[MacedonianHero]

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You're going to like the GS-1 a lot Peter.  When will you have it?  
 
One of the most interesting things to explore is the "holographic effect" Asr wrote about and Shah and I have discussed.  I have always described it as "playing in a larger room".  I'll be curious to know if you hear it too and what you'd call it.
 
Back on topic, this attribute is something the O2 does not possess.
 

Thanks Eric....hopefully by Friday or early next week is the ETA. That  said, I've sold off some gear (HE-6s and Schiit Lyr) and have about $150 left over in my Paypal...what to do....maybe an O2 for my office?

 

 

[xxhaxx]

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Where can you buy a pre-built O2?
Or order parts to DIY build?
 

 
Here you go 

http://www.jdslabs.com/storeAmps.php
 
 
 

 

[purrin]

 
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assuming the amp isn't having its input stage overloaded, and is being used properly in other ways, and is being used with headphones that are within its measured compatibility, than I would go back to my original statement and say its not the amp.

It most certainly could be the amp. Op-amps have different distortion characteristics that could present different tonal balance to the listener. The current suite of FR measurements typically used are on static state (test tones or sweeps) or very short duration impulse responses - not music.
 

 

[upstateguy]

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Originally Posted by estreeter /img/forum/go_quote.gif

<snip>
 
upstateguy, without wanting to insult you, I hope you will give the O2 another 50 or so hours. If you still find it tinny, c'est la vie -
 
<snip>

I will certainly give it some break in time, but 50 hrs is a long time for this little SS amp don't you think?
 
As it stands now, it seems the tinny sound on high gain was caused by clipping.... although if IIRC low gain also seemed to develop the same "sound" <---insert your own adjective, when driven very hard.  I'll double check this later tonight.
 


Quote:

Thanks Eric....hopefully by Friday or early next week is the ETA. That  said, I've sold off some gear (HE-6s and Schiit Lyr) and have about $150 left over in my Paypal...what to do....maybe an O2 for my office?

 

I think the O2 is worth collecting as an example of a measurement driven design.  What would be your office source Peter?
 

 

[MacedonianHero]

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I will certainly give it some break in time, but 50 hrs is a long time for this little SS amp don't you think?
 
As it stands now, it seems the tinny sound on high gain was caused by clipping.... although if IIRC low gain also seemed to develop the same "sound" <---insert your own adjective, when driven very hard.  I'll double check this later tonight.
 

I think the O2 is worth collecting as an example of a measurement driven design.  What would be your office source Peter?
 

iBasso D4 fed by my iPhone or laptop (Apple Lossless).
 

 

[Br777]

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It most certainly could be the amp. Op-amps have different distortion characteristics that could present different tonal balance to the listener. The current suite of FR measurements typically used are on static state (test tones or sweeps) or very short duration impulse responses - not music.
 

 
voldemort tests with music as well.  His whole concept was built around air tight measurements.  He really didnt leave anything to chance.. thats the whole reason this amp and Voldemort have gained the interest they have have in the first place.  There's no wiggle room.

 

[purrin]

Linky or four-five word quote (so I can Google) that he "objectively tests" with music. Unlike AMB's site, his has too much manifesto garbage so it's hard for me to navigate.
 
Also were measurements into a real load (voice coil, back EMF, temperature) or dummy load?

 

[upstateguy]

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iBasso D4 fed by my iPhone or laptop (Apple Lossless).
 

Why bother with a giant portable amp?  It looks like you have a really small package in the iBasso dac/amp.
 
OTOH Peter, we are enablers here, so I'm surprised that you haven't ordered the jdslabs O2 yet.  It might add an entirely new dimension to your office experience.
 
What headphones do you use in your office?
 

 

[MacedonianHero]

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Why bother with a giant portable amp?  It looks like you have a really small package in the iBasso dac/amp.
 
OTOH Peter, we are enablers here, so I'm surprised that you haven't ordered the jdslabs O2 yet.  It might add an entirely new dimension to your office experience.
 
What headphones do you use in your office?
 

Because I have an extra $150 in my Paypal account.

Love the enablers comment...ain't that the truth.
 
I normally use my Ed.8s or Westone 4s. Maybe I'll just pass.
 

 

[zeffa]

 
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As it stands now, it seems the tinny sound on high gain was caused by clipping.... although if IIRC low gain also seemed to develop the same "sound" <---insert your own adjective, when driven very hard.  I'll double check this later tonight.
 

I built my own O2, with gain set at 1x and 2.5x. With standard DAC inputs (grubDAC and NFB-3), the sound using 2.5x gain is noticeably harsher than with 1x. It also gets exceedingly loud very quickly, so I just use 1x gain all the time (and I've never had to turn it up to full volume even with 1x gain). At 1x gain, the sound is very, very good. Very neutral & transparent - it easily highlights for me the difference in my sources.
 
