NSI - the first impressions

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esoxhntr
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NSI - the first impressions

Post by esoxhntr » Wed Sep 19, 2018 5:03 pm

Long post, buckle up…

I imagine that a number of folks around the forum have heard rumblings of the NSI, Gilbert’s ultimate rendering of an integrated amplifier. I know it was on his radar about 18 months ago when I first heard about it, so I’m guessing the idea was formed considerably before that. As usual, all good things Blue Circle come in good time, and with the Toronto Audiofest looming, why not now? And so, the NSI has arrived…

It was not what I expected. As I recall, it was originally going to be a one box unit, and it now has a separate power supply. I think it started off as a solid state only project, but it now has a 6SN7 tube circuit, and adjustable volume controls for both the tube circuit and the solid state circuit, as well as an overall volume control. The initial price point was going to be near $21,000 or $22,000 USD. This version weighs in at about $35000 USD. The NSI on hand here is kind of the “super” version, and will be available in a number of configurations depending on the needs of the end user. There will definitely be less expensive versions.

The NSI has been here and bubbling away for almost 10 days now. Dead cold it sounded really good, with the hint of a rough edge here and there (let’s not forget that this is a brand new unit). An hour later it sounded much better. By that evening, it was much, much better, and the next morning it sounded like a different (and more accomplished) amplifier. I left it playing for 3 days while I went on a fishing trip. When I returned, yup, different again. In point of fact, the NSI made great gains pretty much every day for over a week. It has levelled out a bit now – still improving, but it has stopped being a changeling, so I can start to comment intelligently on it.

The NSI has been rumoured to be a fully fleshed out, deluxe version of the OO2i with the external power supply. That may have been the intention, and that in fact may be the design architecture, but I would hesitate to use that comparison now. Maybe it was true about 10 days ago – not anymore. Having been fortunate to hear most of Gilbert’s creations I can say this, this amplifier is a very logical follow-on from the NSC series of audio components. It displays the best characteristics of the NSC, NSW, NSL, and even the OO2i.

When I first heard the NSL, I thought it was the best amp I had ever heard in terms of speed, clarity, and tonal detail. I wished it had a little more oomph, but in all other areas it was a total winner. Last year, for the Toronto Audio Visual Expo I commissioned the NSW, a 300 WPC monster that the only design request I made was “I want it to be able to drive ANYTHING”. Mission accomplished, the NSW – though not as refined (nor as nearly as expensive) as the NSL – combined with the NSC pre clearly had the edge in presence, authority, and boogie factor. The NSC/NSW combo was very well received at the show.

The surprise of the show was the OO2i integrated. By the time it arrived I had been hearing from Gilbert about the virtues of integrated amplifier design for 6 or 7 months. The OO2i was a revelation – it was refined, reasonably powerful, well detailed, extremely musical, and a relative bargain. The external power supply to it to another level, and matched with a pair of Spendor SP3/1 speakers, became the darling of the show.

So here we are, a month before Toronto Audiofest, and the NSI is here. Imagine if you will, an amplifier that has much of the speed and agility of the NSL, much of the authority of the NSW, the neutral precision of the NSC, the sonic “rightness” of the OO2i, and way more detail and musicality than any of them. THAT, is what you get with the Super NSI. It conveys musical intent and meaning better than anything I have ever heard. Gilbert says that the NSI is the best component that he is capable of building at this time – I have no reason to doubt him. It's #@%$ing amazing.

For those of you deciding which extra kidney to auction on eBay, it would not be a bad way to use the money :D

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Re: NSI - the first impressions

Post by Bob Neill » Wed Sep 19, 2018 9:25 pm

I'll have the proto-type that George is listening to after it's been to the Toronto Audio Fest and will follow up on his report. That said, I don't expect to have much more to say than this! Great report. Many of us have been listening in on Gilbert's thoughts the last year or so and hoped they'd come to something like this appears to be. Huzzah.

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Re: NSI - the first impressions

Post by masluck » Thu Sep 20, 2018 12:21 pm

Great review George!!

