Stromtank S 1000 computer-controlled battery power source

The Kingdom of Audiophiledom rests on a paradox. Inanimate audio systems and rooms aim to deliver music that animates our senses and touches our souls. The inherently lifeless exists to bring music to life.

This holistic reality—that systems and rooms function as living organisms where every part is interconnected and interrelated—came home to me when, during one of the first AXPONAs in Chicago, I entered a long, cavernous basement room with several spongy "conference room" walls. "There is no way that any setup can deliver good sound in this room," self said to self. Yet, the system sounded unbelievably good. Rock-solid bass, enviable transparency, smooth delivery, superb soundstaging, drop-dead beautiful sound. That thoroughly musical presentation compelled me to linger for quite some time.

Before I left, I queried the exhibitors about the one component in the setup that, though conspicuous in its size and design, was unfamiliar to me. Thus did I discover the German-made Stromtank S 5000 power generator (now $50,250), an imposing, 275lb computer-controlled lithium-iron-phosphate battery array behemoth whose 1500VA continuous power capability and 5000Wh (Watt-hour) storage capacity, distributed to six outlets, enables it to power amplifiers and front-end components at once.

I'd long been assured that batteries can deliver the cleanest, most stable power to high-end components, at least until they begin to lose their charge. Had Stromtank developed a practical (if weighty and expensive) solution that might help to connect me (and others) to better sound?

Thus it came to pass
Some seven years later, Alex Wilde of Stromtank America offered me the smaller Stromtank S 1000 audiophile power generator ($15,975) for review. I uttered a silent "Hallelujah!" While the eight Hubbell outlets that transmit the S 1000's 1000Wh can power front-end components for 5–8 hours, its 450VA continuous output power at 77°F is not sufficient to deliver full power via my D'Agostino Progression M550 monoblocks, which output up to 1100Wpc to the 4 ohm (nominal impedance) Wilson Audio Alexia 2 loudspeakers. Still, I leaped at the opportunity to discover how even partial freedom from current fluctuations and AC-line–induced noise generated by computers, appliances, internet, cell towers, LEDs, sunspots, and/or space aliens might influence my system's sound.

722strom.bac

When the 90lb Stromtank S 1000's 19" × 19" footprint proved too large for my rack, I stuck a 1"-thick piece of plywood between the Stromtank and the floor and placed Nordost Sort Kones between the Stromtank and the wood. Directly behind it, on my rack's bottom left shelf, sat the AudioQuest Niagara 7000 power conditioner, whose high-current outlets continued to power the D'Agostino monos. The S 1000 powered the D'Agostino Momentum HD preamplifier, the dCS Rossini DAC, Clock, and Transport, and the HDPlex 300 linear power supply, which feeds an EtherRegen and AfterDark clock. The rack also held a darTZeel NHB-18NS preamp, whose rechargeable battery power supply obviated the need to feed it from the Stromtank.

I found myself drawn in an almost religious way to the "Mighty Fortress Is Our God" face of the S 1000, with its huge power meter that changes from blue to green. I paid close attention to its green LED array, which indicates the amount of charge remaining before the unit automatically switches to wall power. I followed directions and put the unit into blue-lit charge-the-battery mode whenever I left the room. Only once during my listening did the S 1000 run out of charge and switch on its own to AC (footnote 2).

Stromtank claims that its deployment of lithium-iron-phosphate batteries (LFP, or LiFePO4) offers maintenance-free "maximum power delivery, maximum lifetime, voltage stability and intrinsic safety." Smart circuitry ensures that the innately long lifetime of the LFP batteries is realized in practice. Stromtank emphasizes that even during recharging, "you can listen without any interruption. Even when the Stromtank is connected to the grid, current pulses are not taken directly from the grid; they are absorbed by the battery ... [with] less interaction between the grid and your audio/video setup."

722strom.gauge

During a Zoom chat, Stromtank founder Wolfgang Meletzky (who, incidentally, also founded MBL) explained the product's genesis and operation. "I saw Tesla and other companies using stronger and better batteries—superior to lead batteries—and decided to build an audiophile power generator driven solely by a lithium-iron-phosphate battery pack and well-shielded in aluminum, that would eliminate all dirt and deliver perfect amplitude on the sine wave and perfect frequency," he said. "If you move from one house or setup to another, you still have the same power. The Stromtank gives you independence from fluctuations on the grid—even from blackouts.

"Together with the German government's Fraunhofer Institute, we created a battery-management system to keep all batteries at the same voltage and energy level. When you need a strong pulse for drums or something else, the batteries can supply it very fast. We measure each sound in voltage and current, gauge the charge of each battery, and shift current from the stronger battery to the weaker one, if necessary, so that current charge and energy remain constant, and you can generate a fast pulse."


Footnote 1: Pronounced, roughly, "Shtrum'tonk."

Footnote 2: Wolfgang Meletzky sent the following information too late for it to be included in the print version of this review. "There are three service ports located on the back of all Stromtanks. This makes it possible to perform service remotely by our service engineers in Berlin, Germany.

