captainbeefheart

You are twisting the facts to make a completely different argument. I am saying which is fact that the elephant in the room that is almost never discussed is the fact that loudspeaker distortions are magnitudes greater than anything else in the chain which is why many professionals will give the good advice of spend the majorit of your budget and efforts on picking the right loudspeaker, then let the rest fall inline. I never said the electronics make no difference, I am saying their differences will be a magnitude lower in sound performance. So first get your speakers picked as this will be the largest contributing factor on the overall sound of the system and then later improve upon the rest of the chain as they make less of an impact on sound quality. https://audioxpress.com/article/Measurement-and-Perception-of-Regular-Loudspeaker-Distortion

You are not viewing this correctly. If your woofer has 10% THD it doesn't matter what source or amp you use that speaker will always be the limiting factor. You can't increase or decrease your speaker performance, it is what it is no matter what and the transducer distortion will always greatly out weigh anything else in the chain even with low fidelity equipment.

Like it or not the transducers (speakers) will always have the most distortion in the chain and the hardest to get "accurate". It is far easier to get the electronics accurate compared to any speaker. Horns are known for low distortion but also create their own problems. From a technical stand point it is impossible to beat the price to performance ratio using zip chord for speaker wire because nothing else is needed in terms of variables so long as you size them correctly for the run length. You do reach a point where the length is so long it just adds too much resistance and kills the damping factor. The other variables like series inductance and shunt capacitance in the speaker wire do not make "huge" differences and the vast majority of the time the frequencies that come into play are above what humans can hear anyway. This is where the companies get sneaky, of course there may be a difference at 50kHz but who cares about 50kHz? I don't because music doesn't reside up there. So when talking 20Hz-20kHz very little changes if nothing with anything other than zip chord. Just do not tell people they do not have a good enough ear or system to not hear it because nobody can possibly hear it unless your parents were bats. This is why I ALWAYS recommend to keep the speaker wire run length as short as possible because that is the easiest way to make sure you get the best performance. If you are running over 20' of speaker cable then possibly the parasitic properties may start to come down and effect the music frequency range (<20kHz) then try and pick a low inductance cable with enough gauge to reduce losses and keep damping factor high enough.

If it wasn't for the passionate engineers you wouldn't have the great gear you have, it is practically a known rule that THD and "RMS" whatever is meant by that (I think you mean power and low distortion) is not indication of how an amplifier will actually perform or sound good. We are the ones taking it further and making all the correlations between what we hear and the in and out characteristics of a device. I can't speak for others, I only wish to help explain the mechanisms behind the gear that way there people can become more educated consumers. Engineers that dismiss correlations like low THD isn't an end all spec to weigh an a devices prowess, but it should be on the list as it shouldn't be ignored either are just as guilty as the audiophiles that dismiss psychological influence as part of the equation. Cables are of course important, many are on the right track that purchase good quality products at a fair price knowing the point of diminished returns. Hell I don't care if you have so much money to burn that you just need somewhere to spend it, but at the end of the day just acknowledge what it still is, a conductor with predictable equivalent models that adhere to the laws of physics just like everything else. I have mentioned many times that you can hear a difference with examples and explanations. Education is paramount for consumers, wouldn't you like to know that it may not be the conductor making the sound change but the RC network the company hides inside the speaker cable to change the loading on your amplifier? If not that's fine, ignorance can be bliss or hey not everyone cares how things work but if we are going to jump on the internet and discuss these things people will read it and so more information is always best in my book. When someone says speaker cables really smoothed out my harsh bright horns so these $5,000 speaker cables are the best upgrade ever, huge difference!! Wouldn't it be best if everyone knew it was just the $1 worth of resistors and capacitors hidden in the cable that made the sound difference and anyone with $1 can try this on ANY of their cables to see if it improves harsh treble? I personally think that is best for everyone in the hobby to make everyone's life better and easier. It is overwhelming to think that you can only find what is good for you by trial and error, this is the approach many take. Read a review, talk on a forum or two, purchase or take a demo home and listen. The combinations are endless. I prefer to deduce everything down to equivalent models with input and output characteristics. Make correlations between these characteristics and what I hear, or what everyone hears for that matter in regard to "good sound". Then find the best way to achieve the goal with least amount of effort and waste.

