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Post by Deleted on Mar 20, 2012 7:25:24 GMT
Best value: O2 Lowest price: O2 highest output power in low impedance HP's: O2 portability: O2 Size: O2 Weight: O2 highest power in high impedance HP's: CHAmp (marginally) Safety: CHAmp versatility (synergy with most headphones): CHAmp Sound quality: In 0 Ohm, low gain and wide BW setting up to 150mW they cannot be distinguished in any well performed AB test. In all other conditions it can swing both ways. How well both amps compare subjectively is another question and includes more factors than just technical ones. I do not claim my design is, measures or sounds better than other designs. CHAmp keywords are : synergy and safety O2 keywords are: portability and VFM hardly comparable except for both being opamp based amps.
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Post by Deleted on Mar 20, 2012 7:37:54 GMT
I know which one I would rather have to drive AKG 701 or AT W1000
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Post by Deleted on Mar 20, 2012 8:07:25 GMT
I know which one I would rather have to drive AKG 701 or AT W1000 the AK SC A-HA most likely ?
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Post by Deleted on Mar 20, 2012 8:16:31 GMT
I know which one I would rather have to drive AKG 701 or AT W1000 the AK SC A-HA most likely ? That wasn't being discussed here. We both know that these headphones should be driven in accordance with IEC 61938 specifications for best results, NOT 0 ohms .
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Post by pete on Mar 20, 2012 9:42:29 GMT
Best value: O2 Lowest price: O2 highest output power in low impedance HP's: O2 portability: O2 Size: O2 Weight: O2 highest power in high impedance HP's: CHAmp (marginally) Safety: CHAmp versatility (synergy with most headphones): CHAmp Sound quality: In 0 Ohm, low gain and wide BW setting up to 150mW they cannot be distinguished in any well performed AB test. In all other conditions it can swing both ways. How well both amps compare subjectively is another question and includes more factors than just technical ones. I do not claim my design is, measures or sounds better than other designs. CHAmp keywords are : synergy and safety O2 keywords are: portability and VFM hardly comparable except for both being opamp based amps. You missed off build quality in that list , IMO another very important part. Im not sure if we are allowed to mention names here? but I cant see why not, Ive seen a number of people say the JDS is better built than the Epiphany Acoustics EHP-02, with reports of the EHP-02 having anything from bad solder joints, bad connections on the headphone & line jacks resulting in distortion, high gain destroying sound quality, to case issues like wobbly volume knob that also scrapes Perhaps because its cheap means build quality is sacrificed & we cant have it all? but I think when your having to wiggle the headphone plug to get the channel back working really puts a damper on the whole fun factor of an amp to be fair I havent seen much problems with the JDS one & probably even better to just buy the board & do it yourself if your capable. Portable is one thing that I would say its most definately not, transportable perhaps but I cant see anyone going jogging with an O2 strapped on their waste ;D (edit), While I see no other purpose that Oliver could provide on a forum which isnt biased & I have no intention of getting into a debate with him over this, but since you asked Oliver (below) it was on headfi where somebody spoke about poor solder joints & had to solder them to get the amp back working, I dont know anymore other than what I read so dont shoot the messenger! but since it sounds like they fixed it themselves explains why you havent heard of it until now, ive also seen multiple comments about how the JDS labs is better built (thats why I pointed it out to solderdude), so while I understand as the builder of these you would naturally come on here & essentially sugarcoat everything, tell us there are no problems, we are all wrong, it doesnt inspire much confidence in your work when we hear of things like that, sure it is only £100 & perhaps im being to fussy & it seems the cheaper something is the more favourable the comments seem to be, but it seems not everyone is so easily pleased. Also just the other day I saw a video review of the EHP-02 on youtube while searching for cmoys, there was also a comment on there saying something about poor build, however I now see it was removed by the owner of the vid only a few hours after I saw it posted there, so I cant help but be suspicious when any negatives are now allowed, sensored or removed so quickly on your products.
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Post by pete on Mar 20, 2012 9:47:43 GMT
the AK SC A-HA most likely ? That wasn't being discussed here. We both know that these headphones should be driven in accordance with IEC 61938 specifications for best results, NOT 0 ohms . According to NwAvguy every amp that is higher than the 2ohm rule will sound bad (is that even a general rule or just his rule that he made up). In that case I think Beyer will never sell another amp as their A1 is 120 ohms so must sound absolutely terrible, LOL.
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Post by Deleted on Mar 20, 2012 11:52:43 GMT
The O2 was designed as a 'portable' or at least to play disconnected from mains, running on batteries. Personally I wouldn't always leave it plugged in with the 9V batteries in it as the charging circuit is kind of 'basic' and prone to overcharging. NwAvGuy has a point for certain headphones, mainly portable HP's and certain IEM's about his low output resistance. Making it a 'rule' (based on damping factor) is a bit shortsighted IMO.
