Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: g-man on June 21, 2013, 12:00:48 pm
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I don't buy it. But hey, I do have some vintage solder that definitely makes a big difference in tone, and I'll sell you some at a very reasonable price. :icon_biggrin:
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WOW :huh:
I really just want to hear PRR's review......he just has a way with words
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It makes a huge difference. Just ask kwm488. :wink:
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If PT Barnum were here ya know what he'd say...
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It makes a huge difference. Just ask kwm488. :wink:
He'd say, "that brand garbage; you must buy furutech cord."
OK, I've got to ask the real world guys on here...
Most everything for sale in the audio realm is hype and snake oil.
You should even skip guitar amp forums and go to a forum where the guys do radio restoration. They'll set you straight on what's real and what's make-believe. I found after landing on Antique Radio Forum myself that it was the place "Tone Lizard" got much of his info from.
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Not so fast, guys, in Über hi-fi gear, there are some good reasons for these "snake-oil" power cords, but I agree for guitar amps and where they are used, the difference made will be hardly worth the expense.
Here is a snippet: "Mainstream AES-school engineers have ridiculed "audiophile" power cords for many years, but EMI emission from solid-state-rectifier power supplies is no joke. It's hard to identify on a scope (the trace just looks a little thicker), but a wideband spectrum analyzer clearly displays the comb spectra created by the switching devices. The fancy power cords may be doing their greatest benefit by partially shielding the dirty power supplies from other solid-state equipment and CD players." - the complete article is here (http://www.nutshellhifi.com/library/FindingCG.html). See the relevant section on Power Supplies & Noise Spectra. Bear in mind the guys conducting the tests are all Tektronix alums, not your typical "audiophools" :icon_biggrin:
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> want to hear PRR's review
My mother is visiting.
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Here is a snippet: "Mainstream AES-school engineers have ridiculed "audiophile" power cords for many years, but EMI emission from solid-state-rectifier power supplies is no joke. ... The fancy power cords may be doing their greatest benefit by partially shielding the dirty power supplies from other solid-state equipment and CD players." ...
The power cord goes between the wall and the power supply. Their example says the power supply emits EMI. They say the cord shields your device from the EMI emitted from other devices?
The chassis doesn't do that? Or if the EMI is travelling backwards out of the emitting device, along the wires in the wall, through your expensive cord and then into your device... well wouldn't an actual EMI filter work better than an expensive cord?
Lynn Olson is generally knowledgeable, so it seems odd to me that he's suggesting what he does. More specifically, he says that EMI emitted disrupts the circuit within a particular device, but goes on to suggest that the audiophile power cord protects other devices in the chain (rather than the device it is attached to).
I skimmed the article, and notice that his main assertion is sonic don't match THD measurements. He says it's about odd vs even (maybe). I didn't see him mention that feedback reduces THD, and you can get something to "measure perfect" with enough feedback. But feedback doesn't correct intermodulation distortion, which sounds more obtrusive than simple harmonic distortion. You fix IM distortion with good design.
Look... I briefly worked in a wire/cable shop when I was in the Navy doing electronic stuff. They had machines that wove wire and cloth braids around the cables. I notice that all of the audiophile cables have cloth braid over them. Those machine are enormous and must be very expensive; I suspect customers are amortizing the machines the company bought when they pay those silly prices.
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only an 80W iron is the secret to tone nirvana. use no other.
:icon_biggrin:
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The power cord goes between the wall and the power supply. Their example says the power supply emits EMI. They say the cord shields your device from the EMI emitted from other devices?
The chassis doesn't do that? Or if the EMI is travelling backwards out of the emitting device, along the wires in the wall, through your expensive cord and then into your device... well wouldn't an actual EMI filter work better than an expensive cord?
Lynn Olson is generally knowledgeable, so it seems odd to me that he's suggesting what he does. More specifically, he says that EMI emitted disrupts the circuit within a particular device, but goes on to suggest that the audiophile power cord protects other devices in the chain (rather than the device it is attached to).
