Like the old and venerable (Madrigal Labs) Mark Levinson 20.6 Class A monoblocks. I heard they needed at least a day turned on to sound their best....maybe even longer. I didn't have any direct experience with those amps though.
Convergence of sound
- Thread starter mep
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Like the old and venerable (Madrigal Labs) Mark Levinson 20.6 Class A monoblocks. I heard they needed at least a day turned on to sound their best....maybe even longer. I didn't have any direct experience with those amps though.
A few years ago I read about a designer that came out with a solution, he put heaters in his gear! This really is a crazy hobby.
Steve williams
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Hahahaha. No definitely a SS affair. The idea never caught on after that. Maybe he was using steam so was denied safety certification. LOL
Sorry to mention the unmentionable, but has this phenomenon, in SS gear, ever been measured and verified, either with instruments or through blind listening? As usual, I'm skeptical. But beyond that, I'm pretty appalled. If this is real it is screaming for a solution. Gear that needs to warm up for hours before it performs well? Not with my money....
Tim
Tim
For well seasoned gear, 1 hour seems to be adequate,multiple hours is rare.
Are you sure? Are you sure that the equipment running on idle, for any length of time, is adequate at all? For it to come up to its true potential, doesn't it seem that the "warm-up" time would have to be active - you'd have to be playing the system, working its circuits in the same way they're worked when playing (maybe even with the same music?), in order to prepare it for performance? A musician doesn't warm up his hands for a performance by wrapping them in a heating pad, he plays. What could these phenomenon -- break-in and warm-up time -- possibly be unless we're talking about some molecular change, some response, not only to the heat but to the movement of electrons through the circuits? And...come to think of it...why would it always be a positive? Why wouldn't some designs, some cirucuits sound better cold? Or have some peak temperature below or above which the sound is compromised?
Tim
Tim-This has been discussed before. It’s called thermal equilibrium. You don’t turn on any piece of audio gear and think it has reached its optimum temperature as soon as soon as your hand is removed from the power switch. I’m surprised that as long as you have been around this hobby that you haven’t noticed that everything sounds better the longer your system has been on and playing music. The bigger and heavier a piece of gear is, the longer it will take to come up to temperature. The KSA-250 is a monster of a power amp.
I have said numerous times before that when I run SS gear, I never turn it off. That won’t be the case with the KSA-250 because it simply sucks too much current even at idle. Both the Krell KPE Reference phono stage and the KBL preamp have no off/on switch. They are meant to be left on 24/7 so they always sound their best. I never turn off my music server or the outboard DAC either for the same reason. My Denon AVR that is in my home theater system hasn’t been turned off in over 9 years except for power outages and severe thunderstorms.
As for the KSA-250, Dan D. swore that it sounded fine after 15 minutes of warm up. Everyone who owned one said it didn’t come up to full potential until 3 hours.
I have said numerous times before that when I run SS gear, I never turn it off. That won’t be the case with the KSA-250 because it simply sucks too much current even at idle. Both the Krell KPE Reference phono stage and the KBL preamp have no off/on switch. They are meant to be left on 24/7 so they always sound their best. I never turn off my music server or the outboard DAC either for the same reason. My Denon AVR that is in my home theater system hasn’t been turned off in over 9 years except for power outages and severe thunderstorms.
As for the KSA-250, Dan D. swore that it sounded fine after 15 minutes of warm up. Everyone who owned one said it didn’t come up to full potential until 3 hours.
Yeah, I know.
You ever Google "thermal equilibrium," Mark? It's not about high-end audio. How's the Krell sound?
Tim
No, I don’t need to. I don’t google things I understand and already know about. Thermal equilibrium is well known in the audio world. Circuits don’t come up to optimum operating temperature and stabilize until they have been on for awhile. It’s just a fact.
Yes, you can turn on any SS device and it will emit sound immediately. Tubes will take around 60 seconds or so before they emit sound depending on if it's a tube rectifier coming up to temperature (the heater has to heat the cathode until the cathode gets hot enough to start emitting electrons. The electron stream has to get strong enough to provide a continious flow of electrons to the anode of the tube) or it could be shorter if the tube circuit has a SS rectifier.
As soon as I get a handle on what the Krell is doing (and hopefully not doing something it should be doing), I will report some findings.
I'm not arguing with you, Mark, just trying to get to the principles at work. I'm pretty sure there is some reality in warm-up, but also pretty sure there is some mythology as well. Vanquish the myths and the reality may become simpler than you think.
Thermal equilibrium is pretty much what it says. It is heat moving from the warm object to the cold one it is in contact with until the heat of the two is equalized. Think about what that might mean when you turn on a stone-cold amplifier, what's hot, what's cold, and what effect that might have on the flow of energy through the system. You may find yourself enjoying your renewed Krell kit a little sooner than 3-4 hours. Or maybe not.
I'm not saying that the sound of audio kit doesn't change as it warms up; but I know we aren't really talking about thermal equilibrium because, really, you don't want your ICs to be thermally equal to your heat sinks. You're not achieving equilibrium, but you are achieving warmer. How does that effect performance? Why is warmer better? If you took the sinks away, would it keep getting better until it failed? If not, why not? Is there some engineering principle out there that says that electrons flow more freely at X temperature? I like questions, suspect there are a few people on this board with good answers, and have never seen an audiophile conventional wisdom, firmly grounded in the quasi-accurate co-opting of a semi-relevant scientific principle, that didn't call for a few of them. And we've got time; your amp is still warming up.
Tim
Tim-always pushing. In the case of vacuum tubes, the electrons won't flow at all until the cathode temperature reaches somewhere between 1472–1832 °F.
Is Myth Busters your favorite TV show? I can speak from my personal experience from many years of listening to many different systems and tell you that every system I have ever owned sounded better the longer it was playing music. The systems didn't sound better because someone told me they would, it's just a realization of what you are hearing. Have you ever heard anyone remark how much they love the sound of their system when they first turn it on? Ever heard anyone say the love the sound of a stone-cold system so much they turn their system off and let it cool down just so they can have that stone-cold listening experience again? No?
Maybe it doesn't matter if you primarily rock headphones. Not much to get warm there.
Your are reaching both after the long warmup time - a warmer temperature, at which the designer knows that the electrical parameters of the circuit make it sound better (or at less like he wanted), and an equilibrium point at which the temperature gradients inside the unit are stable and the temperature in the amplifier is stabilized.
We have to consider that these Krell's are now more than 20 years old, the existing transistors were quite different from current state of the art semiconductors, and the designing techniques and resources were quite different from current ones.
BTW, Classe Audio do it in a clever way in their new CA-M600 amplifier - they have a microprocessor controlled cooling system to keep the amplifier at the optimal temperature all the time.
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