There have been multiple notes about noise from power supplies, either from charging or from power supplies. Car amplifiers are meant to work with the dirtiest 12v supplies and rarely encounter any noise problems as long as the proper grounds for the input are used.
If you're going to try to replace the split supplies internal to the amplifier, noise could be a problem but PS rejection is fairly good for most of the circuits.
If you're going to try to replace the split supplies internal to the amplifier, noise could be a problem but PS rejection is fairly good for most of the circuits.
Sure, put a 10 bucks power supply in your PC and you'll see how happy your PC will be!
Meanwhile, please could you explain the meaning of the following comment in relation to the subject?
Not really. Because to generate 12V from 120/220 only for the car amp power supply to then generate 36V or whatever is somewhat wasteful. Then again each amp can be different, and sometimes different channels in like a 5-channel amp. So it might make more sense to build a massive 12V supply to feed them all.
Then again again, some Class D amps are really inexpensive now and it might well be cheaper to buy some of those instead 😉
Maybe we should just ask again. The OP requested a dual linear power supply for powering his mobile amps. Are we off target here?
The simplest would be is LM317 with pass transistor for the positive rail and its compliment for negative rail. He need not use a transformer but say 15V switch mode PSU followed by the linear regulator and have a clean smooth, low noise stabilised output.
48V @ 100 AH = 4800WH; roughly a few thousand Watts for an hour, or a few hundred Watts for 10 hours of listening. Conversion efficiencies ignored for the moment...
Who listens to their system at multi-hundred watt levels for 10 hours of accumulated listening time, in a day?
I certainly must be different. I'd crush my listening interest to zero with just 20 WPC after a 10 hour daily exposure. Really dont mean to imply "that's ridiculous", but more to advise OP, others around sizing A-H capacity to a realistic SPL exposure over time.
I'm sure everyone's "daily dosage" is different. Nothin wrong with keeping a fully stocked bar; it's just an expensive initial investment, particularly if you really dont drink that much.
Who listens to their system at multi-hundred watt levels for 10 hours of accumulated listening time, in a day?
I certainly must be different. I'd crush my listening interest to zero with just 20 WPC after a 10 hour daily exposure. Really dont mean to imply "that's ridiculous", but more to advise OP, others around sizing A-H capacity to a realistic SPL exposure over time.
I'm sure everyone's "daily dosage" is different. Nothin wrong with keeping a fully stocked bar; it's just an expensive initial investment, particularly if you really dont drink that much.
Find out how batteries discharge curves work. You do not have to use all the energy in one hour. Also remember batteries self discharge over time. Is a whole science on its own. Your cell phone is about 3800 mAh. Without using it how long will it last. Now use it and see how long it lasts. Also see how long it takes to charge.
a 6AQ5 is a specialized tube made for use in high vibration situations such as mobile devices it's a miniature size 6V6 the smaller size results in lower microphonics and so cleaner sound. computer supplies are made in massive numbers so they cost much less than off the shelf linear supplies. since you could not take the time to look up a tube I doubt that you would bother to experiment with an inexpensive computer supply so pay what you like and buy what you think is best,
Computer supplies are switching supplies and are much cheaper to produce... Less copper, less iron, less weight (shipping), smaller transformers, smaller heatsinks, fewer high-current semiconductors. Linear supplies have virtually all of the disadvantages... but they are quieter.
You may both be right, but linear power supply for audio devices is with rare exceptions a my conviction that is hard to change.
Even more so when I hear about wanting to get a good sound quality like the OP stated.
However, thanks for both of your appreciated replies since a further of the OP's requests was the affordability of the expense.
For whoever is interested...
Look up power supply rejection ratio (PSRR). Amplifiers like op-amps have a PSRR of 80-ish dB and while many may scoff at a measly 80dB, that is a huge value. The generic/common TL072 has a PSRR of 100 (typical).
For switching power supplies, the noise is often at or a multiple of the switching frequency so if the noise does get to the audio circuit, it's inaudible and likely at a frequency well above the frequency bandwidth of the amplifier circuit (most amplifiers have ultrasonic filtering at various stages to prevent high frequency noise issues).
One type of noise that can be an issue with switching supplies (if the circuit isn't working properly or poorly designed) is beat noise. This will often sound like the following (reduce audio level before clicking):
https://www.bcae1.com/temp/cooleditmixedoscillator01.wav
More on this can be found here:
https://physicsmuseum.uq.edu.au/oscillator-beat-frequency
Look up power supply rejection ratio (PSRR). Amplifiers like op-amps have a PSRR of 80-ish dB and while many may scoff at a measly 80dB, that is a huge value. The generic/common TL072 has a PSRR of 100 (typical).