The build quality is dependent on the manufacturer and not the design itself, so the design nor designer can be faulted IMO. Quality issues are a valid point. You can choose to use crappy parts (or one of the 'manufacturers' may choose so for financial reasons) or to use higher quality parts (and thus make less profit or sell it for a higher price) This is true for every DIY product as well as amps made by manufacturers and not only for the O2.
The A1 is 100 Ohms b.t.w. but indeed FAR away from NwAVguy's ideal 0 Ohm. Neither is perfect in all cases.... One HP may sound better (to that individual) driven from a low Ohmic amp, another listener may prefer the same HP on a higher Ohmic amp. It may come down to personal taste/preference as well as being technically more suited.
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Post by epiphanyacoustics on Mar 22, 2012 18:46:11 GMT
Im not sure if we are allowed to mention names here? but I cant see why not, Ive seen a number of people say the JDS is better built than the Epiphany Acoustics EHP-02, with reports of the EHP-02 having anything from bad solder joints, bad connections on the headphone & line jacks resulting in distortion, high gain destroying sound quality, to case issues like wobbly volume knob that also scrapes Hi pete, Whilst I have never heard of any bad solder joints on the EHP-O2 (where did you read that? I'd like to have the opportunity to resolve that problem) nor have I had anyone come to me with issues about bad connections (well, there was one person but he was just using too chunky a cable and resolved his problem by using a smaller cable), the volume knob issues have been sorted. There were a couple of cases of them scraping and coming loose in transit. Both of these issues have been fixed on subsequent batches. I am confident that the current EHP-O2 has exemplary build quality, and am backed up by the positive emails I have been receiving. And a note about the high gain distortion - this is caused by have a source with too high an output for the O2 to handle when in high gain mode. This is a problem that every O2 amplifier, regardless of who made it, can have and is fixed by using a different source or using the low gain setting when using the high output source. Cheers, Oliver Freeborn
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Post by Deleted on Mar 22, 2012 20:53:55 GMT
Oliver Please excuse the scepticism about a "manufacturer" who is only 20 years of age, and has very little technical background. SandyK
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Post by Deleted on Mar 23, 2012 15:36:43 GMT
Oliver, All you seem to sell on your website (epiphany acoustics) is an interconnect cable and a design made by someone else . Everyone needs to start somewhere. Your age, at the same time, doesn't inspire the confidence of many years of experience or make you an expert in manufacturing to some of the regular contributors. a few 'irrelevant' posts have been removed.
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Post by Deleted on Apr 7, 2012 16:17:15 GMT
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Post by dalethorn on Apr 7, 2012 22:56:02 GMT
My experience with the JDS O2 is similar. With the HD-800 I thought it sounded very good, but with the lesser-bass headphones like the Shure 1840 and 940, the Beyer DT-48A and DT-1350, and a few others, not so good. The treble became harsher and the bass leaner when it was already pretty lean. Still a pretty good deal I think, for what I paid.
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Post by Deleted on Apr 8, 2012 6:17:02 GMT
Simply put in a 100 Ohm series resistor (there are provisions for it on the board itself) and then listen to the HD800 and T70/T1 (like with the Beyer A1 amp). The amp totally transforms ... or should I say it sounds different yet the amp itself does nothing different.
That is really all that is 'wrong' with it for certain headphones.
HP's like HD650, HD595, DT770 e.t.c. don't particularly like 120 Ohm outputs. DT1350, T1, HD800, 940 e.t.c. do like it. Or should I say most owners will ptobably like it that way.
It pays to own 2 amps with different output resistances when you have quite different HP's in your armory.
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Post by pete on Apr 8, 2012 14:55:45 GMT
With all due respect solderdude, I tried that once with the AKG 701's on a Cmoy amp, but never heard any real differences so I figured it might be very dependent on the amp or perhaps I was just anticipating a much larger change (never a good thing to do), although I dont mind the AKG's on low impedance amps, I think they sound good.