• Service port 1 controls the DC/AC Converter
• Service port 2 controls the battery management system (BMS)
• Service port 3 is for the emergency charger

There are two different service devices. The 'Service and Diagnostic Systems' (SDS) known as the 'white box' controlling the DC to AC converter over Service port 1 and the 'Battery Service System' box (BSS) known as the 'black box' controlling the Battery over Service port 2. The service ports can be used for software update, identifying problems or malfunction, changing parameters, performance check , battery check and so on. Most customer questions or problems can be solved remotely. If the customer is not sure if there is a problem or if he has a problem he can call in the service boxes from his dealer and we log in for help."

COMPANY INFO
Stromtank
US distributor: Stromtank of America
5855 E Surrey Dr.
Cave Creek, AZ 85331
(480) 575-3069
ARTICLE CONTENTS

COMMENTS
georgehifi's picture

Would love to know for instance, what the series resistance is of the mains power outlet on the back, back to the battery power source?

Cheers George

Jim Austin's picture

Are you in the industry? As a reminder, our rules say that anyone with an industry affiliation must disclose it in their signature. (This also requires the use of your real name.)

Thanks for cooperating.

Jim Austin, Editor
Stereophile

mosfet50's picture

A 20A, 120V common home outlet delivers 2.4kW. A 1000 watt class A/B amp (500 watts a channel) with ~ 60% efficiency requires ~1650 watts.
Are these people kidding?

georgehifi's picture

No retired for well over a year! That's why the avatar has changed to my other love.
And what's wrong with asking what I did, as if there is any series resistance it does not bode well for power amp use, especially linear high bias Class-A because they rely on stiff power supplies which means as close as possible to zero series impedance/resistance from the power source as possible.

Cheers George

Jim Austin's picture

Nothing wrong with your question, no hidden agenda.

We will measure power supplies, power conditioners, and so on when we have the knowledge and the equipment to do it properly.

Jim Austin, Editor
Stereophile

Anton's picture

It would be interesting to see JA1 run an amp through its measurement paces and then repeat the measurements with a line conditioner upstream.

You could even have a ‘reference amp’ to compare different power ‘conditioners.’

Jim Austin's picture

Many years ago, as I was just returning to hi-fi while in my 30s, I had an email exchange with Paul McGowan on a variety of issues--but mostly on power conditioning. I was closer to my physics training back then--it would have been the late '90s--and I think I had some things to offer back then. If I remember correctly, he even sent me one of their Ultimate Outlets to try. I still have it. This was at least a couple of years before I was involved in any meaningful way with Stereophile. It was an important moment in my development as an audiophile.

Jim Austin, Editor
Stereophile

teched58's picture

Who knew? I don't think you've ever mentioned this before.

Jim Austin's picture

PhD UNC 1992. Soon after, I became a grant-supported independent faculty member. I quit and moved to Maine when my wife accepted a tenure-track faculty offer there. I made a transition into science writing and was part of the news department at Science (the magazine) for 14 years. My wife subsequently--about seven years ago--accepted an offer here in NYC as an endowed professor of chemistry at Barnard College. Which brought me to NYC and led, eventually to my becoming Stereophile's editor.

Jim Austin, Editor
Stereophile

jimmyt's picture

otherwise you would still be in Maine. Not a bad thing except for the flies.... Go Duke :)
I'm only worthwhile as a proofreader.

Jim Austin's picture

>>I believe you meant to say NYC.

Indeed, thanks, fixed.

>> Go Duke :)

Them's fighting' words.

With all those Tarheels returning, so many Dukies jumping ship, Hubert off to a hot recruiting start, and Duke at the beginning of a tough coaching transition, it could be a tough time for your folks for a few years. Here's hoping. ;-)

Jim Austin, Editor
Stereophile

mosfet50's picture

Paul is a nice guy but he lacks electronic understanding. I watched a YT video he did on power factor and he was completely wrong.

What are you conditioning? Amplifiers have overhead, a correctly designed power supply, regardless whether it is linear or SMPS (switch mode) draws from the AC outlet, a 20 amp 120 volt outlet produces 2400 watts, there are welders that work on 2.4kW of power!

That power is rectified and amplifiers have overhead, that means they can compensate for and impedance load they are faced with relative to the total load specific to that amplifier. Eddie Aho, a real electronic engineer who designed and received rewards for power supplies for critical government applications did a video on this. I suggest you look it up and watch it.

So what exactly are power conditioners doing? Nothing!

Jack L's picture

Hi

Are you sure ? You've reglected poweline noise "conditioning".

The main function of a power conditioner todate is to filter out the RFI/EMI noises from the powerlines where your audios plugged in.

Powerlines are RF noise 'sewers' as they loop around behind the walls, over the ceiling & beneath the concrete/wooden floors, forming a hugh receiving RFI/EMI noise receiving antenna loop.
So whatever plugged into the wall outs will get the unwanted noises as free bonus. WiFi for sure makes the situation much worseeeeee.

You are right: Any decently design/built brandname amps todate already got their built-in power supplies adequately ready for power fluctuation. But may not be so for powerline RFI/EMI invasion.

