I have found that the 14 is especially sensitive to static and RFI esp as picked up in the AC. The Shunyata Python claims to have beneficial filtering qualities and so on. Perhaps this is why. BTW, what else is in your system? What cables are you using? How long did you use the 14 before you decided to use a DAC?
why do power cords make a difference with transpor
I have been playing around with my Marantz SA-14. It is a great stand alone player that is made even better by a Shunyata Python. Recently I used the SA-14 as a transport with an Electrocompaniet dac. It would seem that the dac would benefit most from a better power cord because it decodes the 1's and 0's. The transport just turns the disc. However, the Python sounded much better on the transport than the dac. More bass, much better separation between instruments, and clearer overall. Why? Surprised? I am not at all technical but I would appreciate any thought you would have. Thanks
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The transport does much more than turn the disc. It's gotta read all those bits without error then transmit them to your dac. What ever is lost here, really hurts. All that circuitry benefits from the power cord filtering. Most folks say put your best cord on the front end 1st. In your case, the transport. Seems like you confirmed that... |
A transport DOES NOT send out "1's and 0's"! It sends out an analog AC signal just like a phono pre-amp, tape deck, amp, DAC, etc. This analog signal is a representation of the digital stream of "1's and 0's". The way the signal is handled with the power supply, circuit elements, transistors and shielding ultimately determines the sound of the transport the way it would in any other component. (The only difference is the transport's signal combines both the L/R channels.) Therefore, the things that affect DACs, amps, etc applies to transports with respect to power cords, IC's, vibration control etc, etc, etc. If all they did was to spin the disk and send out digital bits, then they all would pretty much sound the same. Howerver, the build quality, engineering and design of transports varies and is directly related to price - and why the more expensive ones generally sound much better. |
As far as i know, the signal coming out of the transport that feeds the DAC is centered at 2.822 MHz. This is an RF ( Radio Frequency ) signal. The data is super-imposed or "modulated" on top of the RF signal, much like someone's voice is transmitted over radio waves. Having said that, other signals can be super-imposed or "sneak into" the RF signal ( technically called a "carrier" ) that is carrying the data that was decoded from the disc. Filtering out extraneous garbage, such as other radio waves ( RFI ) that could be using the AC line as an antenna, might make quite a bit of difference in such a case. As i've mentioned before, the more effect a power cord has on a component, the poorer the components power supply and filtering was designed. Taking the above into consideration, rather than spending hundreds ( if not thousands ) of dollars on fancy wire, why not correct the original problem ( poor filtering within the component ) by doing some simple and FAR less costly modifications to the unit itself ? While i know that "fancy cables" add a lot of "prestige" to a system in terms of being able to drop names, etc..., they are nothing more than a phenomenally priced band-aid for what was a lack of engineering to begin with. This is not to say that i don't use "fancy cables" in my systems, it's just that i don't pay hundreds of dollars for them nor do i expect them to solve fundamental problems that are pre-existing within the system itself. As far as price goes, good parts and engineering are not cheap. Then again, they are not THAT expensive. One can literally take a run of the mill product with good basic design, throw $100 - $200 worth of raw high grade parts into it and walk away from competing products costing much, much more money. What do you think that all of these "tweak guru's" are doing ? They are simply swapping parts or putting in "extra" parts that the "cut corner" factory production left out to begin with. It's not hard to read values and perform direct substitutions, yet people think that most "modifiers" work "magic". They don't do anything different than what you can do if you put your mind to it. Why do you think that DIY is getting so big ??? People are finally beginning to realize that they AREN'T getting what they paid for in "high end" audio and are trying to do it themselves. Hell, even Nelson Pass has his own DIY website, contributes to DIY Audio.com AND writes articles for a DIY magazine named Audio Xpress. Nelson knows where the market is going and wants to stay in touch with it. He also knows that DIY is not that hard to do and it is a HELLUVA lot of fun. Sean > |
I too am not surprised that the cord made a bigger difference on the transport, considering that's where jitter originates, and you're talking about a component not necessarily optimized for its functionality as a pure transport or with the greatest of care concerning its digital output. Sean, I would love to possess the confidence to take what you're saying about DIY to heart. I have reason to believe that my '98-vintage VTL MB-185 Sig. mono's could be made better by modding, but the factory wants big bux (plus of course the cross-country shipping costs and risks involved) to do a coupling cap upgrade alone. But I wouldn't feel comfortable, with no prior experience worth mentioning, in mucking about inside a high-powered tube amplifier. I plan on checking around with some local tech guys, but I can't be sure they'd know all the best things that could be done with these. Maybe it's time I started learning something about this stuff, but it seems daunting to an electrically-challenged ignoramus like myself. |
Thanks Sean ... I think that there's merit in the ideas in your post, and the ideas in my post. I guess my previous post suggested that noise FROM the transport was the dominant effect, and that's a bit too sweeping. However I have an old transport that actually interferes with my TV if I have it plugged in on the same circuit. Putting a couple of ferrite rings around the (very cheap, stock) power cord reduced the interference, leading me to try discover that it also improved the sound of the hifi (which initially surprised me). I have to admit though that this is an ancient transport and it's quite possible that some of the large electrolytics in the power supply are not very healthy and contribute to noise being modulated onto the supply lines. If I didn't have an 18month old sapping all my time and energy then I might swap them out and see what difference it makes. I like your point about cables being a patch for a poor component ... I entirely agree. |
I agree with Sean's opinion. My tuner picks up noise when my Cambridge CDP (which I use as transport) is on. Cross contamination is just as important as noise coming through the mains. The power cord I use for my CDP is an Absolute PC, wich has minimal shielding. I have a rather decent isolation transformer unit coming in the mail. It has four isolation transformers enclosed in a coper chassis and each transformer has its own phase reversal *and* on/off switch. Let's see what happens... |
Francisco: One need not shield a power cord to minimize the susceptability of it to picking up or transmitting RFI. All it takes is a common sense approach with a different design / geometry of cables. One can do it using the same exact materials that they already have in an existing power cord. Sean > |