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Post by pete on Apr 8, 2012 15:12:13 GMT
I read the headfonia review last night & would say its the most realistic unbiased review ive seen, as they are not newbies that are so easily pleased or fooled by a bit of marketing, or too friendly with any of the builders, or bought into the hype like all the others, so id rather trust their review. If you feel like a laugh you have just gotta read the response from nwavguy on his blog, its a very entertaining read, if you can actually make it to the bottom of the blog entry as its EXTREMELY lengthy with the most waffle & BS that I have ever seen. Basically nwavguy is saying that the headfonia guys have something wrong with their brains & its all in their head about how they perceive something to sound, he went on & on & made every attempt he could at trying to discredit that review, it was quite funny to read because as the blog goes on he even starts to mention about waterford crystal, WHAT? I started to lose the will to live when I got to that point , but even after that it went on & on & on, my goodness what a load of ball. He really seems to hate anyone saying anything bad about it, thats probably why we dont see any negatives on his blog as like I said before he wont approve them as its all censored, the only one I noticed on there was from somebody disagreeing with nwavguys comments about optical connections being redundant & not needed (he only said that because his dac wont have one), the other person raised some valid points which I also agree with him on, lots of equipment has optical connections, & because nwavguy couldnt really argue that point as he knew he was wrong, he posted "feel free to design your own open source DAC" basically saying bugger off & make your own one then! lol The headfonia review has definitely shown up a few points though, firstly that the O2 amp isnt quite the unbeatable amp that nwavguy or his followers would have us all believe (something a lot of us on here already knew!), also that neutral amps dont all sound the same & certainly dont have to suffer from weak bass & poor mids with the HD650 like the O2, also it shows that measurements & good specifications dont mean a whole lot, nwavguy likes to hide behind his dscope & reel off pages after pages of technical measurements, graphs & so on, & even says that its up to him to expose other makers stuff & keep them honest & reveal their stuff for the half baked designs they are, but who is going to keep HIM honest, thats what id like to know when his whole approach is one of: if he hasnt made it, then its no good, or flawed, so I wouldnt trust what he says as his true "objective" is one that I saw right through from day one, that is to get us all thinking that his amps are the only ones that are any good because they have good specs (just a pity about the sound), & when a review like headfonia pops up, he says its something in our brains that is wrong, well even if that is the case, the fact is if another amp sounds far better then I for one would not be happy with sitting back in my armchair with a pair of HD650's sounding like shite & saying to myself "but nwavguy says its all in my brain & I completely trust him because he seems to know what he is talking about, & that my O2 measures better that anything else so it MUST be great sounding", ;)lol, it wouldnt be long before I would be reaching for a better sounding amp. My thoughts are that specs & stuff like that has always been a big part of the audio world, looking at brochures & comparing specs & things like that can be part of the fun, but he seems to be starting up a whole culture where specs are the final word on how something will sound, which is rubbish as some tube amps measure up terrible, but sound great, just the other day I saw a post on another forum, where somebody said he went for a DAC with asynchronous USB because by having that it would not sound harsh! lol, a classic case of buying into the marketing hype & specs as that means any DAC without the Asynchronous would all sound harsh then, there is so much false information out there its a joke. As always, specs dont mean a whole lot, & those people that are chasing figures which wont make any difference anyway often lose sight of the bigger picture, which is to enjoy listening to the music.
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Post by billyray on Apr 8, 2012 15:24:51 GMT
For what its worth - I like my O2, but can't be bothered with all the noise created about it
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Post by Deleted on Apr 8, 2012 18:49:12 GMT
I happen to agree with most NwAvGuy says, aside a few minor quibles about output resistance and damping factor.
I also feel he has a chip on his shoulder, is not to be questioned and fully agree with your assesment he feels only HIS design is the best. His dismissivenes and loathing of people that like the (nice added) distortion tubes can bring is also something I personally would not do. Everyone hears different and has preferences. Who am I to say only SS is good sounding. It is technically better IF you don't like the original signal to CHANGE. IF you like it when the signal is changed to the better in your personal opinion than this is the case and who gives a f.. about the numbers that go with it ?
He is not saying the reviewers are mad or something is wrong with them at all in my opinion. I can understand your conclusion though. NwAvGuy simply says, with a LOT of words (I didn't make it to the end also) examples and references that the reviewers are very human.
I am not going to convict either side and it's just opinions based on different beliefs with different ears and preferences.
adding 120 Ohm to a 9V C'Moy isn't a good idea... the output voltage is too low. even for an 18V C'Moy it is already on the high side of things. The subtle differences with a K701 you might not be able to detect, many can though. It's even big enough to be measurable and when truly AB'd (with a special switchbox that also adjusts output level) it can be detected in AB tests.
Some headphones are affected in a negative way when the output resistance is higher, others simply sound better to some.
The K701 seems 'sacred' to many owners and feel it is the most accurate headphone on their personal choice of amp in existence, it should/must not be questioned because it is like questioning their hearing capabilities. I say it's a personal thing and and has to do with taste and preference.
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chris1967
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Post by chris1967 on Apr 8, 2012 21:39:45 GMT
If it worth anything...
My O2 doesn't resemble the sound that the review of Headphonia says it has.
Headphones i use are Sennheiser HD800 and HD650, Frans filtered Superlux HD681, modded Fostex T50RP, and AKG Q701.
