monteverdi Posted March 28, 2018 Share Posted March 28, 2018 12 hours ago, barrows said: Because the idle dissipation is the problem. Take my former Pass Labs amplifier, it required at least an hour of warm up to reach thermal equilibrium and its best operating condition. It seemed to sound even better though when left on overnight. In any case, I could not predict with an hours advance notice when I was going to be listening, so if I wanted the amp to sound its best it had to be left on 24/7. Although it was not a high power model, it still idled at ~250 watts. So that is a significant energy waste. With my class d amplifier, which actually sounds a bit better, I leave it on 24/7 and it idles at ~10 watts. Big difference. But, I chose the class d amp because it sounds better, and the energy savings is just a bonus. I had a Passlabs too and I agree with your statement. Also because of the thermal stress their sound deteriorated over time; I guess as mostly the caps aged. Now my main amplifier is a Devialet D250 Pro which is a hybrid classA/D and for my woofers a DIY class D (Anatech). I have Kharma MP150 which are Hypex derived and they are sitting in the garage (beautiful little red things). Link to comment
monteverdi Posted March 31, 2018 Share Posted March 31, 2018 1 hour ago, GUTB said: Class D sounding better than a Pass is fake news. Did you ever had a newer Hypex (or Anaview) derived amp next to a Passlabs? Link to comment
monteverdi Posted March 31, 2018 Share Posted March 31, 2018 Just now, sandyk said: Just remember that many of you would be pitting the very latest technology against a much earlier design Pass amplifier. Linear Amplifier design has also further improved in recent years as evidenced by the extremely high S/N of the Benchmark design. I understand that, and even the newest class D have less good highs than top class A but at least in my case classD is just superior for woofers. I am using for the rest of the frequency spectrum a Devialet D250Pro which is a hybrid design and measures and in my opinion sounds better than any ClassA (orAB). The only linear amp I know of is Benchmark AHB2 amp which has competitive measurements and high efficiency but I never had the chance to listen to them. Also energy efficiency should as important as sound quality in evaluating amps. Ajax 1 Link to comment
monteverdi Posted April 3, 2018 Share Posted April 3, 2018 GUTB opinions are not news. Fake opinions? I heard an early version of the Kaluga and was quite impressed as I was with some Constellation, CH Precision etc. but I never heard them in the same setup and room. Any statement which is better needs to come from comparisons with only one variable but one can have an opinion if one hears various components in various systems. I am happy with my hybrid A/D amp! Summit 1 Link to comment
monteverdi Posted April 5, 2018 Share Posted April 5, 2018 This discussion could be soon replaced by SMPS vs LPS. It depends on inplementation Link to comment
monteverdi Posted April 6, 2018 Share Posted April 6, 2018 So what about LPS. There is a general idea that toroids are the best transformers. They were developed for military reasons for saving space in airplanes and because they were fancy and and expensive (not so much anymore) they were the things to put in better audio equipment. What about R-core transformers, much less primary to secondary capacitance and therefore less high frequency noise leakage. I like that forum to learn and not to preach! Link to comment
Popular Post monteverdi Posted April 6, 2018 Popular Post Share Posted April 6, 2018 14 minutes ago, esldude said: Not trying to be cute with you, but any of those methods can be done exceedingly well. They all have issues to be solved, advantages inherent in the design. But all have to have the devil in the details beaten out of them to work well. SMPS too. In LPS you can have capacitor filtered, choke filtered, and actively regulated just to pick a few broad categories before getting to the xfmrs in use. You can use big xfmrs for good reason and put them outside the main box for the gear to get hum away from it. You can do what some aircraft one did run everything at 400 hz so the xfmrs can be much smaller. The bottom line is any of those can work and work well. If I tell you I have an SMPS it might be state of the art or it might be a wall-wart radiating garbage in all directions. Same for the xfmrs types in LPS. You really can't say, "R-core xfmrs are the only basis for great quiet power supplies." Or EI core or C core or whatever. This is not a bad basic explanation of the issue here: http://www.audioxpress.com/article/Power-Transformers-for-Audio-Equipment I actually read that article before posting. Even toroids can vary a lot in their parameters depending how they are manufactured. My point was that just having preconceived notions that one type of design or part is superior to others without knowing any details does not allow to evaluate anything critically. esldude and STC 2 Link to comment
monteverdi Posted April 6, 2018 Share Posted April 6, 2018 28 minutes ago, esldude said: We just can't do it. I'm stuck with class D. I mean bad enough already right? Mine has toroidal power transformers I think. Bad, bad bad. Leaking noise everywhere. I mean the output noise when idling is literally a couple dozen microvolts. It sounds quiet to me. Quieter than any amp I have ever owned. But I am having trouble sleeping at night. I wake up with nightmares about what might be going on and still think it sounds okay when it just can't be, right? It just cannot be. I have a class D with toroids (Kharma MP150) and a DIY Anaview with integrated SMPS and I like the later much more (if it has to drive the right impedance). Link to comment
Popular Post monteverdi Posted April 8, 2018 Popular Post Share Posted April 8, 2018 6 hours ago, barrows said: I get a little annoyed when i hear about these so called "hybrid" amps. I have heard this term used for things like Devialet, etc. Pretty much every class D amp I am aware of is actually a "hybrid" design in terms of this! All class D amps have a relatively normal, input gain stage, which is accomplished using normal linear circuits, usually running in class A-so every class D amp is a "hybrid" by this definition! Devialet started this naming proposition and it is a bit misleading! For example, all nCore modules require an input buffer in front of the class D switching stage. My NC-400 DIY amp has a fully discrete circuit, linear input stage with discrete voltage regulators as well. The NC-1200 as used in the Merrill amps has an opamp IC based input stage, with discrete voltage regulators, and a linear circuit driving the switching output stage, etc, etc... The Nord One Up amps use discrete class A opamp circuit, with discrete regulators in its input stage. I think we need to stop using this "hybrid" term to describe various class D amps, they are all this way! The Meraks use Hypex uCD modules for their output stage, powered by a linear power supply with a custom input stage designed by Auralic. There is a comparison of the Merak amps with the newer Nord One Up amps at 6moons in the Nord review for those interested in where the older design Meraks stand in relation to newer class D tech (N core). Devialet's ADH is not just a class A input stage (as more or less all class D amps) followed by class D but they claim the class A stage generates the full voltage for the speaker output and 4 class D amps work in parallel to generate the necessary currant. I wish Devialet's technical explanations would explain more than their old white papers. Also I remember reading that the 4 class D stages are arranged in a fashion that cancels switching noise and therefore does not require filtering in the final output stage. Also as the input stage is directly the DAC it is impossible to compare Devialet to any N-core etc. amp. maxijazz and Matias 2 Link to comment
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now