Friday, 17 October 2014

TEST: Archimago's LP Needle Drop Blind Test.

Hello everyone. Welcome to another "blind" test! Unlike the previous High Bitrate MP3 Test last year and the more recent 24-Bit vs. 16-Bit Test, this one is much more subjective and essentially for fun :-). Not that previous tests weren't fun, but the results of this one is more for the experience of having tried (that's at least part of the fun of this hobby I hope!)...

This time, we're looking at vinyl "needle drops"; digitized output from turntable setups. You can download the test file here:
ftp://lptest.dyndns.org 
Login: LP 
Test: test
Download the file "Archimago's LP Test.zip" (~125MB).

Alternate download site (thanks again Ingemar):
www.privatebits.net/archimago/Archimago's LP Test.zip

Within the ZIP file, you will find 3 sample FLAC files - A, B, and C. Each is a high-resolution 24/96 audio recording of 2 minutes, 2 seconds duration. I trust this is a long enough sample to evaluate the sound quality.

Each file was created with the same LP; a 2012 180gm remaster of Paul Simon's "Graceland", specifically the last track on side 1 - "Diamonds On The Soles Of Her Shoes" (Matrix / Runout (Side A): 88691914721-A RE1 20315.1(3) STERLING RKS) so there's maximal inner groove distortion potentially. This LP is completely "virgin", purchased new about a month before I did these recordings and never been played before these samples. The LP looked clean and about as perfect (eg. no warps, dents, fill defects, scuffs, scratches...) as can be. I used an air blower to remove any obvious surface dust. It was NOT washed prior to playback since I did not want to inadvertently add anything (nor can I say I removed any potential deep embedded dust from the factory).

The recordings were done in the following order with the following systems:

1. Roksan TMS (first generation), SME309 magnesium tonearm, Ortofon Cadenza Black cartridge fed into a Whest PhonoStage.20 preamp. Audio output was through a pair of shielded 6' RCA cables plugged into the preamp (no balanced XLR on the Whest). Total cost for this setup should easily exceed $5000 on the used market.

Took a shot right after the vinyl needle drop was done...

2. My own stock Technics SL-1200 M3D turntable. Denon DL-110 cartridge fed into the Emotiva XSP-1 preamp (Gen1). This cartridge is a high-output moving coil (HOMC, 1.6mV) so the preamp was set at standard MM load and 47kohm load. Output recorded off 6' of MonoPrice balanced XLR cables. Total cost of this would be <$2000 considering the Technics was bought used. The Denon DL-110 costs about $150-$200 new shipped.

3. My own stock Technics SL-1200 M3D turntable. Shure M97xE cartridge fed into the same Emotive XSP-1 preamp (Gen1). This is a standard moving magnet cartridge with 4mV output. Again, 47kohm setting used on the preamp. Output recorded off 6' MonoPrice XLR cable. Slightly less expensive than (2) above with the Shure cartridge <$100. Again, total cost of this system would be <$2000.



Technics setup calibrated using Baerwald geometry and SME tonearm using the SME-supplied protractor (Stevenson?). Vertical Tracking Force optimized with digital scale (Ortofon = 2.3g, Denon = 1.8g, Shure = 1.25g dynamic stabilizer disengaged). Azimuth set to perpendicular by visualization using a mirror protractor. I tried to optimize the "stylus rake angle" to something like 92-degrees (I honestly believe it makes no sense to spend too much time or effort on this unless extremely misaligned; vinyl thickness differences and mild but common surface unevenness will easily affect this):

eg. Denon DL-110 stylus on vinyl. Photo taken with Nikon D800 using Tamron SP 90mm/2.8 macro lens at f8, manual focus on small tripod. Angles estimated & measured on screen with MB-Ruler.
Analogue-to-Digital conversion was done with the Creative E-MU 0404USB device at 24/96 using Audacity to record. I can confirm with A/B switching while playing the digital file off a Squeezebox Transporter and the Technics turntable playing at the same time that the sound is essentially identical when volume matched.

For consistency, the digital files were:
1. Trimmed to ~2'02" in length.
2. First second essentially silenced to provide the same "lead in".
3. Last 2 seconds faded out to silence.
4. All file volumes RMS normalized to -18.87dB. Note that there are a few clipped samples due to unanticipated dynamics of this recording but should not impede evaluation.
5. All samples compressed to FLAC lossless and tagged.
6. Randomized to Sample A / B / C.

Other than the above there was no other processing done to the files. Nothing like noise reduction or ClickRepair for example.

As you can see from the DR meter log file (foo_dr.txt from foobar2000 plug-in) in this ZIP file, the music has a good dynamic range of 14dB. (Excellent LP remaster!)

Your task:

1. Listen to the 3 tracks in native 24/96. Which sample did you think was the best? Which did you think was the worst? (It's OK to also feel there's no preference or even if you notice a difference, think that it would make no difference to musical enjoyment.)

2. How much difference did you hear? Although the cost differential is much more between the Roksan vs. Technics setups, suppose your system sounded like the "worst" sample, would you spend $1000 to upgrade it to sound like the "best" sample?

3. Go and fill out my simple survey. All 7 questions are mandatory and I will have to delete responses that have not been filled out correctly. Should take <5 minutes. Please also let me know which computer/DAC and what headphones/speakers used. Also whether you used something like the Foobar ABX tool for evaluation.
(http://freeonlinesurveys.com/s.asp?sid=9qk9tpzbxq8uwlk539831)

As usual, thanks to all who try this out! It's not often that one gets to hear turntable setups side-by-side and this was about as "controlled" as I could find a way to do this to get a taste of what disparate gear could sound like. As usual, although this test is more subjective than previous tests, make sure to listen and not just look at waveforms in an audio editor, also, I think it's better not to discuss one's results until after the test is complete so as not to influence others.

I'm going to run the survey until November 30th - I'll be overseas for a bit so in case there are issues, please leave a note in the comments section if you run into any difficulties. Have fun with this!

Best regards,
Archimago

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Disclaimer: I believe this test conforms to the spirit of "fair use" for copyrighted material for the purpose of education and research. The author derives no financial benefit from conducting this survey.

