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Cheap to Audiophile with Simple Hacks
petertrog writes "The IEEE has a story showing how you can turn a cheap DVD player into something that sounds a whole lot more exotic. All you need is a small budget, a soldering iron and a desire to void your warranty."
Build some cheap speakers to go along with the player http://members.aol.com/_ht_a/Debertin/spbuild.htm
"Simplify, simplify, simplify!" Thoreau
That article makes me embarassed to be an IEEE member.
Those "special $50 capacitors" sound like a rip-off. There are grades of capacitors, but no small-value cap costs $50 from Digi-Key.
Another amusing point is the mania for expensive RCA jacks in the audiophile world. Any BNC connector, which is what you see on pro audio gear (and most video gear), has better high-frequency response than the fanciest RCA jack. And BNC jacks latch, so they don't come loose. Yet the audiophile nuts are still equipping their overpriced amps with RCA jacks.
Really, if you're going to do stuff like this, the first step is to put a scope on the power supply outputs and watch them under load. If you see noise or changes under load, it's time to do power supply work. You may need to juggle capacitors or add inductors, like ferrite beads. It's quite common to see some digital noise spikes getting into the power to the analog circuitry, and you've got to get rid of that. But there's nothing mysterious about how to do it. Without measurement tools, though, you don't get anywhere.
Any BNC connector, which is what you see on pro audio gear
i think you mean XLR's, ive worked in the PA biz for 15years and never seen a BNC for audio (video they use them though)
XLR's are the standard for line input (preferabbly Neutrik(TM)) because its 3 core balanced wheras RCA connectors are not balanced which means interference and crosstalk
Steve
GeminiAudio
.. Of electronics I buy; the main amp in my car I bought for ~$150, put in ~$50 in better transistors, and a few critical resistors, and have a really nice amp, until it overheats. The watercooling project is next, I guess.
The thing in the article that pegged my bullshit detector is the 'audible difference' in capacitors. I design high frequency pulse amplifiers, and at subnanosecond risetimes, capacitors act pretty awful. but in the audio range, there is no way to hear the difference in a good quality capacitor. Below 1MHz there isn't enough difference to measure. You might hear the difference between a low quality, floor swwepings quality z5u capacitor at 20kHz, an a high quality silver mica cap, but I seriously doubt it.
P-channel mosfets are more expensive than N channel mosfets; If you look at the parts in any car amp, the P-channel parts are the lowest rated; replacing them is an easy way to improve the capabilities of an amp. but you have to upgrade the power supply as well, usually to take advantage of the improvement.
And replacing the resistors in the signal path with metal film, if they're not already, is an audible improvement.
Replacing the capacitors, with no design check, will result in shit blowing up, just as specified. Inrush current is a bitch. Replacing the output caps on a power supply board with larger ones is not a good idea; the lead inductance is a design constraint. The need to go in the same holes.
Also, FRED diodes are soft recovery, with no ringing. Schottky diodes ring like a bitch, and are why fred's were developed.
If you add capacitance to a switching power supply, do it at the circuit you want to help out, not at the power supply. The resistance of the wire going to the circuit board will damp the inrush current to the additional capacitance.
1 ohm of wire makes a huge difference in the surge current when you turn it on.
If I spent $10 on a capacitor, I guess I'd say I could hear it too...
Truth isn't Truth - Guliani
Right, so basically I should first get a $30 manual, then replace all the caps with $50 ones, and change the RCA jacks with gold-plated ones?
I am pretty sure that if one conducts double blind tests there will be no difference.
This crap is a lot like the monster cable crap I used to here--to use a *high quality* cable for the toslink digital jack. I mean, I could use my coat hanger instead and still make the bits pass. All BS.
If you have balanced output, XLRs are appropriate. But most consumer-grade (and even most audiophile gear) doesn't have balanced outputs. And, actually, BNC connectors have better frequency response; they're coaxial all the way through, and nearly flat to 50MHz at least. If you have access to a time-domain reflectometer, you can see the difference. Not that it really matters for audio.
For a good laugh, see these RCA cables. Palladium wires with solid silver RCA plugs. "You will enjoy a pitch black background, deep, yet lightning fast bass, smooth midrange, and most importantly, seemingly limitless top end extension. Though not at all bright or fatiguing in any manner, Pure Palladium's sparkling highs allow for the presence of the often coveted sense of air as well as glorious imaging and soundstage. This interconnect possesses the ability to untangle even the most complex pieces of music." $1,550.00 for a pair of 1.5 meter cables.
