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Monitor II headphone amp review

Discussion in 'Headphones & Portable Music' started by davejames, Aug 17, 2010.

  1. TheNameIsJambo

    TheNameIsJambo Member

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    Richer Sounds? ;)

    [tangent]
    I'm not slandering integrated amplifiers here, but you have to watch, sometimes they have a 'large' output-Z on the headphone jacks, meaning that it could struggle to drive headphones that are inefficient.

    For instance if you try to drive 16-32Ohm IEMs or portables from an integrated amp which, say, hosts a 50 Ohm output on the jack, you're gonna be struggling for volume and the sound will probably be skewed (to a degree). You'd have to aim for headphones above 50 Ohms - Which you have anyway (600 Ohms), so it's not your problem.

    The output resistance (by rule of thumb) has to be 1/8th of the impedance of the headphones.

    So your 600Ohm headphones, would ideally be 600/8 = 75 Ohms, or less - Boom, perfect match. Although, you could get away with anything above 50 Ohms and still hit that 'peak' volume.

    You can tell that the bloke over at NJC Audio is an actual electrical engineer, because he posts the Output-Z on his site:

    Output Impedance: 1.3 Ohms (Ref: 600ohm @ 1kHz)

    1.3 Ohms @ 600 Ohms = Excellent. Perfectly tight bass, and very, very little (literally no) THD will be there.

    Although, these output impedance's are usually in place on such devices to serve as short circuit protection, but nonetheless, higher output-Z results in loose-bass (Lower resistance means better bass damping) and also it will result in frequency response errors (distortion - THD)

    Don't get me wrong, I love listening to headphones via a Hi-Fi, you get full control over Treble - Mid- Bass. Allowing you to tailor the music, however you please!!

    [/tangent]

    I've been looking at getting a new dedicated 2 channel integrated amp anyhow!

    I'm not big on 5.1 systems, mainly because the girlfriend doesn't like 'Mess', and I can see all those speakers bugging her. But hey, I <3 good old stereo.

    What Hi-Fi do you have? :)

    I've been looking at the Marantz PM6003 or Yamaha AS500.

    The Marantz is made for music, plain and simple, but the AS500 has extra functionality.

    The AS500 is a bit more appealing due to the fact it has built-in iPod functionality, which also utilises its own built in software from the amp to control the iPhone/Pod, whereas I'd have to use the Marantz CD6003 for that and I don't think it comes with the funky Yamaha style iPod controls!

    Its the classic case of Features vs Sound! (Functionality vs Practicality?)

    I've also been looking at old-school amplifiers, such as the NAD 3020i, which was a beast in its time, and still shines today.

    The Pioneer A400 is another classic example of a giant-killer though. It was an 'entry level' amplifier which stood up to the £1000 big boys of the 90s.. Actually, it still stands out today. You'll still find people praising it compared to modern equipment... Or regretting selling them.

    Hey Dave,

    Ah-ha! Apologies for that error.

    I never realised he had a Monitor I before Monitor I DAC! Silly me. I thought the Monitor I DAC was his first venture - to kill two birds with one stone.

    Well, if that's the case, I'm still in for the Monitor I DAC.

    Indeed, more features + lower price = lower (sound) quality. Which is why the FiiO E5 is so successful. No features + low price = Not bad. The FiiO E7 has extra junk in there, which delivers a similar sound to the E5 with more 'hiss' - Lower sound quality + more features. Saying that, the E7 is a more refined machine, since it utilises a DAC and has an LCD screen. So, the E7 is the overall winner here.

    The same applies to the like of 5.1 AV Receivers. Some stereo amps are the same price as a decent 5.1 receiver, so it begs the question - Why should I buy a shoddy system that only works with 2 channels, when I can have one that upscales audio and video and can host ALL of my appliances?! Even the kitchen sink!!

    When you think about it, the Integrated Amplifier was/is PURPOSE built for that task, and they're always built to stand the test of time... Stereo channels aren't going anywhere fast, since they're pre-defined and set in time, but blue-ray, HDMI - Audio/Visual overall, past stereo, are all evolving at an alarming rate.

    All of those extra A/D->D/A components, extra connections, several outputs, DSP effects, blah-blah-blah, all add extra interference into the fray, meaning that your headphone/audio signal will never be as clean as a stereo amp.