Friday, 10 October 2014

MEASUREMENTS: Apple iPhone 4 & iPhone 6 audio output.

In terms of general look-n-feel, or usability of the product, there's nothing I can say here that has not been said about Apple's most popular devices - the iPhones. Though I'm not an Apple fanboy, my wife loves the Apple "ecosystem" and has been using an iPhone and Mac combination since the release of the iPhone 3G in June 2008.

There is no question that Apple produces some amazing devices focused on usability and pitched as lifestyle products. With enough financial resources, they can of course fund research and compete in the specifications arena as well. In the last few years they did fall behind on screen real-estate but it's good to see that with the iPhone 6, they're making headway in this area as well... This should really give the Android makers like Samsung some good competition in the Asian arena where logosyllabic writing systems predominate and a larger screen size is almost a must.

Since my wife hadn't upgraded her iPhone 4 in quite a while, out came the credit card for this thin "little" guy:



As you can see, this is the "gold" colored version of the regular 4.7" 64GB model (versus the 5.5" 'plus' model with the much-publicized bending tendency). I think the gold color looks nice - at least a little different from the usual silver or white and I'm sure this will sell well in Asia also. Not that it really matters much because if you use a case, the back will be covered anyhow (although the gold trim around the home button looks nice). Notice the camera lens protrusion. Some have commented that this looks bad. Indeed, it will prevent the unit from lying flat and it will "tip" somewhat. Again, it doesn't really matter if you use a back cover. I'd consider this a small cosmetic price to pay for better focusing mechanism, larger aperture, and optical image stabilization (the DxO folks rated the camera function very well).



As you can see, my almost-1-year-old LG/Nexus 5 phone on the right is a little larger with a 5" screen. But check out how thin the iPhone 6 (middle) is compared to the iPhone 4 (left) and Nexus 5. The iPhone 6 feels great in the hand. The rounded corners make it comfortable to hold and it's light but still feels solid. No, I did not try bending this thing :-).

One other thing to notice is that the headphone jack is now at the bottom of the phone. I find this less intuitive than the previous top-left placement.

In use, well, it's an iPhone :-). Runs all the usual apps, nice bright "Retina" screen (all modern 'premium' phones have excellent resolution these days anyhow), very snappy with the A8 1.38 GHz dual-core processor, 1GB of DDR3 RAM (modern Android phones have 2-3GB already). I'm curious what this M8 "motion coprocessor" will bring to the table in terms of future apps (funky 3-axis gyro, accelerometer, proximity sensor).

Let's Talk Sound...

It's interesting after all these years, I have seen few measurements of the sound quality out of these ubiquitous devices which I suspect has taken over the role of the iPod for music playback for many if not most Apple consumers. So without further ado, let's have a look at the output of both the iPhone 4 and 6 to compare and contrast what has happened in the objective measurements of these devices two "generations" apart.

Fist, let's look at the headphone out through the digital oscilloscope. Here's a 1kHz square wave played at full volume (0dBFS):

iPhone 4 - 1kHz square wave 0dBFS.

iPhone 6 - 1kHz square wave 0dBFS.

As you can see, the "square" wave tracings are very similar. Neither phones show any clipping (I confirmed with sine wave as well - not shown). The iPhone 6 is marginally "louder", putting out 1.4V versus the 1.3V from the iPhone 4. Channel balance is excellent on both machines.

Notice the "ringing" in the waveform with both phones... The reason why is readily apparent when we look at the impulse response:
iPhone 4 - 16/44 impulse response
iPhone 6 - 16/44 impulse response
They both maintain absolute phase but as you can see, both phones use a minimum phase filter with no pre-ringing. Interesting! Didn't know Apple has been doing this all these years...

Okay, let's now get to the usual RightMark 6.4.0 measurements.

Setup (the usual):
iPhone 4/6 [100% volume] --> shielded 3' phono-to-RCA cable --> E-MU 0404USB --> shielded USB --> Windows 7 PC

iPhone 4 firmware - iOS 7.1.2
iPhone 6 firmware - iOS 8.0.2

Screen brightness ~50%. These measurements were made with the iPhone 4 connected to my home WiFi router (no SIM card inside) and the iPhone 6 has my wife's SIM card inside and with cell phone and HSDPA data activated. I made no concessions for "better sound" since I don't believe people listen to these devices in a crippled fashion without data connection.

I used the latest ONKYO HF Player (1.2.1, $10 for the hi-res features and FLAC playback) to play the test files. No EQ or any other DSP process like upsampling applied for the test signals of course. I promised folks that I would try measuring the effect of various loads from the headphone output... Alas, I haven't found the time to get this together. Therefore, I'll just give you the results off the E-MU and will update with another post when I get some 30/100/300-ohm load measurements done.

16/44:
The summary result comparing the iPhones with Nexus 5, AudioEngine D3, Dragonfly 1.2, and TEAC UD-501 for a desktop "reference" DAC:


As you can see, the little iPhones hold their own in terms of 16-bit accuracy. As with most devices, 16-bit, 44kHz audio is not an issue these days and all competent devices would have no problem decoding this most basic bit depth and samplerate.

Slightly more high frequency roll-off with the iPhone 6. -0.5dB at 20kHz.

Noise level: All pretty close, Nexus 5 slightly noisier.

THD Graph

Stereo crosstalk: other than the TEAC using stereo RCA connectors, the others all using the same shielded 3' phono-to-RCA cable. The Dragonfly v1.2 has notably higher crosstalk.
24/44:
Okay, let us now go one step up into high-resolution territory. Can the iPhones manage better than 16-bits?


The answer is YES, the iPhone 6 is clearly capable of better noise floor and dynamic range when fed with 24-bit data. The measured performance is between 17-18 bits of dynamic range... Not bad for such a compact device and about on par with the AudioQuest Dragonfly 1.2 previously measured. Since I don't normally measure 24/44 with my other gear, I don't have comparisons in the table to other devices.

