2012, 01:16 am

Are you matching SPL's when making the comparison? It's funny but slightly higher SPL's will give you the false impression of more dynamics or more depth, etc., not to mention placebo affect. I've never tried a bridged ncore but I've tested various amps in bridged mode and they always sound better to me in non bridged mode.

That was my first thought as well. Bridged should give a slightly higher gain, so matching is required to make a comparison.

dan92075 · « **Reply #93 on:** 24 Dec 2012, 09:02 pm »

I went with the assumption of 6dB of gain difference - although on a 2nd test I reduced this to about 4-5dB.

I did the calibration by ear with music, not properly with a meter and white noise.

I plan on repeating this test more thoroughly when I get a chance.

During my 2nd test, my conclusion was the overall sound is very similar, the tonal balance is identical, the low distortion, low noise, etc also sound substantially the same

In trying to pinpoint the difference I would say the diifference would be in the dynamics. I thought the sounds have a little more pop to them then with single amp. Again, I need to repeat the test a 3rd time with more controls to confirm this for sure.

Just to be clear, bridging is not a whole level difference above - as what the NC1200 amp users are reporting.

Bubbleboy76 · « **Reply #94 on:** 11 Feb 2013, 03:39 pm »

I have done bridging with 2 nc400 and 1 smps1200 per monoblock.
It sounds more dynamic and warmer sound than the standard nc400+smps600 in the test setup.

gstew · « **Reply #95 on:** 11 Feb 2013, 10:43 pm »

Can you say more about your system.

Most specifically, are you using a balanced or single-ended source?

TIA!

Greg in Mississippi

Bubbleboy76 · « **Reply #96 on:** 11 Feb 2013, 11:20 pm »

Quote from: gstew on 11 Feb 2013, 10:43 pm

Can you say more about your system.

Most specifically, are you using a balanced or single-ended source?

TIA!

Greg in Mississippi

Balanced source, is there any other way to do it?

I have Burmester cd-player, preamp and speakers.
The first listening was done with an Antelope Zodiac Gold dac/preamp. Also balanced. In a very nicely acoustically treated room.

gstew · « **Reply #97 on:** 11 Feb 2013, 11:55 pm »

Woah! Sounds like a very serious system!

Thanks... I've been a bit cautious about going to bridged on my NC400 until I get a balanced source going, based on some comments from Bruno that I saw in a thread somewhere (maybe this one?). Your experience didn't make me any less cautious... if anything, just a bit more determined to get that balanced DAC project going again.

Of course, the main issue with this for me is that I have no plans for a balanced phono stage!

Greg in Mississippi

HighRez · « **Reply #98 on:** 24 Feb 2013, 03:59 am »

Hello, I'm curious to hear if anyone is bridgng these amps with sucess using a pair of speakers that are known to dip into the 3ohm range?

Personally, I have decided against bridging (at the moment) due to the fact that I know my speakers dip into the 3ohm range (B&W 803di) and according to what I have read about these amps it seems they are already brushing up against the power supply limits into a 4ohm load while bridged.

Are those who are bridging already know their speakers are not dipping below 4ohms?

How likely is bridging with the NCore any better than multi-amping a speaker with the NCore? If anything, it seems from a math standpoint multi-amping has the advantage since one is less likely to run out of power supply steam when considering the wide array of speaker impedances that may be encountered in the real world.

Thanks in advance for your thoughts on this matter.

James Romeyn · « **Reply #99 on:** 12 Jun 2014, 03:24 am »

Quote from: HighRez on 24 Feb 2013, 03:59 am

Hello, I'm curious to hear if anyone is bridgng these amps with sucess using a pair of speakers that are known to dip into the 3ohm range?

Personally, I have decided against bridging (at the moment) due to the fact that I know my speakers dip into the 3ohm range (B&W 803di) and according to what I have read about these amps it seems they are already brushing up against the power supply limits into a 4ohm load while bridged.

Are those who are bridging already know their speakers are not dipping below 4ohms?

How likely is bridging with the NCore any better than multi-amping a speaker with the NCore? If anything, it seems from a math standpoint multi-amping has the advantage since one is less likely to run out of power supply steam when considering the wide array of speaker impedances that may be encountered in the real world.

Thanks in advance for your thoughts on this matter.

I need to build a couple bridged mono blocs, each with one SMPS1200A400. Thanks for all the data and contributions to this lovely thread.

Re. above quote: minus any reference to PS associated with bridged NC400, its performance specs into any particular loudspeaker are unknown and unknowable. Specs for the bridged mono/one SMPS1200A400 or two SMPS600: 400/800/1200W @ 8/4/2 Ohm, safe to 1 Ohm but no rating. With one SMPS600: 400/800 @ 8/4 Ohm, safe to 2 Ohm but no rating. I presume bridged mono not suitable for single SMPS400, but OK for two SMPS400, unknown specs.