Discussion in 'New Gear - Values' started by Poultrygeist, Feb 11, 2014.
The amptastic certainly reviews well.
Still no real answers to any of my questions?
Battery power helps most when you have a noisy AC line or grounding issues, something you tend to notice right away since batteries will tend tol give you a darker more silent background. Because batteries can deliver very high current (think of them as a giant capacitor), they almost always tend to at least subjectively improve a system's bass performance. Most people who've messed with these things seem to come to the conclusion that if you have clean AC and a really well designed well implemented regulated supply, the results are close if not better with the regulated supply that runs off the mains. I do find that battery supplies tend to sound sort of velvety (not sure why and it may just be me), like the way tubes sometimes sound vs. solid state. It's actually not completely natural, but it's really appealing.
Most of us here, however, aren't listening with well designed well implemented regulated power supplies. We're listening with laptop power supplies or under voltaged supplies primarily designed for 2 way radio hobbyists. If you can deal with the nuisance factor, you'll probably find it pretty enjoyable.
Hooked the Volt+ to a battery again.
Sounds nice, but honestly I'm not sure it sounds any better than my Meanwell-type SMPS unit running at 22V.
Could just be a lack of golden ears. Or perhaps personal taste? Hard to say.
That said, I do notice a difference. There's less dynamic range with the battery when hooked to relatively inefficient speakers.
Everything sounds nice and smooth, but more along the lines of sweet background music than something which truly "shakes me".
Actually, that sounds very much like the reason why I quit running SETs.
Just-too-damned-polite for my tastes.
When I get a chance, I'll hook two batteries together in parallel, see if I can get a bit more ummph.
Might as well hook them in series while I'm at it.....try the set-up with my TPA 3251 board.
Edit: didn't see Airbus's post before I hit "post", so not an answer, per se.
Another thing. I have been reading a ton of reviews on TPA and Tripath amps, digital amps and so on. Why does the reviewer always say things like, this is a great amp for a desktop system. Or a secondary system. I hate that they give a good review but then delegate it to some sort of secondary system. Like it isn't worthy of being the heart of a primary higher quality set up. From my own personal experience. I tend to disagree. I don't know, maybe I am missing something. Maybe I shoulf go out and spend $1500 on a so called higher quality amp and do some comparisons. Maybe I am missing some of the performance my ZU's are capable of.
Maybe I have good power to my house. It is a brand new home. But what really impresses me with my Volt+, is it is dead silent! Blacker than black background. I hear no hum, no noise at all coming from my ZU's, unless it's in the recording itself, and that's with the volume turned all the way up and using my Yamaha pre-amp for volume control.
Perhaps the board / amp just doesnt gel in their system. Sadly with this hobby (for some), its not always about about the reproduction of music.
Heres one good review for the amptastic (TA2020):
Tripath closed it's doors more than 11 years ago.
Perhaps the supply of genuine chips has simply run out?
When you read a review that states the amp works great in near field it means the reviewer has never tested them with a pair of 97db Zu floor standers.
45rpm spinner, what was the voltage of your battery?
The gain switch changes how hot the input section of the amp runs. If the gain is high, it tends to raise the noise floor, but it will also make the amp itself louder since the Tpa3118 is take a 26 db signal and doubling the volume (or whatever the multiple is going to be) instead of a 20 db signal. A lot of listeners will hear it as, "hey it's louder" that's good, but the louder the input signal the higher the noise level.
In the old days, a lot of transistor manufacturers recommended leaving the amp on as much as possible for best life. For one thing, starting and stopping a power supply stresses the amp out because it's a sudden change of state which essentially means that it's easier for capacitors or other parts to metaphorically pull a muscle or have a heart attack. Because tubes are more or less a kind of light bulb, it was generally recommended that you turn off a tube amp to save wear on the tubes.
There are a lot of amps and pre amps that are purposely designed to stay on all the time (well when the plug is in the wall) because people think it keeps things more stable and sounds better on full power up.
It might be psychological, but my volt+d does sound a bit better than my Volt+ board to my ear. The stepped volume control helps as does going dual mono and having better quality caps. They are clearly from the same family though and it's more than a $100 difference in price. The volt+D is a bit more articulate and it's a little fuller sounding. IT's still cheaper than a bottom of the line 30 watt receiver was back int he 70's 80's.
