LSA Voyager GAN Amplifier
Not just that, if you read a little more about them, caps of the same uF (capacitance) value, also have different inductance, resistance, and leakage current, and they are made as electrolytic’s, plastic’s, or even paper, this is why they sound different, because of all these specs which can be measured! Andy |
Here is an interesting story. My friend wanted to have some 1uf polystyrene 100 V caps custom made. He got the aluminum foil from Dave Fletcher at Sumiko.....and sent that to 4 different cap making companies along with Mogami wire for the leads, and his own solder for attachment. Since most polystyrene comes from Germany from the same plant.....there was practically nothing different in each custom cap. When we got back all the samples I was the one that tested them for sound. They all sounded different.....yup....that's right.....they all sounded different. Maybe different tension or whatever.....who knows. The "everything makes a difference" game is very very subtle. All brands of polyprop or whatever caps sound different from each other....even if they are the same length. If you orient the cap with the outside foil to the output of lower potential it sounds best. None of this can be measured. Even within brands there are various versions that have different sound. Check out all the versions of Mundorf caps, for instance. Read the reviews of these caps.....they all sound different. If you use silver wire instead of copper wire it sounds different......no difference in measurements. This game is not simple....it is infinite....just like our soul is. If all caps made from the same material sound different....then there are a lot of things coming into play here. Check out VH Audio (V-caps) and their detailed description of how they designed their expensive caps. Measurements can tell you some things......but most things need to be listened to to get to the truth of the purity of the sound.....to really KNOW something. |
By 'potential' here do you mean impedance? Its sensible engineering to have the outer foil connected to the lower impedance circuit, that minimizes RF ingress. |
Trouble is that fast rising distortion into 4ohms after only 20w!! of power. That will not get fixed easily. And this could be the reason why (it’s a bridged amp). Andy Quote: "the fact that there are four amplifiers here, not two. Strange that the company is going after audiophile market yet bridged this amp for higher power."
This is much much better falling distortion into 4ohms all the way up to 200W!!
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I’ve determined execution of power supply in particular (to drive harder loads with lower distortion) and in some cases (like for use with a tube pre-amp, typically higher output impedance) input stage as well are major factors with Class D amps that distinguish the gems from the pack. A limited Icepower Class D amp from an exceptional one. Limited meaning sounds OK with most speakers. Exceptional means brings out the best with most any speakers. Probably same with GaN, perhaps even more so with the stakes raised? GaN based amps are newer so I would expect the best is largely still yet to come there. I have 8 Class D amps running in my house (see system page...can you identify all 8?). Cost ranges from ~$100 MSRP to over 6K. Also done a lot of research and listening to various systems with Class D amps in recent years. Looking forward to trying some newer GaN offerings as well perhaps in the very near future. I’d be willing to bet GaN is a technological enhancement that can deliver higher levels of performance but results may still vary perhaps even widely depending on implementation details and system its used in.
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Its clear that you either didn’t read my post or didn’t understand what is says. As a result, the first statement is false. The second is too- because there is way more than one factor at play! In order to get consisent distortion with less than 1 degree of phase shift at all frequencies in the audio passband there are basically two means to do it- either have wide enough bandwidth with no feedback or to have enough gain bandwidth product that it can support the feedback, especially at 10KHz and above. That’s way more than just ’mainly one factor’: Its more than just two... Look at the two distortion charts two posts above. You can clearly see a difference- the Purifi module has the gain bandwidth product to support the 70dB of feedback that module employs. There’s a lot going on there- Bruno has patents regarding the process. Its not ’mainly one factor’- there is a host of factors- poor choice of words on your part??
