See Stereophile this month. They measured the PONO. The iPhone-5 measured better by another source/review. I would expect the -5 to sound better...... the PONO compared to BenchMark2 is thicker sounding and more veiled over-all. That is usually caused by high 2nd+ It turns out to measure high 2nd also. The -5 would be cleaner, clearer. perhaps the largest difference is found in the analog OPS... PONO is discrete without gnfb. BUT -- as always, the marketing plan is to pay more for memory with Apple products. The max seems to be 32G. The PONO max is 128G - removable-and for less money.
We just cant seem to get it ALL in one place.
THx-RNMarsh
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Me three.
Hi Christophe.
IIRC you advocate CFB opamps.
Any recommendations of single or dual CFB/VFB opamp as 10K volume control wiper buffer capable of driving 2k load (input impedance of SSM2142) ?.
Other values of volume pot can be substituted if you have further recommendations/ideas for volume control/buffer stage driven by SSM2019.
Inverting or non inverting throughput is not important also.
Thanks.
Dan.
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i meant iTouch5. I find that once you get below .05% THD the sound is pretty good. Esp above 0.1% is a problem in HiRes systems. It doesnt matter if the OPS is discrete without gnfb or not.... but the distortion must be very low. The 2nd alone is -70dB re 0FS. Now some here say you cant hear that in most home environments. That might be true however we are only testing with one single tone.... the over-all level of distortion products with music playing is higher.... high enough in some cases to be audible.
Just wanted to be sure I wasnt saying there was a bias towards one OPS design over another --- just the THD was high enough to be detetced compared to lower distortion product. But the PONO long battery life and unlimited memory over shadows the small difference in sound when it comes to portability of music for my traveling and long term listening in other countries. Especially, when files are not compressed 24/96's. If I could get in a -5 the unlimited storage of the PONO with the lower distortion of the -5 at similar price... I would buy the -5.
THx-RNMarsh
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Did I hear -70dB seconds? How does that jibe with 24/96 and the "standards"? What happened to the -120db SFDR? I wonder what Bob Katz would think.
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Dan, if i remember well, SSM21442 have 10K of input impedance. Am-I mistaken ?
I used a lot of them (and still have some), in order to build easily decent symmetrical lines when needed.
To be totally honest, i do not remember them as sounding very brilliant, or light or detailed. So, may-be you'll lost all the benefit of a CFA to drive them ?
My favorite CFA was OP260 (1000V/µs) , obsolete, now, witch was working nicely with a feedback impedance as high as 10K. As i still have samples of them, i continue to use them, so, i'm not very experienced with most recent current feedback OPAs for audio. Sorry to not be more helpful than this.
Why ? Can-you bring technical reasons ? Or is-it some global feedback VS local feedback war ?
Christophe, as far as I know, no-one is tryig to lay down any new laws you haven't heard about yet.
John's view simply corresponds well to my own experience, even if it's way smaller than his. I am definitely not promoting this view in any way, it's just my feeling, and it could always be argued that someone else, like Scott Wurcer for example, woud do better to much netter with the same op amps I used, all the more so since most of them from AD. However, in the end, I always found discrete designs to sound better.
I will keep investigating, though. Currently, I have my eye on Andrew's (Bonsai) op amo preamp and the correscrponding power amp. They look mighty interesting to me, and I feel Andrew knows what he's talking about and the designs are no simple bean counting exercises of how to get High End sound quality for $10 a pop. Just my view.
Oh, Dejan, i've heard about the Higgs boson, but not sure to understand all the calculations that demonstrate its existence ;-)
About IC (or discrete), my position is simple (and not artistic). Take any good system. Insert any pre-amp reduced to gain 1 . Compare with a wire. If i cannot make the difference* i consider it is OK. And if the discrete sound better than the wire... I suspect the discrete ;-)
By the way, one of this days, i need some courage to try this
http://www.diyaudio.com/forums/solid-state/235695-no-nfb-line-amp-gainwire-mk2-new-post.html
Just to figure out, with the closer components as possible, the global feedback influence.
*When i talk about a difference, i mean something more obvious than my own fantasies, or some little changes of temperature or humidity in my listening room.
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When designing an instrument to meet a certain measure of performance it is nice to not have a moving target. So Charles Hansen's open-loop Pono IV wins praise in some quarters I'm sure. OTOH...
So what's the target? The numbers, the right colored sound? BTW dvv don't sell yourself short I'm sure you can make some very credible designs that sound fine even with a bunch of 8-legs
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He would probably stay away from this discussion. I'm sorry to say that, but, some of the guys here, including 'big names' in the industry are way behind in understanding current digital technology..
Vinyl forever? Carry on..
Huuhhh? - a single Wolfson DAC chip, the last time I looked ...
But otherwise, whatever works ... I don't fuss about the technology at the core, I fuss about the implementation, in the system context - over and over again, this has always been the deciding factor ...
Now you're talking, John!
