Switched to Class D or get left behind?

RepublicOfTexas69 said:
In standby mode for clarification.
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Yep, I always leave mine at least in standby. I had a Pass Labs amp I left full on all the time. It was like a tube amp that it didn't sound it's best until about 40 minutes of operation so I got to just leaving it on. Unless I was going to be away for more than a day.
 
I have used class A solid state in the past, and could easily tell the difference in sound after the hour warm up. I was living in Houston, so they got turned off when not in use.

I cannot tell a difference, over an hour, with my class D amps.

I’m going to leave the burn in topic alone.
 
Yea, the Class A amps I have had definitely improved after some time. I think the tubes did also. I did not really notice a difference with the Class Ds after any kind of warm up. My McIntosh I notice very little difference after some warmup time. There was definitely a break-in improvement though.
 
Randy Myers said:
Sure, Class D has always advised leaving them on. Class A/B is usually ok to leave on also. Tubes and a Class A not so much for a variety of reasons.
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Interestingly enough, Ray Leung of Von Gaylord didn’t even put a power switch on the front panel of my LAD-L2 preamp. When I asked him about it, he told me that repetitive inrush current was as detrimental to the tubes as leaving it on. Either way, the tubes have to be replaced every 5 years.

I don’t personally have the technical chops to question his statement, although I guess that it’s also possible that he deliberately runs the 6SN7 tubes on the easy side.
 
Randy Myers said:
Sure, Class D has always advised leaving them on. Class A/B is usually ok to leave on also. Tubes and a Class A not so much for a variety of reasons.
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Pass Labs
  • Pure Class A Amplifiers: If you have a true Class A model (like the XA or Aleph series), leaving them on 24/7 consumes significant electricity (often drawing hundreds of watts at idle) and generates intense heat. This continuous stress can unnecessarily dry out internal capacitors and shorten their operational lifespan. [1, 2, 3]
  • Standby Mode: For models featuring a front-panel standby switch (such as the INT-30A), use it . Standby mode keeps the critical input and voltage gain stages active while shutting down the output stage to reduce heat and power draw. [1, 2]
Randy Myers said:
Sure, Class D has always advised leaving them on. Class A/B is usually ok to leave on also. Tubes and a Class A not so much for a variety of reasons.
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Mr Peabody said:
I'm not sure in general. I know when I had auditioned Merrill Audio he said to actually leave them on. It would be interesting to see what Ralph has to say on the question.
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I have a pair of Ralph's Class D monos and they are turned off when not in use. Unfortunately no 12V trigger, but I have an alternative way to turn them off from my listening position. I don't believe there is any delay in getting them working at best sound quality when first turned on. This is another advantage of Class D - they don't need "warming up" as they run cold compared with most other technologies. However if you prefer to leave them on 24/7 your electicity bill won't be huge, but the life expectancy will be reduced somewhat I suspect - 20 years instead of 25 perhap!
 
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2FarGone said:
Interestingly enough, Ray Leung of Von Gaylord didn’t even put a power switch on the front panel of my LAD-L2 preamp. When I asked him about it, he told me that repetitive inrush current was as detrimental to the tubes as leaving it on. Either way, the tubes have to be replaced every 5 years.

I don’t personally have the technical chops to question his statement, although I guess that it’s also possible that he deliberately runs the 6SN7 tubes on the easy side.
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That is interesting some tube gear is alright to leave on. Maybe just low current. I had an Audio Note DAC the manual said alright to leave on all the time. It did have a power switch if you chose to turn it off at some point. I have a headphone amp with a tube that was alright to leave plugged in, no power switch. I don't use it much so go ahead and unplug that.

I've had solid state with no power switch, Pass Labs preamp and my former AcousTech phono stage.
 
Mr Peabody said:
That is interesting some tube gear is alright to leave on. Maybe just low current. I had an Audio Note DAC the manual said alright to leave on all the time. It did have a power switch if you chose to turn it off at some point. I have a headphone amp with a tube that was alright to leave plugged in, no power switch. I don't use it much so go ahead and unplug that.