I measured the audio output using either the Onkyo HF player (FLAC files) or the Apple iTunes built-in "Music" app (AIFF). As you can see, the iPhone 4 functions as a 16-bit device in terms of noise floor and dynamic range performance when fed 24-bits. It benefits very slightly with 24-bit audio - at best 3dB improvement. Notice that there isn't any real difference between the Onkyo app and standard 'Music' app. Just remember to turn off any EQ feature to make sure it's bit-perfect (I noticed the iPhones Music app had set the EQ to "Classic" or something like that by default; I don't know if this was a setting my wife had previously set).

Some graphs:
Frequency Response: minimal difference.

iPhone 6 benefiting from the 24-bit data compared to the iPhone 4.

THD

Stereo crosstalk. Inter-test variation evident. (The -104.9dB iPhone 6 reading was atypically low; usually around -90-100dB.)
24/48:
Let us now raise the sample rate to 48kHz and see:

Click on the table to enlarge. 
Again, we see that there is essentially no difference between different music player apps on the iPhone (Onkyo HF Player vs. standard "Music" app linked to iTunes). This time I've included 24/48 results from the recently measured Microsoft Surface 3 laptop, the Squeezebox Touch, and a couple of USB DACs - the AudioQuest Dragonfly 1.2, and AudioEngine D3. Note that the Dragonfly and AudioEngine D3 were measured at 24/96 and I mainly wanted to demonstrate the noise floor performance. In terms of harmonic and intermodulation distortion, the iPhones perform well; the only "atypical" performer in terms of distortion is the Dragonfly.

In short, I am impressed by the low noise level and high dynamic range achieved by the iPhone 6's internal DAC! It's getting really close to the AudioEngine D3 in terms of low noise which is superb.

A few more graphs:
Frequency response: Squeezebox Touch seems to have more of a bass roll-off.

Noise floor. iPhone 4 unable to benefit significantly from 24-bit audio.

THD

Stereo crosstalk: Microsoft Surface 3 worst of the bunch here.
24/96:
The chart looks OK (using Onkyo HF Player with FLAC files):

But in reality, it's a no-go:

Neither iPhones are capable of native 96kHz samplerate and the data has been re-sampled down to either 44kHz or 48kHz.

Jitter:
The J-Test audio track was played off the iPhones with Onkyo HF Player for this measurement.



A bit more jitter noted with 24-bit data for the iPhone 4 (sidebands and wider "skirting"). Also notice the iPhone 4 has higher noise level so the jitter modulation pattern in the 16-bit test is not as evident compared to the iPhone 6.

Like essentially all decent hardware measured over the last while, it's hard to make a case for jitter being an audible issue given how low the distortion is; typically way below -100dB off the primary signal. The jitter spectra look the same whether I used the "Music" app or Onkyo HF Player; again, a reminder that software does not affect jitter performance as far as I can tell whether with these portable devices or with computer audio. Remember that this is even with either WiFi or HSDPA wireless data turned on.

Subjective:
iPhones are everywhere, go listen for yourself :-). Heck, bring in your favourite headphones and have a listen at the local Apple Store. Be that the case, I did of course listen to both the iPhone 4 and 6 with my headphones here at home. I really could not put a finger on any significant sonic difference between the two phones so spent most of the time listening to the iPhone 6.

What is most obvious using less efficient headphones like the AKG Q701 is that the headphone amp just isn't strong enough - no surprise there. 100% volume is merely 'loudish' with both the AKG and Sennheiser HD800. One effect of this is that bass frequencies requiring a bit more "oomph" just does not sound impressive using either headphone.



The iPhone 6 comes with the newer EarPod headphones with volume control. These sound better than the old earbuds from previous generations before the iPhone 5. They do feel more comfortable as well in the ear. But there's no denying that these don't sound that good with mediocre treble definition and muddy bass obvious within a few seconds after listening with the Sennheiser HD800.

I listened to both lossy 320kbps MP3 encoded with LAME and AIFF lossless music. The music sounds great using my Sennheiser HD800. Typical audiophile female vocals like Jane Monheit's Come Dream With Me sounded wonderfully detailed with vocal nuances intact. With the iPhone 6 plugged into my AudioEngine A2 speakers for "near-field" listening, the soundstage was excellent and voice well focused. The classic Miles Davis Kind Of Blue sounded nice and warm as it should - nothing was missing, including the elevated background noise and ambient sounds (is that someone clearing his throat 9 seconds into "So What"?). Mark Knopfler's Privateering sounds excellent with multi-layered strings, percussion and vocals on the title track. Loud tracks like Joe Satriani's "Crowd Chant" from Super Colossal (a dynamically compressed DR8 track) sounded fine with the phones capable to rendering details through the "mass" of vocals and playful guitar-voice interchange. More efficient headphones like the closed back Sony MDR-V6 or Audio-Technica ATH-M50 provide plenty of volume and as typical for headphones of this nature, the bass also takes on a more visceral property despite giving up a bit of detail compared to something like the HD800.

Summary:
Apple is without question the "800lb gorilla" of the music industry whether we're talking about music downloads or potentially the future of streaming audio. As a family of audio devices, the iPhone is arguably the most important music player in the world at this point in time. iPhones continue to be a point of entry in portable audio given the popularity. As I publish this post, I see the iPhone 6 is up for pre-order in China today; no doubt Apple will sell massive numbers there despite the higher price point compared to competitors.

While I cannot speak of the iPhone 5's audio performance, there has obviously been an improvement between the iPhone 4 to 6 with the ability to play 24-bit audio. The iPhone 6's DAC measures very well up to the maximum 48kHz samplerate. Furthermore, I was surprised that Apple has been using a minimum phase digital filter at least since the iPhone 4. Not that I really feel it makes much of any difference, but the iPhone can claim "no-pre-ringing" just like the Pono/Ayre folks might claim. Of course, with a typical minimum phase filter like we see here, there is quite a bit of post-ringing. The Ayre folks dampened that with a -6dB at 22kHz slow roll-off filter which IMO isn't necessarily a good thing if you want flat frequency response all the way to 20kHz.

As I mentioned at the start, I unfortunately have not had the time to start measuring using various simulated headphone loads to demonstrate frequency response anomalies especially with low impedance headphones. Ken Rockwell's review of the iPhone 5 puts the output impedance at 4.5 ohms which is excellent! Hopefully the iPhone 6 will be similar in this respect.