If you're not afraid of getting your hands a little dirty, removing one of the gain resistors completely, will set the gain to 1x. I believe some third party manufacturers were using sockets for the gain resistors, so that end users could easily change the gain themselves.

 

[mikeaj]

Quote:

Linky or four-five word quote (so I can Google) that he "objectively tests" with music. Unlike AMB's site, his has too much manifesto garbage so it's hard for me to navigate.
 
Also were measurements into a real load (voice coil, back EMF, temperature) or dummy load?

 
The only tests with music (that are published) into real-world loads, as far as I remember, are just descriptions of blind listening tests.  There's high-speed scope shots of square wave testing into real-world loads, but not music.  Search "o2 square wave performance" and then within the page search for "square wave performance" and that's that.
 
 
This is why I was hoping if somebody with a suitable setup could run an audio differencing test (or pretty much anything) with real music using a real load.  I certainly don't have any interface line in good enough to capture any significant differences, or I would have tried.

 

[purrin]

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The only tests with music (that are published) into real-world loads, as far as I remember, are just descriptions of blind listening tests.  There's high-speed scope shots of square wave testing into real-world loads, but not music.  Search "o2 square wave performance" and then within the page search for "square wave performance" and that's that.
 
 
This is why I was hoping if somebody with a suitable setup could run an audio differencing test (or pretty much anything) with real music using a real load.  I certainly don't have any interface line in good enough to capture any significant differences, or I would have tried.

 
Square waves don't cut it. Only clarinets sound like square waves (or was it saw wave) - and even then - not even close. I would like to see objective tests into real-world loads (headphones or even approximate simulations of such - electrical characteristics change depending upon the position of the driver in the voice coil) using music (or even dynamic signals which are of approximate simulations of music). Square waves are summations of multiples of the odd integer harmonics at a certain volume. I want to see variability in volume. In other words, I don't listen to simulated clarinets at a single volume at a single note.
 
Of particular interest to me is the ability to measure how well amplifiers are able reproduce lower level signals during loud passages or passages of dynamic loudness is music. In addition to the dynamic compression issue I mentioned earlier, I also see this as another major shortcoming  of audio reproduction's inability to give us the immediacy of live music.

 

[PelPix]

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Square waves don't cut it. Only clarinets sound like square waves (or was it saw wave) - and even then - not even close. I would like to see objective tests into real-world loads (headphones or even approximate simulations of such - electrical characteristics change depending upon the position of the driver in the voice coil) using music (or even dynamic signals which are of approximate simulations of music). Square waves are summations of multiples of the odd integer harmonics at a certain volume. I want to see variability in volume. In other words, I don't listen to simulated clarinets at a single volume at a single note.
 
Of particular interest to me is the ability to measure how well amplifiers are able reproduce lower level signals during loud passages or passages of dynamic loudness is music. In addition to the dynamic compression issue I mentioned earlier, I also see this as another major shortcoming  of audio reproduction's inability to give us the immediacy of live music.

If you're looking for load tests, I believe ALL of his tests are into simulated loads.  He doesn't even publish loadless results.
It's only $75 to build.  Build one yourself and test it with your equipment.

 

[upstateguy]

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Because I have an extra $150 in my Paypal account.

Love the enablers comment...ain't that the truth.
 
I normally use my Ed.8s or Westone 4s. Maybe I'll just pass.
 

Now Peter, you know those Ed.8s are just screaming for an amp that has specs like the O2.....

 

 
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I built my own O2, with gain set at 1x and 2.5x. With standard DAC inputs (grubDAC and NFB-3), the sound using 2.5x gain is noticeably harsher than with 1x. It also gets exceedingly loud very quickly, so I just use 1x gain all the time (and I've never had to turn it up to full volume even with 1x gain). At 1x gain, the sound is very, very good. Very neutral & transparent - it easily highlights for me the difference in my sources.
 
If you're not afraid of getting your hands a little dirty, removing one of the gain resistors completely, will set the gain to 1x. I believe some third party manufacturers were using sockets for the gain resistors, so that end users could easily change the gain themselves.

I have extra gain resistors and sockets.  Can I just remove the 6.5 and use the old high gain position for 1x gain?
 
What headphones are you using?
 

 

[purrin]

 
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If you're looking for load tests, I believe ALL of his tests are into simulated loads.  He doesn't even publish loadless results.

You mean into resistors, or network that simulates the impedance curve of actual headphones, or of actual headphones?