Balanced mains transformers, surge protections? [Archive]

HighFidelityGuy

15-05-2011, 14:54

I'm toying with the idea of trying a balanced mains transformer as it seems like it might be a better approach than using tons of mains filtration gubbins. However, what I'd like to know is whether a balanced mains transformer like THIS (http://www.airlinktransformers.com/transformer/bps5120-balanced-power-supply.asp) for example offers any kind of protection against power surges that might damage my equipment?

I currently use some Belkin PF30 units which as far as I know provide filtration and surge protection, so I'm worried that I might loose the protection these offer.

Cheers. :)

John

15-05-2011, 15:00

Hopefuly Marc or Ali be along to answer
Just to say in my view this would be a lot better alternative to what you have at present

Reid Malenfant

15-05-2011, 15:06

I'm using two Belkin PF40s that are being fed balanced mains from my P600 Power Plant. Ok so both the earth & wiring symbols on the display show it's wrong, it still works :eyebrows:

Ali Tait

15-05-2011, 15:14

Looked at one of those myself Dave. It won't give you surge protection, but to be fair, how many folk do you know have had equipment damaged by a mains surge?

You could always just plug the Belkin into the balanced trannie when you get it. It's something I will get round to trying too at some point.

colinB

15-05-2011, 15:30

Those Airlink prices have gone up significantly in the past year.

MCRU

15-05-2011, 15:37

Wall socket to mains purifier/filter/conditioner use a dc blocker incorporated into a mains lead like the isotek syncro (as an example only), I have tried mountains of filters/regenearators/conditioners and the best solution was the dc blocker and an isotek aquarius (for me anyway), the PF30 I had was good but the aquarius tipped it when I wired schuko plugs to all my power cords and used an aquarius with schuko sockets, getting rid of all the fuses in the power cords works wonders.

Welder

15-05-2011, 15:41

Cheap (comparatively)
Balanced (either is or isn’t)
Ugly (non audiophile)
Hums (just audible in the same room at around 45 db ambient noise)

If you can’t go the dedicated mains route with a non grid earth then imo this is one of the few “upgrades” that actually work and is probably worth the money.
What you need to take particular care over is to get a unit that gives ample VA headroom.

Something like this perhaps.
http://www.airlinktransformers.com/transformer/bps5120-balanced-power-supply.asp

I tried the 1.5 kVA model and on non dedicated mains it did make a noticeable difference but I had concerns about the fuse arrangement. On the dedicated mains I came to the conclusion that it didn’t have quite enough headroom.

My view is it’s better to not have the noise there in the first place rather than try to condition it out with various filters.

The best option is probably full mains regeneration but that’s serious money and possibly not any better than a properly done dedicated mains.

Ahh, sry, i see you're there already. I didn't click the link ;)
Like others have said, i wouldn't be too concerned about equipment destroying surges as your amp etc should be fuse to take care of that.

HighFidelityGuy

15-05-2011, 17:06

Thanks for the replies. :)

I was thinking about powering the balanced transformer through a big DC blocker to protect the transformer from DC but I'm still not sure what to do about surge protection. I know surge damage is rare but if I could add the protection without it affecting the sound then I guess I may as well to cover all the bases. Does anyone have any experience with THESE (http://www.ebuyer.com/product/45277) Belkin surge protectors on Hi-Fi equipment? I'm a little worried that they will rob dynamics.

Reid Malenfant

15-05-2011, 17:11

Save yourself some dosh & connect the PF30s after the balanced transformer & you'll have all the surge protection you need as well as a nice load of sockets ;)

worrasf

15-05-2011, 17:43

I tried the 1.5 kVA model and on non dedicated mains it did make a noticeable difference but I had concerns about the fuse arrangement. On the dedicated mains I came to the conclusion that it didn’t have quite enough headroom.