So powerline (noises) conditioners are INDISPENDABLE !!!

FYI, my smart & effective way to save wrecking my bank accounts for acquire some 5-figure power conditioners, is to intall dedecated powerlines from my house breaker panel directly to my audio rig.
5 of them dedicated discretely for my analogue audios & digital audio/4K UHD TV. No zip digital - analogue 'cross-talks'.

Each of these 5 dedciateed powerlines is conditioned by a simple LCR inline RF noise conditioner (made in England) to remove any minor power noises entering my house via the entry distribution transformer outside my house.

Why simple LCR noise conditioner? They do NOT deform the powerline AC current sinewave form like some costly & over-engineered
conditioners do ! Better sound is the bottom line !

Listening is believing

Jack L

mosfet50's picture

Thanks Jack L.
First you can't hear RF. You might hear harmonics but that's doubtful too but let's look at what happens to that AC full of noise or not. It get's rectified, okay so let's say the noise is still there. Now it goes through a large capacitor network that smooths that 120 Hz signal and removes low frequency noise, so let's say there is still some noise there.

What happens next? The smoothed DC goes to chips if it's a solid state amp or tubes if it's not. Any good designer bypasses the Vdd and Vcc with smaller capacitors that remove any high frequency elements. These guys aren't stupid, like me they check that DC meticulously with instruments that can measure well beyond human hearing. I have instruments that can measure nanovolts, that's 10^-9 volts, there's not a person on the planet that can hear anywhere near that.

So that bypassed DC now goes to the chip, the tube, whatever. Chips have something called PSRR and CMRR, Power Supply Rejection Ratio and Common Mode Rejection Ratio. That cleans up anything left if there is in fact anything left! PSRR and CMRR can be over 100 db of cancellation.
Don't believe me? Look at the Benchmark ABH2 amp specs, noise is some ridiculously low figure like 132 db down. There is no one anywhere that can even come close to hearing that.

Bottom line you simple don't need to waste money on conditioners your outlet supplies enough power to weld and your amp cleans up any noise.

Jack L's picture

Hi

Have you checked with Benchmark whether the ABH2 was bench tested with it plugged directly to a wall outlet or to a conditioner ?

Jack L

mosfet50's picture

Manufacturers can't spec a unit conditionally. Besides there's no need to.

Jack L's picture

Hi

Why not since you claimed the Benchmark noise spec is down to -132dB?

So such loooow noise level was meaurured from wall outlet or a conditioner ?

Jack L

mosfet50's picture

A manufacturer can't add external equipment that changes specs then claim those as aspects of a design.

Here's the problem for you. Benchmark tests the noise floor, cross over distortion, etc. with what? With test instruments, so those instruments have to be capable of even lower noise floors than the unit they are testing!

There is no instrument manufacturer on the planet that sells an instrument with the condition that it must have external conditioning to work to it's specifications. If you doubt me then send an email to Keysight, Rohde & Schwarz, Tektronix or any of the other high end instrument manufacturers and ask them. I know what they are going to say because I have instruments from all of them.

ok's picture

..any by-the-book audio amplifier can reject ac noise as effectively as any other. Why then only Benchmark succeeds to that extend? Is there some secret knowledge hiding there that all the others have no access to? And who says that medical equipment has no use for power conditioning? Or that all medical equipment perform the same? By the way I don't use any kind of PC for my audio system although simultaneous use of heavy duty home devices many a time pollutes the sound for no apparent reason.

mosfet50's picture

First, there is no power conditioning on test instruments. Spectrum analyzers routinely measure levels of -140 db, that means they must have a lower noise floor than -140db. An instrument that measures the noise floor on the Benchmark or any other low noise amplifier must be capable of going lower than the device they're testing.

Take an inexpensive Spectrum Analyzer like the Rigol DSA700 series, they have a noise floor below -130db and you can get them for ~$1k.

Opamps (operational amplifiers) have two pertinent characteristics on noise. PSRR (power supply rejection ratio) that rejects noise and ripple at the opamp Vcc, Vss (power) inputs and CMRR (common mode rejection ratio) that rejects noise on the +/- inputs of the opamp. What that means is that it rejects any noise on the input leads of the opamp that is common to both input pins.

Manufacturers today are reaping the benefits of low noise semiconductors. It's the chip designers who are the masters of what you see today and you can't separate test instruments from audio instruments, the only difference in circuit typology is the function of the device, regardless whether you're talking about a rocket guidance system or a DAC.

Low noise floors are not a problem for manufacturers, even the MC275 tube amp from McIntosh has a noise floor of -100db. You can buy an off the shelf ICE class D amp with 110db of range.

Sterophile had this to say about the Benchmark:
"However, the Benchmark amplifier's specifications are close to those of my Audio Precision system, both regarding the purity of its signal generator and the dynamic range of its analyzer."