Any common video cable with BNC connectors will do better than that.
Because the mods were about improving the analog output.
There is not reason for any of the mods if you are going to record the digital out and play it back on another system. Even reducing the jitter of the spdif out will make no difference as long as it's not so huge as to corrupt the data transfer.
i prefer to be satisfied with sound i can feel (vinyl is awesome for that btw)
20hz sub just aint low enough for proper bassline (you just cant beat physics, and no that 6" hifi speaker is not "bass")
and for upper frequencies look up a thing called "harmonics" while you cant hear beyond 16k (adults) you can hear 1st, 2nd and 3rd lower harmonics of 20k+ signals quite easily
Huh?
If they are harmonics then they are higher than the fundamental frequency. So you cannot have 'lower' harmonics of a 20k signal.
If you hear lower frequencies from a 44.1k digital recording of a 20k tone, you are hearing sideband artifacts artifacts and need to repair your equipment.
Incidently, you could record down to 0.05hz on a CD.
I have cut tracks with 2hz sine tones in them and they play back perfectly well. (If you like watching your speakers wobble!)
The roughly 20k top end limitation is caused by the 44.1k sample rate. The lowest frequency you can record could be measured in cycles per year!
There's a tendency in the RF world to run everything through BNC connectors, whether you need to or not. Signal generators and scopes usually come with BNC connectors, so if you have those, you tend to have lots of BNC-BNC cables around the bench. Plus the little drawer of T-connectors, angle connectors, and adapters. Hence its popularity in the ham, broadcast, and scientific instrument worlds.
The main problem with RCA connectors is that they bend and become loose as they wear out. That's why they're avoided in PA gear. XLR connectors self-align better and latch into place.
Actually, I do servomotor control, which has most of the problems of audio but with bigger currents. Keeping the huge chopped motor currents from inducing noise into nearby analog sensors is a major headache. But with extra capacitors and inductors, it's a solveable problem.
In any case, without a scope you can't do anything but guess.
The ARRL Handbook is a good source for info about power supply filtering.
...wasn't TFA itself but its link to the Troubleshooting and Repair of Small Household Appliances and Power Tools FAQ. Good stuff there.
"I came here to kick ass and chew bubblegum. I'm all out of bubblegum." MSE USC APX AIA CSI CASp
Spoken like a first-year undergraduate! Search the literature for microphonic ceramic. The microphonic effect of multilayer chip capacitors is very well known.
Wow... a post that gets rated insightful for ignorance (or just lack of reading comprehension).
Apparently you missed this part of the article:
Taking the modification yet further, you can also replace both of the X-rated capacitors (indicated in orange)around the transformer with 0.47 F 600-V Auricaps. These will set you back about $13 apiece. X-rated capacitors are standard components that meet Underwriters Laboratories Inc. (UL) standards for use on ac mains lines. These capacitors are designed to be self-extinguishing in the event of a big surge on the power line. They're potted in fire-retardant compositions, and are designed to fail open, rather than closed, so components up- and downstream will be protected. Auricap capacitors, a brand of high-end capacitor favored by audiophiles, are not rated against UL standards for ac current.
So, they're not advocating using those 'audiophile grade' unrated capacitors you're blathering about, but instead suggesting that people use actual UL-rated caps.
Jinkies... I think they should change the mod system so that people who are modding up posts actually read the damn article.
Of course this will probably be rated flamebait for pointing out known facts, not knee-jerk conclusions based on a brief skim of the article...
Oh come on now. This is such carp that it deserves to be refuted. I can't believe nobody has. Some of your main points are valid but you back it up by saying correctly functioning players all sound the same?
Sure some people induce voodoo into the audiophile world but that doesn't mean there aren't any real world differences. I would bet you that YOU could tell the differences between two CD players (assuming one was very good and one was merely decent) in a GOOD system setup.
All CD players do not sound the same! I repeat. All CD players do not sound the same. And you don't have to be an audiophile to know it.
They will sound the same in a piece of SH*T system. I repeat. They will sound the same in a piece of SH*T system.
I can put my dad and my mom in front of my stereo system and they can tell the difference. They are the first ones to complain that they wouldn't be able to hear a difference so why waste money. Then all of a sudden they are talking about how clear it sounds. Girlfriend was the same.
I could put them up against two decent CD players (one a Marantz Special Edition and one a Toshiba DVD player) and swap them with very good CD players (a Creek CD player or any CD player with my external DAC1), and they could tell the difference on otherwise equal equipment.
