Luxman SQ-N150 Review (Tube Amplifier)

[sofrep811]

This is why I only keep tubes in the preamp section.

that is the route I want to go right now. Just pricey.

 

[MakeMineVinyl]

In ultralinear mode with manual bias, yes. However 10 watts per channel is exactly what I'd expect from a self or cathode biased design running UL.

Wrong The Dynaco amplifier I posted my test for earlier in this thread is cathode bias and it uses the same output tubes. It will do 17 watts per channel per my own measurements and the published Dynaco specifications (from back in the days when dinosaurs roamed the land and specifications meant something). It also is an ultralinear design like all Dynaco amplifiers of the period.

 

[levimax]

Hmm transistor input stage but output a tube?
Kinda strange decision.

If you believe there is such a thing as "tube sound" (I don't) then it is going to be caused by the output transformers and their inherent non linearities and high output impedance and possibly softer clipping and higher relative levels of second order harmonics. A tube pre-amp on the other hand, unless it is a seriously compromised design, will have none of this and can easily be designed to be objectively transparent. To me if you can actually hear a difference with any tube amp it is because it is broken.

 

[3125b]

This does nothing the most mediocre chip amp can‘t do - except cost 30x as much.
But then again, millions or people believe in homeopathy, at least this doesn‘t do any harm.

 

[tomtoo]

Who would 'feel' that way? If one enjoyed the amplifier to satisfaction on Monday, read about its bench performance on Tuesday, what would they think on Wednesday? Will the Goddess of Disenchantment visit them? I mean, nothing has changed with their amplifier.

I am often perplexed when folks live with an item, like it, but then read a review and change their mind about it. What is anyone really thinking when they buy something like this? That it will have great specs on the analyzer? Why would anyone think that?

I agree that the owner should be commended for sending it in, for

Who would 'feel' that way? If one enjoyed the amplifier to satisfaction on Monday, read about its bench performance on Tuesday, what would they think on Wednesday? Will the Goddess of Disenchantment visit them? I mean, nothing has changed with their amplifier.

I am often perplexed when folks live with an item, like it, but then read a review and change their mind about it. What is anyone really thinking when they buy something like this? That it will have great specs on the analyzer? Why would anyone think that?

I agree that the owner should be commended for sending it in, for review.

I dont know how the owner feels. But somehow i can imagine he/she would feel better, if the amp had done better?

 

[DonH56]

The large difference in distortion for the two channels, and big drop in 2HD on one relative to the other, makes me think they need to pay more attention to final checks and quality control. It looks like the bias/balance adjustment is wrong on one channel? Not that the "good" channel is all that great, but still...

Edit: Skimmed a few more posts and saw @SIY has already responded, what he said.

 

[Helicopter]

Hey, those lawn mowers are great for small city lots. I used one for years until a good battery-powered mower came my way. Way less of a pain than a gas mower, and way less garage space too.

I used to use one of these for the 500 sq. ft. lawn of my Pennsylvania I-house. The little girl, about 9, from the next house in the row was on the sidewalk one day, stopped her bike, looked me in the eye and asserted 'That's not a real lawn mower.'

This thing, with its hybrid front end is impure, like a small riding mower that drives itself, but you have to pedal to make the blades cut the grass.

I love 95% of the aesthetic, which is hugely important at this price point. I don't love the soap dispenser though, and it doesn't redeem itself anywhere with performance.

If they did away with the soap dispenser, and had a tube preamp, I would love to put one with some horn speakers that lack boominess and play around a bit. I would rather use this to EQ my Klipsch Heritage or DIY horn speakers than something active. I don't expect or want performance with stuff like this anyway. Performance is what my main system with Hypex amps and Focal speakers is for.

There are hundreds products I would pick over this one, even for a third or fourth system. The Luxman tube power amps look like fun, and their SS integrated amps are gorgeous, with symmetry and knobs that go all the way through the thick faceplate.

