My growing awareness of the importance of PS in any piece of analog or digital audio equipment has led me to reconsider batteries again as a PS.
Good PS are not cheap and usually not simple. If we are looking for a regulated supply then these can be as complicated as the equipment they are supplying power to. Also if a PS is found to be good in one piece of equipment it is not guaranteed that it will be good sounding in another.
SLA Batteries were dismissed some time ago as being noisy when current was being drawn. I believe these tests (TNT audio) were done with a single battery? Very low internal impedance of the battery was considered the important factor & only achievable through expensive SLA batteries or paralleling ordinary SLA batteries.
I know this seems just as expensive but there are a lot of batteries thrown out in recycling centers whose only problem is sulphation & these more than likely can be reformed.
Has anybody tested this parallel use of batteries against good quality mains powered PS?
What are the thoughts on this?
Good PS are not cheap and usually not simple. If we are looking for a regulated supply then these can be as complicated as the equipment they are supplying power to. Also if a PS is found to be good in one piece of equipment it is not guaranteed that it will be good sounding in another.
SLA Batteries were dismissed some time ago as being noisy when current was being drawn. I believe these tests (TNT audio) were done with a single battery? Very low internal impedance of the battery was considered the important factor & only achievable through expensive SLA batteries or paralleling ordinary SLA batteries.
I know this seems just as expensive but there are a lot of batteries thrown out in recycling centers whose only problem is sulphation & these more than likely can be reformed.
Has anybody tested this parallel use of batteries against good quality mains powered PS?
What are the thoughts on this?
Just curious has anyone compared deep cycle LA to normal automotive LA? The deep cycle batteries have a much larger amount of lead so survive repeated deep discharge. The action is probably a lot of surface chemistry so it might not matter. Also a new way to spend $$ phone closet and locomotive versions are available at 10000's of A/H and several tons. I have not verified the noise myself.
I've used batteries before in parallel with power supply, and it works great! I highly recommend good output filtering in addition to the battery for best results.
I did one power supply with a paralleled 14.4V NiCD battery, and 10,000uf filter capacitor for running a car radio. The peak unloaded voltage of the 2A transformer (~19V) is not enough to overcharge the battery, so it stays cool. When the load got heavy, (more than the rating of the transfomer) most of the time, it would only drop to ~15V where the battery took over, and held the voltage pretty steady, then as soon as the load lightened, the transformer takes back over for the majority of the power.
Another PS I made is for driving 3.7V LED headlights for bicycle. Takes 12V down to 4.2V max, and has a 3.7V Li-Ion directly in parallel, so either the charger and/or battery feeds the load, and the great thing about Li-Ion, is they hold a VERY constant voltage, and don't vary as much as other battery chemistries.
The Lead-Acid battery in your project should be great, but IMO I recommend large filtering capacitors to filter any noise generated either by the power supply or battery.
I did one power supply with a paralleled 14.4V NiCD battery, and 10,000uf filter capacitor for running a car radio. The peak unloaded voltage of the 2A transformer (~19V) is not enough to overcharge the battery, so it stays cool. When the load got heavy, (more than the rating of the transfomer) most of the time, it would only drop to ~15V where the battery took over, and held the voltage pretty steady, then as soon as the load lightened, the transformer takes back over for the majority of the power.
Another PS I made is for driving 3.7V LED headlights for bicycle. Takes 12V down to 4.2V max, and has a 3.7V Li-Ion directly in parallel, so either the charger and/or battery feeds the load, and the great thing about Li-Ion, is they hold a VERY constant voltage, and don't vary as much as other battery chemistries.
The Lead-Acid battery in your project should be great, but IMO I recommend large filtering capacitors to filter any noise generated either by the power supply or battery.
I use cordless tools till they get broken, worn out or stolen and go through battery packs like crazy. The latest is lithium-ion and I have 3 packs that are dead. I opened one up and found that only 2 of the cells were toast - the rest were fine.
I've been looking for a holder for these size cells but there doesn't seem to be any (I guess since these cells are used in packs where the terminals are joined with strips that are spot welded on). I could DIY a holder I guess.
Nice to use some of these in a preamp, phono amp or even a low power amp. Should be ultra quiet, no?
I've been looking for a holder for these size cells but there doesn't seem to be any (I guess since these cells are used in packs where the terminals are joined with strips that are spot welded on). I could DIY a holder I guess.
Nice to use some of these in a preamp, phono amp or even a low power amp. Should be ultra quiet, no?
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TNT link: http://www.tnt-audio.com/clinica/regulators_noise4_e.html
Okapi, you might be correct that these tests were done without capacitor on the output! I believe this is necessary but also paralleling them seems to be essential also for the impedance reasons I mentioned. I know there are single batteries that have low internal impedance such as gel but they tend to be expensive.
Also a review of an overpriced (7000 euro?) battery powered amp from Audio Consulting at 30W per channel (don't believe it's class D) - http://www.tnt-audio.com/ampli/rocksolid_e.html - "Linear solid state amplifier with 30 watts output power" from site. Has anybody heard these?
Edit: Oops it's gone up in price 9,000 euro!!!!!!!!
Eworkshop, you've used batteries in parallel with PS but not as replacement?
TNT link: http://www.tnt-audio.com/clinica/regulators_noise4_e.html
Okapi, you might be correct that these tests were done without capacitor on the output! I believe this is necessary but also paralleling them seems to be essential also for the impedance reasons I mentioned. I know there are single batteries that have low internal impedance such as gel but they tend to be expensive.
Also a review of an overpriced (7000 euro?) battery powered amp from Audio Consulting at 30W per channel (don't believe it's class D) - http://www.tnt-audio.com/ampli/rocksolid_e.html - "Linear solid state amplifier with 30 watts output power" from site. Has anybody heard these?
Edit: Oops it's gone up in price 9,000 euro!!!!!!!!
Eworkshop, you've used batteries in parallel with PS but not as replacement?
jkeny said:
Yes. That way you have the option of both Mains/Battery and run it directly from either or both without overcomplication, and charge and store electricity for battery-only usage.
I've done it in several projects. It makes a convenient power backup/storage and improves supply filtering, and load handling. You still need big capacitors to smooth it out for SQ like normal for audio IMO.
Parallel battery works great for lights you always want to be able to turn on, especially if your electricity shuts off often, you have dependable light.
For Audio, when the bass hits hard, the voltage sags less because of the parallel battery supplies more peak amperage than the power supply, so the bass is much stronger.
Also, you can use a smaller power supply depending on your usage (duty cycle %). Example. 4.2V 90mA limited supply (3.7V Li-Ion) can run 4.2V 150mA lights because light used on or off for short periods of time, so the battery is charged most of the time, and runs the most of the load. With Audio, you are not using 100% all the time either, so a good % of the time playing, is also charging the battery, while only draining it momentarily during peaks.
At least when the supply is shut off, you can run on just the batteries, but I like to have the supply feeding the battery in parallel when you have mains power available. It makes it where you always have power, and never have to wait long for your batteries to charge before use. If you wanted 100% hum free audio for a moment, you can just unplug the mains, and plug in later. No switches needed.
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