Home |
Search |
Today's Posts |
#1
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Hi everyone, hoping some of the experts can provide some feedback here. I've
done the requisite Google-ing and have a clearer picture but I'm still not as certain as I'd like to be before making some purchases. I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. This gear will sit in my studio and not be moved around. Stepdown transformers are common here because UK construction sites by law must stepdown to 110V for safety reasons (good random trivia question to remember). I've found several reputable companies that manufacture their own stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets on the output side, which makes it all really easy. My question is, I can get them in the laminated or torroidal variety, and it isn't clear to me that one is necessarily better than the other (for this particular application...I understand that conceptually torroidal transformers are "better"). The hum of the transformer itself is one consideration. Another is electromagnetic interference and its effect on things like signals in unshielded audio cabling. Torroidal transformers are better in both of these regards, but what I'm not sure about is how much this really matters in this particular usage...is it something to be concerned about? Is it not really a concern unless I'm running cables underneath the transformer, etc? The second question is, does one or the other type of transformer have any particular benefit for providing continuous power? For example, many of the stepdown transformers here seem to be made for intermittent use, i.e. they are made for construction sites where a drill or a compressor kicks on and then back off, etc...but not for powering equipment close to the rated wattage of the transformer for long, extended periods of time. Will a laminated or torroidal transformer inherently perform better in that sort of "continuous" usage? Thanks in advance for the help. -Ben ** Posted from http://www.teranews.com ** |
#2
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Ben Hanson wrote:
Hi everyone, hoping some of the experts can provide some feedback here. I've done the requisite Google-ing and have a clearer picture but I'm still not as certain as I'd like to be before making some purchases. I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. This gear will sit in my studio and not be moved around. Stepdown transformers are common here because UK construction sites by law must stepdown to 110V for safety reasons (good random trivia question to remember). I've found several reputable companies that manufacture their own stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets on the output side, which makes it all really easy. My question is, I can get them in the laminated or torroidal variety, and it isn't clear to me that one is necessarily better than the other (for this particular application...I understand that conceptually torroidal transformers are "better"). The hum of the transformer itself is one consideration. Another is electromagnetic interference and its effect on things like signals in unshielded audio cabling. Torroidal transformers are better in both of these regards, but what I'm not sure about is how much this really matters in this particular usage...is it something to be concerned about? Is it not really a concern unless I'm running cables underneath the transformer, etc? The second question is, does one or the other type of transformer have any particular benefit for providing continuous power? For example, many of the stepdown transformers here seem to be made for intermittent use, i.e. they are made for construction sites where a drill or a compressor kicks on and then back off, etc...but not for powering equipment close to the rated wattage of the transformer for long, extended periods of time. Will a laminated or torroidal transformer inherently perform better in that sort of "continuous" usage? Thanks in advance for the help. Provided you keep them as far as you can from any unshielded cables, that aspect shouldn't matter. As for the other stuff - weight is where its at; the more iron the better. Toroidal has a better iron path, but it is easier to put a good winding on a standard bobbin in a set of E/I laminations. Finally, if you can get to try them on heavy loads, go for the one that stays coolest. Since you don't need the safety isolation for this job, you might want to see if you can find an autotransformer - a single winding with a voltage tap at 110V. That should be cheaper and lighter for the same performance. d |
#3
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Hi Don...unless you're a very early riser I'm assuming that you are also