Given the measurements I'm seeing, the iPhone's DAC is excellent and can produce very accurate output. Given the small form factor and the need to balance power usage with other phone functions, headphone amplifier power is limited out of necessity. For sonic quality, therefore, the most important factor would be how well the headphone matches the amplifier. Assuming the iPhone 6 has an output impedance similar to the iPhone 5 around 5 ohms, a good ~40+ ohm set of high quality, high sensitivity headphones should provide excellent neutral sound. Not that lower impedance headphones would sound bad of course (most IEM's have low impedance for example), just potentially not as flat frequency response.

I must say that I am impressed by how smooth the iPhone 6 is in use speedwise and the thinner profile with softer curves definitely feels very comfortable in the hand compared to the more chunky iPhone 4. It reminds me of the curved iPhone 3G but with a more "premium" feeling metal case. My wife loves it already. Finally... There is one significant feature I wish the iPhone 6 had - inductive charging. Both my Nexus 5 and 7 have this feature and has wide compatibility with Qi chargers. For the better part of a year now, I have not had to plug the Nexus phone/tablet into anything at all. Even if the iPhone 6 were a couple of millimeters thicker, I think this feature would be worth it!

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Epilogue:

Over the past year, there has been speculation about when Apple might go "high-res" with iTunes. Considering that iTunes does not even offer lossless downloads currently, I certainly would not hold my breath! Furthermore, with the iPhone 6 capable of 24-bit but not higher samplerates beyond 48kHz, the idea of 88kHz+ music doesn't even seem to be on the horizon.

Although I think lossless 16/44 iTunes would be a great idea, I believe Apple is smart not wasting their time in the high-resolution space for the masses. As I expressed previously, I believe "high resolution" audio will be a disappointment to most people after the novelty wears off; it just doesn't sound much better if at all given the same mastering. That's one issues. Another issue is that with devices like the iPod/iPhone/iPad, where there is limited storage space, you can already upload music in ALAC (I don't see why anyone should waste space with AIFF these days) if you really want. 24/96 is approximately 250% the size of the equivalent 16/44 lossless files, and 24/192 would be around 500% the size. Considering how little audible difference there is between high bitrate lossy (256-320kbps MP3 or AAC) and lossless already, it makes no sense to load up a portable device with all these  huge lossless high-resolution files when there are so many other things the storage space could be used for (eg. movies, documents, apps, photos, books/magazines, videos...). When you factor in that the typical listener is likely to be enjoying music in suboptimal conditions like the subway, bus, car, walking around the streets, or exercising - having audio files taking up so much space just doesn't make sense.

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To all the Canadians out there. Have a wonderful Thanksgiving weekend! Enjoy some turkey and of course make sure to take in some lovely tunes...

Friday, 3 October 2014

DIY / MUSINGS: Bi-Wired Canare 4S11 And Speaker Cable Discussion...

A couple weeks back I was tempted to make some of my own speaker cables out of bulk Canare 4S11 cables I had at my disposal. Note that with my Emotiva XPA-1L monoblock amplifiers situated close to the speakers themselves, I only needed 4' lengths of speaker cable. As such, it'd be ridiculous to claim that whatever speaker cable I use, there would be "huge" audible differences. I was more interested in upgrading the banana plugs to the 'locking' variant for a better connection and since I'm already constructing the cable, I might as well make a bi-wired set to have a listen and also because it's "cool" :-).

Without any live model willing to don my home made cables, I managed to find a reasonable substitute:

Apologies to this guy, and various ads like this over the years... I could get some heat shrink tubing to improve the cosmetics especially of the amplifier end, I suppose.
Okay then... So basically I have some "star quad" speaker cables now. Theoretically at least, the "star quad" cable configuration will reduce close electromagnetically-induced interference and this can be beneficial especially for low level signals - typically balanced microphone cables (here's Canare's "Star Quad Story"). This is not an issue with speaker cables carrying high level signals.

Canare and other manufacturers of these star quad speaker cables will also espouse the benefits of reduced radiation from the speaker cables (see this Canare PDF). I guess if one is running a pro set-up with very high power amplifiers, long lengths of speaker cable with low-level poorly shielded microphone wires nearby this could be an issue. As for the home set-up - highly unlikely of any benefit unless you do stuff like have long lengths of low level turntable phono cables lying around - obviously not "best practice"!

I found the Canare cable easy to work with, is quite flexible, appears to be constructed well ("Made In Japan") and this little DIY project took maybe 2-3 hours to put together and test. Most of the time was spent making sure I got the lengths correct. The Emotiva XPA-1 has quite a wide physical spread between binding posts - almost 1' apart. At about $1.50/ft, the cable is cheap and quite easily available at many cable suppliers on-line. The 4S11 cable consists of 4 conductors ("quad") under the sheath. Each multi-stranded conductor is 14AWG and a pair would be equivalent to 11AWG; as you can see, this makes it really easy to create a "bi-wire" configuration.

It has been many years since I've seen articles measuring speaker cables (many back in the early 2000's; perhaps controversies have settled somewhat?). Yes, speaker cables can be measured with sensitive equipment and generally, the idea is to keep the gauge/thickness adequate for the length in order to keep resistance low. Kudos to Audioholics for producing excellent no-nonsense articles on cables over the years. They have a nice article on this topic. Despite claims usually by manufacturers, good 12AWG copper zip cord speaker cables are essentially all one ever needs unless you're using >50 feet lengths (and 50 feet is being really conservative). Other parameters like the capacitance and inductance of the cable may affect the sound but we're only interested in audible frequencies up to 20kHz and with typically short runs of cable, these electrical parameters are unlikely to change sonic quality. It has been said that high feedback transistor and push-pull tube designs can oscillate at high frequencies (especially out-of-audio-band oscillations which may not be heard but can burn out tweeters and amplifiers) with high capacitance cables. I've heard legends of Phase Linear designs oscillating with the old Polk Cobra cables (low inductance, high capacitance Litz wire) from the 1970's for example. I suspect this only happens with 'exotic' cables and amplifiers of questionable design (otherwise we'd be hearing about smoking speakers and amps happening frequently)! Some manufacturers have dragged up phenomena like skin effect, but we're talking audio frequencies, not HF here and calculations have not suggested any significant issues.