I have a dedicated mains supply to the audio gear - just a single twin and earth cable from consumer unit with a dedicated RCD going to a twin Russ Andrews non-switch wall socket. I then have a Merlin 4-way distribution box (tarantula & scorpion I think). The cable runs from the consumer unit along one of the joists in the loft before going down to the sockets. Do you think that one of these balanced mains supply units would be suitable to be connected to the cable run in the loft or does it need to be "in view" so to speak for safety reasons etc?

Steve

Reid Malenfant

15-05-2011, 17:57

Do you think that one of these balanced mains supply units would be suitable to be connected to the cable run in the loft or does it need to be "in view" so to speak for safety reasons etc?

Steve
If it doesn't happen to have one already there is nothing stopping you attaching a thermal switch to the transformer windings via some heatsink compound. If it gets too warm it'll be disconnected. Something tells me it'll have some form of protection built in anyway, but there is nothing to stop you being more careful now is there ;)

worrasf

15-05-2011, 18:10

Thanks Mark
Steve

Ali Tait

15-05-2011, 18:28

Save yourself some dosh & connect the PF30s after the balanced transformer & you'll have all the surge protection you need as well as a nice load of sockets ;)

That's what I already said. ;)

Ali Tait

15-05-2011, 18:31

If it doesn't happen to have one already there is nothing stopping you attaching a thermal switch to the transformer windings via some heatsink compound. If it gets too warm it'll be disconnected. Something tells me it'll have some form of protection built in anyway, but there is nothing to stop you being more careful now is there ;)

If you look at the link, it says the trannie has built in thermal overload. ;)

Reid Malenfant

15-05-2011, 18:31

That's what I already said. ;)
So did i in post #3, you were in post #4. I often wonder how many times things need repeating before they sink in :eyebrows:

Welder

15-05-2011, 18:34

I think the 5kVA unit has fuses on both legs.
As for overall safety, well I’m fairly safety conscious so I don’t leave live electrical equipment unattended.
The 1.5 kVA unit I had did get warm, but not overly so. Given the way they are built my personal view is I would want the unit somewhere I could check on it every now and then. I set the unit up behind my sofa in the end which has a sound absorbing foam at the back of the base and a deflector panel at the front (box style sofa construction, read cheap)
I did think about this when considering buying the 5 kVA unit and should I have gone ahead, the plan was to remount the transformer on better bushes in the hope that the hum became less audible.
Bear in mind, just audible above 45 db ambient isn’t what most would call intrusive unless you live in a very quiet environment (think spinning hard drive level of noise) With music playing I doubt it would be noticeable.

Ali Tait

15-05-2011, 18:40

So did i in post #3, you were in post #4. I often wonder how many times things need repeating before they sink in :eyebrows:

No, you stated in post 3 what you already have, I then suggested that Steve could plug his Belkin into the Airlink trannie, which you repeated in a later post.
I too often wonder how many times things need repeating before they sink in. ;)

jantheman

15-05-2011, 18:58

A minor warning........I got one and the v/out was +4.7% of v/in. Not much but when your mains is towards the top of the specified tolerance level, this could push it over. Not saying they are all like that, just that mine is.
Dont use mine, I prefer a plugin like this http://cgi.ebay.co.uk/No-Noise-Ultra-SE-Mains-Filter-Fidelity-Audio-/270652542915?pt=UK_AudioElectronicsVideo_Video_Tel evisionSetTopBoxes&hash=item3f04260fc3

Reid Malenfant

15-05-2011, 18:59

Lets not clutch at straws here Ali :D Yep you are dead right, i stated in post 3 that i was already running a pair of Belkins connected to the balanced output of a P600 ;)

Now apart from the fact that fact that the P600 is a regenerator it's output is still balanced & the Belkins work fine, even if they show things are connected incorrectly (which they aren't - it's just that they get confused with balanced mains) :)

By the way, i'm glad i'm not the only one that wonders :lolsign:

Reid Malenfant

15-05-2011, 19:04

A minor warning........I got one and the v/out was +4.7% of v/in. Not much but when your mains is towards the top of the specified tolerance level, this could push it over. Not saying they are all like that, just that mine is.
What was the rating? 4.7% sounds like it was about 500VA maximum. There is such a thing as transformer regulation & the bigger you go the less this becomes. A typical 3KVA transformer will have a regulation of about 3%, 5KVA maybe 2.5% or less ;)

HighFidelityGuy

15-05-2011, 19:05

No, you stated in post 3 what you already have, I then suggested that Steve could plug his Belkin into the Airlink trannie, which you repeated in a later post.
I too often wonder how many times things need repeating before they sink in. ;)

I know it's already been stated and I had already thought of that option before starting the thread but I've seen it mentioned here and elsewhere that if you're using balanced mains then there's no need for additional filtration. So I was kind of hoping I wouldn't need the PF30's any more and could therefore sell them. I have 4 of them so I could get more than enough money back to buy something else. However, looking at the Belkin Surgemaster jobbie in more detail I notice that it does some EMI/RFI noise filtration anyway, so in the end I'd be swapping one filter for another which is a bit pointless.

My other issue with the PF30's is that I hate the sockets on them, they're shite. So I'd much rather use a quality mains block like those that Mark grant sells but then I'd be back to square one without the surge protection. :scratch:

The other option I've thought of is to try the PF30's as suggested and if they don't seem to have a negative effect I could replace the sockets on them with better ones.

So it's not that I'm not listening, I am and I appreciate the advice, I just decided not to go into great detail about why I'd asked about the Surgemaster. Although I had mentioned in my opening post that I wanted to replace the PF30's with balanced mains. ;)

Reid Malenfant

15-05-2011, 19:07

Balanced mains takes care of any common mode interference or distortion, it doesn't take care of differential mode interference or distortion. The Belkins will help with that :)

Welder

15-05-2011, 19:11

I dispensed with all filters when I moved to dedicated mains.
I tend to agree with you, the Belkin strip units I’ve seen were crap both in construction and performance.
I have a distribution block which I built and that may be the way for you as well.

Ali Tait

15-05-2011, 19:18

I know it's already been stated and I had already thought of that option before starting the thread but I've seen it mentioned here and elsewhere that if you're using balanced mains then there's no need for additional filtration. So I was kind of hoping I wouldn't need the PF30's any more and could therefore sell them. I have 4 of them so I could get more than enough money back to buy something else. However, looking at the Belkin Surgemaster jobbie in more detail I notice that it does some EMI/RFI noise filtration anyway, so in the end I'd be swapping one filter for another which is a bit pointless.

My other issue with the PF30's is that I hate the sockets on them, they're shite. So I'd much rather use a quality mains block like those that Mark grant sells but then I'd be back to square one without the surge protection. :scratch:

The other option I've thought of is to try the PF30's as suggested and if they don't seem to have a negative effect I could replace the sockets on them with better ones.

So it's not that I'm not listening, I am and I appreciate the advice, I just decided not to go into great detail about why I'd asked about the Surgemaster. Although I had mentioned in my opening post that I wanted to replace the PF30's with balanced mains. ;)

You could rewire the Belkins with a good quality socket on end of a short lead, one for each socket on the back.

Reid Malenfant

15-05-2011, 19:20

I dispensed with all filters when I moved to dedicated mains.
I guess you could do, but i decided i wanted to give some isolation between SMPS & linear PSUs so that they didn't interfere with each other. With the seperately filtered outlets of the Belkins this can easily be realised ;)

HighFidelityGuy

15-05-2011, 19:21

:lolsign:

I can see that this is a subjective area where there are people on both sides of the fence when it comes to filtration. That's fine and I know that mains filtering can be quite system dependant. So, I guess the way forward is for me to try both ways. I have a Tacima filtered block to try as well, so I'll try both filters and no filter and stick with the one that sounds best. If that happens to be without a filter and I don't have surge protection then I'll get one of the little Belkin surge protectors and maybe an APC one that I've seen and try them. If they knacker the sound I'll decide what to do from there. At least then I'll have covered all the bases. :)

HighFidelityGuy

15-05-2011, 19:26

You could rewire the Belkins with a good quality socket on end of a short lead, one for each socket on the back.