So if you can make a test instrument or an amplifier without preconditioning that has a lower noise floor than human hearing than you simply don't need preconditioning. a priori

This preconditioner cost what? $5k? So that means people aren't using it on box store amplifiers that cost $49, they're using it on equipment that cost in the thousands. Manufacturers making $5k amps can't get the noise floor low? Of course they can, that's ridiculous, it's not hard to do. Benchmark just proves it can be done and well under $5k.

ok's picture

..cause I mostly agree. In my experience however not all modern electronics are immune to ac fluctuations though definitely better than the average "prototype" of yore. PC/UPS/batteries can solve many momentary problems that don't usually show on typical measurements and are actually a matter of life and death in medical hardware (for a certain kind of audiophile in audio hardware too!). Apparently there is no use for them in test equipment as long as the latter shares the same reference ac line with the tested device. Anyway sometimes PCs do make an audible difference, but not necessarily for the better therefore their considerable cost imo does not really pay off.

mosfet50's picture

AC mains has to be relatively stable. If it is not things start burning out or their life spans are greatly reduced.

Now with the advent of SMPS (switch mode power supplies) you can run any AC in from 90 volts up to 480 volts depending how the supply is designed with 90% and greater efficiencies. You really can't beat the new class D amps run from SMPS, they're beating the pants off everything especially tied to a tube preamp for warmth and second harmonics.

You can buy cheap devices to check your AC line stability but there's really no need to. Any audio equipment worth its salt has sufficient power supply overhead to cover any mains dips and 20 amp outlet can easily power the most demanding audio loads.

Again, the question is: what does a power line conditioner do? No one seems to have a scientific answer and I don't see the manufacturer stepping in to justify its design.

If you're worried about noise in your system then make absolutely sure you have good grounding. If you run several pieces of equipment run them off the same power strip from the same outlet. Different outlets can possibly have problems from ground loops but you don't need power conditioning to resolve that.

Jack L's picture

Hi

What the inexpensive British made inline "powerline conditioner"s I installed in my dedicated powerlines "do" is to provide noise insertion loss up to 52dB@ 32MHz, down to 36dB@ 1000MHz (as shown at chart end) & way way beyond quite a few GHz (covering WiFi bandwidth).

At least such inline conditioners help to save my audio rig (up to 2,700V) in case of electromagnetic meltdowns let alone improving the sonics of my audios.

Have I answer your moot allegation ????

Listening is believing

Jack L

mosfet50's picture

32 to 1Ghz are outside of human hearing and outside of your amplifiers range. It's not capable of "improving sonics" at those frequencies.

You can protect equipment, if you're actually worried about that (I'm not), by using an inexpensive MOV (metal oxide varistor) in the circuit.

Jack L's picture

Hi

So are you telling us all those power conditioners makers should be smarter like your goodself to restrict their product filter bandwidth to audio spectrum so as to save cost to sell more ????

Have you ever heard of RF passive & active intermodulation distortion which is a hugh deal in the RF transmission industries, e.g. cellphones etc etc. RF intermoduation as such can result interruption of the transmission service. RF can also intermoduate onto audio frequency spectrum to cause undue audio distortion.

Read more about RF intermoduation distortion before you comment here, please.

Jack L

mosfet50's picture

I'm not going into this, I don't have to someone already did:

"In fact, my own experience is that well made domestic audio equipment generally does not need to have additional RFI protection for its mains input. Indeed, if it does, my reaction is to be concerned that the audio equipment is unsatisfactory and consider replacing it with another design!"

https://www.audiomisc.co.uk/cables/mains/StringTheory.html

Which is exactly what I've been saying all along!

Jack L's picture

Hi

How do you know that Jim's Audio not telling you the wrong thing????

From what you quoted above, Jim or whoever sounded like so much like you, lacking knowledge of EMI noise on powerlines.

I tested it with instrument, not moot guessing like you & Jim or whoever.

Listening is believing

Jack L

mosfet50's picture

He justified his statements with science but I don't need him to prove my case. That was done by every manufacturer who gets low noise without a conditioner.

Again, your testing is anecdotal, we have no way of verifying your specific tests which also happen to contradict actual facts.

Once data shows, as it has, that low noise can be achieved without conditioning then you're finished because fundamental reasoning eliminates the need for conditioning. a priori

Jack L's picture

Hi

What "science"? Show us !

Since you quoted his statement to back up yr moot asssumption, it is YOUR job to vertify his statement from any other published referemces.

Act like an "engineer" as you claimed you were ! Get real !

Jack L

Jack L's picture

.

Jack L's picture

Hi

FYI, SMPS is a historic stuff dated back to 1936, as vintage as my antique Northern Electric AM radio now providing me background radio music for my electric/electronic bench work.

SMPS were first started to be used in commercial scale back in 1936 to generate HV for tube radios used in cars when MOSFETs were invented the same year.

The huge noise problem of a SMPS is the switching frequency used to generate HV :- up to a few MHz EMI which emit into the air & into the powerlines connected to them. Such EMI is a major issue for commercial application : - effective built in EMI suppression MUST be provided as their electrical code.

Therefore I would NEVER ever used as PS in my audios. No digital electronics allowed in my audio amps, period. Its EMI hurts my ears !!! Class D amps ! Thanks but no thanks for their ear-piercing "efficiency".

