Quote:

pars said:

Do you actually use RMAA and other test equipment? Also, do you have a link to the results in your last statement? Thanks.

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It was in his Clip+ and Cowon i9 reviews, I believe.

I assume linking is still not allowed. 

@Satellite: Indeed.
 
@Pars: The flaws of RMAA are many and documented: as I said above and I believe NwAvGuy has said as well in his post on RMAA, results are not really comparable across RMAA setups, whilst the lack of any concept of absolute levels and the general opacity of operation are also problematic (could say more, but I would just be quoting NwAvGuy's list at this stage.) It also doesn't cover a great deal of parameters and according to NwAvGuy some of the maths behind it seems to be somewhat broken.
This is before you get into the problem of the performance of the recording interface.
 
It is better than nothing and you can't complain too much about free software, but it is totally inadequate if you want to completely ensure an amp is transparent to prettymuch the best of our current knowledge. I suppose it is reasonable for spotting some of the really big possible measurable flaws but even then has to be set up very carefully.

I've had the O2 for a while now.
 
I don't believe in solid state burn in but a curious thing has occurred. 
 
My O2 seems to have improved from it's initial sound, to one that is better than my M^3 or Woo3 and is on a Par with my GS-1.  With careful volume balancing, it becomes hard to tell the O2 (low gain and 9:00 volume setting) from the GS-1.  Not so against the M^3 and the Woo3 which seem to have more, but less articulated bass and not as much HF resolution or clarity.
 
The only problem I continue to have is the default high gain setting which clips and remains useless, even with my Fuze as a source.  If I turn the volume down on high gain to what I can achieve on low gain, it will not clip, but it seems to sound a little better on low gain.... this with my T-1s.
 
There is also a limit on how loud the unit will go before the signal deteriorates.  This is in line with the other portables but not the desktops.
 
Still, the O2 is not a GS-1, which has no issues with the gain settings, or volume settings and is just a marvelous little full featured amp.

Anyone have a picture of the rear? Or is the only input the 3.5mm on the front? I don't like front facing inputs.

 
Quote:

willakan said:

It is better than nothing and you can't complain too much about free software, but it is totally inadequate if you want to completely ensure an amp is transparent to prettymuch the best of our current knowledge. I suppose it is reasonable for spotting some of the really big possible measurable flaws but even then has to be set up very carefully.

Click to expand...

I think the "totally inadequate" is too much of a stretch. If set up properly with care and quality components, very good results could be obtained. The lab grade tools do have much better accuracy, precision, lower noise floors, etc. Even sloppy results could be obtained with lab grade tools if the person doing the testing isn't careful.

 
Quote:

upstateguy said:

I've had the O2 for a while now.
 
I don't believe in solid state burn in but a curious thing has occurred. 
 
My O2 seems to have improved from it's initial sound, to one that is better than my M^3 or Woo3 and is on a Par with my GS-1.

Click to expand...

You've just gotten used to the sound, unless you believe in voodoo capacitor burn in. Typically I've found that bench measurements of equipment get worse over time.

Quote:

mad lust envy said:

Anyone have a picture of the rear? Or is the only input the 3.5mm on the front? I don't like front facing inputs.

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Everything's on the front so it doesn't cost an extra $15-20 for another cut panel.
 
If you want to wait for it, there's "desktop" version coming out in a few months with RCA inputs, 1/4" jack, rear inputs, 'normal' layout, etc.  By ditching the batteries for AC only operation and a few other parts it should only end up a little bit more expensive

 Newbie question, but how well/poorly would the O2 mate up with my Denon D2000 and Senn HD598. I realize they have very different sound signatures, hence my curiosity. 

Quote:

toopoor said:

 Newbie question, but how well/poorly would the O2 mate up with my Denon D2000 and Senn HD598. I realize they have very different sound signatures, hence my curiosity. 