    And when you compare both side by side, you'll always find that the stereo amp will still deliver a far more breathtaking sound than the 5.1 AVR.
    Last edited: Sep 8, 2011
  2. bowenjones

    bowenjones Active Member

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    I thought the price hike might surprise a few people.
    When I inquired about the Monitor II a few weeks ago, just after the price had been taken down from the website, Nick from NJC Audio told me that he had stopped taking orders while he was preparing an updated version of the amp.
    I asked him what the changes would be and would they be reflected in the price. This is part of the reply I had from him ... "the updated version has a completely new PCB design with some truly high end component's, the Monitor II can also now be used as a high quality "Preamplifier" (a feature often requested in the past) & due to the many update's inside I have managed to increase output power to exceed the requirements in order to properly drive the new "Planar Magnetic" type headphone's on the market today, these were not around when I originally designed the Monitor II, also due to the larger PCB & extra component's a longer enclosure is now necessary, however all of this does work out to approx 30-40% more expensive to build, so naturally this will have to be reflected in an updated price."

    So, it's definitely an upgrade. Whether the extra £110 is justifiable or not certainly makes my decision on getting one much harder.
  3. TheNameIsJambo

    TheNameIsJambo Member

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    Understandably the updated components and revised PCB means more R&D and higher production costs. Especially if he extended the housing, that custom made enclosure isn't, usually, cheap. What I don't understand is, the insane power output of his design. Those Planar (AUDEZE LCD-2) headphones, do they really require so much power?! They're kicking it at 60 ohms from what I hear.

    But I should ask, couldn't he build the good ol' version of the Monitor II, for those who don't want a pre-amp?!

    If I already have an Integrated Amp, why would I need his new design? He should of named it the Monitor III. To allow people the choice.

    Currently, I'd be running the sound from a CD player/DAC -> Int Amp -> Speakers OR Pre-Out -> Monitor II -> Headphones.

    That's good enough for me.

    He's suggesting that I can either use it the same as above or go via CD player/DAC -> Monitor II -> Headphones OR Pre-Out -> Power Amp -> Speakers.

    It just means he's given me extra functionality I don't need, just so I have to splash an extra £110, and probably, for ease of use, go and buy a Power Amp and sell the integrated.

    I wonder if he does 'special' requests.

    I might just go for the Monitor I DAC... I need a new DAC anyway, and the Monitor I looks solid enough for my needs!
    Last edited: Sep 8, 2011
  4. bowenjones

    bowenjones Active Member

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    That was my thought when I saw the specs for the upgraded version. I've no doubt that the changes has put this amp in a higher category and will compete well with amps that are a lot more expensive, but, like yourself, I wish he still built the original Monitor II.
    I planned on getting the DAC around the same time as ordering the amp but the combined price of the two units is a bit beyond my budget at the moment. They do look good together though :devil:

    edit:
    Sorry if this seems like a thread hijack dave.
    I thought your initial review was excellent btw, and it was one of the main reasons why I decided to go for the Monitor II.
    Last edited: Sep 8, 2011
  5. davejames

    davejames Member

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    Wow & I thought I was guilty of long posts! :laugh: :laugh:

    Im not too up on the whole output impedance thing but only know that lower is better with the exception of a few headphones that sound better on higher output imdedances, but there arent many like that & not ones id ever want, but most like you say go better with lower output impedance.

    You said there might be better value elsewhere now, yeah I think your right but if your not enjoying something you cant keep saying to yourself "ah this was great value for money though", fiios are great value for money, also if you look on ebay at the chinese amps there is like a new one every week, but judging from my own experience with my monitor 2 & the new one looking like its got some significant improvements I dont think these amps are designed to compete in the whole value for money stakes, china has that sewn up, I dont think any british company can really afford to compete with china, if they did they wouldnt last very long, im glad to see that njc audio is still focussing more on quality than just getting something out there as cheap as possible, its like the Kef reference speakers, you dont buy them because they offer incredible value for money, you buy them because they are a quality speaker with pedigree & sound great, yeah there are cheaper speakers around, the Diamond's are great sounding for their price but they still arent a Kef.
  6. davejames

    davejames Member

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    I dont know about the LCD-2 headphones but I read the HiFiMAN HE-6 require an amp with a minimum of 2 watts per channel :eek:, they are not very efficient, so I guess the extra power is there for headphones like those, more of a future proofing I guess, it looks to me like the main improvements are to the board inside with better parts & design, I doubt if the extra money is all for the preamp part, I think thats just a bonus.

    I would have liked to have seen this as a monitor 3 as well, but I think we have to remember that according to the about us page on the site we are talking a small audio company here that makes everything themselves, with only 2 people, as it is they say on the website it takes 7-10 days to build these amps, imagine if they got 5 orders for a monitor 1, 3 for the original monitor 2 & 4 orders for the new version, I cant see how 2 people would keep up with demand if there were loads of different models to choose from, as it is I see the monitor 1 without the DAC has been removed, like I said in my review they seem to be the opposite of mass produced, concentrating more on quality than quantity, but that in my view makes them special & not really comparable to other amps.