I've had solid state with no power switch, Pass Labs preamp and my former AcousTech phono stage.
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I can see this being the case in a Pre-Amp
 
Shadowfax said:
Do class D amps need breakin time or need warmup time before lisyening?
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As best we can tell, they do.

I don't think its wire; I think its the power supply. The following comes from an engineer to whom I spoke with about 35 years ago who worked with Cornell Dublier: At the factory, electrolytic filter capacitors are 'formed' to a specific Voltage- that of their rating. When they are installed in an actual circuit, they have a different Voltage applied to them which is something less than the rating. The caps have to re-form to that new Voltage. There seems to be a temperature element, which is the higher the temperature the faster they form up.

Class D amps run pretty cool so it might take longer than in a class AB solid state amp, although I suspect not by much.

When the caps are not fully formed they are less effective at their job, which is bypass of the power supply. On this account the supply is going to have more noise which can intermodulate with some portions of the amplifier circuit. The change in noise is slight but it is measurable.
Hear Here said:
However if you prefer to leave them on 24/7 your electicity bill won't be huge, but the life expectancy will be reduced somewhat I suspect - 20 years instead of 25 perhap!
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Actually filter caps like having a charge on them- I would not expect a shorter life. As far as the life expectancy, we expect about 30-35 years since we are using 105 degree Nichicon filter capacitors that are running stone cold. The electrolytics in any amplifier will be the thing that needs service first, assuming everything else is engineered correctly.
 
atmasphere said:
The Avant Gardes were designed with a solid state amp in mind. They are one of the few horn speakers where the Voltage drive rules are used as opposed to the older (pre-1956) Power drive rules that are used with vintage Altec, EV, JBL and the like. For more on this

If you use Power paradigm amps (zero feedback tube amp) on a speaker designed to be driven by a Voltage source, you'll likely get a tonal anomaly. The controls that are on the back of older speakers designed be driven by an amp that behaves more like a Power source are there so the speaker can be adjusted to the power response of the amplifier. So sometimes you can get them to behave with an amplifier that can operate as a Voltage source.

But speakers that are meant to be Voltage driven (which is probably about 98-99% of speakers made) will not have any controls. All I'm saying here is that when you do a comparison, its important to be aware of this; my speakers at home are meant to be power driven so have controls. I was able to find a setting so they work with the class D amps I'm using. But it took some fiddling.


Class D amps vary as much in sound as any other class or as much as tube amps do. Just because you heard 3 or 4 amps really does not say anything.

That 'left behind' thing is from the perspective of manufacturing. I made that comment because I heard a class D amp (about 9 years ago now) that was so good it was obviously challenging our triode class A OTLs. So I figured it was past time to get a handle on it. This does not mean that a consumer is getting left behind.

FWIW Dept.: I really enjoy tubes a lot, they are fun. But they don't sound any better than the class D amps I play at home. When I do comparisons for people, the big tell is that the class D is a bit more focused so its easier to make out stuff in the rear of the soundstage. These are pretty disparate technologies, yet that's the biggest difference people hear??

Put another way, solid state was supposed to have made tubes obsolete in 1965. Clearly it did not, who would take a germanium based solid state amp seriously today? But semiconductor technology has been changing and improving over the last 60 years; eventually its going to be better than tubes. Someday. When is that going to occur? Did it already happen? Without really doing comparison side by side you won't know. In the meantime, I get why someone wouldn't feel the incentive to do such a comparison. Its very easy to be happy with tubes!
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Ralph...I appreciate you responding to my post.

I've owned your M60s and MA1s, along with MP3 and MP1 preamps. All your tube gear sounds excellent...I just don't have room in my setup for those large chassis.

I demo'd your Class D amps last year and (unfortunately) I didn't care for them.
 
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