As the word Über suggests, everything is taken to the nth degree, so we are talking about fairly minuscule differences here... With that said, I think Olson was merely pointing out that unless everything else in the system is well designed, i.e., "noiseless" power supplies, good EMI shielding, proper grounding, etc. in every single piece of equipment in the chain, which even for the audiophools does not happen often. Then a well made power cord could help to provide additional EMI shielding, or to get the background noise down even further - notice he is not even talking about sonic improvement per se, but focusing on the noise spetra, and I think in this case, on how the IMD could effect the digital signals (as opposed to the analog signal in the system).
Just having a bit of a geek moment, anyway, I would not bother with these power cords for guitar amps, we got much bigger noise sources to deal with, at least with my builds :icon_biggrin:
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Here is a snippet: "Mainstream AES-school engineers have ridiculed "audiophile" power cords for many years, but EMI emission from solid-state-rectifier power supplies is no joke. ... The fancy power cords may be doing their greatest benefit by partially shielding the dirty power supplies from other solid-state equipment and CD players." ...
The power cord goes between the wall and the power supply. Their example says the power supply emits EMI. They say the cord shields your device from the EMI emitted from other devices?
The chassis doesn't do that? Or if the EMI is travelling backwards out of the emitting device, along the wires in the wall, through your expensive cord and then into your device... well wouldn't an actual EMI filter work better than an expensive cord?
Lynn Olson is generally knowledgeable, so it seems odd to me that he's suggesting what he does. More specifically, he says that EMI emitted disrupts the circuit within a particular device, but goes on to suggest that the audiophile power cord protects other devices in the chain (rather than the device it is attached to).
I skimmed the article, and notice that his main assertion is sonic don't match THD measurements. He says it's about odd vs even (maybe). I didn't see him mention that feedback reduces THD, and you can get something to "measure perfect" with enough feedback. But feedback doesn't correct intermodulation distortion, which sounds more obtrusive than simple harmonic distortion. You fix IM distortion with good design.
Look... I briefly worked in a wire/cable shop when I was in the Navy doing electronic stuff. They had machines that wove wire and cloth braids around the cables. I notice that all of the audiophile cables have cloth braid over them. Those machine are enormous and must be very expensive; I suspect customers are amortizing the machines the company bought when they pay those silly prices.
Gosh HBP! Don't let the facts get in the way of a Internet lore! What's the matter with you!
If the EMI can be measured at the end of a sonically deficient plain cord (so to speak), providing some sort of magical shielding for the last 48" of a power run is not going to do squat.
Hey! I could sell Jim's Special MoFo Super Uber Sonically Shielded House Wiring! $200/ft. Then I could sell the utility companies Jim's Special MoFo Super Uber Sonically Shielded Service and Transmission Wiring at $2000/ft for special runs to the wine and cheese audio residences. I wonder if Budweiser would spring for my wiring on their neon bar signs.... :hello:
Jim
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One of my Hawaiian friends told me that the un-soldering for replacing the volume pot on an old 30s steel guitar would change it's tone forever & never be the same.....
Hope he never sees this thing about cords.......
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> feedback doesn't correct intermodulation distortion
It does; if you have LOTs of NFB.
Paradoxically (but actually logical), small amounts of NFB increase IM. 6dB or 10dB of NFB maximizes IM. 40dB of NFB really cuts IM.
Most guitar amps are 0dB to maybe 15dB NFB. The classic early 1960s Fenders run around 6dB NFB.
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Without this cord, you muffler bearing in the amp will NOT work. You will lose your keys to the quad and not be able to find any light bulb polish. The tailgate stretcher will no linger enlarge your tailgate.
On the other hand, you will have to learn something about residential/commercial wiring as you will have to insure what you are plugging into is capable of providing a great tone. The electricity in Memphis flows slower than it does in LA, and that is why it is the home of great blues music and why shredding rockers come out of LA.
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I wonder if Budweiser would spring for my wiring on their neon bar signs....
No way! Very little return on their investment. People that buy this stuff don't drink Bud. :icon_biggrin: