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Amplifier Power Supply

modulardesign

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poweramp_pic.png

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modulardesign

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You could also see an amplifier is a variable resistor that sits between your power supply and speakers. If the amplifier is a perfect variable resistor. Then you're simply listening to your power supply distortion free. Whether your power supply has the reserve to reproduce what was recorded is another matter. Many times you'll hear reviewers commenting that this or that amplifier can drive or not drive this or that speaker. It all boils down to the meat on the bone and the characteristics of that variable resistor.

This is a very quiet economical power supply featuring four 8200uf caps suitable for 28-0-28 transformers for up to 2 ohm total load. That is a 4 ohm stereo speaker setup. Amplifiers sound better when reasonably used. You could also use one of these modules per amplifier each with its own transformer for lower impedance speakers. Features high current fast recovery rectifiers for the cleanest switching. Hope you enjoy it.

Dimensions

200.03mm * 106.81mm

Mounting

The module has holes for mounting. M3 screws and standoffs would be suitable for attachment.
 

egellings

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I view an amplifier as a variable voltage source that has a low source resistance. I do not think I'd want the source resistance varying with the music, since speakers will sound different when driven with sources of various output impedances, since that affects damping of cone motion, among other things.
 
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modulardesign

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I view an amplifier as a variable voltage source that has a low source resistance. I do not think I'd want the source resistance varying with the music, since speakers will sound different when driven with sources of various output impedances, since that affects damping of cone motion, among other things.
Thanks. Indeed I am more loose in my modelling. There are many models one can use. The simpler the better if it works as well. Power delivery and control can be perceived. Mostly the brain will compensate and sometimes smear over our perception
 

egellings

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You basically want a good, stiff power supply for an amplifier. Power supply rejection ratio (PSRR) of the amplifier determines how stiff (low source impedance, Zo) the supply needs to be. A balanced push pull or bridge-type one with high PSRR is much more immune to supply voltage variation than a single ended (low PSRR) deign would be.
 
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modulardesign

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You basically want a good, stiff power supply for an amplifier. Power supply rejection ratio (PSRR) of the amplifier determines how stiff (low source impedance, Zo) the supply needs to be. A balanced push pull or bridge-type one with high PSRR is much more immune to supply voltage variation than a single ended (low PSRR) deign would be.
A stiff supply is always recommended. High ripple caps and or regulation usually drives costs up. As a result hi-fi enthusiasts prefer to buy a 300watt amplifier for 30watts duty. That headroom allows one to work with a variety of designs.
 

egellings

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Strikes me as a poor amplifier design. I expect a 300W amplifier to give a good 300W as I would expect a 30W one to do an honest 30W.
 

FrantzM

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You could also see an amplifier is a variable resistor that sits between your power supply and speakers. If the amplifier is a perfect variable resistor. Then you're simply listening to your power supply distortion free. Whether your power supply has the reserve to reproduce what was recorded is another matter. Many times you'll hear reviewers commenting that this or that amplifier can drive or not drive this or that speaker. It all boils down to the meat on the bone and the characteristics of that variable resistor.

This is a very quiet economical power supply featuring four 8200uf caps suitable for 28-0-28 transformers for up to 2 ohm total load. That is a 4 ohm stereo speaker setup. Amplifiers sound better when reasonably used. You could also use one of these modules per amplifier each with its own transformer for lower impedance speakers. Features high current fast recovery rectifiers for the cleanest switching. Hope you enjoy it.

Dimensions

200.03mm * 106.81mm

Mounting

The module has holes for mounting. M3 screws and standoffs would be suitable for attachment.
I understand the desire to make things easy for people to understand but such approximation is misleading... pedantry aside. An amplifier shouldn't be a variable resistor.. ever.. Ideally , you would need to be of a very low and not variable resistance... Let's see the Power Supply, for what it is:, it supplies the power for the amplifier to increase the level of the signal... It seems to me self-explanatory... The better the power, the better the amplification, all things being equal...
 

xpop

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All an amplifier wants is a constant current source. Look at the schematics of the best amplifiers in the world such as the Hexorcist, all based on JFETs. It is composed of a well-filtered power supply (as you mention) but then a current regulation that requires very little filtering (just like a 75xx or a switch mode power supply) which do not support filtering under the condition of lowering its noise capacity and its impulse response. Please read the datasheet of the components that are used and stop guessing !
 
