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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
Nooo, you need MONSTER CABLES for the best quality! Aahhh, your signal!!
Wow, an audiophile article from the IEEE. Next thing you know, we'll have witch doctors contributing to the Journal of the American Medical Association.
Strange things are afoot at the Circle-K.
All you need is a small budget, a soldering iron and a desire to void your warranty.
Small budget - After getting a new computer, I have that
A soldering iron - Oh yeah, I've got that
And a desire to void your warranty - My desire to void my warranty has never been greater...
I'd like to see him put this stuff on the scope before and after each of these changes. That way we could get an idea of what he means by a 'dramatic improvement'. I can see the op-amp changes and the power supply upgrades helping a lot... However I have a hard time believing that he would be able to demonstrate a difference in the analog output with some reference tones by, say, buffering the crystal from vibration on a standard scope. I'm sceptical he can hear the jitter too. Even cheap clocks these days are pretty damned good once everything warms up.
I dunno, my time is too valuable to bother doing the upgrade myself. Better just to buy the high-end at 10x the price and save 100x in the cost of my time.
Ruby Neural Evolution of Augmenting Topologies
That is the first real 'Audiophile' tweaks article I have ever seen. It actually detailed real changes you can make to improve the sound of your equipment.
The only reason people purchase expensive interconnects etc is because those components are very easy to change. NOT because they have a significant effect on the fidelity of reproduction.
To really improve the sound you have to improve power supply, decoupling caps etc, but even though the components are very cheap, it's a lot harder than buying a $500 interconnect cable.
I hope to see more articles like this in the future!
I grabbed one of those $35 "5.1 surround sound" speaker systems from Wal-Mart. They only accept a stereo input, and just kind of mix in the surrounds, center, and sub. So I popped it open and ran the numbers on the chips inside, locating the 6-channel volume control IC. I discovered that if I ran an audio signal directly to the inputs on the chip, it bypassed the stereo upmix. A few wires and drilled holes later, I had actual surround sound for my computer. Not gonna say it's the greatest sounding setup ever, but it was cheap.
This article is basically an advert for LC Audio (whose own stuff doesn't look anything special - look at the ringing on the scope trace of their wunderkind clock oscillator), mixed in with the usual audiophile crap (where's the blind A/B comparison?) with a healthy dose of stupidity; anyone advocating replacing safety-rated components on the mains side with unrated "audiophile" grade parts deserves to be sued by the first idiot who burns his house to the ground. The mains is a hostile environment, those components are designed to fail open-circuit for a REASON!
Jon.
...now I know the purpose of my EE degree.
It seems simple enough. Basically you're replacing components with ones that are better with no major rewiring of the circuitry. Diodes with faster switching times, add noise reducing capacitors, gold terminals instead of nickel or tin, replace the op-amps to get better slew rates and less distortion... etc. All this is pretty much what the more expensive models would have done anyway.
This is a good general reference for those who aren't afraid of electronics. But, I strongly warn against it for anyone who really doesn't know what they're doing (especially the ones who can't solder). These components are simple enough, and swapping identical devices shouldn't be too hard, but going from schematic to PCB is very challenging if you're not used to it.
On a side note... Favorite quote: "Plug it in and turn it on. No sparks or smoke? Terrific!"
My $35 DVD player has a digital (coaxial) output, and my PS2 has an digital (optical) output (but, the laser is blown and it can't play disks with even the smallest scratches). Why mess with the electronics inside when you can get the audio data right off the disk into your system?
autopr0n is like, down and stuff.
.. 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
A signal which comes out cleaner on the scope, up to a certain point, will also sound better to the human hear, but past that point, it just comes down to preference. This is why studio engineers often add "color" to a song, and why some audiophiles still swear by vaccum tubes. The vaccum tubes don't produce anywhere near a flat frequency response through the 20kHz range, but instead color it in a way that people describe as "warm."
The point is, you can try and make changes to flatten the frequency response as much as possible, but it may NOT be the sound output you're looking for. The scope would, of course, be useful to track down problems with power supply noise, but when it comes down to swapping op-amps or other stuff, it's often times more subjective than not, which is what his article says. Here, seeing the scope output is useless, because the only important this is whether you like the resulting sound output.
