View Full Version : I've just bought a balanced transformer!
Hmm... is there no delete option?
Been on the sauce Mark? :)
Basically, yes :). Though I have bought a balanced transformer (from Airlink).
why did you delete the opening post.?
So we were going to hear about it and now we're not going to hear about it?
Tease.
i can think of better things to do when drunk lol
I read the original opening post last night: It seemed fine to me. Apart from transformer size, are all these balance mains devices much of a muchness? I'm guessing there isn't a whole host of balanced transformer makers.
Apparently it's better to have too high a rated transformer. The two UK hi-fi manufactures who do these do make very similar designs, both 1000VA which is considerably smaller than the one I have ordered. They are also considerably more expensive than the Airlink ones (who likely make the actual transformer in the 'hi-fi ' versions).
Have one m'self, the 2KVA one from Airlink.
Be interested to know your thoughts Mark, big improvement here, but my mains quality wasn't the best.
Put a long post on installing mine here on AOS way back when, and for those reading theres 'plug n play' options as well as more hardcore hard wired ones.
If you dont know your leccy then (Blue Peter style) get a grownup to help plumbing the hardwire option in :)
A mate had the Airlink box you just plug in, and that made a worthwhile improvement in his system.
Safety aspects of these have been discussed to death, short version if you have double pole RCBO protection on both primary and secondary windings you'll be fine. Not worth doing it otherwise.
The tripswitches in your consumer unit will probably trip first should anything happen anyway, but safety first.
Wouldn't reccommend a hardwired unit without double protection, even despite the CU tripping.
Dont dick around with electricity folks, not worth it for hifi.
Very worthwhile sound improvement, as used in many recording studios around the world. :thumbsup:
Just know what your doing with them.
@Mark
The higher rated ones are said to have lower impedance, the larger rated ones are big buggers though due to larger transformer.
So we were going to hear about it and now we're not going to hear about it?
Tease.
The first rule of balanced transformers is that you don't talk about balanced transformers.
The one I've ordered is 3000VA and comes fitted with input and output circuit breakers (RCD's on the output) and two 13A sockets. I only actually need two sockets thanks to the extensive use of Hydra style mains distribution. You do need to fit a mains cable to the input but, unless you lack confidence fitting a plug, it shouldn't need an electrician. The box it comes in is a big grey industrial thing but my hi-fi lives in its own room so that's not a problem (for me). Airlink also do ones with smoothing circuitry but I didn't go for that.
Yeah, the plug n play option is by far the easiest to impliment. :thumbsup:
Safety aspects of these have been discussed to death, short version if you have double pole RCBO protection on both primary and secondary windings you'll be fine. Not worth doing it otherwise.
Is this something you have to specify when ordering from Airlink or others, or is it something externally you fit to your mains? Probably a stupid question. If so, please forgive my ignorance. No way would I ever be doing a DIY version. I can fit mains plugs but that's about as much as I know how to do.
You don't have to specify it but it does depend on which model you order.
Arkless Electronics
17-09-2017, 13:05
"They've" got to him....:D
Arkless Electronics
17-09-2017, 14:32
Who ever you want them to be.... Foomintrolls probably...
Oh them - got ya. You would be even less impressed if you could see the two interconnects I've been trying recently with a combined price of over £3.5k.
Mikeandvan
20-09-2017, 23:25
I have a basic question, what does it do?
http://theartofsound.net/forum/archive/index.php/t-11411.html
I have a basic question, what does it do?
As above, or there is this from the manufacturers (Airlink) website https://airlinktransformers.com/category/standard-balanced-power-supply:
•Extensively used in small recording studios and High end audio installations
•Help reduce mains interference
•Range from 500va to 5000va
•True Balanced 230V Power
•Removes Power Line Noise
•Eliminates Ground Loops in House Wiring
•Reduces Radiated Fields from Power Cords
•Soft Start Protects Equipment From Turn-On Surges
•Reduces Interference Between Equipment
Mikeandvan
21-09-2017, 09:54
This seems to be what I need, I've been in my current flat for almost 3 years and have had 3 amps blow on me,2 JVCs, and a Roksan , my Naim stuff and CDPs have been fine though.
As always.it's best to try before you buy,a pal brought one around to one of my bake offs and we all agreed to the differences it made,found mine on the Wam classifieds for less than half price,wouldn't do without it now,but with one caveat,it does hum a bit,but only audible within a meter or so.
Will have to see how badly mine hums - though the 2000VA one I have on loan at the minute (thanks Paul - though I doubt he will read this) is very quiet.
Up until trying this solution I have been quite against any form of mains conditioning, smoothing or regeneration - not on principle, just because of the effect on the sound they have produced for me.
Same here,tried quite a few things on trial,they all went back,the BMS even made a difference just running my TT.I did read somewhere that leaving it powered up all the time reduces the problem,but mine is switched off when not in use.
It doesn't need to be left on all the time but there is a hum when you first turn it on, it subsides after a few seconds (a minute at most).