There is clearly potential for sonic improvement with bi-amping especially with separate crossovers for speakers like with this article by Mitchco. But bi-wiring? I don't see how this improves anything other than potentially lowering resistance (thicker total wire gauge and double the connections to the speakers), or bypassing very poor speaker jumper plates. If anyone has seen analysis to suggest that electrically bi-wiring makes a difference, please comment!

One of my favourite cable review articles is for the classic Kimber Kable 8TC. Now this is the kind of review I wish I saw from the typical audiophile press. For comparison, here are some vital stats between the Canare 4S11, Kimber 8TC, Belden, and cheap zip cord looking at results where available between 20-20kHz (results from Audioholics or from manufacturer where measurements unavailable):

Canare 4S11 (11AWG - 2/4 conductors): (~$1.50/ft, I noticed some Ram Electronics 4S11 cable measurements here)
     DC Resistance: 2.6 mohm/ft
     Capacitance: 45 pF/ft
     Inductance: <0.12 uH/ft

Kimber 8TC (10AWG): (~$6.00/ft)
     DC Resistance: 2.19 mohm/ft
     Capacitance: 100 pF/ft
     Inductance: 0.037 uF/ft

Belden 10AWG: (~$0.75/ft bulk, as used in Blue Jeans cable's 5T00UP)
     DC Resistance: <2 mohm/ft
     Capacitance: 25 pF/ft
     Inductance: ~0.16 uH/ft285285

Zip cord (12AWG): ("Sound King" measured here, ~$0.50/ft)
     DC Resistance: <3.31 mohm/ft
     Capacitance: ~15 pF/ft
     Inductance: ~0.2 uH/ft

These are microscopic variations between very reasonable cables, would it be surprising if short runs of <50 feet or so results in no discernible difference?

Have a look at Audioholics' "Speaker Cable Faceoff 2" article for measurements of more expensive stuff... Here's one:

Cardas SE 9 (9.5AWG): (~$13/ft or so)
     DC Resistance: <3.38 mohm/ft
     Capacitance: <285 pF/ft!
     Inductance: <0.05 uH/ft

It's interesting how high the capacitance result is with the Cardas though, presumably by design. For the purpose of "high fidelity", I think most of us would agree that "the best cable is no cable". If this is true, then in principle shouldn't we be going for the lowest amount of these parameters? (Unless of course one is aiming for frequency coloration - the proverbial "tone control".)

Speaking of capacitance, let's go a little further, using my set-up as an example. One could do it by hand, but here's a quick calculator: Electro-Voice Cable Calculator. Plugging in the number for the Emotiva XPA-1L (250W, 8 ohm, 500 dampening factor), into the Paradigm Signature S8 speaker (8 ohms), with the 4S11 cable (let us be conservative and say 11AWG for 2 strands, 4 feet, 50 pF/ft), the roll-off frequency (-3dB) due to capacitance is at 99MHz; that is to say, capacitance just isn't going to be an audible issue. Play with the calculator using numbers from your own set-up. The fact is that with typical speaker cables, capacitance roll-off in the audible spectrum is not an issue until you're in the 1uF range (1,000,000 pF)! Of course, by the time you run say 2000 feet of cable to reach that level of capacitance, you'd be experiencing >5dB power loss (~60% less watts reaching your speakers), demonstrating that resistance as related to conductor gauge and length is much more important than capacitance in affecting signal integrity assuming the amplifier can handle such an extreme situation.

For those interested in the physics/calculations around inductance, have a look at this post with John Murphy's calculations to demonstrate how unlikely this is an issue as well.

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Since it's impossible to do 'instantaneous' A/B testing with speaker cables accurately due to the time it takes to switch out the connections (unless I had a special switch box), I listened to my set-up with the Canare 4S11 bi-wired to one speaker, and my old 12G zip cord to the other to see if I can hear channel imbalance, tonal change, differences in level of details revealed. I tried and even got my wife and kids involved - no discernable anomaly. Mono music still sounds nicely centered and tonally balanced. Stereo soundstage is maintained; as an example, I love the old Ella Fitzgerald Pure Ella: Ella Sings Gershwin album that I got years ago. Ella still sounds like she's singing right in front of me in a private performance. Fancy stereo effects like QSound stereo widening and "surround" image still produced the 360-degree effect suggesting no significant untoward change in phase relationships between the speakers connected with different cables (remember, I'm only using 4'!).

Ultimately, it's fun doing these little projects... Especially at little cost. Although I felt that there was no audible benefit in this case (hey, I wish I did!), like I said, it was more so I could upgrade my banana plug connectors to the locking variety and having a set of bi-wired cables to demonstrate to friends if they ask and want to listen for themselves. You can easily find pre-built 4S11 cables on eBay or off Amazon from Ram Electronics. Of course, with only a little elbow grease and some time, I put this together with bi-wired speaker connectors for 1/2 the price.

(For more interesting reading: speaker wires and history from Roger Russell.)

Addendum: After about a week, I decided to reinsert the Paradigm Signature S8 (brass?) speaker jumper plates. The rationale is that I feel bi-wiring makes no difference and I didn't want to misplace the jumpers; so might as well leave them in place where they should be. This essentially makes the cables a set of 11AWG wires in star quad configuration with better cable-to-speaker contact since there are now two connectors. Electrons are smart little guys and can decide for themselves if they want to pass through that jumper plate :-).


Addendum 2: Train's new album Bulletproof Picasso just came out. I was having a listen to it and was impressed by how good the dynamics sounded. So I ripped the CD and discovered that it has a DR11 score - shocking for a modern pop album! Considering their previous efforts California 37 (2012) had a result of DR6 and Save Me, San Francisco (2009) of DR5, this was a very pleasant surprise... Could it be? Could it be that record producers are recognizing it's about time to terminate the loudness war? Could it be that they finally realize that distorted audio is bad for the music industry? Here's hoping the tide is indeed turning.