Hey, can you snap some pics of the amp and post them here? Also, it is great to see GilBut offer the Tube/SS summing circuit that he built into my custom 2K4sh - it truly gives you complete control and on mine I can completely shut off the tube section (which is 6SN7 as well) if required. It is a truth and beauty blender so to speak and infinitely adjustable, although I have it set to low gain on the input side with the "volume knobs", as you call them. I find they act a tad more like a parametric equalizer than a standard attenuator. I would love to hear that amp, but alas only the lottery win would produce that outcome!! :D :D :D

Mark

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Re: NSI - the first impressions

Post by Bob Neill » Thu Sep 20, 2018 12:43 pm

You have to wonder what the "lesser NSI" will sound like, don't you! How much of the meal can we get for around half as much? It's still going to be more amp than the NSC/002-ESP I'm listening to. And what I'm listening to is wonderful.
Last edited by Bob Neill on Tue Oct 09, 2018 3:40 pm, edited 1 time in total.

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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Thu Sep 20, 2018 6:22 pm

masluck wrote:
Thu Sep 20, 2018 12:21 pm
Great review George!!

Hey, can you snap some pics of the amp and post them here? Also, it is great to see GilBut offer the Tube/SS summing circuit that he built into my custom 2K4sh - it truly gives you complete control and on mine I can completely shut off the tube section (which is 6SN7 as well) if required. It is a truth and beauty blender so to speak and infinitely adjustable, although I have it set to low gain on the input side with the "volume knobs", as you call them. I find they act a tad more like a parametric equalizer than a standard attenuator. I would love to hear that amp, but alas only the lottery win would produce that outcome!! :D :D :D

Mark
Mark

The NSI is half naked at George's show room right now. I am going to bring it back next week to put the front panel on before going to Toronto show. So no picture until it is fully dressed. Please note, I can build NSI into any two chassis as long as it has enough space for everything. I built the prototype with whatever I had around so it is not necessary the final form.

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esoxhntr
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Re: NSI - the first impressions

Post by esoxhntr » Fri Sep 21, 2018 3:03 pm

... And much better that Gilbert takes the pictures... I am not terrific behind the lens...

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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Fri Oct 05, 2018 7:16 pm

Here is the story behind it.

http://www.bluecircle.com/page170.html

And here is a pictures of the NSI-G, the super NSI as George has been calling it. It measures 17.25" wide x 14.75" high x 21.5" deep plus the binding post. I can make it in smaller multiple boxes.
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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Fri Oct 05, 2018 7:19 pm

The rear end. Three line level inputs. One BAL and two SE. The third pair of SE output is the preamp out. I put that in for my own testing purpose and may be someone can use it to drive sub woofers.
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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Fri Oct 05, 2018 7:21 pm

In case someone ask why blue color base. Not that I wan the blue to be Blue Circle but I couldn't find my black paint and the blue paint was right in front of me on that day. :lol: :roll: :wink: :D :P

Biff
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Re: NSI - the first impressions

Post by Biff » Sat Oct 06, 2018 1:39 pm

:shock: that’s one hefty looking unit!!

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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Sat Oct 06, 2018 7:48 pm

Biff wrote:
Sat Oct 06, 2018 1:39 pm
:shock: that’s one hefty looking unit!!
Biff

Your AG8100 shares some very similar design with the NSI. Remember when I wanted to go as far as you would let me with your AG8100 earlier this year. I was designing, building, testing and back to drawing boarding on the NSI along side with your AG8100. Thanks for let me have fund with your AG8100.

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Gilbert Y
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Re: NSI-G audio porn

Post by Gilbert Y » Sat Oct 06, 2018 7:51 pm

Now for those who like some audio pron once in a while.
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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Sat Oct 06, 2018 7:53 pm

Another one.
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Gilbert Y
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Re: NSI - the first impressions

Post by Gilbert Y » Sat Oct 06, 2018 7:54 pm

The power supply
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BlueKnight
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Re: NSI-G audio porn

Post by BlueKnight » Sun Oct 07, 2018 11:30 am

Gilbert Y wrote:
Sat Oct 06, 2018 7:51 pm
Now for those who like some audio pron once in a while.

I take it you mean 'porn'. And I agree....I had to take a cold shower. he he he... :mrgreen:

Now, is this unit all attached together the way you mated my KQ Boxy?
Image

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