That said, I still used an outboard SMPS to recharge the NMH batteries for biasing all the tubes used in my all-triode power amp.
The SMPS is always 100% electrically separated from my power amp whenever the amp is switched on.

You love SMPS ? Be my guest !

Listening is believing

Jack L

mosfet50's picture

First, MOSFET's weren't invented until 1959. Secondly early car radios used a device called a vibrator with mechanical contacts to create a low frequency pulsed signal that could be induced through a transformer.
SMPS magnetics are a different story, they achieve their small size and high efficiencies with high frequencies using MOSFETS and especially GaNFETS in renewable energy inverters and electric vehicle propulsion systems where efficiency is paramount.

I'm happy to discuss the Miller Effect and capacitance loading on high side charge pumps driving N type MOSFETS in H bridge switching applications for DC stepper motors if you like - since you want to "talk engineering".

Noise problems in SMPS have been resolved. In fact the ICE amplifier in the PS Audio amp and the Benchmark AHB2, class D Purifi Eigentakt both use switching power supplies with extremely low noise.
They're just better.

Listening is not believing, read about cognitive dissonance and the scholarly articles relative to audio enthusiasts by psychologists.

Jack L's picture

Hi

What's those DC stepper motors to do with audio ??

"Noise problems in SMPS have been resolved."

Really ? Your "wrong" assumption fails you again.

FYI, my digital wideband powerline & EMI noise analyzer always shows EMI noise surge in the powerline/strip hooked up to any digital audios with built-in SMPS, like CD/DVD/DAC, whenever they are switched ON ????

Don't forget EMI can be transmitted airborne from SMPS too !

Listening, not reading alone, is believing

Jack L

PS: Yes, mosfets was first invented in 1959 - still half a century ago.

mosfet50's picture

We don't know your equipment, setup, what you're actually reading, grounding, DUT, etc. Anecdotal, you're introducing something into a debate that can't be verified.

The noise floor on the PS audio, Benchmark, Peach Tree, Orchard, etc. amps all prove you can have SMPS with low noise and no RFI problems without a $5k conditioner.

You think those engineers plus the engineers at McIntosh, Naim, Marantz, Yamaha, Phase Linear, Luxman, etc. don't look at the noise on their equipment, that somehow they overlooked proper grounding but you figured it out?

I'm selling bridges all next week, how many do you want?

Jack L's picture

Hi

What is "proper grounding" to do with EMI noises in a powerline ?

Don't you know the main fucntion of "grounding" ? Mr. "Engineer" !

As I already stated in my above posts, hopefully yr memory still serves you, any SMPS used in commmerical premises MUST built-in EMI suppression. Are you telling me commercial buildings do not have "proper grounding" already installed ????????

Wake up & smell the coffee, Mr. "Engineer" !

Jack L

mosfet50's picture

You have only one question to answer:

If manufacturers can make amplifiers with noise specs below the threshold of human hearing, as I've shown they can, why do we need conditioners?

That's rhetorical - we don't.

The end!

Jack L's picture

Hi

Yes, "it's over" on YOU with your erroneous assumption that -130dB nosie level of an audio amp will remove EMI coming in the amp thru the powerline & airborne.

Good luck, Mr. "Engineer".

Enough said! So long

Listening, not reading specs alone , is believing

Jack L

Jack L's picture

Hi

Bingo! This the issues of bench measurements since day one.

Otherwise how come same measurement data on different audio items of SAME model still sound different to many skeptical ears, including yours truly's.

The problem is many technical guys believe in measurement data using static test signals more than the dynamic music signals heard by the ears assuming the measured data will tell how it would sound. Likewise for "momentary" powerline noises which standard noise-level bench tests often fail to cope with.

Say would the bench-tested -130dB or whatever lower levels save the day when RFI/EMI noises surge in through the powerline ?????

Likewsie, would an electrical engineering degree provides the ways to avert disasters like an electrical meltdown ?????

Listening is believing

Jack L

mosfet50's picture

Whose ears? Did they prove it in a DBT? That's science, what people think they are hearing is not science it is subjectivity.

"Say would the bench-tested -130dB or whatever lower levels save the day when RFI/EMI noises surge in through the powerline ?????"

Yes!

What meltdown? What are you talking about?

Jack L's picture

Hi

YOU don't even know what is electrical meltdown ? Mr. "Engineer"?
I am not surprised at all.

"BDT" ?!

So many "BDT"s come out with null & void verdicts. Don't you know why ?
I doubt you know at all ! If you take BDTs as "sciene", it must be some failed "science" then.

Jack L

hiendmmoe's picture

Lost in this article was the fact 16k only buys you the front end. I’m assuming if you want your cake and eat it to, it’s going the cost you 50k? I’ll stick with my PS Audio P20; American made without the foreign price or headache.

georgehifi's picture

"I’m assuming if you want your cake and eat it to, it’s going the cost you $50k?"

Correct, $50k for one that can handle a poweramp, and still the question begs if it's "stiffness" compatibility is there.
With no mention of what "series resistance" from the batteries to it's ac power outlet, to power the poweramps with.

