There are many things that DIY’ers do, including myself, and it makes me wonder if we actually stop to think.
It usually revolves around “overkill”, and the perceived increase in performance that we are sure we will be able to hear.
One such area is power supplies.
I completely agree that a good solid-state amp needs a good, stiff, well-regulated power supply.
Let me elaborate, and use the Aleph 1.2 as an example.
I am currently building an Aleph 1.2 power amp, and on examination of the original service manual and schematics, it can be seen that Mr Pass has employed a standard bridge rectifier, with approximately 100,000uf of capacitor filtering.
(Mine has 120,000uf)
Now to my way of thinking, the original designer, Mr Pass, has deemed that 100,000uf of capacitor filtering is appropriate for an amp of this quality.
If it weren’t, surely he would have added more filtering etc.
Now we take a look at the DIY’ers of this amp.
On this site, and several others, power supply filtering has been increased to 200,000uf, and in some instances up to 600,000uf.
My question is: if the original designer deemed that 100,000uf was enough, what sonic revelation are the “lets increase the filtering by 6 times” individuals expecting?
Is there something that I am missing here?
I would really like to hear from others.
Regards
George.
It usually revolves around “overkill”, and the perceived increase in performance that we are sure we will be able to hear.
One such area is power supplies.
I completely agree that a good solid-state amp needs a good, stiff, well-regulated power supply.
Let me elaborate, and use the Aleph 1.2 as an example.
I am currently building an Aleph 1.2 power amp, and on examination of the original service manual and schematics, it can be seen that Mr Pass has employed a standard bridge rectifier, with approximately 100,000uf of capacitor filtering.
(Mine has 120,000uf)
Now to my way of thinking, the original designer, Mr Pass, has deemed that 100,000uf of capacitor filtering is appropriate for an amp of this quality.
If it weren’t, surely he would have added more filtering etc.
Now we take a look at the DIY’ers of this amp.
On this site, and several others, power supply filtering has been increased to 200,000uf, and in some instances up to 600,000uf.
My question is: if the original designer deemed that 100,000uf was enough, what sonic revelation are the “lets increase the filtering by 6 times” individuals expecting?
Is there something that I am missing here?
I would really like to hear from others.
Regards
George.
GeeVee,
The total capacity of the filtering caps is awesome. You may also need a big transformer. I have tried both in the picture below. They are of the same input and output voltages. The black one is a 750VA made by Plitron. The big one is a 2000VA custom ordered from Amveco. Below the transformer is a 12" ruler.
With the 2000VA installed in a 150W x2 power amp, the difference in sound quality was quite prominent. I could fell stronger low frequencies as if a subwoofer was added to the system.
My two cents.
Xtaltech
The total capacity of the filtering caps is awesome. You may also need a big transformer. I have tried both in the picture below. They are of the same input and output voltages. The black one is a 750VA made by Plitron. The big one is a 2000VA custom ordered from Amveco. Below the transformer is a 12" ruler.
With the 2000VA installed in a 150W x2 power amp, the difference in sound quality was quite prominent. I could fell stronger low frequencies as if a subwoofer was added to the system.
My two cents.
Xtaltech
Attachments
Biggger transformer = lower series impedance in the PS.
This should be noticeable.
My experiences with capacitor values are, that you can hear a clear improvement when you double the value.
That is: Two similar amps, with one that has double capacitance in the PS is clearly noticeable as better sounding.
Why did the original designer not choose this value of capacaitor? Probably a choise of price-vs-performance - the sound improvement is after all not double as good, maybe 5-10%. And you gotta stop somewhere, and even 100.000uF sounds like overkill.
This should be noticeable.
My experiences with capacitor values are, that you can hear a clear improvement when you double the value.
That is: Two similar amps, with one that has double capacitance in the PS is clearly noticeable as better sounding.
Why did the original designer not choose this value of capacaitor? Probably a choise of price-vs-performance - the sound improvement is after all not double as good, maybe 5-10%. And you gotta stop somewhere, and even 100.000uF sounds like overkill.
...I should note that my experiments were with class AB amps, not pure Class A amps.
Anyway:
Here is some good reading:
http://www.fmacoustics.com/set_company.html
...scroll down to: "4. Power supply assembly"
Anyway:
Here is some good reading:
http://www.fmacoustics.com/set_company.html
...scroll down to: "4. Power supply assembly"
I believe it was Mission in the UK who first offered a beefed power supply upgrade option : the PSX for their Cyrus quasi-compl. amp, around 1985.
However, the PSX power supply add-on was not only meatier, but also raised the power output level, as in higher rail voltage.
Sven Berendsen from Germany was the first to offer a power amp in a regular and a Heavy-Duty version with equal power levels afaik, around 1987 : the ES120 Blue edition and ES120 Red edition.
Exact same amp, but with a power supply nearly twice as large, both a bigger toroid and nearly two times larger capacitor size.
Berendsen audio still does a larger lytic can size option nowadays with their STA150 and STA150 SE special edition models, see berendsen-audio.de
Both amplifier models operate in Class AB, which is (should be) considerably less critical than Class A with regard to power supply size.
The bigger the ocean, the less visible a ripple(wave) becomes, but also depends on whether you're floating in a dingy or a giant supertanker.
The loudspeaker behavior is the most dominant factor for how far power supply size should be stretched, imo.
However, the PSX power supply add-on was not only meatier, but also raised the power output level, as in higher rail voltage.
Sven Berendsen from Germany was the first to offer a power amp in a regular and a Heavy-Duty version with equal power levels afaik, around 1987 : the ES120 Blue edition and ES120 Red edition.
Exact same amp, but with a power supply nearly twice as large, both a bigger toroid and nearly two times larger capacitor size.
Berendsen audio still does a larger lytic can size option nowadays with their STA150 and STA150 SE special edition models, see berendsen-audio.de
Both amplifier models operate in Class AB, which is (should be) considerably less critical than Class A with regard to power supply size.
The bigger the ocean, the less visible a ripple(wave) becomes, but also depends on whether you're floating in a dingy or a giant supertanker.
The loudspeaker behavior is the most dominant factor for how far power supply size should be stretched, imo.
My nextdoor neighbor's daily drive is a 2008 M-Merc, '05 model.
In his spare time he's restauring an old VW Bug, sentimental lane stuff for him, the car is parked in the garage 24/7.
The second garage holds a Saab Aero V6 convertible, so the M always has to sleep outside.
Maybe someone with a youth crush on Bryston amps fancies building one himself.
This is DIY, anyone can do as he pleases.
Personally i see this hobby as building hotrods with big engines, big carbs and fat tires, not assembling Bugs.
In his spare time he's restauring an old VW Bug, sentimental lane stuff for him, the car is parked in the garage 24/7.
The second garage holds a Saab Aero V6 convertible, so the M always has to sleep outside.
Maybe someone with a youth crush on Bryston amps fancies building one himself.
This is DIY, anyone can do as he pleases.
Personally i see this hobby as building hotrods with big engines, big carbs and fat tires, not assembling Bugs.
Attachments
Hi Fellas
Thanks to all for your responses.
I agree that in the commercial world, everything has to be manufactured to a price VS performance schedule. It is a commercial reality.
However, when we start getting up to the esoteric / top shelf equipment, I would imagine that the price vs performance line is shifted.
When pepole spend many thousands of dollars (sometimes tens of thousands) for an amplifier, from a respected manufacturer, you would thing think that the product is the best that they can design and build.
Going back to my original example of the Aleph 1.2, this was a very costly amplifier, and I doubt very much that the manufacturer would have built the power supply section below requirements and expectations.
I believe at the top shelf level, amplifier power supplies, and for that matter the entire unit is built well above minimum accepted standards.
Maybe audible improvements are apparent if we double, quadruple etc, the level of capacitance, but how much of an improvement will there be. 1%, 5% ???
Regards
George.
Thanks to all for your responses.
I agree that in the commercial world, everything has to be manufactured to a price VS performance schedule. It is a commercial reality.
However, when we start getting up to the esoteric / top shelf equipment, I would imagine that the price vs performance line is shifted.
When pepole spend many thousands of dollars (sometimes tens of thousands) for an amplifier, from a respected manufacturer, you would thing think that the product is the best that they can design and build.
Going back to my original example of the Aleph 1.2, this was a very costly amplifier, and I doubt very much that the manufacturer would have built the power supply section below requirements and expectations.
I believe at the top shelf level, amplifier power supplies, and for that matter the entire unit is built well above minimum accepted standards.
Maybe audible improvements are apparent if we double, quadruple etc, the level of capacitance, but how much of an improvement will there be. 1%, 5% ???
Regards
George.
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