here in the UK (or parts eastward)...are you familiar with these people at all? They seem to hand-assemble all their stuff and the ones in the silver varnish finish look nice (not that how they look really matters but the all-metal casing will be good at disippating heat). I've spoken with them twice and they sound very knowledgeable and have been helpful. They guarantee that even their "intermittent" transformers will power at max load for hours (they rate their "contunuous" usage transformers for things thata re literally 24x7, like powering a fridge-freezer), and are virtually silent unless you put your ear on them. http://www.newmarket-transformers.co...ansformers.asp -Ben "Don Pearce" wrote in message et... Ben Hanson wrote: Hi everyone, hoping some of the experts can provide some feedback here. I've done the requisite Google-ing and have a clearer picture but I'm still not as certain as I'd like to be before making some purchases. I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. This gear will sit in my studio and not be moved around. Stepdown transformers are common here because UK construction sites by law must stepdown to 110V for safety reasons (good random trivia question to remember). I've found several reputable companies that manufacture their own stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets on the output side, which makes it all really easy. My question is, I can get them in the laminated or torroidal variety, and it isn't clear to me that one is necessarily better than the other (for this particular application...I understand that conceptually torroidal transformers are "better"). The hum of the transformer itself is one consideration. Another is electromagnetic interference and its effect on things like signals in unshielded audio cabling. Torroidal transformers are better in both of these regards, but what I'm not sure about is how much this really matters in this particular usage...is it something to be concerned about? Is it not really a concern unless I'm running cables underneath the transformer, etc? The second question is, does one or the other type of transformer have any particular benefit for providing continuous power? For example, many of the stepdown transformers here seem to be made for intermittent use, i.e. they are made for construction sites where a drill or a compressor kicks on and then back off, etc...but not for powering equipment close to the rated wattage of the transformer for long, extended periods of time. Will a laminated or torroidal transformer inherently perform better in that sort of "continuous" usage? Thanks in advance for the help. Provided you keep them as far as you can from any unshielded cables, that aspect shouldn't matter. As for the other stuff - weight is where its at; the more iron the better. Toroidal has a better iron path, but it is easier to put a good winding on a standard bobbin in a set of E/I laminations. Finally, if you can get to try them on heavy loads, go for the one that stays coolest. Since you don't need the safety isolation for this job, you might want to see if you can find an autotransformer - a single winding with a voltage tap at 110V. That should be cheaper and lighter for the same performance. d ** Posted from http://www.teranews.com ** |
#4
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Ben Hanson wrote:
Hi Don...unless you're a very early riser I'm assuming that you are also here in the UK (or parts eastward)...are you familiar with these people at all? They seem to hand-assemble all their stuff and the ones in the silver varnish finish look nice (not that how they look really matters but the all-metal casing will be good at disippating heat). I've spoken with them twice and they sound very knowledgeable and have been helpful. They guarantee that even their "intermittent" transformers will power at max load for hours (they rate their "contunuous" usage transformers for things thata re literally 24x7, like powering a fridge-freezer), and are virtually silent unless you put your ear on them. Hi Ben, yes I've used them in the past and they make good stuff. If you work out the necessary rating by adding together the power stated on the labels on all your kit, you will find there is still plenty of margin to leave the transformer running cool. If they make what you need, I'd say go for it. d (London, so no, not an early riser) |
#5
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Ben Hanson wrote:
I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. I've found several reputable companies that manufacture their own stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets on the output side, which makes it all really easy. How much do UK IEC power cables cost over there? And how many (honestly) is "a ton?" Over here, a 2-3 KVA 2:1 transformer (a real isolation transformer, not an autotransformer) would cost about as much as about 100 IEC power cables, even at retail prices. What are you looking at that would save you money? ..I understand that conceptually torroidal transformers are "better"). The hum of the transformer itself is one consideration. Another is electromagnetic interference and its effect on things like signals in unshielded audio cabling. Torroidal transformers are better in both of these regards, but what I'm not sure about is how much this really matters in this particular usage... It depends on where you put it. If it's in the basement and the studio is upstairs, no problem. If it's under the console or in the base of a rack, you might be concerned about a strong magnetic field. Not that cables or devices a couple of feet away will be affected, but it's too easy to dangle a cable too close to a transformer. Even a wall wart has been known to cause hum problems when an audio cable gets too close to it. The second question is, does one or the other type of transformer have any particular benefit for providing continuous power? For example, many of the stepdown transformers here seem to be made for intermittent use, This is why you need to spend about a grand for one. If you get a $100 one (which will indeed be cheaper than a ton of power cords) you could be buying trouble. -- If you e-mail me and it bounces, use your secret decoder ring and reach me he double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers ) |
#6
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Ben Hanson wrote:
I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. [...] My question is, I can get them in the laminated or torroidal variety, and it isn't clear to me that one is necessarily better than the other (for this particular application.. [...] There is occasionally a problem with switch-on surges which is worse with toroidal types than EI types. This can manifest itself as an annoying intermittent fault, which occasionally results in a blown fuse or trip, for no obvious reason. At the instant of the mains cycle when the power is switched off, the core of a transformer will be magnetised to some degree or other. A toroidal transformer with no air gaps in its core is more likely to retain this level of magnetism than a set of EI cores would. When the mains is next switched back on, if the polarity happens to be in the same direction as the magnetism already in the core, the iron will be driven into magnetic saturation. The iron can take no further part in the operation of the transformer until it has be demagnetised by the opposite cycle and settled back to normal operation. This mans that the transformer is not behaving like an iron-cored transformer for half a cycle of the mains, it behaves like a coil of air-cored copper wire and draws a huge current. This effect will be worse in a torid because they often run closer to saturation. The larger the transformer, the lower the resistance of the primary winding - so the current will be higher and likelihood of blowing fuses will be greater. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#7
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Ben Hanson wrote:
My question is, I can get them in the laminated or torroidal variety, and it isn't clear to me that one is necessarily better than the other (for this particular application...I understand that conceptually torroidal transformers are "better"). The hum of the transformer itself is one consideration. Another is electromagnetic interference and its effect on things like signals in unshielded audio cabling. Torroidal transformers are better in both of these regards, but what I'm not sure about is how much this really matters in this particular usage...is it something to be concerned about? Is it not really a concern unless I'm running cables underneath the transformer, etc? A good EI-core transformer will beat a crappy toroid. A good toroid will beat a crappy EI-core transformer. What you want is a transformer that has good regulation, so the voltage on the secondary doesn't change a lot with load. And you want a transformer that is effectively a low-pass filter, so high frequency trash doesn't make it through it. It doesn't matter what technology is used to make the core, it matters more how big the core is, what it's made of, and how careful the design work is. The second question is, does one or the other type of transformer have any particular benefit for providing continuous power? For example, many of the stepdown transformers here seem to be made for intermittent use, i.e. they are made for construction sites where a drill or a compressor kicks on and then back off, etc...but not for powering equipment close to the rated wattage of the transformer for long, extended periods of time. We call these ratings "fraudulent" and the products "crap." Don't buy crap. Will a laminated or torroidal transformer inherently perform better in that sort of "continuous" usage? No, crappy transformers are crappy no matter what shape core they use. Do not buy crappy transformers. Don't buy ANY Chinese-made transformers.. they seem unable to get decent quality core steels there. Go to a real industrial electrical supply house and ask about Siemens dry transformers for permanent install use. In the US we also get Acme and Square-D brand in the same market but in the UK I suspect Siemens and Brown-Boveri will be more common. Don't buy crap. If possible, get a real transformer with a primary and secondary rather than an autotransformer. It will be twice as heavy and cost twice as much, since twice the actual power needs to be going through the core, but it will give you isolation and make your life better. All of the construction site crappo jobs are autotransformers, which is fine if you're running a big electric saw but not a very good idea for precision audio electronics. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#8
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Mike Rivers wrote:
Ben Hanson wrote: I have recently relocated to the UK from the States. To save from having to buy a ton of new IEC-to-UK power cables (for the gear that supports 230V) I want to pick up two or three stepdown transformers so that I can just continue to power my gear off of 110V. I've found several reputable companies that manufacture their own stepdown transformers, up to 2K - 3K kVA, which have one or two US outlets on the output side, which makes it all really easy. How much do UK IEC power cables cost over there? And how many (honestly) is "a ton?" Over here, a 2-3 KVA 2:1 transformer (a real isolation transformer, not an autotransformer) would cost about as much as about 100 IEC power cables, even at retail prices. What are you looking at that would save you money? Do people pay actual money for IEC cables? Ask your local computer guy... he will have bucketloads of them. Hell, I have bucketloads of them with BS1363 plugs and Europlugs that came with equipment, even, and I am in the US. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#9
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
"Scott Dorsey" wrote ...
