Thanks! In Phuket I have seen lots and lots of girls wearing t-shirts saying "same same, but different".
At last I understand, they too are audiophiles, and have files that are bit-for-bit equal but sound different.
Daniel, right now I am listening to the files in mention played via a Samsung S5 into a nondescript Yamaha surround receiver and one loudspeaker*.
On this setup the pairs of files still play back differently and obviously despite having been recorded into the phone flash memory six+ months ago.
Previous experiment of uploading these pairs of files to Dropbox and re downloading by myself and other parties confirmed (subtle) differences and preferences.
I will endeavor his week to extract the digit and upload a few files and send you links.
FYI the uploads to the phone were via generic USB A-USB Micro or custom version with treatment within the two connectors.
Dan.
* 'Verge special' 12" 3 way....old school 70's Aus made Plessey 12", Plessey 6" mid, Philips AD 0160/T8....the mate is in pieces until tomorrow.
Caps are some kind of film cap (nasty), crossover is 12" fed full range, 4 x parallel 1.0 uF feeding mid, 2 x parallel 1.0 uF feeding tweeter, all drivers fed in positive phase/polarity.....interestingly the caps are board populated in reversed parallel orientation.
It works, natively no bottom bass, mids and mid highs are strongly predominant, distortion is high, drivers are screaming out for driver directly connected zobels.
Fiter at cabinet input terminals sound is much more acceptable, grooving even with 'treated' files.
Again accept the extraordinariness of this claim, it negates information theory. Submit your files to the Nobel committee ASAP.
At least you admit you have them right now so post them here for everyone like Mooly or PMA, why not?
I'm asking for direct help/advice from those 'practiced in the art' regarding construction of a 'biscuit tin' box that I can connect to such network analyser.
Freeware says the files are identical, the only difference i can think of is file metadata.
Multi level flash memory is sensitive to voltage noise.
Dan.
A Biscuit Tin box would be an enclosed impedance matching network. You would probably need one for each port of your 2-port configured cable. First though, you will need to see how many conductors in your cable and how you want to reduce them to two at a time for testing. Once you do that you can measure the driving point impedance at each port and design a Biscuit Tin to do the matching between your DUT cable ports and your test equipment. However, if you want to look at the cable over a very wide frequency range, the driving point impedance at its ports will probably not be a constant. Rather it will vary with frequency for a variety of reasons, so maybe a set of Biscuit Tin boxes to cover different frequency ranges.
Also, if you want to compare different cables, you may find you need different matching networks as frequency goes up for each cable.
Now, if you ask me, and you haven't, I would suggest a very different approach to start with. A much more practical one, too.
Also, if you want to compare different cables, you may find you need different matching networks as frequency goes up for each cable.
Now, if you ask me, and you haven't, I would suggest a very different approach to start with. A much more practical one, too.
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Dan, if you wanted to make a rough guess maybe you could assume twisted pairs in an AC cable might have a characteristic impedance around 100 - 120 ohms. Maybe some textbook calculations could get you close. Maybe some balun transformers would approximately work for matching, if you want impedance matching. Its not really clear what you do want. Maybe you could connect an AC cable to a vector analyzer and look at the reflections and transmission you get unmatched. Measured that way, at higher frequencies what you would see should be very dependent on cable length because it will be sort of resonant due to the mismatches. Just because you can get your hands on a particular exotic piece of test gear (from an audio perspective) doesn't mean it will be useful, especially if you don't know exactly what you want to do with it.
If you really want to look at RF, maybe it would make more sense to start with TDR and see what you can find out that way. It might also give insight into what impedance matching you would need if you don't want a lot of reflection effects at the DUT terminations.
If you really want to look at RF, maybe it would make more sense to start with TDR and see what you can find out that way. It might also give insight into what impedance matching you would need if you don't want a lot of reflection effects at the DUT terminations.
If the software does not do CRC on the files and come up with the same number, depending on how the comparison is done, there still may be differences.
You could also try this tool
Audio DiffMaker
Modern multi level flash memory is noise sensitive and relies on error detection/correction.