Frequency response all equal? Give me a break. There is NO deep bass coming out of the Toshiba DVD and the Marantz (which I had high hopes for) has no clarity. This isn't the kind where you have to strain so hard to hear the differences.
I don't think I can tell the difference between any pair of decent audio cables but I can hear the differences in the CD players. I would never confidently be able to A/B audio cables. I will A/B anybody on my CD players anytime.
Although I can't say for sure that is absolutely frequency response as it might be some other artificat that reduces the bass response. I'm not an audio scientific expert (though pretty well versed) but perhaps it is a bad harmonic that makes the bass appear weaker. Whatever. I HEAR a difference.
Also, frequency response isn't the be all end all. It measures one specific very controlled setup. The Marantz lacks crispness though it can very well not be frequency response. It could be something else. My DAC has a re-timing crystal that removes jitter. Again. I'm not going to try and explain the differences. Merely that there are differences.
The point is this. You CAN hear differences. ANYBODY can hear differences not just the audiophile elite. I was as skeptical as anybody on first blush. In fact, I always thought all CD players sounded the same until I was demo'd a good system.
But only in a good sytem. And people have A/B'd difference successfully in the past. It is a myth that people can't A/B differences for a lot of components. People have. I would suggest a CD player is one of the easier things to A/B differences on (in a decent system).
In regards to a good system, small differences can make or break it. For example:
(a) If I push my Paradigm Reference Studio/60 speakers anywhere near the back wall (like 95% of people have it set up) the image falls flat and I probably would have a hard time hearing the difference.
(b) I recently re-organized my bedroom so that the bed is now in front of the speakers. Unfortunately, while this config is nicer for me layout-wise, the imaging now sucks due to the bed's intrusion on the signal. I might have a hard time hearing the differences now.
I would agree that you, the reader right now, couldn't hear the difference in your system, as it is now. But in a properly controlled good system, I would be shocked (shocked!) that you couldn't hear the difference between a decent CD player and a lousy one.
p.s. I'm the first one to call bull-carp on the guys at Best Buy. The guy was trying to convince me that the digital HDMI/DVI converter from monster was WAY BETTER than the Acoustic Research (I think) one. I would have bet $10,000 against that he could see the difference in A/B testing unless one was defective. It's DIGITAL!
Sunny
Be my Friend
Clock jitter just isn't a problem in this day and age -- definitely not to the degree that someone could hear it.Yipes, no no no. This gets complicated, bear with me. DSPs may be driven by external clocks, but in any board or chip design having some PLLs (phase-locked loops), the loop has a finite readjustment time to relock after the source clock changes. So any clock jitter causes the PLL to hunt, and then you have timing changes in the system. So, no, it's not phony. A pricy high-end clock module is designed to be rock-stable to provide a solid base for system data flow.
Sony was replacing/repairing all PS2's that go belly up with a "Disc Read Error" on all discs. They did it for me. I only had to pay shipping. Give their 800 number a ring, just tell them what's going on and see if they'll offer it to you.
The problem is the SP/DIF interfacxe which DOES have real issues if the transmitter and receiver was poorly designed. Namely the bitstream has an encoded clock stream that the receiver should only use to sync the incoming bits. Unfortunately some device use this clock to drive the local A/D converters which is a bad idea since even if the recovered clock has the correct frequency in the long term, the short term period can change due to jitter.c fm?stdtype=rp&scope=0 .
The jitter is very small and its mostly due to an uneven number of zeros or ones being transmitted(an encoding scheme like 8B/10B solves this but requires what was large lookup tables in the late 80's). I don't remember it offhand but two studies have been done (with double blind testing) that sub 100ps jitter can be detected by humans. One of them is referenced in an STMPE recommended practice: http://www.smpte.org/smpte_store/standards/index.
The frequencies higher than 20kHz affect the timbre of the frequencies below 20kHz by interference. A hard filter at 20kHz changes the tonality of the sound. While a crossovers rolls off a given dB amount per octive, a CD recording is a hard filter since it cannot reproduce a sound greater than 20kHz.
Also, while the average human can't hear much above 18kHz or so as pitch, the ears and brain perceive higher frequencies as directional information. Similarily frequencies below 20Hz aren't perceived as pitch, but they are felt via light touch, touch, pressure and my favorite pain and those lower frequencies affect the subjective perception of sound.