The Germans got out of the polystyrene film business about 10-12 years ago. Its now made in China, but the Chinese film is thicker (this according to the prior owner of REL, now retired), resulting in lower performance. Termination of the foil used in the cap makes a difference- this is well documented. There probably were differences in the caps- if they were made with German film or not for starters. I’m sure if you did some measurements a correlation to their sound quality could be found. Usually you don’t have to look very hard to find it. Many people think that because we make an all-triode class A fully differential zero feedback OTL with only a single stage of gain that the amp is really tweaky. IME they are surprised to discover that real math went into it and measurements confirm the math, and as a result the amps are really consistent and stable. I’ve been challenged by SET fans that it can’t sound right because it cancels even ordered harmonics; but since it has a cubic nonlinearity the higher orders fall off at a higher rate as the order of the harmonic is increased, allowing the 3rd (which is treated by the ear nearly the same as the 2nd harmonic, meaning its innocuous as long as its at a reasonable level) to mask the higher orders. They are smoother and more detailed than any SET made. As you can see, there’s a lot more to it than just ’the right distortion signature’; to get that a lot of stuff is going on. The same is true of any amplifier. If you get the right distortion signature the kind of amp it is becomes irrelevent. There’s nothing special about any of the technologies- DHTs, pentodes, Static Induction Transistors (VFETs), GaNFETs and the like. The trick it that distortion signature. You can arrive there by tweaking, but if you are only using your ears you’re really taking a shot in the dark. The chief engineer at HH Scott once said "If it measure good and sounds bad, it is bad. If it sounds good and measures bad, you’ve measured the wrong thing." That statement is very much in play in class D. |
Amps can measure great yet sound bad. But you know you have a winner when they measure great and sound great. No need to settle for an amp with a THD+N worse than -100dB to achieve good sound unless you’re paying under $1000. Not these days.
Who’s heard the Icepower 200AS1 modules? They’re based on the TI TPA3255 chips. I could bring a dual mono amp to market with them for $500. THD+N is 10dB better than these EVM boards in this amp. And they sound great as well. But they're newer technology than these GAN modules. So it's expected. |
Like this?
Finished HiFi TPA3255 Class D Power Amplifier 2.1 Subwoofer Bluetooth 5.0 300W*2 | eBay
Not yet.
I have a similar amp by Fosi though a few years old that uses TI TPA3116 chip that I use in a small 2 channel a/v setup. Even these sound very good, amazing for the price, and drive kef ls50s very well. |
It appears this thread gotten off topic. Can we bring it back where it belongs? Reading thru the ARS comments I wonder about Ric’s mods: Did Ric reorient/invert the PS (seems simple enough), and at least check several of the comments about distance under the modules, etc...? He has the mods posted, so Ill be looking them over |
I have already stated several times that my mods to not change the measurements in any way. As I say.....over and over again.....most things that change and improve the sound CANNOT be measured. You ASR objectivists do not believe this and will take it to your grave......good worm hunitng....he he. Beauty if what you experience when you are awake. You can awaken right now. Look in the mirror. You are the most beautiful person in the world. Love and kisses. Most of the assembly and layout things that ASR type people go crazy about have little or nothing to do with the sound. They are making mountains out of molehills...because..........THEY DON’T LISTEN......therefore have NO REAL information about what makes things SOUND the way they do. I want to add this.....what I just said applies to the mods I am currently doing to all class D amps. In the future, I might be changing the input stages to discrete circuits, etc.....and that may change the distortion characteristics......in fact, it is possible that it could even measure worse........but either way, it will sound better. Some op amps have some much open loop gain that they have amazing distortion numbers even though they do not sound that great. Some discrete op amps have less open loop gain (therefore less feedback is needed) and these would not have quite as low of measured distortion but could sound much better. This is why you have companies like Dartzeel, Ayre, etc., etc. using zero feedback or low feedback circuits.....n fact, the LSA is a low feedback system and one reason it does not measure as well as the Purifi module that has a TON of feedback. Lots of belief systems about this feedback thing and measurement thing....no right or wrong here....just stating what I know. |
The biggest question is why you would ask this question? he he. Do jacks measure, do wires measure, does removing a power switch measure, does wire directionalty measure, does damping measure, does removing tons of parts that are not needed measure, do different brands of solder measure, does adding modified bypass caps measure, etc. into fininity measure? You answer.....since you are the one bragging about your test gear. I have no doubt you have measured ALL these things. How do they measure? Can you measure LOVE, JOY, Happiness and Peace? You certainly can FEEL them and experience them. Some day we will figure out how to measure these qualities we all want and also measure what thoughts, feelings, words and actions make these qualities grow. Now, that is some cool measurements....Please make such a machine. Please help all of us become better human beings....more tolerant, more compassionate, more joyful, more fulfilled, more loving......more fruitful.....in every way. |
The biggest problem is, even if you come up with some mods that result in a pleasant subjective experience, without the right tools for the job it's impossible to verify if you have an exact match channel to channel, or mod to mod. With high resolution audio gear even extra flux on one tiny component can add distortion. Just look at the difference 1 bad XLR solder job did on the amp Amir measured. The more mods to do, the higher the probability of inconsistencies. That's why a proper engineer verifies each and every job with the proper tools before going out the door. |
Really!! then those types of mods to me then state, they are brewed up in the darkest recesses of Haiti, by certain tribes, with bone through their noses. Andy.