Cheers George

sw23's picture

Most of the benefit that you ascribe to this product could be realized for a fraction of the price. There is only $800 worth of battery storage in this scaled down version. $4K worth of batteries and a top of the line Xantrex charger inverter will give you nearly ten times the capacity of this unit for a fraction of the cost. Charge the batteries with a PV system and you are gaining the sonic advantages while freeing the planet from the burden of your he-man rig. All could be done for less than the cost of their top line unit. Are there sonic advantages gained by using this product? Surely. But most of the engineering time and production costs of elite products goes into the last 2-5% of performance. Just get off the grid or insert a buffer at least for your system.

Indydan's picture

I would love to see pictures of your home made device, when and if you can actually build it.

mosfet50's picture

What exactly are batteries doing for you going through an inverter?

Inverters, sine wave, modified sine wave, whatever are filled with noise. More noise in fact then your AC wall outlet. Even high end inverters from companies like Outback that makes really good inverters.

You're not gaining anything, you're adding noise. With that said, if you check an amp fed by an inverter you'll find that the amp has filtered that noise too just like it filtered all the noise from the mains.

You gain nothing putting a conditioner or a battery driven inverter into the system, they're simply not needed. See my response to Jack above.

sw23's picture

If PV is too green for you, forget about the solar panels and get yourself a new Ford F-150 Lightening. This is an all electric version of the pick-up that can best be thought of as a huge battery bank on wheels. The list price of the stripped down model is $42K. The storage capacity of this thing is 98 Kw hrs! By comparison the product under review has a storage capacity of 1 KwHr. Its big brother I believe five Kw Hrs but let's just be generous and say 10. Now I respect the folks behind MBL. I have front end units from MBL. And for some folks a single box solution that you could crate around to shows etc might make sense. But for the average suburban homeowner, well let's just say that the numbers don't work. Yes it would take a lot of sophisticated engineering to make something like this work with an undersized battery bank. You would have to be charging a portion of the bank while using the other portion and then switching etc. A lot more noise generated. The best approach if you have the space is just to size the battery array so that there is more power than needed for a listening session. The Ford can run your entire house for 2-3 days! And they throw in a truck.

Jack L's picture

Hi

The very key function of rechargeable battery in a car is to start up the car engine instantaneouly. So larger car engine demands larger startup current instantly & monentaneously from the battery.
Say 1,000 A but for a very very short time, say 1 or 2 seconds most to get the car engine started.

That's why too old car batteries fail to start up a car because of their failure of delivering min 500 or more amperes instantly demanded by the engine to get ignited.

But for powering an audio amp or "entire house" is a continuous uninterrupted cycle until it is switched off.

Totally different ballgame, pal. Don't bark up the wrong tree !

Jack L

mosfet50's picture

The Lightning is an EV (electric vehicle). There is no car engine to start up and like all EV's there is a 12V battery there simply to maintain the system when the EV is off, it also runs low voltage components of the car. That battery does not come into play when V2H is employed.(Vehicle 2 Home feeds the battery pack to the house to run loads when power from the grid is down. Sometimes called V2G, vehicle 2 grid or V2L, Vehicle 2 Load)

The 98 kWh battery will indeed run a house for several days.

Jack L's picture

Hi

So what voltage is the 98kWh car battery ?

Jack L

MatthewT's picture

What does it matter what voltage the batteries operate at? The vehicle itself will output 120 directly through outlets in the bed, or whole-house by a two-way charger. Do you think people are using jumper cables direct to the battery?

Jack L's picture

Hi

So it is 120V AC or DC ????

Jack L

mosfet50's picture

You can't simply run a car battery into your home, it's DC. You need an inverter that the battery interfaces with just the same as it would in an off grid home. Of course the output of the inverter is 120V AC.

What traditionally happens is people with PV or wind systems use the car battery in place of a battery that's normally dedicated to the specific system.

georgehifi's picture

"The best approach if you have the space is just to size the battery array so that there is more power than needed for a listening session."

In amps, the best is to run the amp's DC power rails directly from rechargeable battery DC voltage source.
That way there is no "current limiting" or "series resistances" converting the batteries low voltage to mains high voltages to run 110v/220v amplifiers.
If that was done, then you can loose the amps mains transformer/s, rectification circuits, and storage caps, and so then save a fortune on the amp's build costs at least by half.

30 years ago Nirvana Electric Works (N.E.W DC33 "said" to be a Nelson Pass design) did this, and the idea should have been refined more today and far more powerful if it kept going.

Cheers George

Jack L's picture

Hi

Yup, it could be "the best approach" THEORETICALLY by replacing the power supply of an amp with a bank of rechargeable batteries.

But practically, it would not work. Not for high power solid state amps which demand many rechargeable battereies in series, & not for class A solid state amps which demand constant large current.

Where to get such a high voltage battey bank for tube amps ??????

How about the charging & maintenance of the batteries ??? Thats why the Stromtank AC-DC-AC power conditioners tagged for 5 figures greenbacks ! It is the battery bank, charging & recharging & control/maintenance cost sooo much money to design/build it right !