I can see why people would draw the conclusion that a power cable would make a difference, it is bringing power to your equipment right? The better it can do this the better the amp works right? Totally reasonable assumptions of deduction and logic. Until you understand exactly how your power supply works and then it makes zero sense. Let's think about your 120v household power. Does it remain the same 24/7? Hardly, in fact it jumps around as much as 8%. Not to mention noise and harmonic distortion brought in on the line also. All a power cable can do is increase or decrease it's resistance by conductor size, no other variable in the model can effect anything. For changing loads within the amplifier you will get a drop across the resistance of the cable, more drop (loss) the more current, so ideally you want a large enough conductor to not drop much across it. Still with me? Ok, well run the numbers and you will see the amount of drop is nothing compared to the normal voltage fluctuation of the main power normally that the cable can never change. The cable cannot change the noise or the harmonic distortion either. We engineers know all of this so we design the power supply to not even care about what is happening on the mains or from the mains power. The active components in your gear modulate the DC power supply, that's it, that's literally all we are doing. We make the DC supply from the AC and if you have ever looked at the 120v AC 60Hz sine wave on a scope before and after the rectifiers you would see why nothing on the mains side would ever matter. First we filter out the garbage on the AC side anyway but the rectifiers are grossly non-linear loads, they chop up the 120v 60Hz which produces nasty harmonic distortion, but it doesn't matter because we filter all that out also. After filtering and smoothing we then REGULATE (if a good design) the DC supply in the device so no matter the load we have low impedance source that remains a constant voltage no matter the load. There is absolutely no way a power cable can do anything that many people claim they hear. The only thing the power supply will not fix is if there is too much distortion on the line or DC, that makes the power transformer very unhappy. I would love for anyone to show any sort of correlation between output of amp and it being different with different power cables.

Great example where Speaker cables can make a difference, especially with that 50' run length. 18awg = 6.5m/foot .0065*50= .325 ohms That will kill your damping factor 12awg = 1.6m/foot .0016*50= .08 ohms The 18awg you were using was 4x more resistive vs the the 12awg per same run distance of 50' Thank you for showing a clear example of when speaker wire can make a difference. Remember the longer the run the larger the gauge you want as that will have the biggest impact on sound.

Please explain the benefit to the amp and then how it effects the speaker? You are in this business and I expect you to have a lot of data to follow up these questions since you need to R&D your products to make them function as you claim correct? It is not pandora's box really, it's just technical explanations which you shouldn't mind sharing if they work as described.

I can only tell people what they can or cannot hear because the function lives within predictable physics, our ears are nothing more than transducers changing physical energy (sound pressure) into electrical/chemical energy. This entire function is well understood and predictable, the psychology of the matter is what you are talking about which is your perception. Eat some LSD and your perception changes but physics has not. This is why when you have no idea what you are using in terms of cables you cannot hear any differences because your mind cannot set a bias. This spill over into many other topics. I am also into wine and the same bias is seen in that as well. One study involved renowned wine connoisseurs, where cheap wine was secretly poured into bottles from expensive brands. When the wine was poured for the tasters from the cheap-label bottle, they described it as bitter, crude, and unpleasant; but when the same wine was poured from the expensive-label bottle they without exception described the taste as lovely, refined, and full of subtle nuances. This is why companies with profits to gain only have reviews and testimonials to fall back on as they really have zero actual substance to peddle their wares. I am not telling anyone what to purchase and this is all for recreation and pleasure so do what makes you happy. I only take aim at the manufacturers of this stuff and charge way too much and make up 99% techo-babble to mystify you into purchasing their garbage.

This is a myth. Everything you hear is without a question measurable since it resides in our predictable Newtonian physics world. The key is knowing what to measure. The only thing that cannot be measured is psychological which is what accounts for 90% of what people hear, it's all in their minds not their ears.

