I agree, It can't be too big!
However, there is more to it than that, so simulating it will probably 'force' you to to use a bigger cap than you even dreamed of.
https://www.lautsprechershop.de/hifi/aka_tief_c_en.htm (complicated theory, simple to simulate in Xsim)
I use single supply and the supply caps to create a floating ground, so they are large, and 2 in 1 for saving space
(see sublimed JLH thread). This does require dual mono though. Since I use SMPS the low PS ripple in the 'floating ground point' is out of the audio band too. It's super quiet.
Well the Cartesian mapping is the right way to look at it, but I don't agree entirely with the author. Series R in the drive is not entirely the same as a weaker magnet. He's only looking at amplitude. And only from the "driving" POV, not the "sensing".\
Good luck to anyone trying to use a passive highpass for a subwoofer!
I use single supply and the supply caps to create a floating ground, so they are large, and 2 in 1 for saving space
Most of my experiments so far are with so-called "mini JLH" versions using linear-impedance regulated supplies. Noise of any knid has not been a problem.
You were one I have not named, all these new avatars and funny usernames confused me I am not familiar even with DIY web any more and battle to find what was so familiar to me for many years. You are one of those guys that persisted until you found enjoyment in the result of your efforts which you never even bothered to calculate time and cost over what is a probably the most simplistic but brilliantly simple design, (John taught nothing of it and just demonstrated that those old devices can sound just as nice as a valve job), and when you do, so much and so proud. Yes! That is what it is all about, very few of us or any audiophile will become world renowned, such as Nelson. He was born in the right decade when this could only be real, when bands were live, when crowds went bonkers and do not leave. When women went mad over the ugliest baster and least sexy man on earth, when a guitar player could make a sound he wanted, and you heard what he felt and what moved you (Hugh must have had this ABBA experience when they toured Aussie maybe what triggered his passion) meant and the actual noise floor was thundering while the dynamic range staggering with 10kW of raw PA power designed around kW transmitter tubes and hundreds of parallel amps wall of 1000s of speakers, phase correction never even crossed anyone's mind as bad as imaginable the real things have perfect tone, learned how to listen and what he believes sound real to him, done it. Became the gurus they are now. That in itself is a developed art. He can probably hear a tune instantly whistle it in the right key of the original or that of choice, pick the perfect harmony with a brain that filtered the background noise, (better than any DSP) not likely he was born with it but acquired it thought his passion of trying to reproduce that feeling he had then. This is what amazes me about these fellows, some of them never did anything of the sort, let alone design anything that people now crave. Passion drives men..... You will be a converted if you carry on and hate the word audiophile that has become synonymous with a nerdy jerk to anyone else.Well... just a thread to say that at last I finished my JLH 10Watter last weekend... I dicided to buy a commercial lab-powersupply.. this made things alot easier..
The results: Great!
Sound is a difinite upgrade from my Sony integrated amp .. more instruments are comming through even in loud part of the music.. high's are excelent .. well at least for me they are.. and supprisingly the bass somehow has more detail.. I experienced the new sound like I experinced my first Grado headphone listeing, but now with the stereophonic effect working..
The amp was easy to build, I even flipped a transistor around but the amp still worked.! just a little noisy.. Iq is set at 1.2A@ 27Volt, the 4 heasinks get hot but can be touched for more than 10 seconds.. well permanent actually higher voltages and Iq goes really hot!
10Khz square wave looks crystal clean but a 50KHz reveals the assymetric slewrate.. bandwidth goes from 10Hz to beyond 200KHz...
conclusion are that it is a very simple amp to build, no PCB used, no instability of any kind.. and sound is quite revealing.. highly recommended
but then again, my initials aren't H.H.