    Also when you mentioned about hiss on that fiio, no matter what price I paid for it whether it was regarded as great value for money or not I know that would annoy me every night listening to my favourite music, im not hearing any hiss at all, its like its not even powered up its so silent, but I think I already said that on my review so thats going over old ground.
  7. davejames

    davejames Member

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    Not at all, isnt that what forums are about, healthy debate & all, yeah I saw the photo showing both together, does look might impressive when seen as a pair like that, I wouldnt mind getting the DAC myself after seeing it on there :devil:
  8. judge56988

    judge56988 Member

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    I have read through this thread (and others) with great interest - it's a refreshing change from some other headphone forums...
    Anyhow, I'm looking to upgrade my current old Sennheiser EH 2270 plugged into my laptop, playing FLAC files. My question is whether you think the Monitor 1 DAC/Amp would be powerful enough to satisfactorily drive the DT880 600ohm cans? I use it mostly in hotel rooms so am looking for something transportable as opposed to portable. I am very pro buying British, even more so Cornish!
    I've more or less decided on those particular phones after a lot of research, other suggestions for something that would be a good match for the Monitor 1 are welcome. I only wish that I could find somewhere reasonably close (Derbyshire currently) to listen to and compare different headphones.

    BTW, Dave James - your review is excellent, as are your contributions in general. I've found more very good down to earth advice at NwAvguys site - although I'm pretty sure you will have seen it.
  9. davejames

    davejames Member

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    Thanks :smashin:

    As for the monitor I with the DAC unless somebody actually has one here with the 600ohm beyers I dont think any of us can really give you a definate yes or no, I dont really know much about the monitor I other than what is mentioned on the njc website, the specs say that it can drive 600ohm headphones so I wouldnt have thought it would be a problem as ive found with my amp the specs are quite realistic & accurate.

    I think the best thing you could do is contact njc audio & ask him what his opinion is of those headphones with that amplifier, he would no doubt be more qualified to answer this since he makes them.
  10. bowenjones

    bowenjones Active Member

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    I finally ordered the Monitor II last week and it arrived yesterday morning. Great service from Nick, who kept me updated during the build. It really does look a lovely bit of kit, even my wife was impressed with the build quality.
    For the past 6 years or so I've been listening to my cd's through the headphone out of my Marantz CD5001. One of the main reasons for getting that particular player at the time was because it had a pretty decent headphone amp for the price and I was quite happy with the sound quality using firstly my now sold Sennheiser HD650's and now my HD600's (I prefer the sound of the 600's). Recently though, I've been thinking more and more about what I'm missing by not having a dedicated headphone amp. After reading many positive reviews for the Monitor II, especially Dave's views in this thread, I decided to go for one a few months back. Unfortunately for me, it was just as Nick was preparing the updated version so I had to put ordering one on hold as I couldn't justify the extra expense at the time. With Christmas coming up, my wife offered to get me one as a gift so here we are. Only trouble is, I have to get her something back in return :laugh:

    I had a few hours using it in the afternoon. I didn't really know what to expect to be honest. As I said, I was happy with the sound quality of my Marantz headphone out, which seemed to be driving my 600's well enough, so I couldn't imagine the Monitor II making that much of a difference.
    Still using the Marantz as my cd player with the on board dac, I put the 40th anniversary of Aqualung on. I chose this because I had read many reviews positively glowing on how great the remix and mastering was and I just wasn't feeling it using my Marantz headphone out. What a difference! Clearer, punchier, better dynamics and better separation. I now know what those reviewers were on about regarding Aqualung (great classic album btw). I tried many more cd's over the hours and the improvement in sound quality really did take me by surprise. Listening with my 600's through the Marantz headphone out sounds quite a bit muffled in comparison now, but it's still a great little player which has served me well over the years.

    I know a few people were put off the updated Monitor II due to the extra cost and, to be honest, I can't see me getting any use out of it as a pre-amp. But the function is there so I think £365 for what this amp can do and especially what it sounds like is well worth it.

    I've sadly got to pack it away now on the wifes orders :(
    Roll on Christmas (I haven't said that for a few years :D)
  11. Dorsetado

    Dorsetado Member

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    Just ordered NJC Amp and DAC, is anyone using these with the Denon 7000?
  12. LC155

    LC155 Member

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    Hey there.