That's the sort of thing I was thinking. :)

I guess you could do, but i decided i wanted to give some isolation between SMPS & linear PSUs so that they didn't interfere with each other. With the seperately filtered outlets of the Belkins this can easily be realised ;)

Balls! I'd forgotten about that and that was one of the main reasons I got so many PF30's. :doh: So I might be sticking with them, or at least some of them after all. :lol:

Ali Tait

15-05-2011, 19:26

Welder

15-05-2011, 19:30

Well Dave, whichever way you go I would be very interested in hearing how you get on with the 5 kVA unit if you get it :)

With regard to SM PSU the answer of course is not to have any on the dedicated spur ;)

Reid Malenfant

15-05-2011, 19:38

How much of an improvement did you find the regenerator?
Humungous Ali, i would never want to be without one (even if the twat uses loads of juice & acts like a space heater :eyebrows:). For the first time ever, even with a dedicated mains spur i have zero pops, clicks or any other form of annoyance from my system.

It appears that the front end is the important bit for this as the power amps are not connected to the P600 ;)

Ali Tait

15-05-2011, 19:51

I'd like to give one a go, it's the prices that put me off!

Ali Tait

15-05-2011, 19:52

Reid Malenfant

15-05-2011, 19:58

I'd like to give one a go, it's the prices that put me off!
Ali, if you ever bought one i have a very strong feeling you'd never want to be without one ;) I don't know about the Premier as it's different & much more efficient so must work on a different principle, but the earlier Powerplants are a revelation when powering front end kit.

It gives that dead of night sound all the time. When everyone has fecked off to bed & the mains is cleaner....

To me that's worth a lot!

Ali Tait

15-05-2011, 20:09

Aye, I'll get round to one sometime. So it's no good with amps then?

John

15-05-2011, 20:12

I used to have the P500 was really nice but now very happy using just decent balanced mains unit which I perfer. Sometimes after long stints it makes a noise from the transformer thats in the background that would be my only real issue with mine. But you cannot hear this most of the time and never when the music is playing.
I also have dedicated spur with all new boards and its still makes a difference but I do have factories quite near me
I have no idea of this is right or wrong but I think the quality of the transformer can make a difference

Reid Malenfant

15-05-2011, 20:18

Aye, I'll get round to one sometime. So it's no good with amps then?
Not with mine, the small one can draw over 1200W when pushed :eyebrows:

jantheman

15-05-2011, 21:34

What was the rating? 4.7% sounds like it was about 500VA maximum. There is such a thing as transformer regulation & the bigger you go the less this becomes. A typical 3KVA transformer will have a regulation of about 3%, 5KVA maybe 2.5% or less ;)

1500VA

Reid Malenfant

16-05-2011, 09:30

1500VA
Hmmm, something like this then (http://www.airlinktransformers.com/transformer/bps1520-balanced-power-supply.asp) :scratch: I just looked at Airlinks 1500VA toroidals & they are about 4% regulation, perhaps due to winding resistances because of the higher than average output voltage it makes it a tad worse ;)

jantheman

16-05-2011, 10:19

They have changed the cases but the one I have is a BPS1500...maybe about 2 yrs old now.

worrasf

16-05-2011, 10:45

Just placed an order for one of these:
http://www.airlinktransformers.com/transformer/bp3120-bp3120-balanced-power-supply.asp

I hear the sense of having as big a power supply as possible but decided to go for the 3.12kVA as opposed to the 5kVA on cost grounds. That VAT hike is a killer:(

Anyway, as I am going to install it in the loft in the direct path of the dedicated mains cable a screw terminal device is to be preferred to the socket outlets.

I'll report back my experiences in due course.

Steve