Never believe simulations, it is just a tool to help you make a decision, not what it will sound like. I did simulations most of my life and nothing that was in the perfect scientific realm, or subjective nature, not even close. My simulator have not been upgraded for years, it really only gives one an idea of what could be in a perfect environment in a finite time under a finite condition. MicroCap 12 which I paid dearly for even allowed you to simulate the sound by means of a WAV file, brilliant software exceptional technical understanding. Where is the designer now, everyone on earth either copied his SW freely and distributed it. Now he made it free????? I am sure this was not his intention or his electronic expertise. You can take the WAV and play it through your favourite gear and listen if the specs meant anything or almost everything in a subjective world. You can throw almost any problem to the scientific community, and they will have some objective analysis and solve it empirically. Furthermore, you become converted, you glance over a spec, seeing how absolutely well it is specified knowing the that even the identical part made by a different manufacturer anywhere in the world has to be catered for in the design, for no particular reason and listen to it, and it sounds crap! If it sounds good and have the ability to simulate it, see what was more or less done and then wonder why you have been fooled all your life. Both Nelson and Hugh, probably used slide rules when they started out, a vastly forgotten art. To calculate values and tinkered, listened and better specify and understand the design for years, I tinkered with a single design for the best of seven years simulated every attempt to prove I must be right because I am so smart, so be very careful of automated things, nothing is what it seems trickery and illusions, ask any of the old grandpas around here some probably just shake their heads at all the jargon that developed over time. Width, breath, depth, 4 dimensional, space and so on. You cannot recreate what was recorded or heard by the engineer and messed with or where the mikes were when there were no scientific proof of the event unless you have been there and experienced something extraordinary. Simulators are used by true designers to quickly test a concept, not design to a specification and use as subjective actual outcome. Too many have tried to predict an objective outcome to sound equipment and hearing and brain activity and personal stimulation, etc. just an opinion, sorry if I offended anyone, probably be banned again soon.I agree, It can't be too big!
However, there is more to it than that, so simulating it will probably 'force' you to to use a bigger cap than you even dreamed of.
https://www.lautsprechershop.de/hifi/aka_tief_c_en.htm (complicated theory, simple to simulate in Xsim)
I use single supply and the supply caps to create a floating ground, so they are large, and 2 in 1 for saving space
No worries. Unless you use paragraphs to organize your thoughts into managable chunks, noone will read the inner 80% of it...
that's cool, a bit of life breathed into this thread!
I think we all agree that beyond simulations and recordings, the most important thing in the end is what we feel when we listen to our music with an amp.
It's a bit like art, we can debate for hours on a work or on an artist but in the end, the most important thing is whether we like it or not and there, no need for references or technical knowledge, ask a child what he thinks of a painting by Magritte, Braque or Mondrian, he will answer you whether he likes it or not but without judging technically.
In short, all that to say, the most important thing is what you feel and in my opinion, the technical data are less important.
As already said many pages before, I had a lot of amps, really a lot and from all price ranges and in the end, I only kept the ones I like and without technical consideration, like a child .
What we're doing here is fun and it's an endless debate, but in the end we don't really know much because an amp may work well on a 2-way speaker but not on 1-way or 3-way and if it works well on a 2 way, it may work well on an average impedance of 4 ohms but not 8, and if it works well on 4 ohms it could work well on a closed load but may not be in bass reflex etc etc etc etc.
I am one of those who think that there are so many parameters to take into account that it is hardly lost to try to simulate anything, only the listening experience is important.
finally, I have for years, in any case more than 10 years, tried my amp in the same reference room, with the same reference speakers, the same reference cd player, and the same reference cds having relentless judgment on this or that device, now I moved to another house and one of the first things I did was install my new reference system in its new room and it was a disaster , which was valid yesterday and was judged as a reference yesterday is no longer so today when only the part has changed (the famous experience of: "yet it worked great at the store" after bringing an amp or a pair of speakers at home) and that, no simulation can predict, it's experience that counts, only experience can predict a result and even then, there is still a 50% chance that it will match or not ...
I am now ready to start my umpteenth and maybe ultimate JLH69 and these last two pages make me want to start it again.
I think we all agree that beyond simulations and recordings, the most important thing in the end is what we feel when we listen to our music with an amp.