    You had any more time to listen to it? I'm thinking of grabbing HD650s and this amp and DAC really perked my interest. Even at the increased price, it's still a bargain if it can surpass the Slee Solo II for a fraction of the price.

    I was thinking either those two, a Graham Slee with a HRT II setup, or a Schit Bifrost and a Lyr.

    I'd prefer to grab the Monitor II series if it's as good as this thread makes it sound. :)
  13. bowenjones

    bowenjones Active Member

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    I've listened to the amp quite a bit since and I have no hesitation in recommending it. Although the Monitor II has been updated since dave's first review in this thread, all the positives that he mentioned regarding build and sound quality are spot on. He's had the chance to compare it to another amp, whereas I've only been able to compare it with my headphone out of my cd player, and I have no reason not to believe him when he said that he prefered the sound of the Monitor II. I've read quite a few other reviews which backs up his opinion too.
    What impresses me the most is the extra detail and separation that the amp brings out. An absolute joy to listen to.
    • Thanks Thanks x 1
  14. mike25

    mike25 Member

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    This is an amp I have had my eye on for some time, thank's for coming back on here with an update Bowenjones, it sounds excellent.

    Ive followed this thread for a few months now, it really has been a good read, while Dave obviously prefered his monitor 2 over the slee, based on my own recent observation's of the monitor 2 that is now on their site it would appear to be much better than the others I have looked at, it has better specs, features, internals & the price is much better too :thumbsup:

    If I had to compare to something, at a push it might be a Burson, but even then the monitor 2 amp still has better spec's, feature's & price, so I think it has to be viewed as an amp based on its own merit's, as other amp's I have been looking at really have no similarity other than they all share headphone jack's & volume control's :p
  15. tokyo_blues

    tokyo_blues Member

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    Mike25 - Sorry it's not really clear to me - have you actually listened to this amp, the Burson and the Slee?
  16. taloden

    taloden Member

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    I purchased a Monitor II back in December after reading Dave's excellent review. I doubt I'd ever have heard of it if I hadn't found this thread, so I'm very glad I did. I actually got it within a week of ordering as they were closing for Christmas, so needless to say I was pretty pleased with the speed of service. :)

    It's the first and only headphone amp I've ever owned so I can't do comparisons, but after having had the pleasure of listening to it for about a month I thought I should sign up to the forum and add my opinions here as well.

    I have to agree with everything said about build-quality - it's really very good. The switches don't feel loose or delicate, the volume control glides smoothly when you turn it, there's a lovely solid metalic feel and sound when you slide headphone plugs into the sockets, and all those gold connectors just look amazing. Its a real pleasure to have on the desk beside me. lol

    The sound quality is great. It's made my Grado SR225i headphones really come alive bringing out the bass which was previously lacking. I've gone from merely liking them to loving them thanks to this amp (though in fairness I suspect most amps could have done similar).

    I also brought a pair of Beyer DT990 600ohms just after the amp arrived and I have to say these run perfectly on the middle gain setting and sound great for orchestral music and soundtracks. I've no doubt it'll be powerful enough for any future head phones I buy.

    I don't mean to derail the thread but I do have one question. Has anyone had chance to try out NJC's Reference DAC or can anyone recommend DACs that will pair well with this amp?

    I've been looking at the Arcam rDAC which seems very popular (especially combined with TeddyPardo power supply) and has Asynchronous USB which apparently improves the sound quality considerably. The NJC DAC doesn't mention having Asynchronous USB, but I don't know how important this is - is it just marketing hype by Arcam?

    At the moment all I have as a DAC is a (£30-40) Creative x-fi extreme soundcard providing music to a £365 amp and 2x £220 headphones, so I'm thinking I should really improve the source to get the best out of everything.
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  17. mike25

    mike25 Member

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    Thanks Taloden for that, it's very good to hear as this is an amp that I am giving some consideration in upgrading to, so thanks for sharing your experience with us & for signing up to do so.

    I don't know much about that reference DAC or the Arcam, at a guess I would say the NJC dac would pair better being from the same maker, also the internal component's look better, but please don't take my word for it as I have not tried that or the Arcam so it's purely an observation, I did see a review of that njc dac when searching on google.

    My take on the Asynchronous USB is that it's one part fact, two part's marketing, it is supposed to allow for improved data transfer, but it's not quite as clear cut as Arcam would suggest, also I would rather believe what others say than them. To me Asynchronous is just the latest buzz word & it's not a straight forward yes it's better as some would have you believe.