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Perhaps we should reflect for a moment on the length of time that the Voyager was in "development". It was announced and then its release was repeatedly pushed back over a considerable period of time. This is pure speculation, but it makes you wonder if the original idea was for something proprietary and unique to LSA, and that for whatever reason (technology, supply, cost) that eventually didn’t work out, at which point the more "off-the-shelf" items found inside were substituted. |
EPC:
Hired EAS to build them a demo board to show off their GaN devices. It was for sale for a few years at Digikey and other distributors around the world. Digikey discontinued it due to lack of sales (because of cost and no improvement in performance over several other cheap class D amps). Then EAS decided to rework the module for OEM sales. However since then companies like Icepower came up with better performing amp modules with integrated supplies for only $68 each including shipping worldwide in lots of 20. So I don’t expect much further interest.
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So I take that as a no. I’ll make a proposal for you that will result in exploding sales. Send me 3 samples of a product you modified and verified with your ears to be "golden samples". I’ll video record the process in 4K right from unboxing, to measuring without stopping the video. So you can see there’s no funny business going on. If all 3 products are perfectly matched channel to channel it will be incredible advertising for your service. |
Most all products have perfectly matched channels (maybe a few tubed based zero feedback circuits do not...because of differences in tubes)......at least to what we can hear....so who is going to buy my things because you say what you measure matters? What universe do you live in? Who do you think cares about what you say? Who? I care about what you say.....because every thought you think, every word you speak, every feeling felt and every action taken.....not only creates your reality....but affects the greater consciousness.....all of us. So, please choose your thoughts, words, feelings and actions wisely. Would you rather be right or lovng? Would you rather be miserable or happy. You choose. |
All the photos of bare shelves were from years ago and from different countries. That lie was debunked quite some time ago. Even the job numbers were cooked by a person imbedded by the previous guy to lie and make Biden look bad. Once exposed, they added over 600K jobs to the equation. But by all means, keep up with the BS, or you can leave politics out of it and not look so dumb. All the best, Nonoise |
I take it by the photo that you shop at Whole Foods, which has been experiencing shortages like the one you show since 2018 when Amazon bought them out. The empty shelves have been happening ever since. They prioritize Amazon home delivery over direct store sales and use Order-To-Shelf which doesn’t allow stocking of foods locally requiring deliveries to go straight from the truck to the shelf. Their employees hate it. My local Ralph’s, Trader Joes and Gelson’s have had no problems since the early days of the Pandemic (that was over a year ago). Full shelves everywhere. All the best, Nonoise All the best, Nonoise |
I take it you’re 1 of the 22% (according to far left NBC) from the recent polls?
https://www.realclearpolitics.com/epolls/other/direction_of_country-902.html |
jerry, jerry, jerry, I see you're still at it, trying to play the role of Switzerland, and we all know where they stood. Like I've said countless times in other threads and even pointed it out just a few posts above, I asked him to stop with the political BS and countered it when he kept it up. So go take a cold shower. All the best, Nonoise |
So I stated 2 absolute facts: 1: Biden’s been a politician for 50 years. 2: The shelves are bare at my local grocery store. In which I proved with a photo Tell me the misinformation that was spread that warrants this topic being escalated to inflamed levels? Which is what you did after hearing my accurate assessments on Biden. Which has now been verified to be accurate. So the only 2 appropriate actions now, are either to apologize, or explain why you shouldn’t. Step up to the plate. |
