Daddy Dee Posted May 11, 2007 Share Posted May 11, 2007 I just want to know why these amps don't have the grunge I hear in other solid state amps. No, they don't have the midrange bloom of a good tube amp, but they are devoid of the primary thing I find objectionable with solid state. Dean, Your description reminds me of something LeoK said. Sure wish I could articulate it, but as I understood him, he was saying that most people are accustomed to hearing distortion in the HF (I think) and listening to the T amps might be the first time they've heard music without that. I'm also understanding him to say that T amps have some things they don't do so well with. I guess I'm pretty well taken with what I'm not hearing. My apologies to LeoK for a poor representation (if it was that) of your take. edit: that post is in this thread if anyone had not already read it: [:$] Quote Link to comment Share on other sites More sharing options...
Deang Posted May 11, 2007 Share Posted May 11, 2007 "Grunge?" "Bloom?" - - What? Now, you're falling back on all those "old man audiophile" words? Just go measure it, man. Be careful, or I may pepper you with foul expletives. You still need the words, right? Even after you measure and have all the numbers -- you still have to use words to describe what you're hearing (or not hearing). Quote Link to comment Share on other sites More sharing options...
sfogg Posted May 11, 2007 Share Posted May 11, 2007 Mark, "More significantly a PWM signal needs only to be filtered through an ordinary L-C filter to regain the original input signal. Now, if the PWM were a string of bits, that would not be possible." Sorry, but that is just wrong. It is a string of bits and it is recoverable with a simple L-C filter. Again, you can keep arguing this is not the case but there are real world examples showing that it is. SACD..... and of course all these digital amps. The D/A and A/D of a single bit system are conceptually much simpler then multibit systems such as PCM. BTW... have you ever actually looked at the output of a PCM DAC ahead of the L-C filter? If so all you would see there is basically a string of fixed width square waves of varying amplitude. A simple L-C filter recovers that back to analog too...... Or are you going to claim a string of square waves clocked at a specific frequency can not pass data? If so the number of examples to the contrary are legion..... "In summary what you have is this simple analog process: Input Sig integrated with Carrier Sig = PWM Sig---->Low Pass filter = Input Sig." Bad summary. The triangle wave is never on the output of the amp therefor it is not possible for it to be 'carrying' the audio signal. The carrier is either the square wave output itself or one could possibly consider the modulator frequency itself as the carrier depending up ones point of view. The triangle/sawtooth/whatever signal is not really overlaid on top of the input signal (though pictures always show it this way to make it easier to understand what happens in the comparison), the input signal is compared against it. Your own earlier picture depicted this as two different inputs into the modulator. The amp, real amps the ones actually on the market not some idealized theoretical thing, at a specific frequency compares the input signal against the triangle/sawtooth/whatever and in effect assigns a bit value to the input signal based on the relationship between the two. That bit value is simply on/off and the amp turns the output transistors on/off based on that. That creates the PWM signal (square waves) and when it passes through the low pass filter recovers an amplified version of the input signal within the bandwidth limits of the amp. "(A PWM signal is NOT a "square wave")" ?????????????????????????????????????????????????????????? Please show a reference for this claim as this is just 'out there.' Your own earlier posts show it as square waves. Any time you cycle a transistor on/off you create square waves. A PWM cycles a transistor on/off... Are you now arguing with yourself and changing your own position? Never a sign of a strong position.... Shawn Quote Link to comment Share on other sites More sharing options...
