• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

The Truth About HiFi Amplifier Power Supplies

Honu

Member
Joined
Dec 18, 2022
Messages
28
Likes
11
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

Addicted to Fun and Learning
Technical Expert
Audio Company
Joined
May 26, 2021
Messages
501
Likes
779
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

Master Contributor
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
7,834
Likes
16,496
Location
Monument, CO
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

Major Contributor
Forum Donor
Joined
Sep 8, 2021
Messages
1,995
Likes
1,772
Location
London UK
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

Member
Joined
Dec 18, 2022
Messages
28
Likes
11
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

Member
Joined
Dec 18, 2022
Messages
28
Likes
11
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

Major Contributor
Forum Donor
Joined
Sep 8, 2021
Messages
1,995
Likes
1,772
Location
London UK
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

Major Contributor
Forum Donor
Joined
Mar 18, 2022
Messages
3,326
Likes
4,829
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

Senior Member
Joined
Jul 20, 2022
Messages
326
Likes
187
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

Member
Joined
Dec 21, 2022
Messages
30
Likes
14
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

Major Contributor
Forum Donor
Joined
Aug 27, 2018
Messages
1,340
Likes
688
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

Member
Joined
Dec 18, 2022
Messages
28
Likes
11
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

Major Contributor
Forum Donor
Joined
Mar 18, 2022
Messages
3,326
Likes
4,829
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

Senior Member
Joined
Jul 20, 2022
Messages
326
Likes
187
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

Major Contributor
Forum Donor
Joined
Aug 27, 2018
Messages
1,340
Likes
688
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)
 
Top Bottom