Kickstarter: Headphone Audio Amplifier

[P_Doped]

https://www.kickstarter.com/projects/853021962/headphone-audio-amplifier

If 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.

[BravoV]

I guess using an iPad scope    is quite convincing and more than enough for the "crowd". 

[sarm]

The first try failed funding https://www.kickstarter.com/projects/853021962/super-low-noise-headphone-and-stereo-amplifier?ref=users the only pledge available was 2000$ 

[EEVblog]

But, but, "it sounds great"! 

[Legion]

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.

He definitely doesn't pass himself off as a hobbyist.

My career started off at the University of Washington Redmond Plasma Physics Lab developing fusion energy and space propulsion.

I've designed an atmospheric entry system for a manned vehicle entering the Martian atmosphere, contributed to a Lunar Rover Design competing in the Google Lunar X-Prise. Spent one summer developing fuel cells and the manufacturing process.

[Tris20]

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.

[Legion]

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?

[Legion]

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"?!

There 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.

[FrankBuss]

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"

[linux-works]

I know it's pitched as a headphone amp, but the amp is definitely not portable.

huh?

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.

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.

IF 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).

[linux-works]

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).

[FrankBuss]

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.

It 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.

[linux-works]

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 (?)

[Legion]

huh?

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.

IF 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).

The 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?

[calexanian]

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.

[Skimask]

<DELETE>

[godfrey]

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…   

[Fsck]

Oh…don't forget to order your set of oxygen free copper wires…   

you mean silver plated c10100 right?

[godfrey]

Oh…don't forget to order your set of oxygen free copper wires…   

you mean silver plated c10100 right?

Whatever fancy exotic marketing term you want to use for plain wire!  lol

It comes with "Way Better Sound Technology"

Put the word technology behind 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.

[Fsck]

Oh…don't forget to order your set of oxygen free copper wires…   

you mean silver plated c10100 right?

Whatever fancy exotic marketing term you want to use for plain wire!  lol

I 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.

[Richard Crowley]

and I'm not quite sure if there's actually a discernible effect (other than cost) of the plating for audio applications.

Only "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.

[peter.mitchell]

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

[linux-works]

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

that 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...

[peter.mitchell]

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

that 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...

I 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/

[Halfdead]

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

that 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...

I 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/

I use his Amp and USB DAC as well. No idea whatever happened to the guy though.