I'd like to agree with you on the part about the clock though, but I have never looked clock outputs when they get shaken/etc, so can't really comment.
Screwing around with the power supply is just stupid, a decent Tripp-lite conditioner or a UPS would handle line noise much better, simpler, and more safely..
Replacing the op-amps with better ones is probably the best tip in the whole article, and the only thing that is likely to have a serious impact on the sound. Replacing caps and other components in the signal path will have some effect.
The jacks have to be the dumbest thing I have ever heard.
All this 'gold-plated, super oxy-free' stuff is pure hokum. Sure, the cables might conceivably make a difference when you're using an Apogee converter to run audio from your RME Hammerfall through your $50K amp to your $250K mastering monitors.
But on a consumer-level system with unbalanced jacks? Please.
Unbalanced cable can only be run for 3 feet without serious risk of RFI and EMI corrupting the signal. You can run balanced cable 1000 feet before you face similar risks.
Pro recording and audio environments use almost entirely balnced gear, because it provides the signal quality necessary for major recording projects. For cable, it's plain old Mogami or Belkin. We break out the fancy-looking gold-braided super cable when we get a cranky performer who insists that our gear is simply not capturing his muse, because he always delivers perfect performances. Slap those into the mic chain, and watch them listen to the playbacks, nod knowingly, and say "Yeah...it sounds right now"
Nothing has acutally changed, but it sure makes some people feel better, and the same thing is at work in the audiophile arena.
Sure, different compositions of metals have different abilities to conduct signal, but once you get to a certain level of qaulity (which all basic cables meet), it doesn't matter too much.
"Why don't you interface with my ass...by biting it!" -Bender B. Rodriguez
- Making the power supply filter capacitors "20% bigger" is a silly idea, for MANY reasons:
- Most electrolytics come with a -20% to +100% tolerance. Because of their construction, it's hard for the manufacturers to get them much closer than that.
- Plus in any well-designed power supply the capacitors are intentionally chosen a bit oversize to handle 50Hz or low line voltage situations.
- Electrolytics have a steep cap versus temperature curve. The engineers know this and specify 40% bigger caps to handle the times you use your CD player in Alaska.
- The filter caps are isolated from the audio circuits by a voltahge regulator chip, which provides about 60 to 90 db of isolation. There's just NO WAY one can notice the effects of a 20% change in capacitance, when the effects are mulffled by a factor of a million to a billion.
- The original filter caps have to be very specially chosen for compatibility with the high frequencies and ripple currents. Is it likely the average joe tweaker is going to choose something that approaches what the actual power supply designer chose? Not likely.
- Replacing the power supply diodes with "faster" ones is a waste of time and money. Any noise the old diodes generate (if any) is many decades above thre audio range. Plus the CD player has to pass FCC emission limits, so they can't be too noisy to begin with. Skip this mod.
- Changing op-amps is really ridiculous. Op amps are always used with huge amounts of negative feedback, which reduces their individual quirks and distortion by a huge factor. I've worked with dozens of op-amps, and have never found one that's not capable of handling your typical audio. A typical 30 cent op-amp already has about 0.001% distortion, thousands of times lower than a golden-eared indivuidual can discern. Skip this step too.
- Tapping into the DAC outputs is a REALLY bad idea. Apparently this guy hasnt a clue about Nyquist limits and sampling rates. You HAVE to filter the output of the DAC's, as they're intrinsically rife with sampling-rate related harmonics and aliasing. Those op-amps are there for a reason!. Don't even think of doing this.
- Putting caulking on the crystal is wet-your-pants funny! There's absolutely no need for this. Crystals are designed to resonate at one frequency. They're totally insensitive, by factos of a billion or more, to any other vibrationary frequency. As an example, there are very precise aerospace radios, with dozens of crystals, none of them caulk-damped, used for life-critical navigation and landing systems, and they work just fine for decades of constant use in vibraty, shaky old prop planes. Put the rope caulk around your windows, not on your crystals.
- If you like the look of gold-plated jacks, install them. There will be absolutely no discernible difference in the sound, but they look neater.
Sorry to rain onthis guys parade, but IMHO there should be at least a token nod towards reality.