Even for DIY hobbyists, it would still be a very costly & tedeous project with no sure-win prospect. I, as a DIYer, would not touch it.

Jack L

PS: above said, the heaters of all the triodes used in my tube phono-linestage are powered by a 500A-capacity car battery (delivering only 1A continuously for many many many hours). Pure DC power - zip hum noise !!!!

mosfet50's picture

Tube filaments run best on current control, not voltage control. If you take a high quality tube, let's say a reissued Gold Lion 6922 which is a pretty good sounding tube you'll find the specs for the filament at 375 mA. if I remember. If you run, say, five of those tubes at 6.3 volts you'll get five different currents, some well over 375 ma. It's best to current regulate tubes and the best and simplest way is with a three terminal regulator and an isolated filament supply.

Pure DC isn't going to give you any better sound or any lower noise. What's going to happen is your tubes are going have a shorter life.

Jack L's picture

Hi

Great imagination, pal.

In the phonostage I design/built in 2014, being used till now, 2x 50+ year-young Telefunken ECC83 & the linestage which was added on in 2016: one Mullard ECC82 (made-in-Great-Britain). The heaters of those triodes have been powered with a 500A car battery as a totally separated outboard power supply since day one.

They are still kicking around like nobody's business - superb sound with dark background consistently since day one. Soooooo !

Why you start to worry about the current regulation of tuhe heaters ? Show me any reference papers to substantiate your claim for such tube heater CURRENT regulation.

Or simply show me any such heater regulation schematics ever employed by any brandnamne tube phono-preamps !

Otherwise yr claims will be dismissed as yr sheer imagination.

Jack L

Jack L's picture

Hi

Yes, BUT not for tube heaters, pal.

When the voltage for the tube heaters is 6.3V constant from a charged car battery, the current supplied to the heaters will be constant accordingly - 375mA for a 6922 per its specs as in yr case.
Unless the tube is faulty.

No need any CURRENT regulators for tube heaters !!!!

I did install a 3-leg HV chip regulator for my vintage first-generation Dynaco PAS-2 HV power supply, set it to 208VDC for the RIAA phonostages. It was in 2010. Probably the only crazy-enough DIYer ever did so on this planet. I did it primarily to eliminate hum noise for the 2 phono stages as for class A amplificatin, the HV current consumption should be constant once the HV voltage is regulated.

By the same token, do we NEED to regulate the operating currents of a Class A solid state power amp which should be constant ?

Jack L

mosfet50's picture

A car battery is not a regulated source. Float voltage of a 6V L/A (lead acid) battery is 6.75 according to Trojan, settling VOC is 6.37, low voltage ~6.11V.

You can charge batteries below their intended charge point but their capacity is diminished. The 500A car battery designation is CCA (cold cranking amps). Car batteries are not designed for nor intended to be used in deep cycle applications, there are much better options, LiFePo4 batteries for example.

Charging a L/A battery indoors is a bad idea because of hydrogen gas emissions.
You can use a Sealed battery (SLA) to overcome the hydrogen problem but the poor regulation of the battery still remains and because of internal resistances of L/A batteries their voltage drops quickly after the charger is removed. Worse SLA batteries have a VOC higher than flooded L/A batteries ~6.44V.

A three terminal regulator does exactly that, it regulates voltage, it does not remove hum and noise, those are addressed before the regulator. Regulator manufacturers and data sheets advise not to add high capacitance filtering after the regulator as it interferes with regulation.

With that said, this discussion is about conditioners and you still haven't shown their benefit in modern circuit typologies.

Jack L's picture

Hi

Yes, it is a SLA car battery I am using since 2014.

Contrary to what you stated, it works like a chime - my phono=preamp works hours & days & weeks, without need of recharging at all (1A drawing from the 500A reservoir). It needs only randomly charged for a few hours conveniently in my basement audio den - done. The battery is absolutely totally disconnected from the charger while powering my phono-preamp.

I can't complain at all as this is the second SLA battery which replaced the first one 3 years back. Maintenance free !

Why don't you bother to ask me what voltage is the SLA battery before you keep on ASSUMING it were a 6V battery & then blah blah blah????? Your imagination fails you again.

So you are insulting my intelligence! You think I don't know there is always voltage drop across the 8-ft battery cable to my phono-preamp ?
If it were a 6V battery as you assumed, the crucial voltage drop (1A heater current) across the battery cable would have surely jeopardized
the performance of the tubes therein - operating at heater voltage below 6v !!!

The only logical choice is a 12V 500A SLA battery, no 'and' or 'but' !

So the 12V battery provides me the luxury of battery output current conditioning & optimum heater voltage adjustment - slightly higher than 6.3V (manual adjustment to make things simple & east).

The 'raw' battery current (1A) will first pass through a standalone battery conditioner (design/built by me), which is comprised of choke & 2 huge capacitors hookup in parallel & output voltage manual adjuster - from 12V dropped down to 6.8V+ to allow voltage drop across the battery cable interconnecting the battery conditioner & the phono-preamp.

Enough said. Please stop bluffing !