Yes, I would find it interesting to get to the heart of where the issues with the Oppo are - there is obviously the very extensive thread here, http://www.diyaudio.com/forums/digital-source/222596-oppo-s-bdp105-discussions-upgrading-mods.html, which goes into myriad aspects. Quality of power supplies and voltage rails and references seem to be a major element - anything with a SMPS inside it is asking for trouble, when there are DACs, etc, in the same box. I personally noted that an Oppo used purely as a transport degraded the system sound quite badly in a demo, so some things could possibly be looked at ...
The member up the road using a DEQX ripped out the switching supply that this component used as original, and replaced with a quality linear unit, with, in his words, huge improvement. He interacts a lot with the designers of this gear, and believes he has influenced them to now switch to linear supplies in the current product.
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Welcome back Brad !
There was a Keith Howard’s article about the myth of euphonic distortion from 2006:
Euphonic Distortion: Naughty but Nice? | Stereophile.com
I’d love to see a link to the 'breath of fresh air' you mention.
George
Don't get a hangup about technology! Almost anything can be made to work, is my angle - but the implementation has to be done well enough not to be audible is the kicker ...
As regards the "sound" to seek, that should be what was encoded in the album! I listen to some system trying to sound like who knows what, and I think, hooo boy!! What I should hear is the distinctive sound of the album, a combination of the artists, the equipment they used, and the recording technology involved - as systems get better, they all end up sounding exactly the same, which is just a "transparent" window on the recorded event ... I don't want to hear how good the bloody speaker is ... I just want to hear the music, reproduced correctly!!
Info --
For those not skilled in correlating harmonics and their levels with audible sound -- this is how I describe what I hear:
A single tone harmonic level of -70 applied to many tones gives the effect of thickening the sound and to some extent to reducing inter-transient silence or reduction in crystal clarity. -60dB harmonic would thicken the sound more. Sometimes higher thd levels will seem like reducing the dynamic range much as broad band noise would when listening to music..... but if a harmonic dominates and with many tones simultaneously (music) there is a freq bias component to the 'noise' which can affect a character to the sound.
When I get masters of 24/96, and compare to CD/16b, the 24/96 recording can be recorded further down and away from clipping -- a common problem for recordest. If I need to be at least -20 down to avoid clipping of pop music or -30 down for other types of music, without compression, it brings me closer to the noise floor. With a 90dB dynamic range on 16b that will put me close enough to the noise that it can be heard. But with a 24/96 recording, I have so much dynamic range that i can record at much lower levels and still be far from the noise floor. And, with techniques which move certain 'noise' above the 20KHz audio range, it makes it harder on the audio OPS to handle the HF 'noise' linearly. That can add its audible affect to the music.
Clipping is so common in recording that there actually exists software that will put the peaks back on a flat top/clip waveform. Thats an interesting trick to enhance effectively dynamic range while staying further from the noise floor. Dont know what that does for the distortion caused, though.
THx_RNMarsh
For those not skilled in correlating harmonics and their levels with audible sound -- this is how I describe what I hear:
A single tone harmonic level of -70 applied to many tones gives the effect of thickening the sound and to some extent to reducing inter-transient silence or reduction in crystal clarity. -60dB harmonic would thicken the sound more. Sometimes higher thd levels will seem like reducing the dynamic range much as broad band noise would when listening to music..... but if a harmonic dominates and with many tones simultaneously (music) there is a freq bias component to the 'noise' which can affect a character to the sound.
When I get masters of 24/96, and compare to CD/16b, the 24/96 recording can be recorded further down and away from clipping -- a common problem for recordest. If I need to be at least -20 down to avoid clipping of pop music or -30 down for other types of music, without compression, it brings me closer to the noise floor. With a 90dB dynamic range on 16b that will put me close enough to the noise that it can be heard. But with a 24/96 recording, I have so much dynamic range that i can record at much lower levels and still be far from the noise floor. And, with techniques which move certain 'noise' above the 20KHz audio range, it makes it harder on the audio OPS to handle the HF 'noise' linearly. That can add its audible affect to the music.
Clipping is so common in recording that there actually exists software that will put the peaks back on a flat top/clip waveform. Thats an interesting trick to enhance effectively dynamic range while staying further from the noise floor. Dont know what that does for the distortion caused, though.
THx_RNMarsh
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Thanks George. Rumors of my death were somewhat exaggerated.Welcome back Brad !
There was a Keith Howard’s article about the myth of euphonic distortion from 2006:
Euphonic Distortion: Naughty but Nice? | Stereophile.com
I’d love to see a link to the 'breath of fresh air' you mention.
George
I've found Keith Howard's pieces to be reassuringly coherent and well-informed, including that one you linked. I wrote to him yesterday thanking him for the letter to Stereophile as one that I didn't thereby need to write. Although I don't know its original length, it says much of what needs to be said about IM distortion, and makes some other good observations about nonlinearities and how they tend to work.
Brad
I am mistaken, you are correct.
It can try, only the wallet gets hurt.
Ok, thanks for that.
Dan.
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