Speaking of the AKG, i listen to them still, but i dont like them so much as the rest of my phones because they sound treble happy and bass shy... not to mention the artificially inflated stereo imagery... these phones always sound to my ears this way whatever amp i use them on...
I never felt the O2 has diminished mids or bass, nor that it has accentuated treble... even with the AKG Q701.
Just my findings...
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Post by dalethorn on Apr 8, 2012 23:15:49 GMT
Being banned from headfi can make a person feel like .... well, like not having the mark in your forehead or right hand, so you can no longer do business with the rest of humanity. That may sound absolutely silly, the 666 part, but the other part is not so silly.
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XTRProf
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Post by XTRProf on Apr 9, 2012 1:02:04 GMT
Being banned from headfi can make a person feel like .... well, like not having the mark in your forehead or right hand, so you can no longer do business with the rest of humanity. That may sound absolutely silly, the 666 part, but the other part is not so silly. Actually, I find this real silly. We can always do business with God instead of 666. However people must know what to say and how to say it in a civilised and cultured way. Banned is a sway 666 but ....... It's always better to do things with God instead and have our CONSTRUCTIVE FREE SPEECH. Btw, I'm not holy but a holistic type just in case people misunderstand me.
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Post by dalethorn on Apr 9, 2012 2:09:34 GMT
Actually, I find this real silly. We can always do business with God instead of 666. However people must know what to say and how to say it in a civilised and cultured way. Banned is a sway 666 but ....... It's always better to do things with God instead and have our CONSTRUCTIVE FREE SPEECH. Btw, I'm not holy but a holistic type just in case people misunderstand me. Those who have such an extreme need to exert such extreme control over such a large forum are in the negative category. There's no way around that. When you decide as a business matter that you want to be so big and such a comprehensive, representative and authoritative source on this tech, you have an obligation to represent everyone fairly. Those who disagree are really suggesting a small, non-comprehensive forum that serves a small special-interest clientele. The principle isn't difficult to understand. When legislation was created in the U.S. circa 1900 to reign in monopolies, there was no law against such capitalism, and free enterprisers could certainly argue against such govt. restrictions. But the public interest demanded legislation, no matter that certain people cried foul. And so it is with the ban-happy forum - they want the power but not the responsibility. Facebook is an example of a better idea, but that's only good until they have total power, then all bets are off.
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Post by Deleted on Apr 9, 2012 11:03:42 GMT
The 'Evil Twin' talks a lot of sense and what he spouts is all probably perfectly correct. There are three things I really don't like about him though: a) He presumes there is only one way - his way. b) He presumes that everyone likes the same sound and criticises people who like something different to him. c) He doesn't seem to be able to cope with an opposing view. At least he gives that impression. He's not 'open' and the fact that he heavily mods his forum suggests he has things to hide. He also seems to be doing what was done to him on HF but even worse. Anyone can spout from a book but in audio, there are many variables which he seems to turn his back on. If he's making an amp for himself, then he can do as he likes. It doesn't matter. But selling one and touting it as perfect kind of 'screams' at me. I don't believe that and does he really think that? If he does, he's extremely arrogant and deaf. Peronally, I would pay more for something like the C.H.A.M.P. given that a) the maker has more humility (slightly ) and so is open to discussion. (It's a joke Frans!!!) b) it caters for taste in sound and doesn't spout rubbish about perfect sound. c) problems would be solved and not denied. Although it would cost more than this perfect amp, it would sound more perfect to me since it's configurable to what I want and not what someone tells me I want. I hope there's no update for this amp, because that would suggest it wasn't perfect after all. He has a bag of chips on his shoulders.
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XTRProf
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Post by XTRProf on Apr 9, 2012 12:15:22 GMT
I hope there's no update for this amp, because that would suggest it wasn't perfect after all. Oh, he will but claim it's V1.000000000001. Too minute to change the sound.
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Post by dalethorn on Apr 9, 2012 14:19:18 GMT
The good news is he doesn't make the O2 - he just advocates the design. So being his design, it makes him the god of that tech, yes? It's really hard to pick on him, since he's not offering an opinion on someone else's design and then banning people who disagree with his opinion, on something he didn't create. He's the creator after all. How many guys who designed a well-known headphone or amp would even be willing to go onto a forum and discuss it at that level? I could be wrong - just trying to relate this to other examples, if there are any.
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xerxes
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Post by xerxes on Apr 9, 2012 15:26:55 GMT
The Headfonia review was kind of how I imagined the O2 to sound. I know that's a load of nonsense, because I've never heard the O2. However, I've been reading the reviews over at Headfonia for a while and I think I have a handle on the sort of sound they like. They seem to favour gear that is the warm, dark, full, lush side of neutral. Therefore, if the O2 is very neutral and analytical, it doesn't surprise me that they're not so keen at Headfonia.
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