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Should go good with D2000. D2000 really needs bass control (low impedance +current). HD598 should be OK. I don't feel the O2 (as equipped with the op-amp used for voltage gain) does deep bass as well as others.

 
Quote:

purrin said:

 

You've just gotten used to the sound, unless you believe in voodoo capacitor burn in. Typically I've found that bench measurements of equipment get worse over time.

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Um, no.  I compared it to my GS-1 when I first got it and I'm comparing it to the same GS-1 now. 
 


Quote:

maverickronin said:

Everything's on the front so it doesn't cost an extra $15-20 for another cut panel.
 
If you want to wait for it, there's "desktop" version coming out in a few months with RCA inputs, 1/4" jack, rear inputs, 'normal' layout, etc.  By ditching the batteries for AC only operation and a few other parts it should only end up a little bit more expensive

Click to expand...

OTOH, is MadLust looking for SQ or a jack on the back?  I like everything on the front of this amp.  It gives me more flexibility in positioning.
 

maverickronin said:

Everything's on the front so it doesn't cost an extra $15-20 for another cut panel.
 
If you want to wait for it, there's "desktop" version coming out in a few months with RCA inputs, 1/4" jack, rear inputs, 'normal' layout, etc.  By ditching the batteries for AC only operation and a few other parts it should only end up a little bit more expensive

Click to expand...

Hmm, the desktop version has me more intrigued, as I don't need a portable.

I just love my Objective O2 amp. I have used it for several hours each day since I got it from Mr.Slim. It is paired with a Cambridge Dacmagic and a desktop computer. I like it more than my Decware CSP2 and Stax Srm-1/Mk2 with Stax lambda Pro. My Decware is for sale, and the Stax system was sold today. Some of the money from the Stax sale will be invested in another O2. 

Quote:

upstateguy said:

 

Um, no.  I compared it to my GS-1 when I first got it and I'm comparing it to the same GS-1 now. 
 

OTOH, is MadLust looking for SQ or a jack on the back?  I like everything on the front of this amp.  It gives me more flexibility in positioning.
 

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He's probably right. 
 
 
I want an ODA!
 
If all goes well I will build one over my spring break, instead of doing whatever normal people with lives do over spring break. . . 

 
Quote:

pars said:

Do you actually use RMAA and other test equipment? Also, do you have a link to the results in your last statement? Thanks.

Click to expand...

Quote:

willakan said:

 
@Pars: The flaws of RMAA are many and documented: as I said above and I believe NwAvGuy has said as well in his post on RMAA, results are not really comparable across RMAA setups, whilst the lack of any concept of absolute levels and the general opacity of operation are also problematic (could say more, but I would just be quoting NwAvGuy's list at this stage.) It also doesn't cover a great deal of parameters and according to NwAvGuy some of the maths behind it seems to be somewhat broken.
This is before you get into the problem of the performance of the recording interface.
 
It is better than nothing and you can't complain too much about free software, but it is totally inadequate if you want to completely ensure an amp is transparent to prettymuch the best of our current knowledge. I suppose it is reasonable for spotting some of the really big possible measurable flaws but even then has to be set up very carefully.

Click to expand...

I take it the answer to my 1st question is "no".
 
All test equipment (or anything for that matter) has anomalies and flaws. I agree with Purrin in that if you are careful and examine the results, you can get useful data from RMAA. DMMs, oscilloscopes and such don't run themselves either, and getting useful data from them requires knowledge of measurement technique in order to get what you are looking for. I would agree that just tossing a couple of cables on your soundcard and blindly running RMAA can be problematic. And also that any measurements or values coming from it should not be taken as absolute values. Most of the time when I am doing measurements (of DIY stuff), I'm not necessarily interested in the absolute value anyhow, but relative. This includes use of DMMs, scopes etc.
 
Obtaining solid absolute values would require something like the dscope or AP units, and that their hardware is kept in calibration. Since RMAA has little knowledge of the hardware being used, it obviously cannot be counted on for these types of measurements.