Battery Power

[Holmz]

yes , but i cant see how dc can exisit on a signwave . possible as noise . the term dc on the mains is the effect not acual dc.
if the signwave is not .

sine wave… but calling a DC biased sinewave a signwave is clever.

here is an AI reply but this is not really correct but does yield effects and why the term is used
…

Start with a sinewave and ran it through a diode.

Or start with a sine wave and run it through a bunch of SMPS up and down the streets and boulevards.
Then see what the sine wave looks like at your end.

 

[Kingrex]

These comments don't address what gets rid of DC. Perplexity is just confusing. It seems to say an isolation transformer does not "directly" block DC. You need a Capacitor to block it. But after 5 or so prods, its says sorry for the confusion. An isolation transformer will block the DC itself and it won't let the sift in sine wave up or down due to DC on the primary to pass through to the secondary. So, I see a isolation transformer as a block to DC and its effect on the sine wave. You don't need a capacitor to block it.

At the moment, I don't have any low quality amplifiers that are affected by DC. I have had them in the past. I don't remember what a Topaz transformer did. I remember using a Isotek Syncro power cord to shut the hum down.

And DC is only one part of the noise and sine wave distortion. The other is low order harmonics based on the fundamental 60 hertz wave. And high frequency harmonics. Low order harmonics seem to walk through any filter I have seen. Higher order harmonics are usually effectively blocked by most filters. The effect the filter has on the sound varies. I have not idea why.

On the surface, a Capacitor seems a bad way to filter noise. That rapid open and close of a cap in a filter or amplifier or shall I say, power supply of any audio device seems to create a lot of measurable noise on the power line feeding it. So why would a capacitor used to block DC not create the same clipping of the waveform leading and lagging edge that filters and audio equipment power supplies do.

 

[thedudeabides]

Lithium batteries are indeed dangerous. Many EVs catching fire and burning everything around them (entire parking lots, cargo ships etc), also scooters and bikes.

Entire parking lots and cargo ships? Please provide some where's and when's. Surely this would be in the public domain somewhere.

 

[Kingrex]

Entire parking lots and cargo ships? Please provide some where's and when's. Surely this would be in the public domain somewhere.

I did a quick search and found a ship with 3000 EV that burned and sank.

 

[Kingrex]

I would put a well designed lithium in my house. With a charger and BMS made specifically for that battery. I would not go buying bulk foreign low cost lithium to save a $. Not unless I was placing it in a outbuilding designed to house the equipment. This is not at all unusual for off grid people to do when building out solar, wind, hydro and storage systems. You only need a 8x8 shed.

 

[Kingrex]

The distortion from an inverter is most likely 20,000 hertz. The Fets switching speed to turn DC to AC.. The distortion on electrical power lines is usually 180 herts, 300 herts and 420 herts. The 3rd 5th and 7th of the fundimental 60 hertz. Most filters start filtering a 10,000 hertz, and they're more optimum at 20,000. I have been told some people like a Puritan 156 following the inverter. I have been told a very nice option is a Puritan 156 with 2 x Torus 8 kVA Tots plugged into the Puritan. One for amps, the other for front end.
So yes, a filter can be beneficial.

This person got back to me. Now that all the work he did to his electrical infrastructure has settled, he found the Puritan is subtracting from the system. He's still using the Torus. But now going to move to a Torus AVR-2 Elite 20. His big Accuphase amps are drawing up to 3.5 amps. The little Tot 800 watt units might be distorting under that load.

 

[Holmz]

This person got back to me. Now that all the work he did to his electrical infrastructure has settled, he found the Puritan is subtracting from the system. He's still using the Torus. But now going to move to a Torus AVR-2 Elite 20. His big Accuphase amps are drawing up to 3.5 amps. The little Tot 800 watt units might be distorting under that load.

How would one go about determining ^that^?

 

[Kingrex]

How would one go about determining ^that^?

He put an amp probe on the line feeding the amps. Get one of these. Plug the load into the device, the device into the wall. The amp probe clamps around one lf the legs.

 

[Holmz]

He put an amp probe on the line feeding the amps. Get one of these. Plug the load into the device, the device into the wall. The amp probe clamps around one lf the legs.

Yeah Thanks - but I meant the part about distorting.

... His big Accuphase amps are drawing up to 3.5 amps. The little Tot 800 watt units might be distorting under that load.