Jack L

mosfet50's picture

You can put all the batteries you want in your configuration but, as the Benchmark amp proves, you don't need them. Manufacturers can, and have, built low noise amps without any batteries at all.

As for voltage drop from your batteries to your phono preamp I never said anything about voltage drops, I have no idea what you're referring to. Your post however does contain a number of engineering errors but let's stay on topic.

Bottom line, no one has given any scientific proof that conditioners improve sound or reduce noise. That includes you.

Jack L's picture

Hi

First off, please state clearly what "engineering errors" I've committed. Let talk engineering !

Socondly, you started talking about the LA battery blah blah & I did simply correct yr wrong assumption on mine.

FYI, you are talking to an electrical engineer with decades involvement in power engineering, including VHV power transmission. Audio electronics is only my DIY passtime.

Listening is believing

Jack L

mosfet50's picture

Your post has nothing to do with conditioners.

Do you have scientific proof justifying conditioners?

Jack L's picture

Hi

Your memory failed you like your imagination here ! Pal.

Your bluffed here 7/14: "What exactly are power conditioners doing? Nothing."

I responded to your moot claim 7/18 pointing out power conditioners are
"INDESPENSABLE" substantiating with the real world RFI/EMI situaition.

I even endorsed my statement with my effective yet low-costing power conditioning system installed for my home audio rig decade back, without need of wrecking the bank acounts in aquiring some very costly & over-engineered brandname conditioners which might deform the pure sinewave form of the AC supply current passing thru them.

Please stop bluffing again - making yourself a huge laughing stock here again.

Your one-track mind stuck with yr Benchmark amp which you claimed got noise level -132dB "down". So what? it is only BENCH test!

So show us the realtime noise level measurement with RFI/EMI injected into it.

That's why I asked you how Benchmark measured it but so far you failed to teil me, just passing buck to the makers !!

You ASSUMED the bypass filter caps could do the job of filtering out powerline noises 100%. So your conclusion is no power conditioners are needed.

Substantiate your assumption with reference technial papers. As an electrical engineer, I demand it from YOU.

Otherwise, please stop bluffing here again.

Enough said.

Listening is believing

Jack L

mosfet50's picture

First, your claim that your system reduces EMI is anecdotal, in science we call it anecdotal fallacy. We have no way of verifying your claims. You could be completely wrong. You can't introduce an argument into a debate from information that is not verifiable.

Neither you nor anyone else has proven that conditioners in fact reduce anything.

The Benchmark proves that you can achieve 132 plus db of noise limiting. It has been verified. If you don't believe me go look it up and look up the tests on it.

The instruments that measure that low noise have to be lower noise than the Benchmark or find no noise at their lowest measurable value.

We don't have to inject anything into amps or test instruments, all we have to do is plug them into wall outlets.

I have no idea what you are. That's anecdotal again, for all I know you're plumber. I have no way of verifying your claim nor do I care to.

mosfet50's picture

Running directly from DC, regardless of the voltage, will not run an amp. Amps have several different power rails. For example opamps often use +/-15V to +/-20V DC.
Most PV systems run batteries at 48 volts because it's the highest voltage that you can use without requiring high voltage code.
So now you bring 48VDC into an amp, how are those opamps going to work? They're not.
There is nothing wrong with AC conversions and power supplies we've been doing it for 100 years. For some reason people think if you eliminate or isolate the AC you'll isolate the noise - you won't.

Think about this everyone. Electronics today is very, very sophisticated. Do you think medical instruments and test gear that measures down to picovolts and amps have noise in their circuits? Do you think the EKG at the hospital has noise? It doesn't, those machines are working with very low signals, much lower than audio, even some moving coil cartridges.
INA (instrument amplifier) chips today are ridiculously precise and low noise, much lower than you'll ever need in an audio design.

georgehifi's picture
mosfet50's picture

All there is a are a few posts on this amp from 18 years ago, we don't know if it was designed by Nelson Pass or not. We can't see the circuit to analyze it or Google info either.
It certainly is not one of his current designs if he is involved in it at all. It's here say, it establishes nothing.

Glotz's picture

Lol, I love German! I could say that all day long...

Jason Victor Serinus's picture

I love the sound of it too.

Anton's picture

For those prices, a person better be prepared to offer up a lot of Drachenfutter for a spouse who learns how much it cost!

I admit that I might have a little Schadenfreude watching an audiophile friend go through that.

Anton's picture

I wonder if Dan D'Agostino is making OEM steam punk meters?

David Harper's picture

mosfet50 sounds like he knows what he's talking about. At last. A rare and welcome surprise.

Jack L's picture

Hi

Are you sure ? Not to me though.

Jack L

georgehifi's picture

Quote"Amps have several different power rails."

Not so, many classic linear poweramps had same dc voltage for - and + on their input stage and output stage rails.
So all you need is to series up the batterie's for - and + rails so they are say 12v over what you need. And then have a - and + voltage regulators to regulate down to the rail voltage the amp needs.
And if you want to get elaborate you could have an auto battery re-charger to come on when the regulators reach their drop-out point, but then you'll be listening to ac mains again while it's re-charging the batteries

Cheers George

X