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modulardesign

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All an amplifier wants is a constant current source. Look at the schematics of the best amplifiers in the world such as the Hexorcist, all based on JFETs. It is composed of a well-filtered power supply (as you mention) but then a current regulation that requires very little filtering (just like a 75xx or a switch mode power supply) which do not support filtering under the condition of lowering its noise capacity and its impulse response. Please read the datasheet of the components that are used and stop guessing !
Where we have reserves we can use voltage regulation. Where we have unreliable supply we use reservoirs as buffers
 

LTig

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From an engineering perspective a regulated ps makes no sense for power amps. For music full power is needed for short time only (peaks, see crest factor) so the reservoirs (caps) need to be sufficiently large to handle those peaks and the transformer must supply enough current to refill them between the peaks. Almost all class A/B power amps use such supplies and I'm not aware of any controlled blind listening test which proofs the sound advantage of an amp with regulated ps over one with unregulated ps.
 

solderdude

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You could also see an amplifier is a variable resistor that sits between your power supply and speakers. If the amplifier is a perfect variable resistor.

Not really...
That said a class-D can be kind of seen as this (before the post filter) but they usually don't use linear unregulated power supplies.
 

Holmz

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... Let's see the Power Supply, for what it is:, it supplies the power for the amplifier to increase the level of the signal... It seems to me self-explanatory... The better the power, the better the amplification, all things being equal...

The “power amp” is mostly am impedance match between the preamp to the speaker.
It does a little gain, but mostly it is converting between a 100k input and a 4 ohm output impedance.


All an amplifier wants is a constant current source.

I thought that most all the time the amplifier wants a constant voltage source?
 

LTig

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The speaker wants a constant voltage source. How the amp delivers it is another question. ;)
 
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modulardesign

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The speaker will get fed a varying voltage depending on the input signal, so in-order to maintain fidelity the amplifier in essence the power supply should be able to handle and provide the required current to keep the voltage true and keep distortion down. On the other hand the amplifier expects that the power supply to not collapse under heavy current swings. Usually depending on the design of amplifier they are quite immune to power supply misconduct it is on this ground that we have the tracking down converter power supply by Bob as well as class H power supplies. Although sometimes its all relative
 
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modulardesign

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It is especially crucial to have a reasonable power supply when employing negative feedback in a power amplifier architecture. Back in the good old days when solid state amplifiers came into the market there were scenario's of harshness due to generated harmonics under various circuit conditions. The reason LPs still carry the day is that they have information loss or warmness that seems pleasant to the ear. In the end even in any recording its about the harmonic signature from the studio as well as secondary harmonics from your equipment under normal as well as fault conditions.
 

SIY

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It is especially crucial to have a reasonable power supply when employing negative feedback in a power amplifier architecture. Back in the good old days when solid state amplifiers came into the market there were scenario's of harshness due to generated harmonics under various circuit conditions. The reason LPs still carry the day is that they have information loss or warmness that seems pleasant to the ear. In the end even in any recording its about the harmonic signature from the studio as well as secondary harmonics from your equipment under normal as well as fault conditions.
Do you want a white wine or balsamic vinaigrette with your salad?
 

joeren

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Not really...
That said a class-D can be kind of seen as this (before the post filter) but they usually don't use linear unregulated power supplies.
No amplifier acts like a variable resistor and class D amplifier does not look like a variable resistor. It applies the full rail voltage to the output, with PWM regulation. The only resistance is the the semiconductor switch’s on resistance, very low. It appears more as a current source to the load, since it’s the current that builds through the inductive filter and load.
 

solderdude

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Class D switches to either full rail. When you modulate that rail that modulation will also be present in the output signal (poor PSRR) so class-D will benefit from good power supply regulation.

And indeed no amplifier acts like a variable resistor. It was modulardesign that made that comparison.
 

egellings

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A good audio amplifier is a hard (low source impedance) voltage source.
 
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