I think the Volumio review that said it's a good second system amp was based on a comparison to something ten times more expensive. With average efficiency speakers in a large room, the volt+ wouldn't be a great amp for the slam or pace whatever they say you need for rock and roll or for say Mahler, Bruckner complex wall of sound with 120 musicians and chorus or the Saint Saens organ symphony. I listen on 6.5 inch 2 ways, so it's not something I can evaluate well.
There are some high-end types who don't seem happy with the treble with the TPA 311X amps. I'm not one of them, but the distortion at 6-7k may be a problem. I'm fairly old, so I suspect my treble hearing isn't super sensitive. Someone younger listening through ribbon tweeters might have to comment.
I'm using 18V lithium-ion batteries made for Milwaukee cordless tools.
I've been using a 2Ah version, but have several rated at 6Ah as well.
You can get then up to 9Ah, but they're expensive.
There's a guy who makes "wired mounts" which allows you to use them for other applications.
Makes the hook-up a lot less sketchy.
Currently awaiting delivery of a second wired mount so I can do parallel and series combos.
I'm a little surprised that 18 volts sounded so tame, but that's why you have try things.
I'd tried a 12 volt battery with the Volt+ and thought it sounded good, though not I want to
listen this way all the time good. I suspect what you're hearing as "relaxed", I'm hearing as "velvety".
Maybe someone here can jump in about why batteries seem to do that.
Hmmm, so would a 20-33 volt lithium battery (2.2-3.0Ah) be a good match for 311x?
They are often used in cordless vaccum cleaners. The cheap vacs are notorious for short life spans, mostly because of cheap parts/construction so finding one discarded with battery/charger should be easy.
I wouldn't go over 24 volts with any power supply for a tpa311X. One of the pains of using lithium ion batteries for an amp is that, I think, they lose voltage as they discharge. They also over voltage at the beginning, so a 3.6 volt cell charges to 4.2. The voltage rating is sort of an average. I think that's why the folks who are into the battery thing tend to use lead acid batteries, which have some issues for indoor use, like clouds of poisonous smoke. That said, if you find a vacuum cleaner battery that's under 24 volts (I'd stay below 22), it's worth a try.
I"m not a battery guy, so I don't know a lot about the discharge profiles of various battery types and would say they're also changing and improving constantly, as people are trying to make them work in cars.
I wonder if a vacuum battery would work best with a vacuum tube amp?
Batteries dont have high frequency noise on the voltage line. Despite the TPA311x having a degree of power supply noise rejection, noise on the power line is not the best thing to have.
Commonly, switched mode gear has noise on the DC line which increases with load.
The noise can show itself as harsher sound (artificial detail perhaps). This will be more evident on the boards without the capacitance multiplier.
The pic below gives a rough idea of the switching noise..
A transformer, rectifier and a regulator is often a big step up from the "common" switching supply. There is still noise but its nothing like whats seen in alot of the switched mode gear.
The battery output is usually a straight line across.
Sorry, but imo some of that info isn't quite correct.
Firstly, all batteries tend to drop voltage as they're discharged.
Secondly, lithium-ion batteries actually have tighter voltage tolerances than lead-acid batteries....it's one of their main attributes.
Biggest voltage variation I've seen with my lithium-ion batteries is +/- 1V off 18.5V.
By the time a lead-acid battery is 50% discharged, the voltage will have dropped.
I've been giving one of my lithium-ion batteries a workout today.
Currently it's showing 50% discharged with 18.8V on the multimeter. It showed 18.7V this morning.
Thirdly, when I check my battery with a multimeter in the morning....what I see after charging is a momentary spike at 20V+ which settles down to 18V+ within seconds.
Do the same with a SMPS when you first plug it in and you'll probably see something similar.
I just did.
Btw, not all lead acid-type batteries put out Hydrogen gas anymore. Some are considered safe for use indoors.
People use them because they're quite cheap given the high amp-hour ratings available.
Me? I just happen to have more expensive lithium-ion batteries around.
Actually, glad to have the information. When I was fiddling with batteries, a lot of people were insisting that lead acid was the way to go. It was quite a while ago though.
Thanks for the correction.
The tripath chips were really sensitive to going over 12 volts. I did blow up an amp once by putting what I thought was a safe combo of batteries together. It was supposed to be 12 and it went a bit over on startup.
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