Friday, 26 September 2014

MUSINGS: Stereophile's "Recommended Components" & the shift to objectivism.

The other day, I was perusing the Steve Hoffman forum and ran into this thread. Yup, Stereophile's Fall 2014 Recommended Components list is up.

A thread poster noted that the Sony Playstation 1 remains on the list again. And it's a beautiful reminder of how questionable a list like this is.

Ridge Racer! This first generation game fits in the 2MB RAM of the PS1. After loading the game you could take out the CD and put in your own (audiophile) music while racing... Nothing like chillin' to some Diana Krall while pulling power slides :-).
As someone who has listened to and tested the PS1 (my objective results are about the same as Stereophile's), I can say without a doubt that this makes no sense even though they list it as Class C (lower fidelity but "far more musically natural than average home-component high fidelity"). The device has been discontinued since 2006 worldwide but nobody has said good things about the sound of the later PSOne iterations (and the PS2 came out by 2000 already). The user interface is atrocious - skipping through tracks with the PS1 controller? Hook up to TV to see what track you're on? Pop-up plastic lid? It's not a good looking device - all plastic, cheap gray, ugly controller wires... Has a paucity of features: no digital output to hook up your own DAC for example. Is somewhat noisy in operation and has reliability issues (I know, because I traded in a really well constructed 3DO FZ-1 for an early PS1).

Which then leaves only the sound which is objectively noisier than most cheap CD players and has a characteristic uneven frequency response curve starting around 2kHz and up.

It's a beautiful example of how a particular reviewer (Art Dudley) took an idiosyncratic subjective interest and spun it into something which to this day still "graces" the memory of audiophilia.

Objectively it's far from ideal and subjectively I found it sounded fine but nothing special... But isn't being a "Recommended Component" an achievement to suggest special redeeming qualities found above the equipment's peers? Even if one believes that the standard objective measurements typically performed like noise floor, harmonic distortion, crosstalk, etc. are incomplete, how is it ever "good" to promote a device that can't do these basic parameters of accuracy well? And to even mention something like this in 2014!? I might as well happily recommend my <$100 JVC 5-disk CD changer bought at Costco in 2000 over the PS1 in every way I can imagine - including having cleaner sound quality and the option to hook up a DAC through TosLink. 

More recently, consider the 'promotion' of something like the Lector Strumenti Digitube S-192 as a Class A Digital Processor. Well, at least they didn't list it as A+! But how is this a "good" DAC when objectively it's a fact that this thing can't even reproduce down to the 16th bit accurately? That "192" in the product name implies that it's capable of 192kHz "high res", but what's the point when the output noise level is so high? If this was 1995, then maybe it'd be competitive with other DACs; but in 2014, isn't this a bit of a joke? Just because again, a certainly reviewer (Art Dudley) seems to like this type of inaccurate sound? (Oh, pardon me... Music reproduced with this kind of sound.)

As others on the forum post had suggested regarding the Recommended Components list, I agree that it represents a form of vacuous entertainment (I see the word "porn" offered). While I of course agree that many of the A+ components are excellent, there's clearly much that's questionable and I surely hope few readers take these lists seriously!

In cases like the Strumenti, I wished Stereophile took the approach of saying that the objective measurements supersede the subjective opinion because the facts say so (oooohhh... scary thought...). I know Mr. Dudley is well known, has worked in the industry for years and has heard a lot of good quality gear... But I know nothing of how well he hears at his age, and whether he should hold a Golden Ears certificate. Nor do I agree with the philosophy that subjective reviewers somehow have the task/responsibility of tapping into and reporting on "musicality". Please, let the artist do his/her thing, let the gear be accurate, and let the listener judge if what the artist did sounds musical or not. As discussed previously, purely subjective reviews I believe have limited utility once equipment is tested with objective scrutiny in regard to audio quality. This should not be surprising.

Don't get me started on the Cables or many of these "Miscellaneous" recommendations :-).

Despite my criticisms, I still think Stereophile is the best audio publication these days. The fact that they are the only ones in North America (with wide circulation) to attempt balance is to their credit. And the fact that it irks me enough to bother writing this obviously also means I care enough to wish that it could get better.

Here's a thought. In my opinion, change the list to "Recommended Current Components" to identify that this list is meant to contain equipment currently available or reviewed over the last few years. The PS1 should really not be there. Then create a supplemental list of "Recommended Vintage Components" which contains a running list of all the gear previously recommended over the years. Forgo the paragraph blurb in the Vintage list but identify which past issue it was reviewed; maybe create a link to a $1 PDF for purchase of the review... Might as well make a few bucks and I for one probably would be happy to purchase a few at that price point which I think is very reasonable considering how cheap an electronic subscription costs!

PS: Speaking of using the PS1 as a music player, here's a cool DIY site.

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This brings me to some final observations and parting thoughts for the week. I'm definitely into major speculative musings here.


I think the tide towards "more objectivism" has started. The forces of change are many, some of which have been highlighted by AudioPhil's personal journey. I suspect his trajectory isn't all that uncommon; a shift over time from the grasp of the so-called "high end" of subjective hype and superficial reputation / appearance, into a realization that "good sound" these days should not be determined by a fascia made of aeronautical milled aluminum nor has anything to do with extravagant cost.

The rationale I believe is fourfold:

1. Technology has advanced and engineering has easily reached a level where affordable equipment can surpass human auditory acuity. This has been the case for more than a decade now where reasonably well engineered devices can achieve >16-bit resolution as a concrete example. The cost of a device that can objectively achieve this should be <$500. A simple DAC like the <$200 AudioEngine D3 or my AUNE X1 DAC (<$300) are examples of this at low price points. That's just plain reality. Good, accurate sound should be a pre-requisite for "recommended" gear by default, and if one is recommending based on a "colored" sound (tube sound, NOS DAC sound), just say so.