For switching power supplies, the noise is often at or a multiple of the switching frequency so if the noise does get to the audio circuit, it's inaudible and likely at a frequency well above the frequency bandwidth of the amplifier circuit (most amplifiers have ultrasonic filtering at various stages to prevent high frequency noise issues).
One type of noise that can be an issue with switching supplies (if the circuit isn't working properly or poorly designed) is beat noise. This will often sound like the following (reduce audio level before clicking):
https://www.bcae1.com/temp/cooleditmixedoscillator01.wav
More on this can be found here:
https://physicsmuseum.uq.edu.au/oscillator-beat-frequency
i cannot help myself but today amps and power supplies can be small and lightweight and I am not prepared to accept big and heavy electronics any more
As for combination of small 12v battery together with a 12v charger:
theoretically the battery alone works quieter but this does not mean you enjoy more the music.
Often I appreciate a small amount of distortion being pleasant to the ear.
A true art can be to compose a system - mostly on the loudspeaker side - which makes fun (due to the right dose of distortion)
As for combination of small 12v battery together with a 12v charger:
theoretically the battery alone works quieter but this does not mean you enjoy more the music.
Often I appreciate a small amount of distortion being pleasant to the ear.
A true art can be to compose a system - mostly on the loudspeaker side - which makes fun (due to the right dose of distortion)
Beneficial distortion can be hit or miss. A slightly underbiased amplifier can add harmonics and that might make something like a cello sound a bit better but that same distortion can make a pure, wonderful female voice sound harsh.
When it comes to tube amplifiers... that's a whole new ballpark. They generally have more distortion than common solid-state amplifiers because they don't use global negative feedback. Sometimes (with the right speakers) the tube amplifiers can have a wonderful sound but that perfect combination can be difficult to find.
When it comes to tube amplifiers... that's a whole new ballpark. They generally have more distortion than common solid-state amplifiers because they don't use global negative feedback. Sometimes (with the right speakers) the tube amplifiers can have a wonderful sound but that perfect combination can be difficult to find.
Perry, Please share by how much under biased an amp should be to add the harmonics necessary to make a cello sound good. Can one place a switch in the circuit differentiating Female Vocals and Cello? What about piano and saxophone are there different biases for every instrument. Is there one for a big orchestra that corrects the distortion for all cases? What a load of cr@p.
Also share with us from your vast experience what the right speakers sometimes does to make tube amplifiers sound wonderful. Are there speakers for more or less wonderful? Do we need different speakers and bias switches to hear anything wonderful. Also by who's standards would we measure wonderful.
We should design an absolute audio meter with a scale from horrible to wonderful, would that not be something?
Also share with us from your vast experience what the right speakers sometimes does to make tube amplifiers sound wonderful. Are there speakers for more or less wonderful? Do we need different speakers and bias switches to hear anything wonderful. Also by who's standards would we measure wonderful.
We should design an absolute audio meter with a scale from horrible to wonderful, would that not be something?
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Audio is subjective. Wonderful to one person could be awful to another.
As stated, hit and miss. The underbiasing adds harmonics. That's good for some things but not for others.
Tube amplifiers interact with peakers. Various tube amplifiers have different output impedance vs frequency and speakers have various impedance vs frequency. Sometimes these work together, sometimes not.
You seem hostile that someone stated their opinion and it doesn't align with what you believe. That's very odd to see on this forum.
As stated, hit and miss. The underbiasing adds harmonics. That's good for some things but not for others.
Tube amplifiers interact with peakers. Various tube amplifiers have different output impedance vs frequency and speakers have various impedance vs frequency. Sometimes these work together, sometimes not.
You seem hostile that someone stated their opinion and it doesn't align with what you believe. That's very odd to see on this forum.
Not really, to argue about subjectivity is great because everyone is right not aggressive. So what I understand is over bias is better. Then why not just build class A tube amplifiers, they are overbiased. So that is my opinion. Disagreement is not aggression, just debate.
Edit: Every sensory feedback is subjective. There is no right answer, just my gut. Scientific observation could be objective but probably starts off as subjective until proven otherwise. No pun intended.
Edit: Every sensory feedback is subjective. There is no right answer, just my gut. Scientific observation could be objective but probably starts off as subjective until proven otherwise. No pun intended.
Hi ! thank you very much for your kind and precious advice
I think i will stay away from batteries I intend to use the amp in a flat And i have only this one where to live
What i like of the power supply that i mentioned is that they already have a switch and a iec socket for a standard power cord
Very very handy I am quite doubtful about the output 12VDC + and - clamps I much prefer clamps with big screws Love them