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The Truth About HiFi Amplifier Power Supplies

Honu

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Amp designers need to control all aspects of the operation. If they allow third party power supplies or even DIY ones, then it could impact the sound quality of their beloved design, or worse, blow up, and they get sued!
If you want to risk a DIY job, you need to open your amp up to find out what voltages the amp is working with on the rails. It could be +/- 35V or higher.
Then jury-rig batteries to supply both voltages (the plus and minus). Run it on charged batteries.
Then jury-rig a charging solution to charge the batteries overnight! a bit of a hassle, you might realize, it ain't worth it, unless you really have to.
That's what i was asking myself ... are ther only one main voltage in an amplifier or multiple, cause i would be able to remove the internal transformer for one external single voltage but not for multiple (seems too complicated).

Now i got an old Yamaha RXV800, i will open it to see how it goes on the power input side.

Yamaha-RX-V800-RDS_D_600.jpg
Yamaha-RX-V800-RDS_P_500.jpg


The other thing is that i'm off grid .. and Class D amplifier are pretty energy efficient, that's an other point to take into account.
 

atmasphere

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That's what i was asking myself ... are ther only one main voltage in an amplifier or multiple, cause i would be able to remove the internal transformer for one external single voltage but not for multiple (seems too complicated).

Now i got an old Yamaha RXV800, i will open it to see how it goes on the power input side.

Yamaha-RX-V800-RDS_D_600.jpg
Yamaha-RX-V800-RDS_P_500.jpg


The other thing is that i'm off grid .. and Class D amplifier are pretty energy efficient, that's an other point to take into account.
Expect to see a bunch of different power supplies in that one. The power transformer is likely to have multiple windings for them and most of them are probably regulated except for those running the output section.
 

DonH56

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That's what i was asking myself ... are ther only one main voltage in an amplifier or multiple, cause i would be able to remove the internal transformer for one external single voltage but not for multiple (seems too complicated).
There will be high-voltage rails for the power amplifier, probably +/-5 to +/-15 V for opamps, and several rails for digital circuitry. There may be only 2-3 transformer taps used and the other voltages regulated from those, but there is almost certainly more than one. I'd guess 3-5, be interested to see what you find.
 

Ken Tajalli

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That's what i was asking myself ... are ther only one main voltage in an amplifier or multiple, cause i would be able to remove the internal transformer for one external single voltage but not for multiple (seems too complicated).

Now i got an old Yamaha RXV800, i will open it to see how it goes on the power input side.

Yamaha-RX-V800-RDS_D_600.jpg
Yamaha-RX-V800-RDS_P_500.jpg


The other thing is that i'm off grid .. and Class D amplifier are pretty energy efficient, that's an other point to take into account.
Living off grid and you want to run that thing?
Invest in a used warp engine, make sure you check the plasma manifolds.
:)
 

Honu

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Expect to see a bunch of different power supplies in that one. The power transformer is likely to have multiple windings for them and most of them are probably regulated except for those running the output section.
Hooo cooomooonn ... do not say that before i open it .. ;)
 

Honu

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Living off grid and you want to run that thing?
Invest in a used warp engine, make sure you check the plasma manifolds.
:)
Lol, yea .. i'll start the thing only on heavy sun days to start up the RXV800 and celebrate for the day ... i got lot energy to spare on sunny days.
More seriously, i ordered 2 fosi audio Class D, but i'm curious to see what is there in the Yamaha and since the thing ccertainly worth near nothing today ...
 

Ken Tajalli

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Lol, yea .. i'll start the thing only on heavy sun days to start up the RXV800 and celebrate for the day ... i got lot energy to spare on sunny days.
More seriously, i ordered 2 fosi audio Class D, but i'm curious to see what is there in the Yamaha and since the thing ccertainly worth near nothing today ...
Where are you? I am jealous.
Here in UK, we don't get enough sunshine to run garden LED lights.
 

HarmonicTHD

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Didn't ask for his address! Off-grid to me, means off electricity grid, what does it mean to you?
Approximate area will do! :)
Relax. Just kidding.

I am no native speaker either but “living off the grid” can mean that one wants to stay anonymous, doesn’t want to be found, become untraceable….
 

dorakeg

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That's what i was asking myself ... are ther only one main voltage in an amplifier or multiple, cause i would be able to remove the internal transformer for one external single voltage but not for multiple (seems too complicated).

Now i got an old Yamaha RXV800, i will open it to see how it goes on the power input side.

Yamaha-RX-V800-RDS_D_600.jpg
Yamaha-RX-V800-RDS_P_500.jpg


The other thing is that i'm off grid .. and Class D amplifier are pretty energy efficient, that's an other point to take into account.

ITs usually multiple. Most amplifiers reuqire different voltages and the transformer will have several output taps with different voltage. Power amp section will require higher votlage (Eg. 50-63V) but pre-amp section lower (eg. 30V). For other votlage (Eg. 5V, 12V etc... they will be supplied via voltage regulators instead.

If you open up your AVR, you should see 1 big transformer with multiple wires on the secondary side.

Some high end devices will have mltiple transformers. Eg. 1 transformer for power and another for pre-amp section.
 

TrippRyder

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Hi all,
I'm living off grid, i find it pretty inefficient to convert DC (batteries/PV) to AC for it to be convert back to DC in my amplifier.
Why are there no amplifier with external power supplies, i do not know what kind of internal voltage amplifiers are using, but i can easily provide 12V, 24V, 36V or 48V from my batteries.
I ordered a Fosi Audio class D cheap amplifier cause it's the only one i could find ... working directly on 36V. (one TB10D and one BT30D Pro)
But my question, is more .. why are there not more amplifier with external swappable power sources ?
Look into hi-end car stereo amplifiers.
 

Head_Unit

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why are there not more amplifier with external swappable power sources ?
Because there is zero market demand. Your use case is really specialized. However there are modules available without power sources-though you'd need to get a case as well. There are also amps with no power supply, or just wall warts, although those tend to be small chip amps. I'd recommend posting a thread "looking for amp modules to match a XX volt battery supply" here and maybe https://www.diyaudio.com/community/forums/power-supplies.67/
 

Honu

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Where are you? I am jealous.
Here in UK, we don't get enough sunshine to run garden LED lights.
Hello,
I'm not far from you, i'm in south west of France, garden lights works fine if they are of quality. Just 20 days in a year maybe where the day is too grey for them to recharge for the next day. You can swap their cells for better ones to improve that.
 

HarmonicTHD

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Hello,
I'm not far from you, i'm in south west of France, garden lights works fine if they are of quality. Just 20 days in a year maybe where the day is too grey for them to recharge for the next day. You can swap their cells for better ones to improve that.
As @TrippRyder suggested. Car hifi amps are an excellent idea. No DIY needed. No niche product (produced in big enough quantities). Environmentally robust.
 

dorakeg

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Yes fully agreed.
Because there is zero market demand. Your use case is really specialized. However there are modules available without power sources-though you'd need to get a case as well. There are also amps with no power supply, or just wall warts, although those tend to be small chip amps. I'd recommend posting a thread "looking for amp modules to match a XX volt battery supply" here and maybe https://www.diyaudio.com/community/forums/power-supplies.67/
Yes, fully agreed. I am one who really hates external power supplies. I prefer the unit to have everything built in and not having an external power brick.
 

Head_Unit

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Here in UK, we don't get enough sunshine to run garden LED lights.
Having just been in the Lake District over the summer, I attest to this. (Though when the sun does peep out, OH how GLORIOUS. And those gingerbread cookies mmmmmmm)
 
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