Why no all-battery-power-option audio systems?

While reading in the most recent issue of Stereophile (Sept/2005/Vol.28 No.9) a look at the Belkin PureAV™ Home Theater Battery Backup at $599 and APC S15 at $1499, I was amazed to learn there were small batterys capable of powering 250 watt stereo amps for 110 minutes.

I immediately thought of accounts of the quietness of battery power in phono preamps like the $3K Sutherland Ph.D., all the time, effort and money some spend on power conditioning units and pricey power cords. I couldn't help but wonder if battery power was one way to get superior sonics and, for some, savings and why it's not included in stereo components.
I don't sit in the sweet spot for hours at a time and would switch via remote to AC power when my attention is elsewhere.

Or am I nuts?

 

You may be nuts, but not for this reasoning.

I agree that every dc power supply in any audio amplifier strives to be a battery. A battery is a virtually perfect power supply except for one problem. They lose their charge.

I've mentioned this many times here, but once I was at a studio doing a string date and the power supply of our large Helios console went down. I sent somebody to Pep Boys for some car batteries and lashed them up to power the console. The session came off and the console never sounded better.

 

Well yes but it's a rechargeable battery and like I said, I (and maybe others?) don't sit in concentration for three hour periods.

I suppose there could be some who don't mind buying $3K power cords.

 

You have been able to buy battery powered hi-fi pre and power amps from Final for some years. They use a lot of batteries though, and not rechargeables either.

 

I believe Tom Port of dccblowout.com uses battery power for his system. I think he talks about it someplace on his website. It must be a hassle setting it up and constantly recharging, but there should be real sonic benefits.

 

So true. Caps last a long, long time. Batteries.....don't.

 

Until about four years ago, Technics' European division used to sell a $2K stereo preamp equipped with a built-in lead acid rechargeable battery (here's a review of it). My own Technics SA-DA8 receiver shares this preamp's special volume control system.

 

It is the amps that can really eat your lunch, pulling that current down.

 

36 C batteries? You have to question the environmental impact (and cost) of that many dead batteries. I'm surprised they haven't re-configured to use rechargeables.

 

Tom set me up with a 125 watt inverter to plug in my pre-amp and turntable (he recommends I get a second inverter to separate out the turntable). I already had the battery. It's a noticeable improvement IMHO. I recharge the battery after each listening session, not a big deal.

Yes, the amp would use up the battery quickly. Need a higher watt inverter, too.

 

Curious as to what kind of noticeable improvements you are hearing? Or are the improvements things you are not hearing now?

 

More immediacy to the music (lack of stuff getting in the way?). Better soundstage, greater depth from front to back. More warmth.

 

I've got about a farad of capacitance on the power supply of my main amplifier. When playing at full volume I can turn it off and it will still play for at least 10 seconds before the voltage starts to drop. I guess this is pretty close to having a battery. The power supply is basically acting as a charging circuit to keep the capacitor bank at full voltage. As a result the amplifier has an extremely solid and stable sound. This also isolates the amplifier from the AC power supply it is plugged into. The voltage on the power supply rails does not fluctuate regardless of the signal presented to the amplifer. With most amplifiers the power supply voltage will drop when the amplifier wants a lot of power. Not only that, but there can be a lag between the signal and when the amplifier can deliver the current. This is often due to the output impedance of the power supply. When the amplifer wants current it wants it immediately. Often when the current is delivered the demand for it has passed. Remember that these current demands are transient in nature and can be very fast. This creates all types of issues as well as a type of audio compression.

The goal of any power supply is to be a virtual battery which maintains it's voltage under all conditions. An interesting test would be to hook a scope up to an amplifer power supply. Set one trace to dc and put it across the supply. Hook the other trace up to the signal. In most cases you will clearly see the power supply voltage drop when the signal demands more current than the supply can immediately deliver and then it will rise back up when the demand has passed. On my amp I can see none of this.

 

Some thoughts on battery power by Tom Port (Humorem) on a forum thread:

http://www.stevehoffman.tv/forums/showthread.php?p=25484&highlight=battery

 

I recall Edge electronics has preamps with a gel battery within.

Also I'd think those with SET tube amp systems would go all-battery all night.

Hey thanks for that link!
I'm not entirely alone here, there are two of us, a crazy & a nut.

 

Interesting... Thanks.

 

The guy behind Red Wine Audio seems to be a battery fanatic:

http://www.redwineaudio.com/Products.html

I have no experience of his products, though they're well reviewed --- I found him while idly browsing the mods people have done on the Sonic Impact Tripath amp.

 

Didn't Technics (as someone mentioned) put out a number of battery powered audio components? They certainly have the marketing prowess to pull it off. Did the public hear an improvement? I don't recall there being much of a response. Does anyone remember?

 

I've found that Technics isn't gear people like to voluntarily admit owning for some reason, though many people still own them anyway (going by profiles and/or passing mentions of them in the middle of a non-related post), just like Infinity and Boston Acoustic speakers. They always seemed like a poor man's NAD to me--i.e. no nonsense designs w/quirky but useful features--but with a more analytical sound. BTW: I currently own a Technics receiver, single-disc CD player and turntable.

 

My Michell Orbe SE is now available with Michell's new "never-connected" technology, which is a cool way of saying that the electronic motor and speed control is now battery-operated. It adds about $2250 to the price of the 'table, though. I may take the plunge in the future. I'd have to hear a big difference in sound quality for that kind of money, however.

 

ummmmm.....guys?

There's some pretty substantial batteries in these things!
cheers,
Douglas

 

Aha! Good point!

 

If that is a hybrid or electric car, the batteries get recharged when the brakes are applied. I wonder if we could harness the power of a heavy spinning turntable platter to recharge the batteries? Or the taping feet of the listener....


.

 

Yes, but both could affect tracking. Of course, there would be a new cottage industry in tweaks to address it.

The car battery thing was brilliant. Of course, those of us who listen to miniature CDPs and downstream headphone amps are also completely battery-powered as well.

 

ummmm, Cunningham? this:
If that is a hybrid or electric car, the batteries get recharged when the brakes are applied.

is not exactly accurate.

It is *ONE* of the ways its batteries get recharged. It is a Hybrid Escape by Ford. It has a battery capable of multi-kW output at a few hundred volts. It keeps its batteries in an operating window such that it can either accept a large charge event from braking, or deliver one for an acceleration.
cheers,
Douglas