Do people pay actual money for IEC cables? Ask your local computer guy... he will have bucketloads of them. Hell, I have bucketloads of them with BS1363 plugs and Europlugs that came with equipment, even, and I am in the US. I've paid for 15-foot IEC cables. (The ones I use on my powered PA speakers.) The longer lengths aren't commonly available just lying about. |
#10
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On Wed, 27 Aug 2008 08:15:48 -0700, "Richard Crowley"
wrote: Do people pay actual money for IEC cables? Ask your local computer guy... he will have bucketloads of them. Hell, I have bucketloads of them with BS1363 plugs and Europlugs that came with equipment, even, and I am in the US. I've paid for 15-foot IEC cables. (The ones I use on my powered PA speakers.) The longer lengths aren't commonly available just lying about. Have you always had this genius for unearthing a special case to contridict ANY statement? :-) |
#11
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Richard Crowley wrote:
I've paid for 15-foot IEC cables. (The ones I use on my powered PA speakers.) The longer lengths aren't commonly available just lying about. Same for short cables. I have a couple of 2' cables that I use on my workbench. I think I paid $3 for them at a hamfest where the same guy was selling standard length (6' or so) cables for what seems to be the standard hamfest price of a dollar. Even if you have to buy one at Radio Shack in an emergency, they're only $9. -- If you e-mail me and it bounces, use your secret decoder ring and reach me he double-m-eleven-double-zero at yahoo -- I'm really Mike Rivers ) |
#12
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On 27/08/08 13:26, in article ORatk.869$p72.769@trnddc05, "Mike Rivers"
wrote: (...) How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 And how many (honestly) is "a ton?" Good question. Don't know about the OP, but when I'll relocate, I'll need at least 30 of them. But I might just put BS1363 plugs an my multi-plugs... The BS1363 plugs are only £1.29 ($2.35) -- Joe Kotroczo |
#13
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo
wrote: How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 Also translates into about half that almost anywhere else. Or free for the asking if you're lucky. |
#14
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On 29/08/08 22:05, in article ,
"Laurence Payne" wrote: On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo wrote: How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 Also translates into about half that almost anywhere else. Or free for the asking if you're lucky. Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll point me to the place when I'm there? (Really soon now....) -- Joe Kotroczo |
#15
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Joe Kotroczo wrote:
On 29/08/08 22:05, in article , "Laurence Payne" wrote: On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo wrote: How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 Also translates into about half that almost anywhere else. Or free for the asking if you're lucky. Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll point me to the place when I'm there? (Really soon now....) If you don't mind secondhand cables (test them thoroughly before use), there is a system called 'Freecycle' in most of the larger towns in the UK, where you can use e-mail to offer and request surplus stuff so as to prevent it from going into landfill. Often the items are well past being useful, but occasionally they are brand-new-but-unwanted and are being thrown out from a factory or office. Local independent hardware or electrical shops are not common nowadays; but if you can find one, the prices will be very competitive. Large national DIY stores often have very low prices with low quality to match. RS Components (RadioSpares, not Radio Shack) supply a huge range of electronic and electrical stuff by post; their delivery is superb but their prices are high. If you are doing a lot of electrical fitting-out, you might find it worthwhile to open an account at a local electrical wholesalers or just find one which accepts cash over the counter. In smaller towns, personal recommendation is a good way of finding the best places to buy things, but it may take a while to become accepted as a straight dealer and gain the confidence of the community (it varies considerably from place to place, England is compact but each area has its own distinctive character). Double-check and then check again that each appliance really is set to work off 240v mains. Any mistake will be very expensive. There also used to be in issue with 60c/s mains transformers overheating on 50c/s supplies, but that was a long time ago and I don't suppose you will ever encounter a problem like that. Earths must be properly connected. The first time you receive a 240v shock, you will be forcibly reminded of the difference between UK and US supplies. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#16