2. I believe the Music Industry will start "objectivisation" of music further. As much as I feel it is misguided (vis-à-vis the 16-bit vs. 24-bit test) to sell more remasters in the form of a veiled attempt at promoting sound quality, the marketing departments are gradually "educating" the masses about lossy vs. lossless vs. hi-res. And they're doing it using the lowest common denominator - promoting the parameters of the file container (simplistic idealization of high bit depth and samplerate while demonizing MP3/AAC). Look at how Pono idealizes "24-bits!" and "192kHz sampling rate!". I believe soon, digital equipment reviewers will need to prove that indeed the piece of gear is capable of benefiting from the greater bit-depth - the only way would be at least a partial acceptance that measurements are necessary. This isn't all bad since it will promote more accurate devices. In time, I believe purely subjective reviews will ultimately lose readership; essentially becoming an extension of the advertisement arm of the Industry. (I believe those glossy picture-filled audio magazines are already there.) Depending on the desperation of the industry to promote the high resolution digital meme, there will be continued push towards a (again misguided) comparison with vinyl in order to sway those who have special reverence towards all things analogue. There might even be increased animosity between the two camps to gain market share.

3. In the big picture, generational dynamics will IMO strike a blow against subjectivism. As the Baby Boomers age, diminish in societal influence, and depart, those that come after will take up the audio hobby in their own way with their own values. The so-called Gen X and Gen Y (Millennials) are without question more technologically savvy. Raised in an environment witnessing the rise of digital in all areas of communication and media since a young age (and noting benefits of the digital age without undue fear or sentimentality), the new generation will gradually dilute analogue biases and practices. Something as simple as lossless file formats being free from multi-generational copies or that the sound of FLAC is no different than WAV/AIFF (this seems to be lost on folks like Cookie Marenco) will be as obvious as swiping a touch screen. In any other area of digital gear evaluation, it is well accepted to use objective measurements (is that SSD faster than HDDs? How much faster is USB3 vs. USB2? Does the Retina iPad Mini display look clearer than the new Galaxy Tab? So how good is the color space rendition of that new monitor?). For decades now, computing sites like AnandTech or Tom's Hardware have done reviews demonstrating objective ability. Look around your local bookstore, at least around here, gone are the 'generic' thick monthly computer magazines like PCWorld and in its place are either enthusiast magazines like Computer Power User (chock with reviews using objective measurements) or the various "iPad for Seniors" special editions. There is no reason audio hardware should be spared from a greater level of scrutiny. Of course, I do believe subjective opinions have their place and would be valued when it comes to usability, look & feel, verification that the sound isn't unexpectedly awry, some music recommendations, interesting anecdotes, and of course general entertainment value.

4. With generational changes as big as what we are likely to witness with the Boomers,  there will come societal changes in terms of wealth and values (among a myriad of other issues like health care entitlement, debt obligations, environmental concerns, even the fabric of societal morality). For example, I think most of us would not argue with the idea that there's something wrong with how things are going with the economy. Disparities and inconsistencies appear the norm rather than the exception all over the place. It will not be a surprise to see a shift in the appetite of debt and consumerism to one of saving and maintaining wealth in the decades ahead. This will change our values and attitudes about luxury goods and what really is "good". Although a miniscule piece of the big picture, tides of change will not spare the "high end" audio industry. These are massive issues and not ones I can fathom discussing with any sense of justice to the topics in this humble blog.

No, I don't expect these themes to take hold overnight. Fundamental shifts almost never change quickly (sometimes they do during times of revolution of course) but these are some of the trends I'll certainly be looking for in the days ahead. Hey, maybe in 10 years I'll come back to this post and review the scoreboard assuming I care about audio hardware at that point!

Until then (2024), get a nice seat in front of your favourite audio set-up. Put on some good tunes. Enjoy the music. :-)

Friday, 19 September 2014

MUSINGS: Vinyl Paraphernalia & Good Old (Free) Vinyl :-)

As I mentioned before, I've been going through the bargain bins at the local LP stores and it has been great finding stuff I hadn't listened to for years! Tonight, as I'm typing this I'm getting reacquainted with Henry Lee Summer's I've Got Everything album for example [recent article on Summer]. It indeed has been decades since I've heard "Hey Baby"...

Yup, old memories of high school - Gen-X and proud of the 80's :-)

Okay, on to the main topic for this post.

I noticed over the last month how getting into vinyl resulted in an accumulation of "paraphernalia". I've got a little collection of "things" now on my music rack that wasn't there before. Plus I've got a compartment where I keep my albums for a few of these things. It's all part of the ritual of maintaining a clean LP collection. I suspect you can tell the "serious" vinyl audiophiles from the "casual" based on whether they have these items hanging around; many of which I would consider essential! I'm sure this is 'old hat' for you vinylphiles already, but for those curious, without further ado, let's have a peek at what I've accumulated:

I. Cleaning Supplies:



Without a doubt, this "class" of products is essential. There's just no way to experience decent LP sound unless it's clean.

For dry cleaning, I started with the Vinyl Styl anti-static carbon fiber brush. It's relatively cheap at $15 or so and good to brush off surface dust as the disk spins on the platter before dropping the needle. Often dust is just moved around and you end up with a "line" of dust unless you direct the dust off tangentially. I've also seen a demo where the brush is moved medially towards the spindle to touch the central metal part. Supposedly this discharges the brush allowing it to hang on to the dust particles. I personally have not found this consistently does the job.

There are of course many such brush products out there. I've heard of folks complain that carbon fiber brushes can leave "hairs" or micro-scratches on the LP. I have not had either of these problems. Just don't press down too hard when cleaning the vinyl surface.

To the left in the clear plastic box is the Nagaoka Rolling CL-1000. I got this off eBay for about $120 from Japan shipped. It's not cheap. Basically it's like a fancy sticky (elastomer) lint brush meant for dry LP cleaning. I have wondered if the cheap sticky roller from the local store would do the trick but too chicken to try :-). In any event, this thing works quite well. I don't know how deep in the groove it can get but the ability to lift dirt and dust off is better than the plain carbon fiber brush. I had noticed with the first usage that I saw a little bit of residue which was removed with a second round of cleaning and no problem thereafter - I think it may have come from the clear plastic protector wrapped around the elastomer that had to be peeled off. I usually will use this on new LPs just to remove the small amount of dust/particles rather than doing a wet clean. Static charge builds up when rolling so make sure the environment is clean - I often will do the rolling on top of an anti-static inner sleeve. (I've noticed some much cheaper ones like the Stop-a-Clicks; I presume this would be fine at a much lower price point.)