pauln Posted May 11, 2007 Share Posted May 11, 2007 Pauln, More significantly a PWM signal needs only to be filtered through an ordinary L-C filter to regain the original input signal. Now, if the PWM were a string of bits, that would not be possible. In summary what you have is this simple analog process: Input Sig integrated with Carrier Sig = PWM Sig---->Low Pass filter = Input Sig. (A PWM signal is NOT a "square wave") Maybe we can all agree on the operation of PWM by not using the word "digital" at all. Since all these modulation concepts and their mathematical treatments were worked out long ago without using the word "digital", I am beginning to suspect that the word "digital" was adopted by the marketing folks... like "plastics": My 1959 Information Transmission Modulation and Noise covers all the pulse modulation family (PCM, PWM, PPM) and nowhere in this book of 460 pages is there any use of the word 'digital"; doesn't even appear in the index. "I want to say one word to you. Just one word." "Yes, sir." "Are you listening?" "Yes, I am." "Plastics." The Graduate, 1967 Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 6. If it's not expensive, it can't perform well. It doesn't matter that technology and manufacturing evolves - put a higher price tag on it and it will always perform better. Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 I just want to know why these amps don't have the grunge I hear in other solid state amps. No, they don't have the midrange bloom of a good tube amp, but they are devoid of the primary thing I find objectionable with solid state. I think we might be hearing the same thing. I also don't know of any live acoustic instruments that have midrange bloom [] Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 6. If it's not expensive, it can't perform well. It doesn't matter that technology and manufacturing evolves - put a higher price tag on it and it will always perform better. ================= I think when a $39 thing performs as well as a $1500 thing, that's "amazing performance!" Indeed! That's like buying a $1,000 car that outperforms a $38,000 car. I'm certainly not slighting the achievement at all. I would probably use the analogy of a modern $300 computer versus a $10,000 computer in the 80's... Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted May 11, 2007 Share Posted May 11, 2007 Mark, Thanks for your take there. I think you mention some things that are certainly in play in popular perceptions. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted May 11, 2007 Share Posted May 11, 2007 Why have I yet to see these little things turn up in any audio store locally? I know how to order on line but where can you find them to audition? Quote Link to comment Share on other sites More sharing options...
sfogg Posted May 11, 2007 Share Posted May 11, 2007 Mark, "Square waves are an even period wave, just like a sine wave is an even period wave. This is a kind of semantic argument that is really pointless....Again, the definition of a square wave is even periodicity. PWM has no such even periodicity. Thus, PWM is not a square wave. " Feed any PWM a fixed input (say 2v DC) and you will get a square wave output with an even period. The reason the square wave output of the PWM varies when you feed it music (or even a simple sine) is because the input varies. Nothing more complex then that. This would be like claiming music is not sines because it does not have even periodicity throughout the song. But you are right this kind of semantic argument is completely pointless, which begs the questions why did you bring it up? "I agreed already that SACD is a different animal and a fully digital one. I am not sure why interjecting SACD and PCM has meaning." SACD has meaning because it is PWM, digital and conveys data as bits. Something you have said PWM is not. "Now, you have a different amp in mind, it has a clock, and only compares the signal to the carrier when the integrator is clocked, and this creates "bits" instead of modulated duty cycle pulses. Well, ok, if you say so, that's fine with me. " I never said it created bits *instead* of pulses/switches/squares. I said the pulses/switches/squares *are* bits. From the above the obvious question is very simple... do all the digital amps on the market (Tripath, TI, Spectron, B&O, Hypex...etc....) work off a modulator/switching clock? Every one I have looked at mentions a clocking/modulating/switching frequency. All of them. Shawn Quote Link to comment Share on other sites More sharing options...
maxg Posted May 11, 2007 Share Posted May 11, 2007 6. If it's not expensive, it can't perform well. It doesn't matter that technology and manufacturing evolves - put a higher price tag on it and it will always perform better. ================= I think when a $39 thing performs as well as a $1500 thing, that's "amazing performance!" Indeed! That's like buying a $1,000 car that outperforms a $38,000 car. I'm certainly not slighting the achievement at all. I would probably use the analogy of a modern $300 computer versus a $10,000 computer in the 80's... Probably more like a $10,000,000 computer if we are talking about the 80's - but without the graphics and the sonic stuff..... Quote Link to comment Share on other sites More sharing options...
Mallette Posted May 11, 2007 Share Posted May 11, 2007 Why have I yet to see these little things turn up in any audio store locally? I know how to order on line but where can you find them to audition? Because they're about as welcome there as a turd in the punch bowl. You think they want one of these sitting next to a 5k amp for comparision? Frankly, I don't blame them... Dave Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 Probably more like a $10,000,000 computer if we are talking about the 80's - but without the graphics and the sonic stuff.....lol [Y] I didn't want to be accused of exagerating a point [] Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 Why have I yet to see these little things turn up in any audio store locally? I know how to order on line but where can you find them to audition? Because they're about as welcome there as a turd in the punch bowl. You think they want one of these sitting next to a 5k amp for comparision? Frankly, I don't blame them... We sooooo need to have an amp shootout at the Pilgrimage this year. We've got a bunch of guys that play guitar....we should sit down and record them playing for everyone to hear and then play back the recording on all the various amps, speakers, etc....Dean and Mallette can bring their digital amps, Mark can bring his tube stuff, Craig can bring his tubes (maybe meagain will bring her stuff...), Roger can bring his Aragon and Sunfire stuff, and then I'll work on getting some good Crown amps (I wonder if Klipsch ever got their K2 fixed?). I can also provide a computer and MAudio USB device that we can use hooked up to everything. Not super ideal, but should be sufficient for comparison. Speaking of which - you gonna be at the pilgrimage Mallette? I'd love to meet you in person sometime. Quote Link to comment Share on other sites More sharing options...