 

[newaudioguy77]

Yikes! I guess 90% of their budget went in to making it look pretty. Thank you so much for your reviews Amir. Thanks to you, people can find gear at affordable prices that performs well. Without ASR, audiophiles would be shooting in the dark.

Although some audiophiles only rely on listening and strongly dislike measurements. Lol to them.

 

[anmpr1]

If you believe there is such a thing as "tube sound" (I don't) then it is going to be caused by the 1) output transformers and their inherent non linearities and high output impedance and possibly softer clipping and higher relative levels of second order harmonics. 2) A tube pre-amp on the other hand, unless it is a seriously compromised design, will have none of this and can easily be designed to be objectively transparent. To me if you can actually hear a difference with any tube amp it is because it is broken.

1) Any tube amplifier sound that is real is, of course, related to its interaction with the loudspeaker. The transformer was always the suspect part. Compare Julius Futterman's hand made OTL amplifiers-- always got good 'subjective' reviews, and were praised for their 'sound'. If that wasn't just imagination then it wasn't attributable to an output transformer. Which actually supports what you say. On the other hand, I don't recall his amplifier ever being described as sounding 'tube-like'. Mostly it was other superlatives like 'open and transparent'.

2) Pace Futterman, who always argued that a tube should be the first stage in any circuit, in preamps it is pretty common to find a SS device followed by a tube. Here, the idea is (as I generally understand it) to reduce noise, especially in phono stages when needed gain can be difficult for tubes to silently handle. I have two homemade 'tube' based preamps-- the phono stages are either dual opamps or VFET based. They are certainly quiet enough for playing records with MM cartridges. In fact, I have a little stand alone MM phono stage (nice distortion factory) that uses an opamp followed by a 'conditioning' tube. I think the tube is an afterthought, and in any case it is more noisy.

In the recent ART phono thread someone commented on the relatively expensive Manley phono stage. 6DJ8 (6922) based for both MM and MC. I personally have not had good results with tube based MC circuits, but I've not heard the Manley (or any modern tube based MC phono stages). I recall Michael Elliot (designer of the Counterpoint SA-2 MC stage) saying that if he had to do it over again, he'd never use a tube in a MC phono stage, but rather a transformer--because of noise. This (i.e. noise) was Mitchell Cotter's argument during the great MC debates of the late '70s, although at that time arguments tended to turn on SS based 'head' amplifiers, where the cartridge's low voltage (and not high current) was being amplified.

When Japanese MC cartridges (such as the Denon DL103) were first becoming known within the American 'high end', old timer subscribers may recall how Gordon Holt famously 'put a moratorium' on reviewing MC cartridges because of noise related problems.

I have somewhere in my closet a knock off of Marshall Leach's battery powered Audio magazine DIY head amp. It is pretty clean, noise-wise, but susceptible to external hum if you place it too close to anything. A tube sticking out of the top would likely not help.

 

[dtaylo1066]

As one who enjoys tube amplifiers (as well as my Hypex and other solid state amps), I concede their distortion and measurement downfalls and shortfalls. I personally do not see much benefit in an amp of this low a power rating unless one's speakers are extremely efficient. To that end, I have never heard any advantage or fallen in love with low output power tubes and high efficieny or single driver horn speakers. Most sound quite underwhelming to me.

I have come to the conclusion that my enjoyment of some tube amps must relate to 2nd harmonic distortion, and a few studies have shown some listners preference for such distortion. I could give a poop about nostalgia, as I grew up with SS and have no affinity to old audio products.

I say too bad this amp was not desinged for some EL34s or KT88s. While it looks really nice, I would not spend 3K on such an amplifier and will stick with my modernized Dynaco.

 

[SIY]

1) Any tube amplifier sound that is real is, of course, related to its interaction with the loudspeaker. The transformer was always the suspect part. Compare Julius Futterman's hand made OTL amplifiers-- always got good 'subjective' reviews, and were praised for their 'sound'. If that wasn't just imagination then it wasn't attributable to an output transformer. Which actually supports what you say. On the other hand, I don't recall his amplifier ever being described as sounding 'tube-like'. Mostly it was other superlatives like 'open and transparent'.