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On 30/08/08 12:17, in article
nvalid, "Adrian Tuddenham" wrote: Joe Kotroczo wrote: On 29/08/08 22:05, in article , "Laurence Payne" wrote: On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo wrote: How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 Also translates into about half that almost anywhere else. Or free for the asking if you're lucky. Hey, I haven't moved to the UK yet. But 30 of them for free? Maybe you'll point me to the place when I'm there? (Really soon now....) If you don't mind secondhand cables (test them thoroughly before use), there is a system called 'Freecycle' in most of the larger towns in the UK, where you can use e-mail to offer and request surplus stuff so as to prevent it from going into landfill. Often the items are well past being useful, but occasionally they are brand-new-but-unwanted and are being thrown out from a factory or office. Local independent hardware or electrical shops are not common nowadays; but if you can find one, the prices will be very competitive. Large national DIY stores often have very low prices with low quality to match. RS Components (RadioSpares, not Radio Shack) supply a huge range of electronic and electrical stuff by post; their delivery is superb but their prices are high. If you are doing a lot of electrical fitting-out, you might find it worthwhile to open an account at a local electrical wholesalers or just find one which accepts cash over the counter. In smaller towns, personal recommendation is a good way of finding the best places to buy things, but it may take a while to become accepted as a straight dealer and gain the confidence of the community (it varies considerably from place to place, England is compact but each area has its own distinctive character). Good info. Thanks! Double-check and then check again that each appliance really is set to work off 240v mains. Any mistake will be very expensive. There also used to be in issue with 60c/s mains transformers overheating on 50c/s supplies, but that was a long time ago and I don't suppose you will ever encounter a problem like that. Earths must be properly connected. The first time you receive a 240v shock, you will be forcibly reminded of the difference between UK and US supplies. Err... I'm from an 230V Europlug country actually. And I've had the experience of a 230V shock... Unpleasant. -- Joe Kotroczo |
#17
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
Joe Kotroczo wrote:
On 30/08/08 12:17, in article nvalid, "Adrian Tuddenham" wrote: Double-check and then check again that each appliance really is set to work off 240v mains. Any mistake will be very expensive. There also used to be in issue with 60c/s mains transformers overheating on 50c/s supplies, but that was a long time ago and I don't suppose you will ever encounter a problem like that. Earths must be properly connected. The first time you receive a 240v shock, you will be forcibly reminded of the difference between UK and US supplies. Err... I'm from an 230V Europlug country actually. And I've had the experience of a 230V shock... Unpleasant. Sorry, I incorrectly assumed you were from the USA. Surprisingly a 500v shock (across one hand) doesn't feel significantly worse than a 240v shock at the instant it occurs, but the resulting damage is more extensive so it hurts a lot more soon afterwards and takes longer to grow out. The smell of burning flesh is never pleasant, but when you can see the smoke coming from your own fingertips, it is a lot worse. -- ~ Adrian Tuddenham ~ (Remove the ".invalid"s and add ".co.uk" to reply) www.poppyrecords.co.uk |
#18
Posted to rec.audio.pro
|
|||
|
|||
Advice on stepdown transformer types for audio applications
On Fri, 29 Aug 2008 21:05:40 +0100, Laurence Payne wrote:
On Fri, 29 Aug 2008 21:57:54 +0200, Joe Kotroczo wrote: How much do UK IEC power cables cost over there? £5.99 at Maplin. Translates into $10.92 Also translates into about half that almost anywhere else. Or free for the asking if you're lucky. http://www.scan.co.uk/Product.aspx?WebProductId=1838 (£1.65 inc VAT) Postage is a bit high, but if you're buying a couple dozen it's not a bad deal. -- Anahata -+- http://www.treewind.co.uk Home: 01638 720444 Mob: 07976 263827 |
Reply |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Virtual Audio Environment - any pro audio applications? | Pro Audio | |||
PCI Firewire card for audio applications | Pro Audio | |||
Linux audio applications ARE PROFESSIONAL! | Pro Audio | |||
fa stepdown transformer 220 to 110 $1 | Marketplace | |||
Help: How to wind a toroidal output transformer for push-pull applications? | Vacuum Tubes |