First hifi advice

[CAT-THE-FIFTH]

The more I look into it, the more I'm drawn towards getting a second hand Chord Hugo as my portable pre-amp and then buying active studio monitors from the likes of JBL or Yamaha. My thinking is: the difficult conversion and filtering work will have been done by the Hugo so I just need a pair of reasonably neutral and transparent speakers which, I'm assuming, the studio monitors should be? After reading about modern Class D amps I think I'm reasonably happy that the small amps in the active speakers should be OK and have reasonably minimal distortion, especially being studio monitors, and would save me space and money (which might be sensible for a first hifi setup).

I'm pretty much decided on the Hugo since I need a portable DAC and headphone amp anyway, I just want as transparent a path as possible to make the most of it with speakers. Do you guys think this would be directly into active studio monitors or would feeding a power amp + passive floorstanders be better? Also does anyone have any experience with budget studio monitors in terms of detail and quality of amp inside them?

Even though Shure SE846 are good headphones they are tiny IEMs,and I personally think spending £1400 on a headphone amp+DAC combo to run them is a waste IMHO OFC- maybe if you had a decent pair of full sized high impedence headphones perhaps with much larger drivers which,but half the reason for IEMs is so they can run easily off portable equipment like iPods,etc and this is why they are also noise isolating.

If you look at the impedence of the SE846 is only 9 Ohms,so they are quite low impedence headphones so really don't need expensive amplification. This is much lower than my full sized Grados which are only 32 Ohms.

Also regarding spending £1400 on the Chord Hugo - you are basically paying for a nice box and a brand name.

Yes,the marketing is all about its custom bits but honestly we have had a few decades of DACs,etc already -it is not like 20 years ago when these electronics were very exclusive and low volume and it was all new and experimental,these things are very well characterised now - read what nwavguy said on his blog,ie,the chap who designed the ODAC. I would even argue a decent sound-card probably would be fine too,but I find DACs are more flexible(and more importantly somewhat isolated from a computer).

Many companies try to up-sell their stuff by boasting about XYZ random stuff(which might actually not be needed in the first place) and the hifi press will be quite happy to wax lyrical about it all. I mean I have listened to all kinds of format,records,reel to reel,mini-disc,HDCDs,SACDs,etc,and one of the most important aspects I came to realise was the mastering as much as the quality of the playback format.

If you are buying the Chord Hugo,do it because it looks a nice bit of kit(which it is),but I would be very dubious about whether it will magically make anything sound 10x better than going for one which is one fifth of the price or less.

So I would be tempted for you to listen to some DACs in a shop from cheap to expensive,ignore the salesman,ignore the price and see if you actually hear a difference.

I actually listened to a £100000+ DAC,headphone amp,CD player with a pair of £5000+ headphones and you know what,me and my mate actually listened to another set of headphones from a small relatively unknown company running through a battery amp which probably cost closer to £2000 though a portable music player using FLAC(and our phones also) and it actually sounded better.

If I were you I would actually spend more of the budget on the amplification and/or speakers themselves. I have seen the Chord stuff at shows and it is very nice,but I was always felt you are kind of paying more for the design in some ways.

Epiphany Acoustics have ceased trading

That's a shame!

[Dashers]

Aren't pretty much all A/V receivers digital amps? They all handle digital inputs (optical, coax, hdmi) directly. Or am I missing something?

[matts-uk]

Aren't pretty much all A/V receivers digital amps? They all handle digital inputs (optical, coax, hdmi) directly. Or am I missing something?

The digital inputs on traditional, Class A/B, amps take the digital input, run it through a digital to analogue convertor within the input stage, then amplify the analogue signal using 'linear' mode output transistors. In linear mode, the output of the transister follows the input signal but with greater amplitude (gain). The signal that reaches the speaker is a constantly varying Voltage. The signal is susceptible to noise and Voltage drop all the time it is in the analogue domian, from the DAC output to the speakers.

Transistors can also operate in 'switched' mode, when the input voltage is sufficiently high the transistor is saturated and the output signal is 'clipped' at the maximum. Instead of a constantly varying voltage, the output signal of a transistor in switched mode appears as a train of square pulses. Class D amps use output transistors in switched mode, and that is why they are called digital. Essentially a Class D amp utilises pulse width modulation.

Class D amps were originally developed to cut the size and cost of amplification in portable devices driving tiny speakers, with relatively low <1W outputs. As the signal remains digital to the voice coil, it is less suscptible to electrical degradation and fewer peripheral components are needed.

