The NSL was one of the best-sounding power amplifiers I have ever heard. I give it my highest recommendation.SoundstageNetwork
It underscores the fact that the equipment exists because of the music, not the other way around.TheAudioBeat
The NSL did some things I’ve heard no other amplifier do. Then again, I’d never heard a power amp based on op-amps. No amplifier I’ve heard, whether tube or solid-state, has sounded as lifelike or as real as the NSL did. The palette of tonal colors with which it painted sonic portraits was breathtaking.
We spelled out the 28 watt per channel and the almost Class B business just to get the audiophile non-approved stuff out of the way early. Now, down to business. If you have an open mind and have managed to read past the first sentence, you can read on to see why we are offering this amp at this price. Ultraudio
It's all about the sound or, if you prefer, the music. Music is just sound. In order to reproduce good music, we have to make sure it sounds right. That means accuracy and accuracy is, in great part, a result of low distortion. Low distortion to us means more detailed information can pass through without any alteration. Almost Class B means we just bias it just enough to
get rid of the unwanted stuff but keep it running very cool.
The NSL has a measured output of 28 watts into 8 ohms and 56 watts into 4 ohms per channel. Not impressive? Well, it also has an output impedance lower than most 300 watt power amplifiers. Instead of using a few big transistors like most common designs, we parallel 288 op amps at the output stage. This is like using multiple smaller capacitors in the power supply instead of one big capacitor to obtain faster and smoother response. In power output stage terms, it can get the output impedance lower than ever before. This yields much better control of the speaker drivers and as a result this amp sounds more powerful than power amps with many times the output wattage of the NSL. The NSL demonstrates measured output numbers don't necessarily determine how it sounds.
Very Low Noise:
With the parallel op-amps, it has less noise than headphone amps. The residue noise is very low within the waveforms human hearing interprets as comfortable sound. With the lower noise floor more musical details come through without the distraction of the noise.
Many line level components offer battery operation. Some of our preamps use supercaps instead of batteries with the same goal in mind. They can run for hours without ac power. AC powerlines have all kinds of noise which is impossible to totally filter or eliminate. Totally off the grid is the only way to avoid any powerline noise.
It’s easy to make line level components work with batteries. Power amps are a different
matter. Since power amps draw a lot of power and batteries usually only come in 12V form, there are a lot of things to do in order to make an amplifier run on batteries and most battery operated power amps don't have a lot of wattage Those that do run for only short periods of time before requiring a recharge. The NSL has dealt with both issues. The NSL is can run on batteries. With two 115Ah 12V deep cycle batteries, it will run up to 24 hours with one charge.
The output stage of the NSL is a modular design, more output modules can be added to increase power output. It is possible to have the NSL output increased to over 500 watts into 0.5 ohms.
If you’ve been here before you know don't talk about the sound because we would rather have people who have heard this amp talk about it. What we can tell you is if it didn't sound good, we wouldn't be telling you about it and we sure wouldn’t be producing it.
Time and time again, as I worked at the computer in an adjacent room, I scurried out to the listening area just to be sure of what I was hearing, so finely drawn and powerfully real was the music -- especially piano.
amplifiers like the NSL prove that his way of doing things not only has its place within the audio industry, it continues to make its mark as well. The NSL is unlike any amp I've reviewed or heard, both for its use of small-signal op-amps as output devices and its sonic character. The harmonic refinement it packs into its 28 watts is truly unique in my experience, bringing music to life in a fresh way. Its overall ease and elemental rendering of transients seem at odds, while its silent background makes it suitable for use with high-sensitivity speakers -- or any speakers, when you consider adding one of the outboard power modules. A me-too product it's not, although the NSL makes a strong case for inclusion among amplifiers with greater mainstream recognition.
What Gilbert Yeung, the nonconformist, the iconoclast, will come up with next is anybody's guess. A preamp powered by plasma? A turntable that uses the earth's rotation to wind its drive mechanism? The NSL further proves that his ideas are not just novelties. They add to the breadth of high-end audio and to the music-listening experience as well, and there aren't many products about which you can legitimately say that
It’s one thing to be able to make an amplifier with the wonderful sound of the Blue Circle NSL. It’s another thing altogether to ask $19,500 for an amp that generates only 28Wpc into 8 ohms.