You realize with pharmaceutical studies why they add a control placebo? If people think they are taking a medicine even though it is just a sugar pill they often psychologically feel better. The human perception and mind is extremely deceitful, you do not even see everything in your sight, your mind fill in lots of blanks to make the processing faster. Now that is exactly what I am talking about because there is zero chance a power cable will do any of this. Since you are in this market then you will not mind explaining exactly how a power cable will make his horn less harsh? I am an engineer so don't refrain from technical explanations.

Not exactly. And I hear this argument very often that if you don't hear a difference in cables then "your system is not resolving enough" which may or may not be the case, most likely not. There are some major issues I do not expect non-engineers to understand, one is phase margin. Amplifiers are tested on resistive loads which do not tell the whole story, speakers are not resistive loads, they do have a DC resistive element to them but this is only one variable of the complete speaker model. The phase margin of an amplifier can be reduced to instability on reactive loads like real speakers and yes even extremely expensive amps or well regarded amps can have this issue. When I say "well engineered system" I mean not someone that purchased high quality gear and installs it themselves, I am talking about an engineer that sets up the entire system and validates performance. Speaker cable manufacturers are making the "cable sound" issue more compounding with the fact that they know MANY amplifiers DO NOT have networks to keep loading flat, speaker coils increase impedance with frequency, this leads to loading issues and phase/gain margin issues. Speaker cable manufacturers are hiding an RC zobel network inside their cables to change the loading characteristics of the speakers which can definitely account for a change in sound. You are not hearing the difference in a conductor or the conductor material as those properties are extremely small but you can get a cleaner/smoother high frequency response with these added networks so that is what you are hearing. This goes back to a well engineered system, unless one knows what to look for or test for when setting up systems you wouldn't know if you need a zobel network. Some good amplifiers already have them but many do not. It is good practice to compare input to output signals from an amplifier driving loudspeaker systems with real music playing, this gives great insight to what is actually happening between the two. I am certain these networks built into many of these aftermarket expensive speaker cables is what people are hearing. Anybody can add these to their own system for a couple of dollars, you do not need to spend thousands of dollars. Without the networks a cable is modeled as series DC resistance, series inductance, and parallel shunt capacitance (parallel to load). No matter what cable you choose these variables change very slightly. I have measured many cables in real world and also have used these numbers to use simulation software to help predict cable behavior. The longer the speaker cable the more these variables can possibly alter the sound but for the most part with normal to short length cables the difference is so small you cannot hear any difference but start to get into slightly longer cable runs and these variables can start to show losses or change phase/gain margin. There is a simple solution for the average audiophile, use true balanced/differential interconnects from source to amplifier, these will be the longest runs in length. Place your mono amplifiers as close as possible to the speaker binding posts to keep speaker wire as short as possible, mine are maybe 18" maximum length, this makes the variables moot and they cannot really change the sound being such small values of DC resistance, inductance and capacitance. I find this practice is by far the easiest way to get great results and remove cabling from the equation.

Wow!!! Never seen that before. Very curious to how you have it all setup. Two separate 2-channel rooms or a surround sound with them all in one room? How are they all powered? Pair of LaScala's and Heresy's in parallel for a 2-channel setup. Same for the Cornwall's for another 2-channel setup? Inquiring minds want to know

That's all that matters is it did help. I see passive preamps have become popular for "purity" purposes and here is where interconnects can definitely have a big difference due to the higher impedance's and the cable capacitance. Funny thing, this is only a problem in the hifi world because honestly just about all mid-fi and even low-fi gear have low output impedance from opamps. Speaker cables like I said is where you will more so get sound differences, they become very minor if gauge is appropriate for normal to short cable lengths, this effects low end. High frequencies are little more complex, cable geometry effects inductance which can create losses (reduction in treble). Or skin effect which is for the most part moot because surface depth for 20kHz is deep enough with almost any cable you choose to not suffer losses. There can be high frequency information or oscillations on high bandwidth amps and gear where maybe you actually want some losses in the upper treble range because the ear is sensitive to odd harmonics and or oscillations up there and the losses soften the sound making it less harsh and more enjoyable. It is very interesting stuff. I hardly believe 95% of the garbage these cable companies say and how they grossly make ridiculous claims, yes there are differences between cables but they are very minor and usually on well setup systems not needed if engineered correctly.

