Originally Posted by Gizmologist
When you hear the technically inexperienced folks (modders and their clients) make claims about a power supply "opening up the soundstage, bringing out the instruments true resonance" etc in the case of audio or "deepening the blacks or extending the whites"in video systems, it proves one thing. These guys may know the names of the parts but they have no clue as to how the circuitry actually works.
The power supply does 2 things only. It takes the 120volt AC power input from the grid and rectifies it either in a linear style design or in switching design and outputs whatever filtered DC rails are required by the circuits.
The voltage and current required are dictated by the circuit design and basic components used to achieve the operation and output levels required by the original design specifications.
I have yet to see any modder/upgrader provide actual calibrated measurement changes they claim result from their "work" in a chart side by side, item by item, with the specs from the unmodded original. These would include the original specs such as output power, impedance, THD, gain, signal to noise ratios, channel separation, freq deviation, freq response, noise floor, input sensitivity, black levels, overall current consumption, ripple, overvoltage protection, etc. All you see is anecdotal claims of wonderful performance-post mod.
If you alter any circuit from any standpoint, claiming improved performance using any parameter, those changes MUST show up in some sort of electrical format and therefore CAN BE MEASURED-pre and post modification. This is a basic fact of physics.
There are a few "modders" that even claim the improvements are outside the realm of measurability by any current test instrument yet the same system is connected to existing technology speakers or video displays.
Modifications such as adding transformer-isolated inputs and outputs or preamp outs in the case of audio modifications is done all the time, I have been doing that sort of thing for 40 years on pro and consumer products. That is not claiming to improve the performance, only the connection possibilities.
There claims are made for cables as well, yet not one single claim can be verified by lab testing. There have been numerous cases where uber expensive cables such as "Munster" were compared to off the shelf bulk cables or even coat hangers. No improvement was ever noted when the cable gauges were matched to the system requirements using standard resistance and impedance charts. There are lots of offers out there to anyone claiming they do but no takers yet. They just keep falling back on the "your ears simply cannot possibly hear what mine do" response. That is not exactly accurate or testable.
Ever hear the commercials about Carfax? The used car dealer just tries to assure the potential buyer that the car is primo and the buyer just says "show me the Carfax". Same thing here. Ask for the "upgrade" specs that you will get on your specific model after the work and what is the guarantee that those specs will in fact be true and testable.
Save your money. Buy a quality device with a good warranty, don't "upgrade" it and enjoy the music.