It's a bit like art, we can debate for hours on a work or on an artist but in the end, the most important thing is whether we like it or not and there, no need for references or technical knowledge, ask a child what he thinks of a painting by Magritte, Braque or Mondrian, he will answer you whether he likes it or not but without judging technically.
In short, all that to say, the most important thing is what you feel and in my opinion, the technical data are less important.
As already said many pages before, I had a lot of amps, really a lot and from all price ranges and in the end, I only kept the ones I like and without technical consideration, like a child .
What we're doing here is fun and it's an endless debate, but in the end we don't really know much because an amp may work well on a 2-way speaker but not on 1-way or 3-way and if it works well on a 2 way, it may work well on an average impedance of 4 ohms but not 8, and if it works well on 4 ohms it could work well on a closed load but may not be in bass reflex etc etc etc etc.
I am one of those who think that there are so many parameters to take into account that it is hardly lost to try to simulate anything, only the listening experience is important.
finally, I have for years, in any case more than 10 years, tried my amp in the same reference room, with the same reference speakers, the same reference cd player, and the same reference cds having relentless judgment on this or that device, now I moved to another house and one of the first things I did was install my new reference system in its new room and it was a disaster , which was valid yesterday and was judged as a reference yesterday is no longer so today when only the part has changed (the famous experience of: "yet it worked great at the store" after bringing an amp or a pair of speakers at home) and that, no simulation can predict, it's experience that counts, only experience can predict a result and even then, there is still a 50% chance that it will match or not ...
I am now ready to start my umpteenth and maybe ultimate JLH69 and these last two pages make me want to start it again.
The listening room is of paramount importance for the sound of the audio system.
JLH centre top in wood. My brother is more fanatic than anyone else I know. He bought literally 10s esoteric amps (including Accuphase, Naim, Pioneer SA9100, Cambridge. Audio Evo 75, Krell KSA50) of amps over his mania period. He has not changed in I think 5 years, The built-up amp chassis was lying in my junk cupboard since maybe 1980 the sound to him is perfect, uses KEF drive units B200 plus T27, old audiophile units he eventually bought from hearing my very first speakers, Concerto almost 50 years ago. Furthermore, he is an audio nut. Will Never listen to streaming, only lately buy a Topping DAC was never impressed with it - collected I don't know possibly 7000 CDs, of every genre you can imagine and uses a classic Marantz DVD, player, swears by it.
Never listened to audio reviews in his life only trusted what he hears and liked, never had or will have a DSP or room correction EQ, never a piece of sponge, egg box or anything in his listening area - cared nothing about brand, always gave his amps and stuff to mates for free, so his wife did not get upset with his collection of crap as she called it. Never knew a thing about electronics, he is a devoted pastor, hardly has time for himself but cannot wait to get home just for an hour of bliss in his favourite leather recliner not even centred between the speakers. Hated the word Audiophile....... Travels the world works for Open Doors, spreading bibles to God knows where....... was locked up for three months in Vietnam for his illegal smuggling activities as a calling. Now, that is a devoted audio freak! Never listened to what I had to say, could not care less.
Never listened to audio reviews in his life only trusted what he hears and liked, never had or will have a DSP or room correction EQ, never a piece of sponge, egg box or anything in his listening area - cared nothing about brand, always gave his amps and stuff to mates for free, so his wife did not get upset with his collection of crap as she called it. Never knew a thing about electronics, he is a devoted pastor, hardly has time for himself but cannot wait to get home just for an hour of bliss in his favourite leather recliner not even centred between the speakers. Hated the word Audiophile....... Travels the world works for Open Doors, spreading bibles to God knows where....... was locked up for three months in Vietnam for his illegal smuggling activities as a calling. Now, that is a devoted audio freak! Never listened to what I had to say, could not care less.
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You guys are all spot on. Look at my previous reply. His auto Room EQ was momentarily corrupt. He has to do a complete reboot and re EQ and phase adjustment and reflection interference and Dolby recalibration and god knows what?