meagain Posted May 11, 2007 Share Posted May 11, 2007 6. If it's not expensive, it can't perform well. It doesn't matter that technology and manufacturing evolves - put a higher price tag on it and it will always perform better. Only if one is an idiot. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted May 11, 2007 Share Posted May 11, 2007 Why have I yet to see these little things turn up in any audio store locally? I know how to order on line but where can you find them to audition? Because they're about as welcome there as a turd in the punch bowl. You think they want one of these sitting next to a 5k amp for comparision? Frankly, I don't blame them... We sooooo need to have an amp shootout at the Pilgrimage this year. We've got a bunch of guys that play guitar....we should sit down and record them playing for everyone to hear and then play back the recording on all the various amps, speakers, etc.... Dean and Mallette can bring their digital amps, Mark can bring his tube stuff, Craig can bring his tubes (maybe meagain will bring her stuff...), Roger can bring his Aragon and Sunfire stuff, and then I'll work on getting some good Crown amps (I wonder if Klipsch ever got their K2 fixed?). I can also provide a computer and MAudio USB device that we can use hooked up to everything. Not super ideal, but should be sufficient for comparison. Speaking of which - you gonna be at the pilgrimage Mallette? I'd love to meet you in person sometime. Dr. Who, You have a most interesting idea to throw in the comparison mix. To record a performance and play it back through various amps for comparison is a most interesting idea. It there was some way to throw in a blind comparison, that would be very cool, but a significant challenge in terms of logistics. Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted May 11, 2007 Share Posted May 11, 2007 Why have I yet to see these little things turn up in any audio store locally? I know how to order on line but where can you find them to audition? Because they're about as welcome there as a turd in the punch bowl. You think they want one of these sitting next to a 5k amp for comparision? Frankly, I don't blame them... Dave What is your fascination in regards defecating in someone's drink?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Quote Link to comment Share on other sites More sharing options...
kaiser SET say Posted May 11, 2007 Share Posted May 11, 2007 Dave has probably hit the nail head more than you think! As small as these are someone should bring one or a pair to Indy's gathering this year. What a hoot it would be to have you socks knocked off on a pair of 103db+ speakers[] Quote Link to comment Share on other sites More sharing options...
DrWho Posted May 11, 2007 Share Posted May 11, 2007 You have a most interesting idea to throw in the comparison mix. To record a performance and play it back through various amps for comparison is a most interesting idea. It there was some way to throw in a blind comparison, that would be very cool, but a significant challenge in terms of logistics. There have been comparisons done like this in the past where there was a scrim hiding the speakers and performers. Everytime I've read about the comparisons, more people preferred the sound of the recording! []If there was significant interest, I bet we could get Klipsch to let us borrow their blind listening room that already has a scrim set up. If we did acoustic guitar, the listeners would be in the nearfield, so we would probably need to run a single speaker in mono. Do we have any sax or trumpet players on the forum? That would allow for more far-field listening and allow a much larger crowd. We should probably still keep it mono, but it might be feasible at the mixer Friday night. Scrims can be fairly easy to come by. Quote Link to comment Share on other sites More sharing options...
Mallette Posted May 11, 2007 Share Posted May 11, 2007 "Speaking of which - you gonna be at the pilgrimage Mallette? I'd love to meet you in person sometime." When is it? These things have got to be a blast, but the nature of my work leaves time off problematic. On the other hand, Hope is just 35:00 from my ancestral estate in auld Texarkana, now occupied by my brother. If the time were right... Dave Quote Link to comment Share on other sites More sharing options...
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