Which speaker cable were you using before the Duelund? And which Dueland did you choose, flat silver, tinned multi-strand copper, or solid copper? What length was the original speaker cables compared to the new Duelund cables? I firmly believe cables make very little difference, specifically interconnects. Speaker cables more so and I am very interested in easily figuring out the differences, usually geometrical differences sometimes insulation. Of course true for all types is length and diameter.

The Technics is a digital amp, although they have made big improvements I would only ever consider them for sub-woofer applications. I have K.I.S.S. attitude to many things and feel there are better ways of an amplifier properly driving a reactive speaker load. Who knows how long the amplifier will last, I like the idea of equipment being passed around the used market for a healthy amount of decades, I doubt these amps will ever achieve that due to cost/repair issues when the unit starts to get old and parts start to degrade, entire circuit boards will be needed to swap out and when will they become obsolete? I don't think these amps pair well with Klipsch heritage series speakers but that is my $.02

Hey y'all, I am new here and have seen there is quite a diverse range of gear from the enthusiasts on here and I would like to know if anyone else here either has or had any of the Audio Matre tube amplifiers in their system? Specifically the "Equilibre" model.

Indeed a huge problem for Klipsch sub-woofer's which is why I keep my older linear power supply with full complimentary Class AB output stage. Yes it is heavy but more reliable and easy to repair. I am new here but reading through there seems to be a guy that takes care of these for everyone? They must just send him the plate amp section in the mail. He must have more work than he knows what to do with 🤣 If anyone is in the North East, specifically the Boston area feel free to private message me and I don't mind helping out. I have a Day job that puts food on the table but I do help friends and anyone in word of mouth shot (friends of friends etc..) with repairing or modding gear. I have been told many times that there is great demand for good techs, especially ones that just don't follow schematics with basic skills but with actual engineering experience. Tube amplifier interest has gone through the roof and I get asked a lot to help a friend of a friend with a tube amp they purchased from China. These have flooded the market because of the price but they are not really good designs and many have errors and or fail often. With minimal effort these can be made into great amplifiers and contrary to belief you do not need to replace the output transformers, they can actually perform quite well with some control theory knowledge and get great square wave response at extended bandwidth. Ahh the wonders of proper application of feedback and increasing phase margin. I like my day job to stay there but I love this hobby enough to bring happiness to anyone that is passionate about music and their gear. I elected to help my friend in Maine with an Audio Matre Equilibre amplifier that is known for blowing the power transformer. I have done a few of these now and it is tough getting the old power transformer out of the enclosure and potting a new replacement in there. The problem was many didn't have a soft start and with so much capacitance in the power supply they just smoke the HV windings. Funny, they put these potted "magic box" components that are told makes the magic of these amps do what they do. Well I tested to see what it did and well it didn't do anything, even cut it open and viola snake oil, it just connects the two types of output tubes that in parallel (triode || pentode) and what has been done since the 50's called "extended Class A" amplifier, well that was the earliest article I found on the topology. I am surprised other companies have not adopted this topology as they actually do sound very good.

That is certainly a sign of instability with the amplifier. I highly recommend getting it to an amp doctor right away before you start burning up speaker parts from oscillations. You may only hear the noise during power up/down but it may also be present during listening but above the range of hearing, most oscillations I find in tube amps are between 30kHz-60kHz. Sometimes you may notice the amp sounding a little fatiguing to the ear or most likely you don't notice anything until speaker parts start to fry or eventually the issue gets so bad the amp gets further damaged. Squealing during power on/off is in no way normal.