Digital amplification is not a panacea however. As the power and length of the signal path ramp up, so does the transit time from 0V to MaxV on each edge of each pulse in the pulse train. The size and weight of the speaker cone add further latency. Eventually this 'jitter' becomes audible, like listening to a rubbish CD player. The high-end marketing claims these issues can be solved with money. YYMV.

[matts-uk]

Also does anyone have any experience with budget studio monitors in terms of detail and quality of amp inside them?

In my experience studio monitors of any sort can sound terrible outside of a studio. You need to listen to the pair you are interested in, in the setting you will use them. Buying studio monitors blind [or is that deaf] could be an expensive mistake.

[Dashers]

Ah PWM, my old friend. The thing that introduces whine on fans and causes a nightmare upgrading lights in cars.

[Zhaoman]

CAT: I completely agree that marketing (which includes most review magazines/websites these days) are mostly about hype and less about objective performance. I don't really trust most of them now like games reviews and What Hifi looks like they just want to spout a lot of guff to push you to upgrade to ever more expensive things.

I am wary of the Chord products and I read what the designer wrote on Head-Fi, which was mainly a lot of long-winded description of how humans hear and how his products are 1000x more powerful but without going into much real detail. The only useful bits that I took away was:

1) Mojo/Hugo has lower noise floor (-170dB) compared with the ODAC (-103dB)
2) Mojo/Hugo has immeasurably low noise floor modulation (i.e. stays at -170dB) compared with the ODAC (absolute value not given, but -90dBFS is given);
3) Mojo/Hugo has better transient "timing" due to a "1000x more powerful" interpolation filter compared to other DACs;
4) Mojo/Hugo has lower output impedance (0.07 Ohms) compared to O2 amp (0.54 Ohms).

For points 1 and 2, nwavguy claims that it is transparent past -100dB and -90dBFS anyway. The Chord guy claims noise floor modulation in particular is important for determining the timbre of instruments and depth of sound (important down to "well below -200dB" apparently but nwavguy claims it's transparent past -90dBFS which the ODAC achieves).

Point 3 doesn't make sense to me because first of all the timing for transients below 20kHz should be unambiguous since they would be below the Nyquist frequency and I don't care about frequencies above my hearing range. Secondly, the interpolation filter is only required (from my limited understanding) because they implement a digital volume control so while it's great beating their drum that it's really (1000x really) good, all it does is ensure there are no artifacts introduced by the digital volume control which is a problem the ODAC+O2 would not have.

Point 4, I think, is actually relevant to me because my SE846s are 9 Ohm and the damping factor of the O2 would be 17 while 129 with the Mojo/Hugo. Given that a value of 60 or above is considered excellent, this might suggest that using the Mojo/Hugo would give me a (very?) slightly tighter bass compared with ODAC+O2.

In the end, I think I'm pretty happy that both products probably will deliver excellent audio fidelity and I don't intend to spend £1400 on a DAC/amp - the Mojo can be had for £300 second hand and the Hugo for £700. I couldn't find any second ODAC+O2 in the UK so the cost of new will be roughly £200 delivered from the US. Given that I'm sure they're all excellent products, the extra advantages of being portable and having a lower output impedance swung it towards the Chord products in my mind. The extra £400 outlay for the Hugo compared to the Mojo though is admittedly outrageously steep and I haven't made my mind up on that yet. The advantages of the Hugo would be built-in Bluetooth AptX (which actually would be very useful for me), the cross-feed function for headphones (might be a gimmick), RCA outputs (not that necessary) and arguably cooler looks. I guess I'm also thinking that £700 isn't too bad for a (I assume) 'transparent' DAC that can double up as a high quality pre-amp that is also portable and has good build quality. But in reality I would just be spending £400 on looks and bluetooth since I can get a Mojo for £300. I think I've actually talked myself into just getting the Mojo, thanks!

[Zhaoman]

As an update, I forked out for a second hand Mojo in the end and I'll give a few impressions. For comparison I have a Sony WM-A35 portable player which I thought was good (and a Surface Book but I never listen to music on it because it's so bloated in the bass, it's horrible). The Mojo music output was through MusicBee on the Surface Book using Chord's ASIO drivers via USB output.

The Mojo made little difference to my SE846 earphones compared to the Sony player which was a surprise because I thought they might give a tighter bass. They basically just sound lush, detailed and with huge deep bass slam and the Mojo didn't make much difference compared to my Sony player. However it made me realise the treble coming out of my Sony player was ever so slightly grainy sounding (veering towards harshness) whereas the treble out of the Mojo sounds super smooth. It's subtle and hard to describe and not something I would have ever noticed but it's there so maybe there is a bit of audible treble distortion (apparently common with cheap Class D amps) coming out of the Sony. It is subtle and I hope it's not confirmation bias but I do think it's there.

I have a pair of B&W P3 (first gen) headphones which I always thought were pretty mediocre with a bloated bass, rolled off treble and only saved by having above-average detail. Being somewhat disappointed with the Mojo so far, I plugged them in not expecting much difference since they are 32 Ohm with decent sensitivity and not exactly hard to drive. But wow was I blown away... It was like listening to completely different headphones. The detail was improved so much that I'd say it's competing with my SE846 and the soundstage was noticeably wider and deeper. Considering I bought them five years ago for 200 euros and they're worth less than £70 new now, it's pretty incredible that they had all this latent ability. Despite the still bloated upper bass and lower midrange, they became much more enjoyable to listen to and the bass bloat actually made them sound warm and pleasant to listen to instead of muffled. Compared to the Sony, I noticed that the bass coming out of the Mojo sounded more flat and clean while it was more textured and sounded fuller out of the Sony. I knew there was something funny going on with the bass out of the Sony when I first got it because it just sounded textured and lush and unlike my previous Sony players or PC soundcards. I suspect it might be a bit of extra second harmonic that gives the Sony player such a rich bass and makes the Mojo sound a bit lean in comparison. Again this is subtle but I'm pretty confident there is a difference here. I didn't notice this while listening with my SE846 which might be because the bass is so detailed and deep anyway that they make even my Surface Book sound good.

So what I've learned about the Mojo is that it gives an extremely smooth sound from the bass all the way up to the treble, while my Sony player has a funny textured bass boost (which I arguably prefer in some songs) and a slightly grainy treble (which I do not prefer). I paid £290 for the Mojo second hand so was it worth it? I'd say just about. I was considering replacing my P3 headphones before the Mojo gave them a complete new lease of life. The lesson to take away from all of this? Just buy a pair of SE846 and enjoy huge lush sound out of anything!

As an aside: I have also bought a pair of Sennheiser HD600 now that I have a DAC/amp that can power them and there isn't a big difference between the Sony (at near max volume) and the Mojo. In fact I would say the richer bass on the Sony makes them sound slightly better but the Mojo gives slightly smoother and more detailed treble. The HD600 are not as detailed in the bass and midrange as the SE846 or P3 but they have much better treble extension and they have a very nice neutral sound which was exactly what I wanted for home listening. Both the HD600 and P3 have decent sub-bass extension, not nearly as visceral as the SE846 but it's there which is nice. I wish I could do some ABX testing between different sources like Mojo, Sony, and my android phone but I'm not sure how to cheaply and reliably switch sources blindly. Next step now is to demo some amps and speakers!

[Zak33]

input from moi

new speakers really do need running in.

i was doubtful...so, long ago with a new pair of speakers.. i ran one for hours on its own...
then compared

they were obviously and notably different

I've still got them (Gale Golds) 10 years later....somewhere the thread exists....

[Zak33]

http://forums.hexus.net/consumer-ele...-speakers.html

there you go... a DECADE ago...

tell me I'm old ....and I bury your body on the wasteland out-back ;-)

[Dashers]

My speakers came with instructions to stand them facing each other and leave them playing to themselves. They started off sounding very muddy but sharpened up nicely after a few days of use.

I've heard people say that some speakers need regular use or they stiffen up again and need loosening up after being sat idle. I'm not entirely convinced on that though.

[g8ina]

Id agree with that... My 15 yr old AEs get used every single day and still sound amazing. If we go away on hols for a week, I *do* notice a reluctance on their part to *sing* to me on our return..

[drak15]

Transistors can likewise work in 'exchanged' mode, when the information voltage is adequately high the transistor is soaked and the yield flag is 'cut' at the most extreme. Rather than a continually shifting voltage, the yield flag of a transistor in exchanged mode shows up as a train of square heartbeats. Class D amps use yield transistors in exchanged mode, and that is the reason they are called computerized. Basically a Class D amp uses beat width balance.

Class D amps were initially created to cut the size and cost of intensification in compact gadgets driving small speakers, with moderately low <1W yields. As the flag stays computerized to the voice loop, it is less suscptible to electrical corruption and less fringe parts are required.
thanks