2) Pace Futterman, who always argued that a tube should be the first stage in any circuit, in preamps it is pretty common to find a SS device followed by a tube. Here, the idea is (as I generally understand it) to reduce noise, especially in phono stages when needed gain can be difficult for tubes to silently handle. I have two homemade 'tube' based preamps-- the phono stages are either dual opamps or VFET based. They are certainly quiet enough for playing records with MM cartridges. In fact, I have a little stand alone MM phono stage (nice distortion factory) that uses an opamp followed by a 'conditioning' tube. I think the tube is an afterthought, and in any case it is more noisy.

In the recent ART phono thread someone commented on the relatively expensive Manley phono stage. 6DJ8 (6922) based for both MM and MC. I personally have not had good results with tube based MC circuits, but I've not heard the Manley (or any modern tube based MC phono stages). I recall Michael Elliot (designer of the Counterpoint SA-2 MC stage) saying that if he had to do it over again, he'd never use a tube in a MC phono stage, but rather a transformer--because of noise. This (i.e. noise) was Mitchell Cotter's argument during the great MC debates of the late '70s, although at that time arguments tended to turn on SS based 'head' amplifiers, where the cartridge's low voltage (and not high current) was being amplified.

When Japanese MC cartridges (such as the Denon DL103) were first becoming known within the American 'high end', old timer subscribers may recall how Gordon Holt famously 'put a moratorium' on reviewing MC cartridges because of noise related problems.

I have somewhere in my closet a knock off of Marshall Leach's battery powered Audio magazine DIY head amp. It is pretty clean, noise-wise, but susceptible to external hum if you place it too close to anything. A tube sticking out of the top would likely not help.

Futtermans gave vastly non-flat frequency responses with most speakers.

If you're interested in the combination of tubes and transformers for a high performance phono stage, I wrote an article some years back for diyAudio. I'm pretty sure it's still there in the Articles section. "His Master's Noise."

 

[newaudioguy77]

Yikes! I guess 90% of their budget went in to making it look pretty. Thank you so much for your reviews Amir. Thanks to you, people can find gear at affordable prices that performs well. Without ASR, audiophiles would be shooting in the dark.

Although some audiophiles only rely on listening and strongly dislike measurements. Lol to them.

"Did you listen to the cable?"

"Longer runs of speaker cable sound better."

"The sound quality can't be measured."

"I paid x amount for quality - the more stuff that is inside (parts) means I'm getting my money's worth."

Just some of the goofball statements I've dealt with on other forums.

 

[DSJR]

There's another view that ANY number of components is too many to mess with the signal so keep the circuit as simple as you can get away with.. Trouble is, many amps which look complex have these 'extra' components doing 'housekeeping' and the signal path is actually very simple... I'll ignore the other comments you've read elsewhere.

 

[MaxBuck]

It's great for Luxman's shareholders that a number of people like this kind of stuff.

I'm not one of those people.

 

[ROOSKIE]

This does nothing the most mediocre chip amp can‘t do - except cost 30x as much.
But then again, millions or people believe in homeopathy, at least this doesn‘t do any harm.

Pretty sure that conventional western medicine has your Benjamin's er I mean back. Same as this cash grab amp does.

Funny anecdote, GF's son was premature and has had dry skin and other issues on his hands all his life. No western treatment has ever helped at all. Believe it or not after finally trying a homeopath, the little white dots helped something open up in him and the issue completely cleared up in 2-3 days after 9years. No kidding. Probably the Placebo effect but that is the thing right? When a placebo has an effect, it is not a placebo anymore. One of the most fascination subjects in the western world and a great doorway to something very cool IMHO.

Seriously though, ultimately wasteful products like these add up and up and up to a pretty big pile of literal garbage with all the requisite industrial+consumer impacts. Plus, maybe even worse is that things like this are fairly normalized to the point folks are so used to this they have forgotten over consumption and poor choice consumption is unhealthy for us all. $3.3k for $45 performance is really inefficient, no different from an automobile that gets 0.5mpg.