If you look at all the $15,000-and-up amplifiers on the market, most look pretty much formulaic on the inside: they’re all laid out pretty much the same. You see transformers, power-supply capacitors, rails on either side, transistors running from front to back, and wires leading to the outputs. But the NSL’s rear third is filled, top to bottom, with two towers of circuit boards holding nothing but those 288 op-amps. That represents a lot of detailed and fastidious work, and such work comes at a cost. The NSL operates in very low bias class-AB, and never came close to running warm while in my system. In some of my listening sessions I played house music, Euro-techno, and Middle Eastern electronic music for two to three hours, and the NSL got only lukewarm. I caution listeners not to mate it to other electronics that aren’t up to the NSL’s sound quality. I hooked it up to preamps such as Blue Circle’s own BC109 ($7000) and the Herron VTPH-2 ($3650). The sound was good, but nowhere near where it could have been. When I swapped out those preamps for my Purity Audio Silver Statement ($20,000), the sound reached much higher levels of musicality, fidelity, and bass dynamics -- levels I otherwise would not have known were possible. The NSL deserves to be used with the best gear available -- it won’t be embarrassed.
I compared the Blue Circle NSL with my McAlister OTL-195 monoblocks ($8500/pair). The McAlisters are very dynamic and musical, very powerful at 195W, and have never made me wish I owned something else. When I restored the McAlisters in my system, after listening to the NSL for a month, I thought they were broken. I wondered what happened to the sound. I was on my hands and knees a good hour, checking out everything, trying to find what I’d done wrong to lose out on the music reproduction I’d been enjoying. Then I reinstalled the NSL.
Everything was right again. The NSL’s highs were more extended, its bass went deeper and with more authority, instruments and singers sounded eerily real. Overall, music was just more enjoyable with the NSL than with my McAlisters, and that was hard for me to admit -- the OTL-195s have always made other amps I’ve listened to sound not as musically involving as themselves. But the NSL was much better overall.
Is the Blue Circle Audio NSL a world beater? I don’t know how well it would work with 4-ohm speakers. Neither the Meadowlark Heron i nor the Dynaudio Sapphire, both 6-ohm models, presented a difficult enough load for me to be able to say that the NSL won’t be all things for everyone. However, I can say with confidence that if you have speakers that it can drive, the NSL will be a revelation of just how wonderful music can sound, rewarding you with making your music sound special in ways you probably haven’t heard from your system. The NSL was one of the best-sounding power amplifiers I have ever heard. I give it my highest recommendation.
. . . Michael Wright soundstagenetwork
-Output: 28 watts into 8 ohms and 42 watts into 4 ohms per channel.
-True balanced from input to output with both positive and negative binding posts being "hot with signal.
-DC coupled from input to output.
-Local "on board" filtering capacitors located less than an inch away from the actual output devices for better transient .....response.
-600VA power transformer supply for output stage only.
-Over 2,000,000uF (2.0 Farad) in power supply filtering.
-14Ga steel chassis for mechanical integrity.
-1" thick MDF base tightly coupled to the bottom of the chassis for ultra rigid damping control.
-Various colours of faceplate, base and cover as options.
-Two pairs of binding posts per channel for shot gun biwire.
-RCA and XLR inputs.
-Battery connection jacks for external battery module(s).
-Output module expandable jacks to connect additional output stages.
-Ground lift switch to eliminate ground loops. This switch will only lift the signal ground, the chassis is connected to earth ground ....at all times for safety.
-Dimensions: 20.5" wide x 9" high x 21.5" deep.
-Battery module for off the gird operation.
-Output modules for increased power output
-Rails voltage meter to monitor battery life
-Residue noise reference to full power output: >-106dB or <75uV non weighted
-Residue noise reference to full power output: >-113dB or < 30uV within audio band
-Tracking error: < +/- 0.09dB
-Frequency response (10W into 8 ohms): 5Hz to 50K +0.00db, -0.05dB; -0.9db point at >100kHz
-Distortion at 10W into 8 ohms: <0.05%
-Voltage gain: 26.0dB
-Input sensitivity: 0.75V
-Input impedance: 6.3K (SE); 12.6K (BAL)
All of our products can be made in a variety of different finishes and colors.
If you have something in mind and don't see it as an option contact us.
The Custom Shop isn't limited to finishes. If you're looking for a unique combination of inputs/outputs and functions or want something brand new built from the ground up just let us know.
We enjoy the challenge of creating something unique for our customers.