esldude Posted November 26, 2018 Share Posted November 26, 2018 1 hour ago, GeneZ said: I think I found it. They tell you to stay away from 2 Ohm speakers. That causes problems. https://www.superbestaudiofriends.org/index.php?threads/nuprime-sta-9-power-amplifier-mini-review.3932/ Well I notice their amps usually spec same wattage at 8 and 4 ohms, or sometimes even less into 4 ohms. This would indicate they are rather limited in current capability. Some 4 ohm rated speakers with odd phase angles or impedance dips could cause issues with such an amp. And they do say in the manuals do not use 2 ohm speakers. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted November 26, 2018 Share Posted November 26, 2018 1 hour ago, GeneZ said: Do you have a 2 ohm speaker? Know anyone that does? Most people should not be so concerned. These amps sound VERY good. All this data dumping, but no listening? I am sitting here listening to my ST-10. Silly fear mongering arguments is all I see. 2 Ohm speaker? Google it. Most are car speakers. You asked this question to the wrong person. I've got a speaker that dips to an ohm. And the Nuprime won't handle the load well. I do realize it is not typical, and no need to get defensive about your amp choice. The reality is many speakers that are rated at 4 ohm and better have some portions of the frequency band that will require additional current. You may not understand how phase angle can have what seems an okay impedance yet will suck much current from an amp. The Nuprime may still sound fine for most of the time, but could struggle vs beefier amps. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted November 26, 2018 Share Posted November 26, 2018 30 minutes ago, crenca said: For those of us that have observed this for awhile (e.g. check out JA's measurements of the usual "audiophile" brands going back years) it is the norm that an "8 ohm" speaker is really a 6 ohm or 4 ohm speaker (that dips below 4, 3, or even lower). Interesting what you say about REL (I run REL's). REL's tap the amp's outputs with a high impedance (going from the top of my head, >10K) simply for a signal. Can't think of a reason this would be a problem for an amp. What's NuPrime's explanation as to why it is for their circuits? I'd need to check, but I bet Nuprimes are actually differential output. So there isn't really a ground. Just plus and minus polarity at the output. That could be a problem input right into a REL or any of the multitude of other subs expecting a single ended input with ground on one side. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted November 26, 2018 Share Posted November 26, 2018 4 minutes ago, GeneZ said: What speakers? Soundlab electrostats. Not just low impedance in the upper frequencies, but a nasty phase angle approaching that of a capacitor more than a speaker. This is it below. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted November 26, 2018 Share Posted November 26, 2018 12 minutes ago, GeneZ said: Well folks ... That low impedance issue was apparently 'old news.' With normal low impedance speakers there is no problem with "current" models. Here is an excerpt from the Nuprime STA-9 manual. (which is below the ST-10) Features: Single End Class A + D amplifier design Bridgeable allowing switch between stereo or mono mode. Enhanced even-order harmonic (H2) circuitry resembling the most attractive features of tubed-amp sound without its drawbacks and limitations. Highly reliable under no-load condition and enhanced short circuit protection.High output current drive capability for low impedance speakers. 550 KHz switching frequency for accurate reproduction of musical signal. New linear power supply with a high-efficiency toroidal transformer. Reduced high-frequency noise and strengthened low-frequency performance. Signal path avoids cross-linking capacitors, thus achieving a frequency response at DC level for pure musical enjoyment. https://nuprimeaudio.com/product/sta-9/?v=7516fd43adaa Well their specs don't jibe with that claim exactly. They show the same peak power output at 8 and 4 ohms. Amps with healthy current should come close to doubling the rating at 4 ohms vs 8 ohms. It is a goodly amount of power, and might not be an issue usually. But the amp is incapable of big current output should it get connected to a speaker that needs it. I've long thought speaker makers should try harder to make easier loads, but that rarely happens. Now something like a Maggie which is 4 ohm, and needs a bit of power, the Maggies are almost entirely resistive. So the Nuprime type amps would likely be fine and dandy with those. crenca 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted December 1, 2018 Share Posted December 1, 2018 29 minutes ago, GUTB said: I just got in a Maraschino used for $650. I’m curious about these amps because they achieve 2x the bandwidth as other class D designs, they’re unique, and pretty cheap used. If nothing else it’ll be good enough for my PC. It’s plugged into a Furutech NCF outlet via a LessLoss standard + Firewall 64X. Initial listening impression is that they don’t ruin the soundstage or my ProAc’s ability to image which is good. The midrange isn’t very convincing but not that bad either. They seem to make my vinyl sound like CDs, possibly robbing it of some dynamic performance. It plays well both connected to my tubed pre and directly to my tubed DAC. Gain is low so I’m finally spared my pre’s tube hiss. Anyway we’ll see. Now it is all so clear to me. This must explain the following strange seismic waves. It was GUTB finding a class D amp that DID NOT SUCK! And then the earth shifted beneath his feet just a bit. https://www.nationalgeographic.com/science/2018/11/strange-earthquake-waves-rippled-around-world-earth-geology/ And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 18, 2019 Share Posted January 18, 2019 On 12/22/2018 at 7:34 AM, Matias said: I would really like to see NuPrime's measurements like the typical THD x power graphs by frequency, as ICEpower and hypex use. I could not find any measurements on their website or manuals... Not that I am an objectivist only but still I enjoy analyzing the differences. Specially with all the hype around the Evolution One. https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-nuforce-sta-200-power-amp.5039/ Measured results for a Nuprime amp. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 18, 2019 Share Posted January 18, 2019 The new Icepower also works at a higher switching frequency. Over 400 khz vs 110 khz. Means reduced interaction between speaker load and treble response from the output filtering. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 19, 2019 Share Posted January 19, 2019 2 hours ago, GeneZ said: Nuforce is no longer in business. The Nuforce STA 200 was a class AB amp was designed in part by Goldmund - as in the JOB amplifier. Nuprime was created to transfer the high end line of Nuforce, and to continue with only that level of product. These links provide some significant measurements of some of amplifiers, and the new the Nuprime Evolution Amp.. https://totallywired.nz/nuprime-2/nuprime-evolution-one/ https://www.hifi-advice.com/blog/review/analog-reviews/amplifier-reviews/nuprime-st-10-power-amp/ Where are the measurements in those links? And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post esldude Posted January 19, 2019 Popular Post Share Posted January 19, 2019 3 minutes ago, GeneZ said: Measurements? What ones are you looking for in particular? Will they tell you how good/bad it will sound? Some specs are given while the reviews I linked was being written. Input impedance, switching frequency, etc. Look. I am biased. The ST-10 I own. I used to own a MC275. Nuprime captures a unique midrange that I have only heard with tubes. Specs? This much I found online... Power Output: 150W x 2 at 8 Ohms; 150W x 2 @ 4 Ohms Gain: X 28 Input Impedance: 23.5k Ohms 12V trigger input. It can use any standard male to male 3.5mm (3-pin type) cable. Sensitivity: 0.89 V to rated power THD+N: 0.01% Frequency Response: 0 Hz to 50kHz (-3dB) S/N Ratio: 91dB @ 10W The signal to noise ratio I believe was effected when Nuprime decided to add selective even order harmonics to capture that tube sound I mentioned. Its the end result that counts. I've been a bit suspicious of specs by manufacturers. Some I trust, some I don't. Having seen some measurements over the years by Soundstage, Stereophile, and other places that is more so than ever. Now I'm not calling them wrong, but that is not quite as convincing as the reviewer having supplied us with some independent measures. Plus those aren't fantastic specs vs some available gear. Their okay. THD+N is low enough probably, but not great at -80 db and that didn't say what frequency, what power or anything. Response to -3db at 50 khz is also not great. SNR is probably alright. So I wouldn't have called those measurements. I'd have called them manufacturer specs. Sorry for the semantic quibbling. Ralf11 and fas42 1 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 21, 2019 Share Posted January 21, 2019 2 hours ago, GeneZ said: Why not cut to the chase? Someone ought to manufacture an amplifier and call it... "The .00001 THD." It would eventually gain the nickname... "Are you Happy Now? Amp." I think benchmark and mola mola are one decimal point or less from being there. crenca 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 21, 2019 Share Posted January 21, 2019 1 hour ago, audio.bill said: Maybe this was mentioned previously, but to be clear (given the subject of this thread) the Benchmark AHB2 power amp is not a Class D design. To quote from their website: "The AHB2 has a bipolar class-AB output stage." It uses some unique error cancelling technology and "achieves a power efficiency that rivals that of a Class D (switching) power amplifier." Yes, but I was replying to GeneZ's post which didn't seem concerned with class of operation. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post esldude Posted January 21, 2019 Popular Post Share Posted January 21, 2019 45 minutes ago, GeneZ said: What if we found out that if we finally achieved the theoretically perfect home system? That the music and how it was recorded would not sound as good without some help from system coloration? And, that our home system could never be a recreation of the actual event? Our home system becomes its own event in its own right? That we need to make our own event by how we put together our home audio system? It can never sound like the actual event did. And, in theory, may end up sounding even better. I have witnessed to this myself by hearing playback of recordings of a live band I was in years ago. The recording (in my opinion) made us sound better to listen to than being there. So... we must discover what combinations of colorations suits us just fine. And, leave all the opinions of others walking down a path having no end. Find what you need to enjoy and have your own home system be truly our own. Not a slave to trying to please the opinions of others who constantly wander seeking today's ideal that is not really the answer needed. For, when does distortion become a none issue? This isn't much different than my thinking. I think we should have all the playback fully transparent. Then use DSP to flavor to each person's taste. But we've these disagreements where people don't wish to believe the transparency of most gear because they prefer a group of colorations which they consider evidence of superior Fidelity. Which leads to confused and profitable chasing of ghosts. Ajax and marce 2 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 22, 2019 Share Posted January 22, 2019 12 minutes ago, GeneZ said: Do you know that some scientists believe that those who find true love can be measured? Though, they have not found true love themselves? How ironic life can be! Life can be ironic. But this is no example. I can measure height without being tall. If love is measurable, there no reason it can't be measured by some one not in love. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post esldude Posted January 23, 2019 Popular Post Share Posted January 23, 2019 2 hours ago, GeneZ said: What science can only measure is sexual arousal and euphoria... by hormones present in the body. But, that's not love. That is why amplifier measurements are not enough to know which amp will sound the best. Though measurements will be valid in showing which amps will sound bad. Well you missed the point completely. If science can measure love (I've no interest in discussing whether it can or what it is), then whether the measuring person is in love, out of love or never known love is of zero relevance. If it is a quantity/quality that is measurable, then having that quality in the scientist doing the measuring makes no difference. Amplifier measurements are valid to know which amplifier is of highest fidelity to the signal. If you start talking preferences, then it is another thing altogether. And you are displaying exactly and precisely the error in thinking I've mentioned earlier. The confusion this creates is a problem because you aren't thinking rationally about the difference in best sound as determined by individual preference and best fidelity to the signal. Until you get your head around this concept you'll wander aimlessly in the wilderness longer than Moses was in the desert. Trapped by your primacy of feelings for what should be design decisions. Rt66indierock, crenca, Sal1950 and 1 other 3 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 24, 2019 Share Posted January 24, 2019 1 hour ago, GeneZ said: I do not do blind tests. I live with a piece of equipment for several weeks to become accustomed to it. I will then try the other. It should not be hard to hear a difference if there really is one. Also not hard to hear a difference when there really isn't one using this methodology. 1 hour ago, GeneZ said: If the differences are not obvious? Or, just another flavor? Then its not worth making any change. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted January 25, 2019 Share Posted January 25, 2019 20 hours ago, GeneZ said: In some cases, yes. But not when its obvious. You need to learn something.... https://www.zdnet.com/article/research-shows-musicians-have-better-hearing/ https://www.newscientist.com/article/dn28266-musicians-brains-fire-symmetrically-when-they-listen-to-music/ No one can hear a difference that isn't there. And until you have the study showing musicians aren't humans, we'll know when there is no difference they are prone to hearing one anyway. Plus equating audiophiles with musicians is leap in logic. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted February 7, 2019 Share Posted February 7, 2019 4 hours ago, Ralf11 said: we need a good SET Class D amp with high bandwidth... Spoken in the voice of John Wayne, "You think a gigahertz would do it, pilgrim?" And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted February 7, 2019 Share Posted February 7, 2019 3 hours ago, GeneZ said: Could a tube possibly switch that fast with precision? ............... They use them in microwaves. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted February 7, 2019 Share Posted February 7, 2019 12 hours ago, GeneZ said: @ a switching frequency to 600 KHz? At higher frequencies than that. Tubes aren't inherently low bandwidth. Transformers can be limited in bandwidth. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted February 7, 2019 Share Posted February 7, 2019 6 hours ago, GeneZ said: What kind of tubes would be needed in a class D amp? Are these for output? KT88's? What are we talking about? 🧐 All depends upon the designer. David Berning has made amps for years that have switching supplies and a carrier frequency based OTL use on the output section. Here is one using 211's providing 60 watts of power. http://davidberning.com/products/zh_211_845 A more powerful version. http://www.hifiplus.com/articles/the-david-berning-quadrature-z-mono-power-amplifiers/ Another good review. https://www.soundstageultra.com/index.php/equipment-menu/442-david-berning-company-zh-230-stereo-amplifier They are reputed to be very easy on the tubes with long life as well. You could read his patent of how he does this. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5,612,646.PN.&OS=PN/5,612,646&RS=PN/5,612,646 Or read about Berning's products. http://davidberning.com/ And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
esldude Posted February 8, 2019 Share Posted February 8, 2019 2 hours ago, GeneZ said: I do not think even with supplementing with my monthly SS check could I cover that.... I guess I need to just depend on having a good dream about having one. https://www.usaudiomart.com/details/649246104-berning-28-wpc-triode-zotl-quadrature-z-mono-amplifiers/ I'm not sure of the actual relationship. But this company has rights to produce Berning designs at much lower cost. https://www.lineartubeaudio.com/power-amps/ They appear to generally be lower powered,though one is 40 watts, and a little lower spec'd performance, but still the basic Berning kind of amplifier circuit. And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
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