Kickstarter: Headphone Audio Amplifier - Page 1
Forum section: electronics / general

author: P_Doped
author_rank: Contributor
timestamp: April 11, 2014, 02:36:01 am
content: https://www.kickstarter.com/projects/853021962/headphone-audio-amplifierIf the small schematic is accurate, this appears to be nothing more than 2 channels of an opamp closing the loop around a discrete output stage.The creator describes this as: Ultra clean, super low-noise audio for the purists.The charge for 2 channels + power supply = $500, no enclosure. Has the following warning: Final assembly will affect the quality.It could be a hobbyist designer thinking they've got something cool and not realizing how simple the implementation is. But when they charge this much, I've got to lean towards total ripoff.

author: BravoV
author_rank: Super Contributor
timestamp: April 11, 2014, 02:38:54 am
content: I guess using an iPad scopeis quite convincing and more than enough for the "crowd".

author: sarm
author_rank: Contributor
timestamp: April 11, 2014, 03:16:13 am
content: The first try failed fundinghttps://www.kickstarter.com/projects/853021962/super-low-noise-headphone-and-stereo-amplifier?ref=usersthe only pledge available was 2000$

author: EEVblog
author_rank: Unknown
timestamp: April 11, 2014, 03:25:59 am
content: But, but, "it sounds great"!

author: Legion
author_rank: Frequent Contributor
timestamp: April 11, 2014, 03:33:39 am
content: Quote from: P_Doped on April 11, 2014, 02:36:01 amHe definitely doesn't pass himself off as a hobbyist.Quote

author: Tris20
author_rank: Regular Contributor
timestamp: April 11, 2014, 03:34:51 am
content: Sorry, but how the utter fuck can you claim your amp is giving a really clean sound when your video demonstration uses speakers that you got for "a buck"?!Also, what is this even supposed to show?And finally, for the money he's charging I'd at least want a treble/bass boost/cut with the option of bypassing to provide the cleanest signal.This guy can't be for real.

author: Legion
author_rank: Frequent Contributor
timestamp: April 11, 2014, 03:53:49 am
content: I just looked at the Kickstarter guidelines for hardware projects. His project page looks like he through it together as quickly as possible and just checked off all the requirements as he went. Do you think he kept the schematic small so no one would learn the "secret" of his audio amp technology?

author: Legion
author_rank: Frequent Contributor
timestamp: April 11, 2014, 03:58:53 am
content: Quote from: Tris20 on April 11, 2014, 03:34:51 amThere seems to be a big mismatch between his price and marketing position which is geared toward audiophiles, and the contents of the video. I know it's pitched as a headphone amp, but the amp is definitely not portable. If it's going to be stationary why not get the audio through the microusb port/bluetooth/whatever iphones have. Seems like it would make more sense to keep everything digital and have a high quality ADC in the amp.

author: FrankBuss
author_rank: Unknown
timestamp: April 11, 2014, 04:02:41 am
content: The spice diagram shows some really nice clipping. And no data at all, like THD+N, amplification factor, input impedance. Only "best used on 250 ohm headphones"For audiophiles some techno talk is missing, like "this amplifier reduces the electron quantum entanglement for a distinguished and crisp sound"

author: linux-works
author_rank: Super Contributor
timestamp: April 11, 2014, 04:10:31 am
content: Quote from: Legion on April 11, 2014, 03:58:53 amhuh?headphones (not earbuds) are a home thing more than an 'away' thing (office=home, btw). there are small phones amps, too, for total portable use, but there is a new HUGE market for high-end discrete and semi-discrete phones amps. sometimes they are mostly buffers without much gain, and sometimes there is 10x gain or so.QuoteIF you do have a digital-out of some sort, sure, you'll want an outboard dac and then outboard phones amp. not every player has a digital-out and so you may be stuck with the 'lowly' line-out or phones-out jack (via jack or connector).

author: linux-works
author_rank: Super Contributor
timestamp: April 11, 2014, 04:13:05 am
content: oh, and one reason not to bundle the dac and the phones amp: dac tech changes very fast these days. every year, sometimes. audio guys like comparing each new dac chipset (and implementation); while amp tech does not change all that much over time. you may want to invest in a good amp and keep it for a long time. the dac may be 'yesterdays flavor' in just 6months time.best to keep them as separate boxes so you can always stay current (lol).

author: FrankBuss
author_rank: Unknown
timestamp: April 11, 2014, 04:22:22 am
content: Quote from: linux-works on April 11, 2014, 04:13:05 amIt is difficult to tell, because he didn't write any technical information about his project, but from the schematic and the video it looks like it has just analog input. But no worry, "fiber optic input" is planned.

author: linux-works
author_rank: Super Contributor
timestamp: April 11, 2014, 04:27:46 am
content: it did not look like a dac; just a phones amp with lots of bulk filtering. I missed the schematic, I see a tiny one but I can't see any version that is readable (?)

author: Legion
author_rank: Frequent Contributor
timestamp: April 11, 2014, 01:54:48 pm
content: Quote from: linux-works on April 11, 2014, 04:10:31 amThe point I'm getting at is there isn't a portability size requirement, so why would you restrict your input to a single 1/8" jack?

author: calexanian
author_rank: Super Contributor
timestamp: April 12, 2014, 05:37:15 am
content: I remember that circuit in my intro to solid state design class under the heading "How to increase the current capacity of IC op amps" This magic chip that cost about $2 called the TDA2020 came out, also the LM387 I do believe, and made all of those circuits obsolete cause they did the same thing cheaper, with lower distortion, and greater efficiency! I get it.. You have no design skills, but you like playing with this stuff and want somebody else to pay for your hobby. I, and most of the other people on this forum can build a better design with the junk laying on our benches in an afternoon and be just happy with it.

author: Skimask
author_rank: Super Contributor
timestamp: April 12, 2014, 05:50:37 am
content: <DELETE>

author: godfrey
author_rank: Contributor
timestamp: April 12, 2014, 06:15:25 am
content: Hmmm… $500 is a bit high in my opinion -- though I know a lot of audiophiles will make claims that some piece of hardware they own improves the signal. If it wasn't recorded right, no amount of money is going to improve the output.I use a Behringer HA4700 headphone amplifier, an Alesis 3630 Compressor and an Alesis DEQ230 equalizer with a pair of Sony MDR-7506 headphones. It sounds fantastic…and the entire setup cost less than $500.Oh…don't forget to order your set of oxygen free copper wires…

author: Fsck
author_rank: Super Contributor
timestamp: April 12, 2014, 06:52:52 am
content: Quote from: godfrey on April 12, 2014, 06:15:25 amyou mean silver plated c10100 right?

author: godfrey
author_rank: Contributor
timestamp: April 15, 2014, 05:04:01 am
content: Quote from: Fsck on April 12, 2014, 06:52:52 amWhatever fancy exotic marketing term you want to use for plain wire! lolIt comes with "Way Better Sound Technology"Put the wordtechnologybehind anything and it gets stupid people lining up to buy it. It's one of the most overused (and useless) marketing words."with water filtration technology""with ion air technology""with paint drying technology""with grass growing technology""with butt wiping technology"To be honest…I hate the word.

author: Fsck
author_rank: Super Contributor
timestamp: April 15, 2014, 05:26:37 am
content: Quote from: godfrey on April 15, 2014, 05:04:01 amI was just taking your OFC joke one step further with silver plating. C10100 is >99.99% copper and IIRC something like <0.0005% oxygen.and I'm not quite sure if there's actually a discernible effect (other than cost) of the plating for audio applications.

author: Richard Crowley
author_rank: Super Contributor
timestamp: April 15, 2014, 05:50:20 am
content: Quote from: Fsck on April 15, 2014, 05:26:37 amOnly "golden-ears" folk with excellent imaginations (and meta-knowledge of the "technology") can discern the difference.That is why they refuse such mundane things like double-blind tests. We ordinary people just "don't understand".That is a completely ordinary circuit. No amount of "gold plating" could justify a 10x inflated price like that. But there is a sucker born every minute.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 15, 2014, 09:08:52 am
content: I'm looking at this and thinking "what does this have over an O2 amp?" Ref;http://nwavguy.blogspot.com.au/2011/08/o2-details.html

author: linux-works
author_rank: Super Contributor
timestamp: April 15, 2014, 02:41:26 pm
content: Quote from: peter.mitchell on April 15, 2014, 09:08:52 amthat navguy was a huge mess. he came on the scene, threw lots of insults at people, acted like a smart-ass and then left the scene. good riddance! never found out what his story was and I have a lot of doubts as to his design ability. I'm not impressed by his work, but I guess some are. you have to admit that to enter and leave with such mystery raises a lot of questions, and not only about his motives...

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 15, 2014, 03:41:21 pm
content: Quote from: linux-works on April 15, 2014, 02:41:26 pmI know nothing of him as a person, though I do share quite a few of his sentiments... As i said in another thread; the amp is good, but no amazingly revolutionary designs or anything, just a LOT of searching through datasheets and cost optimization, which is good enough in it's own right to make the amp a good amp/

author: Halfdead
author_rank: Contributor
timestamp: April 19, 2014, 07:50:54 am
content: Quote from: peter.mitchell on April 15, 2014, 03:41:21 pmI use his Amp and USB DAC as well. No idea whatever happened to the guy though.

author: AlienRelics
author_rank: Unknown
timestamp: May 01, 2014, 04:34:52 pm
content: Why does he need a $4000 scope for audio? Oh, right, to make sure his amp isn't biasing any theta waves with shear phasing. I hate that, it makes the sound all muddy and obsequious.

author: madshaman
author_rank: Frequent Contributor
timestamp: May 01, 2014, 06:04:51 pm
content: I'd be *very* interested to know how many audiophiles are actually musicians; I suspect it's a very low percentage.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 01, 2014, 07:08:53 pm
content: Quote from: madshaman on May 01, 2014, 06:04:51 pmA significant number of musicians are "audiophools" with magical beliefs in certain brand-names.Common-sense and hard-science be damned. They know what theythinkthey hear.

author: old gregg
author_rank: Regular Contributor
timestamp: May 01, 2014, 09:11:22 pm
content: Some guitarists for instance are great audiophools. Most swallow craps form manufacters in an interesting fashion. Cables and buffers are great exemple. Do you know "monster cable" and how a cable can make your hi-mids more mellow ?Ignorance and makerting stupidity is the key I guess.

author: linux-works
author_rank: Super Contributor
timestamp: May 01, 2014, 09:16:16 pm
content: musicians often are lousy techs. techs are often lousy musicians. musicians often cannot build or design gear. and designers often cannot play musical instruments.SO WHAT?

author: madshaman
author_rank: Frequent Contributor
timestamp: May 01, 2014, 10:27:28 pm
content: I'm a musician. I play both piano and guitar and did conservatory training for the former.I do agree with some of what's been said, but please be aware that correlations have been shown between mathematical ability and learning to play music. I don't think one can say that being a musician implies that one cannot do engineering/science/math or the reverse.

author: Jarrod Roberson
author_rank: Regular Contributor
timestamp: May 01, 2014, 10:30:26 pm
content: Quote from: madshaman on May 01, 2014, 10:27:28 pmI agree 30 years of a software development career and 9 out 10 of the Best people I have worked with as peers were musicians of some sort, majority of them self taught in both fields and always more informed than their CS wielding degree counterparts.

author: janoc
author_rank: Super Contributor
timestamp: May 01, 2014, 10:47:39 pm
content: Quote from: AlienRelics on May 01, 2014, 04:34:52 pmE.g. to check that his darn thing isn't oscillating at a few MHz? Doesn't need a $4k scope, but I doubt that that iPad will cut the mustard there.

author: FrankBuss
author_rank: Unknown
timestamp: May 01, 2014, 11:09:34 pm
content: Quote from: madshaman on May 01, 2014, 10:27:28 pmThat's an interesting topic. I started a new thread for it:https://www.eevblog.com/forum/chat/how-many-engineers-are-artists/