The yellow box is of course the Spin Clean. IMO wet cleaning is essential! There's no way I'm going to play the majority of my used purchases unless they've been through a wash cycle. The Spin Clean Mark II works great. I have had some albums cleaned at a local store with their VPI 16.5 machine and I thought the result was really quite similar so long as I took care with the Spin Clean. I have not had any issues with scratching or abrasions. A few observations / suggestions:

1. Use distilled water especially if your region has high mineral content 'hard' water (not really a problem here in Vancouver).

2. After the wash, hold the LP over the Spin Clean to let the residual water drip off the disk before drying for about 10 seconds. This reduces the amount of fluid to wipe off and noticeably less water spots after drying.

3. Buy some good, soft, absorbent microfiber cloths to use for drying. The Spin Clean kit comes with a couple of rather substandard drying wipes.

4. I never use much of the provided cleaning fluid. My formula: fill the Spin Clean up to 90% distilled water, 10% with isopropyl alcohol, and just 1 cap of the starter kit fluid (they recommend 3 cap fulls).

5. Don't let the reservoir fluid get too dirty... I usually wash less than 20 used albums before throwing the fluid out.

II. Needle / Stylus Cleaner:



Have to keep the stylus clean of course. On the right is the "free" stylus brush provided in the package with my Denon DL-110 cartridge. Does the job with very delicate fibers.

On the left is the Onzow ZeroDust. Removing the plastic cover reveals a piece of convex gelatinous substance you can gently "drop" the needle on, removing any dust or pieces of vinyl stuck on. I first saw one of these at AudioPhil's place and liked it - easy and quick.

III. Calibration Paraphernalia:


Then I got all this stuff:

Precision electronic VTF scale. Good down to +/-0.01g. The manual scale on the Technics SL-1200 standard tonearm counterbalance is quite accurate already down to about 0.1g from experience. It's nice to have this for confirmation though plus it's not expensive (~$20).


Without question, the most arduous task with turntable setup is getting the cartridge aligned. A reflective alignment tool such as the ruler-like device to the right is helpful. However, with my Technics, the freely-available-to-print Baerwald Arc Protractor off Vinyl Engine is all I really need. Just make sure you print it out 100% with no print scaling to keep the dimensions accurate and punch the center spindle hole accurately.


I got one of these inexpensive ~400gm record clamps off eBay from Asia. I don't buy noticeably warped records so I don't use this much but there is a convenient spirit/bubble level on top to make sure the turntable is flat. The 50Hz stroboscope is useless for me here in 60Hz AC land.

Some people will use things like USB microscopes to check the Stylus Rake Angle (SRA) for VTA calibration. I haven't gone to this level of fine tuning yet (and possibly never will plus I really doubt it's all that important since slight warping is common yet I don't generally hear any difference when the needle tracks over those areas!). One idea has been to use a macro lens on my dSLR to take close up pictures using a well aligned tripod... I'll maybe give that a try.

IV. Sleeves:



After cleaning used vinyl, there's no way I'd put them back in the original old record inner sleeves. So far, I have found the Mobile Fidelity "Original Master Sleeves" a must have. They're soft, thin, and I have not had any problems with powder residue some have complained about. At about $20-25 for a pack of 50, they're not cheap though. One gripe I've had with a number of new 180g remasters (like my new Guns N' Roses Appetite For Destruction) is the shiny paper used without any soft inner lining. Often with the tight fit of thicker vinyl, the paper sleeve almost guarantees abrasions when putting the LP in or taking it out. Disappointing and all too common to take out a new LP for the first time feeling the resistance of the inner sleeve when pulling out and finding abrasions already on the vinyl.

Then there's the transparent outer sleeves which will keep the outer artwork safe from scratches. I've been able to find good 4 mil locally for about 25 cents a piece.

Summary:


Well, that's not too long a list of paraphernalia I suppose... But it's certainly more than one ever needed for a CD collection (all I had was a soft microfiber cloth to wipe off smudges and a few extra jewel cases). Taken together, there's at least $300 of "stuff" purchased; not counting the extras for the sleeves and obviously I'm not buying anything extravagant here. Of course, not all of this is essential, but significant considering the price of my used Technics SL-1200 M3D (only around $500). Something to keep in mind for those getting into vinyl. However, the bargain used LPs (at least a lot of the 80's stuff I like) can be had for really cheap!

I'd love to hear what other items you've found useful with your LP rig... How much difference do you think a vacuum record cleaning machine makes compared to washing by hand or a relatively inexpensive system like the <$100 Spin Clean?

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To end off this post, I remember awhile back reading one of Stephen Mejias articles in Stereophile where he observed that when others realize one has a record collection, friends and associated will start offering up LPs they don't listen to any more... Indeed, I was fortunate enough to have a friend offer the following:


Interesting early Beatles pressings from Asia purchased when first released - Abbey Road and Let It Be appear to be pressed in Hong Kong, With The Beatles from Malaysia, and Sgt. Pepper's from Singapore. I'm not sure about the Red and Blue compilations.

I have both an early Canada pressing of Abbey Road and later pressing of Let It Be from the mid-1970's for comparison. As best I can tell, the Asian Abbey Road sounded cleaner and Let It Be was about the same. I compared Abbey Road with the recent 180g LP remaster and not unexpectedly, these older pressings sound softer, and perhaps less detailed compared to the more compressed and digital remastered LPs. This is the same impression listening to an early Dutch pressing of Dark Side Of The Moon (thanks Ingemar!) compared to my new 180g remaster. It's subjective which mastering one prefers of course but there is something special to be said about holding and playing an album of historical importance physically created before I was even out of diapers. As I have noted before, these properties of a physical object add to the joys of vinyl collecting irrespective of sonic quality (obviously I'm not getting the same vibe with new digital remaster LPs).

Finally, I also received the following box:

The Beatles E.P. Collection of 45's in both original mono and stereo! Mint vinyl condition! Thanks Paul :-).

Have a great weekend and week ahead. Gotta run off to listen to some "classics" now...