The bottom right of your picture you posted you will see red and black wires running from the flat power supply board over to the vertically mounted amplifier board. Measure DC voltage here, either black to red and or both red and black in respect to ground as these are +/- rails. You should see something like: Red to black = 50v Red to ground = +25v Black to ground = -25v This will determine if the power supply board is bad which is very common with these and many subwoofers with switch mode power supplies. I still use an older Sub with a honkin big power transformer for a linear supply because they are just so much more reliable and simpler to repair.

So the tube functions properly and then tests accurately. I have never heard of anyone doing this before testing. If I get a tube that acts weird and tests gassy on a tube tester THEN I may try and activate the getter with an inductive heater to suck up the gasses and hopefully come back to life. It works but many times the tube just becomes gassy again because it has a compromised vacuum but it is well worth trying for very nice tubes you wish to not throw in the rubbish. That's why they are called vacuum tubes, they don't work so well in an atmosphere of gas molecules floating around.

You would be surprised how many amplifiers misbehave with real reactive speaker loads especially when pushed hard. Capacitors voltage/power handling is de-rated by more than half the higher in frequency you go. You can easily damage crossover parts with too much high frequency energy. This doesn't have to be audible and most of the time isn't because the spurious oscillations and high distortion at high frequencies that chew up crossover parts and tweeters are well above human hearing. Another reason I care less about hf bandwidth specs or more importantly to have an unconditionally stable amplifier. Side note: Amplifiers are tested on the bench with purely resistive loads. Thorough engineers with good designs have enough phase margin to be unconditionally stable and is put through reactive load testing to ensure stability. You would be amazed how many amps I have tested that misbehave on even slightly capacitive loads.

Yes it can be difficult at times but I do not always listen to the gear, if it is good enough for decent sound I can easily just get into listen to the music mode and not listen to the gear mode. It is the same as anyone into hifi that goes to someone else's house with mid-fi or worse and you still try and enjoy the music but in the back of your mind you know how it should sound and want to hear it on your own hifi system. I am also a classically trained musician so that too has almost ruined music for me in a way, I am not only critical of the overall sound via gear or acoustics but I am also dissecting the musical movements and performances. Sometimes I do wish to remember being a kid and hearing my first hifi system or a good symphony and being mesmerized by it all thinking it was just magical. I wanted to learn as much about it as possible so the thirst for knowledge is immense! But to tell the truth, my hair still stands on end when hearing any good music on any piece of equipment so I know deep down I haven't lost the magic of it all. Oh and don't get me wrong I would take the Alan Eaton 45 amp over the Decware any day of the week!!

Forgot to answer your question about low signal listening and tube life. An operational tube is DC biased so current always flows through the tube with no signal. If the tube is say a preamp tube and biased well below the max plate dissipation and or max cathode current then it will last a very long time regardless of signal or not. If you have a power tube, say single ended triode output, this is a Class A circuit so bias current will be high to keep it in conduction the full 360° signal waveform and they are almost always biased near max plate dissipation. These will wear out the soonest no matter what. A Class AB amp biased for decent power will have relatively cool bias, say 60% of max dissipation, yes the tubes are passing current with no signal but most likely half of what it would be in a Class A circuit so they last longer. Run that amp at high powers for long periods the amp goes into Class B with large current swings and so yes the tubes will last longer here if you are just listening to it at lower power/signal levels.

When the cathode is heated emissions release an electron cloud, with a negative enough bias or no plate voltage the cathode will wear out much less than if the emissions are being pulled out of the cathode and up to the plate. This is why a high idle bias current like in Class A amps they wear out faster vs a very cold biased amp running Class B operation. Of course if you are pushing the Class B amplifier to maximum output all the time the tubes will wear down. McIntosh amps are known to have their power tubes last very long because of the latter, cold bias heavy into Class B operation. What can happen is with the hot cathode and no current flow to plate the cathode becomes poisoned and behaves like a degenerated common cathode stage, high output impedance low gain. With a tube like the 12AX7 you can actually heat just one triode via using the center tap. The 6SN7 does not have a heater center tap so when the filament is powered it is always heating both triode sections cathodes.

I really love the Shishido designs. Single ended triode output, they can drive grid current into power tube and not afraid to use feedback.