I assume that the 3.5 amps is some low passed (averaged) current, and maybe when the bass gets kicked then the inrush current might be somewhat higher.

Would they then need some data capture to look at things happening with respect to time and load?
And see if the distortion is going high when the demands for current are also going high?

 

[Kingrex]

3.5 amps is 400 watts. Almost half the value of the transformer. You should not load a Isolation transformer more than 30%. Not for audio. Its not a commercial transformer that wants to be loaded to 70%.

 

[Crom]

I think a quality inverter and Lithium battery will sound better than a Eaton UPS with AGM batteries.

It does ;-)

 

[microstrip]

Please have your favorite amplifier altered by the manufacturer to run on a battery. I will give you a battery at my cost.

Oops. Let is hope that there are not many people owning the Rowland model 8 amplifiers - you would be ruined!

At some time most Jeff Rowland electronics could be run from batteries with a little modification, that could be carried by dealers.

 

[Kingrex]

Oops. Let is hope that there are not many people owning the Rowland model 8 amplifiers - you would be ruined!

At some time most Jeff Rowland electronics could be run from batteries with a little modification, that could be carried by dealers.

Plug it into a battery if you have one.

 

[Holmz]

Plug it into a battery if you have one.

Which sort of battery?

My power supply had an option for a battery, but I think it would be better to use a different battery.. mostly because I heard that the battery option has been unavailable.

 

[microstrip]

Plug it into a battery if you have one.

I listened to it, but more than 20 years ago. A good friend had the model 8 with the Rowland battery power supply. Latter Jeff Rowland replaced the battery power supplies with switching power supplies, as at that time batteries were giving a lot of trouble, and people reported improvements. It would be very interesting to listen to them with modern lithium batteries.

 

[Kingrex]

Yes it would be intetesting to hear it with a modern lithium.
@Holmz
Talk to jeff. You probably have some jumpers to rearrange inside the amp. And you need to get the right voltage battery.

I have not proceeded with a lithium inverter option. The only reason being I can't find the inverter with the THD I seek, but also being quiet in the room.

 

[wil]

Stromtank advertises less than 2% THD on their AC output. Does it use a fan? What distortion levels are you looking for?

 

[microstrip]

Yes it would be intetesting to hear it with a modern lithium.
@Holmz
Talk to jeff. You probably have some jumpers to rearrange inside the amp. And you need to get the right voltage battery.

I have not proceeded with a lithium inverter option. The only reason being I can't find the inverter with the THD I seek, but also being quiet in the room.

What is the total power consumption of your system?

 

[Kingrex]

Stromtank advertises less than 2% THD on their AC output. Does it use a fan? What distortion levels are you looking for?

Stromtank is a 750 watt inverter in a $34,000 box. Its dead quiet.

3% or less THD is my threahold.

Exeltech has a 2000 watt inverter that is 1.8% thd.

Exeltech Cost $1000 for the stand alone inverter.
You can get a rack system for Exeltech. Then you group up to 6 units per phase. Then you have 12,000 watts or 100A. But that is an expensive system. About $24,000 for 100A. With batteries and installation, you would be more than a Stromtank S5000. But your talking 6 amps compared to 100 amps.
And, once you rack, you have the whole NEC to deal with. That means a switch on the outdoor wall of the house, next to the utility power meter. That kills the AC output. You also need a battery disconnect switch. A break in the DC cable. And physical protection when mounted on a wall in a garage. And then cables to the room. And probably a filter.

The guy I talked to who has an Exeltech. He said he changed some capacitors in the unit for better sound. Who knows if Stromtank modified their inverter or what they have done to optimize it. Stromtank really needs a larger inverter.

People are buying Powerwall as a easier all battery/Inverter power supply. I know one person in the middle of doing this for stereo only. Might work well. Powerwall still needs a switch on the outside wall to kill it. But all the disconnects and controls are built into one 400lb plus box. Then you have to wire to the room.

 

[microstrip]

Stromtank is a 750 watt inverter in a $34,000 box. Its dead quiet.

3% or less THD is my threahold.

Exeltech has a 2000 watt inverter that is 1.8% thd.

Exeltech Cost $1000 for the stand alone inverter.

At some time I owned a PSAudio P10 regenerator - the output distortion was always less than 0.5%. The new PSAudio P20 also lists THD < 0.5%, output impedance of < 5 milliohm, 85% efficiency, maximum continuous load 2000 VA.

Probably it could be powered by lithium batteries.