Linear Vs Switching Supplies In Audio Equipment

[Th3_uN1Qu3]

Re: Linear Vs Switching Supplies In Audio Equipment

I hope I have conveyed this concept in a coherent manner. Powering an analog amp it is not as important how close the PSU stays to the design input voltage, rather it is important that the PSU voltage never drop below the minimum threshold (58V in my example above) and that it change values with the least frequency possible...

That is true. But unless you sacrifice maximum power output for quality and use a limiter to never exceed +/-30v out, there is no way to be sure of that.

that is also assuming the unregulated PSU wasn't designed with grossly undersized capacitors which could cause significantly increasing voltage change rate.

And that is also true, unfortunately.

[999999999]

Re: Linear Vs Switching Supplies In Audio Equipment

That is true. But unless you sacrifice maximum power output for quality and use a limiter to never exceed +/-30v out, there is no way to be sure of that.

Well, a real world example would be that if I want a volume level from my speakers that requires 200W peak, I'd buy an amp capable of a fair amount more than that and I suspect most people also do this, except if low budget or size are the primary factors when buying or designing, but on the other hand trying to squeeze every last watt out of an amp tends to cost more in the long run from blowing out transistors or speakers.

My example was an extreme one though, you'd seldom find voltage sagging much within a 120Hz window of opportunity unless the problem (beyond trying to use an undersized transformer) is impedance between the output and the amp's onboard filter caps, or someone uses an overall bad design with overly small value filter caps on the amp board and then off-board main energy storage caps with a wimpy little high gauge wire relative to the current... which would cause a voltage drop whether it was SMPS OR unregulated/linear.

[Th3_uN1Qu3]

Re: Linear Vs Switching Supplies In Audio Equipment

Well, a real world example would be that if I want a volume level from my speakers that requires 200W peak, I'd buy an amp capable of a fair amount more than that and I suspect most people also do this, except if low budget or size are the primary factors when buying or designing, but on the other hand trying to squeeze every last watt out of an amp tends to cost more in the long run from blowing out transistors or speakers.

For home audio, that is largely true. In the "pro" world things change quite a bit. Most sound guys go with less watts than needed for that particular gig. So, it's then up to squeezing the last watt out of the amps and speakers they did carry.

That's why the need for all those limiters and highpass filters... and the limiters are useless anyway because that awesome DJ they hired will clip the mixer, because, y'know, that fancy LED meter is there to be lit from end to end. Good thing the highpass filters save the bass bins from all that subsonic material generated by clipping. The tweeters don't always survive the HF overload however.

[999999999]

Re: Linear Vs Switching Supplies In Audio Equipment

^ You're talking about an issue when they buy incompetently designed products, anything decent will have the gain # set within the capabilities of the amp at full volume and still have sufficient voltage margin for 1/120th of a second (120Hz doubled main frequency, though it's only 50Hz/100Hz in many areas).

Sure you could put the signal through enough preamps or mixers to have a signal at dangerously high levels before the amp gets its turn to amplify it even higher, but in context, with or without the voltage margin, with or without it being unregulated/linear vs SMPS powered, that would still have the potential to fry the amp in an apples:apples comparison if neither of them have output protection circuits. One running from a SMPS does have an advantage here that there could be a 2nd shutdown circuit in the PSU itself, but by the same token if the decide to design it with one, they can design the linear with a low voltage shutdown too.

[japlytic]

Re: Linear Vs Switching Supplies In Audio Equipment

There are some pitfalls in using switching power supplies in audio equipment, but provided you follow good design principles, there should be no problems.

[PCBONEZ]

Re: Linear Vs Switching Supplies In Audio Equipment

Howdy Nine Nines, long time no see!

[999999999]

Re: Linear Vs Switching Supplies In Audio Equipment

Howdy Nine Nines, long time no see!

I try to stay off the internets, but sometimes they trick me with iPhones and cookies as lures.