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."

Comments

What about the speakers?

[bigwavejas]

Build some cheap speakers to go along with the player http://members.aol.com/_ht_a/Debertin/spbuild.htm

Re:What about the speakers?

[MrHanky]

You can build OK speakers at low cost, but not really good ones. There's a reason why manufacturers like B&W use exotic materials like kevlar for their speaker membranes: It's light and very stiff. And good speaker membranes have to be just that, because they need to move easily without bending (which distorts the sound). There are some good paper drivers out there, but even those are rather expensive.

On the other hand, good speaker design is quite difficult. It's both acoustic and electrical engineering, and a bit of black magic (or luck). Or you can buy a speaker kit, and build from other people's designs. I did that, and my $1000 speakers sound like $2000 speakers, and look like $20 home-made shit.

Re:Let's see some scope output....

[Animats]

Yeah.

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.

I regularly improve the quality...

[Grog6]

.. 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...

Re:Let's see some scope output....

[Animats]

BNC on audio gear is rare, but not unheard of. There's a trend away from it, though, because consumers are used to BNC for video and RCA for audio.

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.