What can switching supplies be used for?
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sismofyt
Well-known member
The _only_ reason to use switching suppiles in progear is economics :!:
They suck :twisted:
Samething with wall warts :roll:
volki, what piece of gear was that?
They suck :twisted:
Samething with wall warts :roll:
volki, what piece of gear was that?
NewYorkDave
Well-known member
Wall-warts are a pain in the ass, I agree, but sometimes there are good reasons to use them besides cost.
owel
Well-known member
[quote author="NewYorkDave"]Wall-warts are a pain in the ass, I agree, but sometimes there are good reasons to use them besides cost.[/quote]
Technical reason: Reduction of hum
Real reason: Liability costs. "Don't sue us. We just made the audio-enhancer-box. Sue the wall wart maker that caused the fire in your house."
Technical reason: Reduction of hum
Real reason: Liability costs. "Don't sue us. We just made the audio-enhancer-box. Sue the wall wart maker that caused the fire in your house."
sismofyt
Well-known member
Well, I'm all for outboard transformers and PSUs, but I wouldn't call what GML & Avalon uses a 'wallwart' :wink:
A wallwart is usually only used in cheapass gear. And the internal regulation etc is ****** too.
No, the real reason is that there is a difference between the approval rating of high and low voltage gear... I think :?
Also, it's chaper to ship the gear sans PSU around the world, so the local distributors/dealers find the wallwarts themselves.
A wallwart is usually only used in cheapass gear. And the internal regulation etc is ****** too.
No, the real reason is that there is a difference between the approval rating of high and low voltage gear... I think :?
Also, it's chaper to ship the gear sans PSU around the world, so the local distributors/dealers find the wallwarts themselves.
NewYorkDave
Well-known member
Regulated wall-warts do exist.
Instances where a wall-wart might make sense:
Equipment in small cases where the presence of a power transformer and mains wiring inside the case would cause intolerable noise levels.
Equipment that must be UL-approved if connected to the mains. Gaining UL approval costs thousands of dollars, but approved wall-warts are available off the shelf. Some facilities will not use mains-powered equipment that is not UL-approved.
In my facility, there's a number of items of expensive broadcast gear that use wall-warts or "line lumps", so it's not just for cheap, crappy gear.
Do I dislike wall-warts? In general, yes. But sometimes, I can understand very well why a manufacturer chose to use them.
Instances where a wall-wart might make sense:
Equipment in small cases where the presence of a power transformer and mains wiring inside the case would cause intolerable noise levels.
Equipment that must be UL-approved if connected to the mains. Gaining UL approval costs thousands of dollars, but approved wall-warts are available off the shelf. Some facilities will not use mains-powered equipment that is not UL-approved.
In my facility, there's a number of items of expensive broadcast gear that use wall-warts or "line lumps", so it's not just for cheap, crappy gear.
Do I dislike wall-warts? In general, yes. But sometimes, I can understand very well why a manufacturer chose to use them.
BradAvenson
Well-known member
[quote author="sismofyt"]The _only_ reason to use switching suppiles in progear is economics :!:
[/quote]
Actually not all switching supplies are cheaper. Often they are used for their power density. I know the new EQ from Great River uses a, to quote Dan, "Evil switcher."
[/quote]
Actually not all switching supplies are cheaper. Often they are used for their power density. I know the new EQ from Great River uses a, to quote Dan, "Evil switcher."
sismofyt
Well-known member
In general they're cheaper. I know they're power density is good, you can get a hefty current output from a small package. A similar linear PSU would be bigger and.. more expensive.
Maybe Dan would tells why he needed an evil switcher in his pre. Is it in the 4 channel one? I could imagine that would be pretty crammed.
Maybe Dan would tells why he needed an evil switcher in his pre. Is it in the 4 channel one? I could imagine that would be pretty crammed.
sismofyt
Well-known member
Sorry, you wrote EQ :roll:
Still, I'd like to know why he picked a switchmode PSU...
Still, I'd like to know why he picked a switchmode PSU...
sismofyt
Well-known member
What law?
Ecological? Yeah, let us all stop using analogue class A gear.. we can all do it in the box then.
I don't think it's 'overkill'.
Ecological? Yeah, let us all stop using analogue class A gear.. we can all do it in the box then.
I don't think it's 'overkill'.
dale116dot7
Well-known member
Heat generation is likely a good reason to use a switching supply as well. Probably the most significant cost item in a linear supply is going to be heatsink. A switcher needs little heatsink, linears do - that cost is substantial.
sismofyt
Well-known member
No, the big saving is the power trannie. If it's big and heavy it'll need a more substatial chassis too. A heatsink it's just a piece of aluminium. Sometimes the casing acts as the heatsink..
Back when I repaired laser power supplys for low power argon lasers there was a cool power supply design IMO.
What this supply did. It used a switching supply to reg the voltage to just a little more than was needed. Then a linear supply was used to reg the final output. I never did get to work on that model supply they did not break.
This gave low heat in the linear supply section and an overall smaller, lighter unit than a linear only supply it also had cleaner power.
What this supply did. It used a switching supply to reg the voltage to just a little more than was needed. Then a linear supply was used to reg the final output. I never did get to work on that model supply they did not break.
This gave low heat in the linear supply section and an overall smaller, lighter unit than a linear only supply it also had cleaner power.
sismofyt
Well-known member
This is common. I've seen switchmode PSUs followed by ordinary 78/7915s.
Pretty much none of the audio companies make their own switchmode supplies, they buy them from manufactures who specializes in those evil things.. I've seen pricequotes from Asian companies and they're _really_ cheap! Much cheaper than getting any kind of linear PSU in Europe. And they certainly do look good on paper (at least some of them). But I don't record specs..
Pretty much none of the audio companies make their own switchmode supplies, they buy them from manufactures who specializes in those evil things.. I've seen pricequotes from Asian companies and they're _really_ cheap! Much cheaper than getting any kind of linear PSU in Europe. And they certainly do look good on paper (at least some of them). But I don't record specs..
Actually cost was the biggest factor for wanting to use a switching supply. I've seen them for around $2.00. My other thought was putting a couple wallwarts inside the enclosure. Any facts on why that wouldn't work (how much current do some of the discrete designs draw?)?
sismofyt
Well-known member
Well, it would work. But would it be good? Putting a couple of wallwarts inside the enclouse would be a bit messy I think.
Wallwarts don't have high quality trannies inside btw.
You _could_ use a switchmode PSU, but it's really difficult to filter the garbage out. And expensive.
Wallwarts don't have high quality trannies inside btw.
You _could_ use a switchmode PSU, but it's really difficult to filter the garbage out. And expensive.
sismofyt
Well-known member
If it's only two dollars, why don't you try to buy one and see if it works? If it doesn't you can use the PSU for experimenting..