Anyway, not trying to solve world hunger here, this amp is just another great example of hifi in need of help. Maybe it needs an Adderall prescription so it can pay more attention to the signal. It looks to stiff for yoga classes.

 

[DonR]

Luxman is now part of the IAG Group of companies along with Wharfdale, Castle, Mission and several others. Based out of Shenzen. Another beautifully overengineered product from Luxman that screams quality but performs like garbage.

 

[brandall10]

Makes me wonder what is the performance limit for a tube, surely it can be much much cleaner than this

FWIW, these tubes are common in guitar amp applications - often times 2 x el 84 amps hit between 15-18 watts. That said, that rating is taken at some level of audible distortion.

 

[MAB]

Who would 'feel' that way? If one enjoyed the amplifier to satisfaction on Monday, read about its bench performance on Tuesday, what would they think on Wednesday? Will the Goddess of Disenchantment visit them? I mean, nothing has changed with their amplifier.

I am often perplexed when folks live with an item, like it, but then read a review and change their mind about it. What is anyone really thinking when they buy something like this? That it will have great specs on the analyzer? Why would anyone think that?

I agree that the owner should be commended for sending it in, for review.

I get your point, but some people might be too materialistic to be in that space. I think I am.
If I bought something, and it turns out it has flaws that indicate poor design, doubt creeps in. Doubt is a negative emotion, ruins a nice piece of fish, or a fun drive, or listening to music.
Yeah, likely most of those doubts are just emotion. And emotion can be conquered or suppressed if that is your way.
Some doubts are real, like: Is a piece of equipment with poor design and architecture also unsafe?
And, it seems that the measurements on this Luxman are bad enough that in many applications it will be audible. So, that is real, especially at this price.
And, every time you turned up the volume and heard the distortion that Amir noted, you would no longer just think that was part of the recording and you were hearing the truth at higher volumes... Instead you would be realizing that the amp sucks at high volume. And you were actually using a different emotion before this review (hope) to get over what you had been hearing all along; distortion.
So, while everybody is different, lots of people do this for emotional reasons and a steaming pile of junk that they spent $3k on is going to degrade the experience.

 

[aschen]

Looks lovely to me, id buy one for a bedroom system with some vintage looking but modern JBL horns maybe a nice LP12 to complete the theme.

This of course if I already had a high performance main system. Audio as a hobby isn't always about straight performance for some, its OK to have a bit of fun as long as you are realistic about what you are dealing with.

 

[Bill Brown]

I had forgotten that Stereophile reviewed this amp and JA measured it. Please note that I am not arguing for this amp's ultimate value to anyone, and I wouldn't buy it (speakers aren't efficient enough), though I have used and enjoyed tube amps in the past (currently use a Benchmark ABH2), but there are many nuances involved that make simplistic statements like "piece of SH#*" and "money grab" not completely applicable. Also, if I were gifted one I would listen and enjoy the heck out of it, even if it ended up as part-time only.

JA's measurements can be trusted, I feel (I know many prefer Amir's Klippel measurements to JA's, I am thinking of source components/amps in this instance). In this case, his experience shines through. All of Amir's measurements could be calculated from JA's and JA's provide the needed additional information to add the nuance described above and a better understanding of what is going on with the amp in actual use. This doesn't even include the squarewave measurement with accompanying explanation I mentioned earlier.

"Look at how early THD+N starts to rise with output power too" was written above

I actually look at the graph and see likely inaudible distortion up to at least 1 watt. Ok, not terribly impressive, but.....

Klipsch sensitivity figures were doubted earlier. That is justified. But, JA also measured the Klipsch the reviewer used and found that it's sensitivity was 95.2 db/2.83V. Not considering music's crest factor for a moment, when the reviewer was listening at 95db, THD was 0.04%(not accounting for distance, but also not counting that two speakers playing at 95db = 98db). What is your typical in-room listening level? Mine certainly isn't 95 db (again, excluding transients). Amir's might be, seems he listens loud!