The rest will happen automatically with in a few listens, he will suddenly recalibrate, do exact DSP in his head, within a few hours, If he crawls around the floor to hear a sub that actually worked before is nuts. He would not know. It is an automatic processor called experience and preserved in E² only can be instantly corrupted by any external stimulus but has built-in auto protection, whether he is technical or not, is irrelevant.
Whether he reads and believe the jargon and chooses to ignore it, is an absolute.
Wondered how he ever learnt his mother tongue, would be phenomenal, is not science. DSP'd or what not in any environment, no anechoic chamber reference ever how does he do that? Understanding specification? Having a conversation while showering and his girlfriend/wife somewhere else would be impossible. Well done guy, you got it! You have DSP of the highest calibre, impossible to measure. Give it a thought. Ask Hugh if I sound like and African or where I learnt a little English, he was a language teacher, what an achievement! Must have taught in an anechoic chamber and not to children but adults. Kudos to Hugh!
The rest will happen automatically with in a few listens, he will suddenly recalibrate, do exact DSP in his head, within a few hours, If he crawls around the floor to hear a sub that actually worked before is nuts. He would not know. It is an automatic processor called experience and preserved in E² only can be instantly corrupted by any external stimulus but has built-in auto protection, whether he is technical or not, is irrelevant.
Whether he reads and believe the jargon and chooses to ignore it, is an absolute.
Wondered how he ever learnt his mother tongue, would be phenomenal, is not science. DSP'd or what not in any environment, no anechoic chamber reference ever how does he do that? Understanding specification? Having a conversation while showering and his girlfriend/wife somewhere else would be impossible. Well done guy, you got it! You have DSP of the highest calibre, impossible to measure. Give it a thought. Ask Hugh if I sound like and African or where I learnt a little English, he was a language teacher, what an achievement! Must have taught in an anechoic chamber and not to children but adults. Kudos to Hugh!
I use single supply and the supply caps to create a floating ground, so they are large, and 2 in 1 for saving space
Is this a SMPS feeding a pair of series-connected big caps and balancing resistors, with the amplifier grounds and speaker returned to the junction of the caps?
I have a 48V SMPS that I'd like to use with a split-rail JLH. I was thinking I'd need to have something like a power op-amp to maintain the virtual ground, do you find this unnecessary?
thanks to all for a very useful thread
An Op-amp will be a better reference but not as the ground terminal as the speakers, it will destroy your op-amp very rapidly. The Double capacitor as Rallyfinion described is the better option. Since the two caps can never track at start-up unless beautifully matched, there may always exist a small thump, not too much with an SMPS which is basically pre-regulated, that should start up relatively quiet. Some SMPS even has an inherent delay and soft start. Your 48V supply probably does. I own the Meanwell works beautifully for class A operation since (with only 2 x 20 000uF), SMPS like running at a real (almost) constant current load and not varying like class AB. Class AB can sometimes be heard and most definitely measured unless the built-in regulation of the SMPS can track and change voltage fast enough at varying current of the Class AB, not always as perfect as one may think. Remember to have the discharge resistors and 100nF or so bypass caps across the big ones. Also keep in mind that some cheap SMPS can not source high current instantaneously, and may turn off several times during the initial turn-on because of the High capacitance that would appear as almost short circuit to the SMPS at start-up. Other than that, I think you should absolutely do it, if you get the stuff right you can be assured of perfectly operating JLH, no hum or noise. Hope this was no too long-winded.
Super analysis, I like you already! Even a change in mood will make something that was perfect a day before sound like crap.
Thanks, certainly not too long-winded. My smps is also a Meanwell, 150W. I'll give it a go.
I was a member of an audio-related forum that hosted a particularly grouchy and argumentative troll. When he wanted your opinion he'd give it to you. His stereo was the only one worth listening to and you don't know what you're talking about. Anyway. Someone posted, and we all agreed, that however hi the fi it'd never sound good to someone that miserable. Beauty, as Lol Coxhill reminded us, is in the ear of the beholder.
Sorry, proper off-topic.