    It makes very little difference & in some cases Asynchronous can sound worse (not as musical), it's much the same as when people compare the actual DAC chipset, a lot of DAC's use the same chipset inside & yet why is it that some sound better than other's, it's all about the design & not whether it has this or doesn't have that, it's ok to compare spec's, I am doing that myself at the moment with all these amp's, but you need to keep it balanced with some real world opinion's too.
  18. mike25

    mike25 Member

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    Rather than start a whole new thread, I thought here might be as good a place as any, especially as this amp is one of many I am considering upgrading to.

    The Slee that was mentioned a few post's back is one I used to own but then I upgraded to a Burson amp, I am going to get some new headphone's soon, possible's are the Beyer T1 or HD800 & I am also looking at the Hifiman HE-500 or HE-6.

    I've had a few cheap amp's prior to the Slee & Burson, but they were nothing special & offered no improvement's over the common headphone out jack's, all my headphone's (Sennheisers, AKG's & Beyer's) performed well on both the Slee & Burson, but I found some sounded better on the Slee & some better on the Burson. When I sold my Slee this pairing issue was more of a problem, the HD650's were in my opinion better on the Slee, but I would now like something with more power, especially for either of those Orthos that i'm considering. If at the same time I can get an amp that pairs much better with all my headphone's then that would be nice.

    Presently I am comparing specs & quality of many amp's online, including this one before making any final decision, I want an amp that I can settle on & one that will do justice to top tier headphone's. There were certain things I didn't like with the Slee & there are also things I don't like about my Burson, I don't want to keep changing amp's as mistakes are costly.

    At the moment the monitor 2 amp is a real contender, it seems to have more going for it than others I have seen so far, according to the spec's it would have the power I would need for the Orthos, the internal's look excellent quality & the price is very attractive when weighing up everything. Judging by the posts on here people also love these amp's.

    I am still looking & far off from making any final decision, I want to get it right so I am looking at all option's, but at the moment I have not found anything as good.
  19. rigman

    rigman Active Member

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    Hi Mike

    did you go for the NJC then?

    I have just bought a pair of Sennheiser HD800 and at the moment I am using them on the bog standard Anthem D2V headphone socket (which is a home cinema processor).

    The HD800's seem to be settling in quite nicely but I want to a separate headphone based hifi system so I am on the search for a headphone amp to do them justice. The source player will be a Musical Fidelity Nuvista CD player although I am eventually going to go to a music server with a dac.
    The NJC seems to tick all the boxes but I would like other peoples opinions hopefully those that have tried the same combination and either gone with it or went with a different amp.

    thanks for any advice
  20. mike25

    mike25 Member

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    Not yet, I have spent a lot of time looking at amp's & I am now definitely going to be getting the NJC monitor II, simple reason is I don't see anything I like better or that has the same appeal as that amp.

    The problem I have at the moment is with the headphones, I just can't decide on whether to get the HD800's like you have, or the Hifiman HE-6's. I have heard that the Sennheiser HD800 pairs very well with the Monitor II amp, but something is pulling me towards the HE-6's.
  21. rigman

    rigman Active Member

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    I ordered the Monitor 2 this morning so should get it in a couple of weeks. Lots of testing to look forward to :)
  22. CARLOS

    CARLOS Active Member

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    Be interesting to hear your thoughts on the headphones, have you also considered the LCD2's ?

    I am also trying to decide between the HD800, T1's and LCD2's but hadn't really thought about the HE-6's, must admit i'm swaying towards the LCD2 as i fancy something a little smoother and i think the other 2 may be a little bright and harsh at the topend.
  23. mike25

    mike25 Member

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    I have considered the LCD2's but I can't help thinking how much of my money has gone on all that wood, it even has a lovely wooden box but all that has to be paid for, unless i'm mistaken you also have to order direct from the US? which would mean import duties to add to the total price.

    More than any of that & the main reason I went away from those is that the LCD2's have quite rolled off highs, their bass performance is said to be their strong point since it's the only headphone that is completely flat down to 1hz! but they look like they have sacrificed the top end & are more rolled off than the HD650, as much as I enjoy my HD650's they do lack the detail that my AKG K-702's have, I fear the LCD-2's might be smooth sounding but at the risk of losing detail or appearing that way, I could be wrong though as remember I have not tried them, this is all from what I have researched.

    I read that the Hifiman HE-6's are quite detailed & have good highs, from what other owners say they are quite bright but only become harsh if they are plugged in an amp that can't give them enough power, these are all the little snippets of info I have found online so far.

    Once I have come to a final decision I will come back with an update.

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