Look at the above graph in terms of the following (and the corresponding numbers for a more popular/typical-here speaker of say 86 db/2.83V- and many of those are actually nominally 4 ohms, so their true sensitivity for 1 watt is 83db). Think of your typical listening level:

83 db output for the Klipsch, (86 db for a pair) requires 62.5 milliwatts. Typical speaker for 83 db requires 500 milliwatts (62.5 milliwatts into the typical speaker yields 76 db)
89 db output from the Klipsch requires 250 mW, the typical speaker 2 watts
95 db output from the Klipsch requires 1 W, clearly, the typical speaker 8 watts. (then 98db= 2 and 16, 101db= 4 and 32, 104db= 8 and 64, etc. etc.)
98 db = 2 and 16 W respectively

So then you say at 1-2 watts the Luxman THD is approaching audibility. But it has been shown over and over again that distortion spectra are vital when determining audibility (total THD, measured for ages is incomplete at least, more likely misleading). 2nd and 3rd are very difficult to perceive until levels are fairly high (especially what y'all are used to seeing), where higher orders are much more audible. Also, distortion in the low frequencies is very hard to detect and should be measured. JA also helps us with this. First the second feature:

The blue and red traces are into an 8 ohm load at 2.83V, or 98 db from a pair of the Klipsch. Increasing distortions in the low frequencies (transformer), but less audible, but pretty darn low through the most critical (ear's most sensitive) range.

Now the harmonic spectra of a 50 Hz (see above) signal at 3 watts (102.5 db from the pair of Klipsch):

A 1 khz wave being produced at the same 102.5 db:

Someone mentioned (I don't know how to multiquote....) "The boominess that you mentioned could very well have been caused by the typical Ohms-law interaction between the speaker's complex impedance curve and the amplifier's output source impedance. I did not see that you measured the amp's output driving impedance, and I think you should. With tube equipment this becomes especially important as it has a major impact on sound. Some tube amps have flat FR when driving a resistive load but drive a speaker and I have seen ± 6 dB variation in output! You're gonna hear that! Amir, you're an engineer, you should know this. Please, measure the output impedance of this amp- it's simple enough to do."

Certainly I agree- not about the marked possible variations with this particular amp (not the case), but the need for additional measurements. Impedance relationships are almost never addressed in the measurements here. How can you measure a passive volume controller out of the low output impedance and into the high input impedance of the Audio Precision, show the frequency response, and think you are done?? It is presented authoritatively, but is almost meaningless. One must factor in the two impedances in their system to know what frequency response they will get. It is simply ohm's law.

And re. the quote, JA has given us these measurements- output impedance and response into a simulated load. Again, it is ohm's law (look at the impedance curve of your speakers and that will be the trend in FR with increasing output Z).

"The Luxman amplifier's output transformers have a single tap, which is optimized for a 6 ohm load. The output impedance from this tap was relatively low for a tube design at 0.7 ohm at 20Hz and 1kHz, rising to 0.83 ohm at 20kHz. As a result, the modulation of the Luxman's frequency response with our standard simulated loudspeaker was a modest ±0.5dB (fig.1, gray trace)."

Luxman SQ-N150 integrated amplifier Measurements

Sidebar 3: Measurements Nostalgia struck when I unpacked the Luxman SQ-N150 and hoisted it onto the test bench. This compact integrated amplifier uses a pair of EL84 tubes for each channel's outputI used to own a sweet-sounding Vox AC30 guitar amplifier back in the 1960s, which also used a...

www.stereophile.com

I like to read Amir's measurements, that's why I come here. In many cases there are good. But....nothing in this world is perfect, and he has some gaps. To look at something's SINAD without understanding the nuances and immediately rush to an absolute judgement (joining the bandwagon of increasingly dismissive derision) is simply not based on what is known, and frankly isn't that smart. After going through the above, is it possible that the Stereophile reviewer heard a transparent reproduction via the Klipschs'.

Bill

P.S. I hope I got all my db match correct!