This could explain phone playback, but not Dropbox playback.
Scott, there are other observations like changing the sound of car stereo AM and FM by clamping a filter around the base of the standard panel mounted telescopic antenna.
Clamp filter around modem/router DC supply and telephone cable changes streaming sound across wifi network link.
I don't have explanation for these.
Forget expectation bias etc, I am way past such confounders.
Yes, I will endeavor to do so tonight (Friday) night.
Dan.
This in paticular could have a basis in reality. But I doubt a clamp-on filter would improve things unless you have a ham nearby or possibly an inverter-type air conditioner (some of those have horrendous RFI too)
There are some modems with really noisy wifi signals and as such the noisier a wifi signal is the more packets that will be dropped and re-requested. The old budget circa-2011 Cisco's WRT54G2 routers in paticular would interfere with the HAM bands.
Also the quality of the power supplies of even supposed-to-be-quality stuff like Huawei is atrocious. I've had to replace the psu on my vdsl2 modem already and I replaced it with a medical-grade Phillips 12v psu, it fixed the modem from not booting, but I suspect the modem was struck by lightning a few months ago.
My line speed never recovered back up to the full 82mbps after the PSU replacement but it did when I replaced the modem. So I replaced the modem outright and it has all gone back to normal. But there was a period of time in which replacing the psu of the old modem with the medical one improved things a great deal in terms of modem stability, goes to show you just how rubbish the packaged psus are. Never measured it for ripple as I don't have the equipment, kinda wish I did.
It should be noted that I got 10+ years of service (Counting from 2001) out of my old Billion 711CE before I retired it and that PSU was a linear transformer type.
I suspect that my ISP is using these shitty modems that die a month after warranty runs out just so they can extend the contract length another 6 months. Thats what I had to do to get a replacement and I can't just go out and get a new modem as the modem they provide has their VOIP settings embedded in the firmware.
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Yeah I know all about that stuff, HAM 101 when I was studying.
Only problem with putting a ferrite bead on your line is it will attenuate the higher frequencies that ADSL2+ uses. Take it off and fix your line instead, get a linesman in and make a single phone socket point at the front of your house and remove all of the old copper cable underneath your house. And while he's there get him to replace the copper going to your nearest pit.
So maybe because of the attenuation at higher frequencies, whats going on is your modem is choosing a different modulation or choosing to use only the lower frequencies and therefore is having a faster response time (ping) or its interleaving which then affects your streaming quality.
VDSL - Wikipedia
Who knows. All I know is using wifi is dumb. Its just... wrong. Lay down some cat5 dude.
Only problem with putting a ferrite bead on your line is it will attenuate the higher frequencies that ADSL2+ uses. Take it off and fix your line instead, get a linesman in and make a single phone socket point at the front of your house and remove all of the old copper cable underneath your house. And while he's there get him to replace the copper going to your nearest pit.
So maybe because of the attenuation at higher frequencies, whats going on is your modem is choosing a different modulation or choosing to use only the lower frequencies and therefore is having a faster response time (ping) or its interleaving which then affects your streaming quality.
VDSL - Wikipedia
Who knows. All I know is using wifi is dumb. Its just... wrong. Lay down some cat5 dude.
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6 moons review of Audiozone of Pre T-1 & Amp-2
"The square brass bar for the rear support was also chosen for its specific influence in the amp's overall voicing. If you add rubber or neoprene pads under that bar, the sound becomes less bright but also less airy, with more emphasis on the midrange, which may actually be beneficial in some systems".
Its possible that I missed something in the text but the reviewer appears to suggest that a metal part supporting this piece of industrial design affects the sound output.
"The square brass bar for the rear support was also chosen for its specific influence in the amp's overall voicing. If you add rubber or neoprene pads under that bar, the sound becomes less bright but also less airy, with more emphasis on the midrange, which may actually be beneficial in some systems".
Its possible that I missed something in the text but the reviewer appears to suggest that a metal part supporting this piece of industrial design affects the sound output.
Oh yeah. Made some attempts years ago on preamps, still not sure if the data collected were valuable.
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