Ammonite Audio
21-09-2017, 11:24
I'm following this with interest. My phase of the local mains supply is shared by hundreds of other houses and some mains transformers in the system (eg the HCDR) buzz like buzzy things at certain times, so my concern would be physical noise from one of these balanced mains units. There is only one way to find out, of course, and these Airlink devices are notably well-priced, so not the greatest financial risk.
Hugo, the mains transformer in one of my power amps buzzes quite strongly at certain times of the day* but as soon as it is plugged into the Airlink it becomes almost completely silent. As you say, the Airlink designs are very competitively priced compared to those from 'hi-fi' manufacturers like Russ-Andrews etc.
* It's always done this - when in Manchester and the two houses in Sheffield it has lived in.
sq225917
21-09-2017, 16:48
Curiously, at Pauls, his TV made his airlink buzz. So they themselves aren't immune to hash and the chopped waveforms you find on the mains from poor/old smps.
Main quality is the one area of fooery that I subscribe to. Off course one draws the line at balanced installs and true regeneration.
If there is DC on the mains (>100mV) feeding the BMU, and if the transformer in the BMU has a rating of > 100VA, then it will most likely 'buzz'. Toroids are more susceptible to this than say, bi-limboid designs, or those using E-I laminations.
Received, wired up, and testing:
https://i.imgur.com/zW8rAwil.jpg
sq225917
27-09-2017, 22:40
I bet that's all air inside.
You need a gland on that cable.
Yeah, I’ve got one coming.
————
The top section of the box is relatively empty except for the 13A sockets (MK ones) and the circuit breakers. The rest of the box is pretty much taken up with the transformer.
https://i.imgur.com/hPSl4B2l.jpg
A friend brought round the 3K version,but it would trip the circuit breakers in the distribution board when powered up,fortunately the 2K works fine.
Hmm..odd, it's got an element of anti-surge and turning mine on and off a few times hasn't caused any issues. In a very quiet room there is a very low level mechanical hum from the transformer, it is very quiet though.
(sorry about the massive pictures, I've resized them now)
The [edit] 1000 VA BMU I use seemed to make a positive difference and it was missed when I took it out of circuit, so I ended up buying it. The mains here isn't bad, unlike the dire mains we had in Luton, but I still prefer the 'sound' through the workroom setups (headphones and various amps and speakers) with it in place. Not sure a 3000VA isn't overkill to be honest, but if noise isn't an issue from the transformer, then fine I reckon and none of my amps are power-houses to be fair (100WPC max) :)
BMU's seem to be dependant on where they're used I'm told. I think the 'principle' is sound, but not everybody is going to 'need' one I reckon.
The Black Adder
28-09-2017, 09:18
When you don't have any hifi on... does it still keep running or does it go in to sleep mode? If so, does it constantly use the same energy, 1K,2K,3K or whatever?
It doesn't have 'sleep mode' or anything like that (it doesn't need it) - it doesn't really use anything if nothing is being powered from it. Of course you can switch it off with the switches on the front, either switch off at the input or the output, or both.
I don't have 'problem mains' as such, though I'm not even sure what that means! I never get clicks or pops when appliances are being used or the heating comes on for example. The previous owner of the house had the whole place rewired and the main input fuse uprated - my hi-fi has its own dedicated ring.
The electrician at work has just supplied me with a 20mm cable gland and a couple of blancking washers - should have it all installed this evening :).
-------
Airlink, who supplied this unit, primarily sell them to recording studios. I notice the 'hi-fi' manufacturers who do them (like Russ Andrews*) leave out the circuit breakers (which are fitted for safety reasons). Presumably they feel removing these safety features improves sound quality - personally I feel uncomfortable with this approach and prefer the well engineered and safer route!
EDIT: * I've just read the Russ Andrews info for his and this isn't true:
Protection is afforded by twin, resettable thermal fuses on the transformers together with a 2 pole (live and neutral) circuit breaker for the output, specifically selected for its high sound quality.
As I understand it, it consumes nothing when 'idling.'
I leave mine off when not in use.
I've just read the Info for the Russ Andrews unit and he does use protection on his:
Protection is afforded by twin, resettable thermal fuses on the transformers together with a 2 pole (live and neutral) circuit breaker for the output, specifically selected for its high sound quality.
However, his unit is £3,600!
Hmm... interesting that looking at how the 13A sockets on the Russ Andrews unit are wired up they don't follow the 'star' method recommended by many (including Russ himself):
http://hifipig.com/wp-content/uploads/2016/11/Russ_andrews_balanced_mains_unit_BMU3000_1online.j pg
Firebottle
28-09-2017, 12:06
When no load is on these transformers they just consume the 'magnetising current'. This amounts to only a few watts consumption.
When no load is on these transformers they just consume the 'magnetising current'. This amounts to only a few watts consumption.
Agreed.
Hmm... interesting that looking at how the 13A sockets on the Russ Andrews unit are wired up they don't follow the 'star' method recommended by many (including Russ himself):
http://hifipig.com/wp-content/uploads/2016/11/Russ_andrews_balanced_mains_unit_BMU3000_1online.j pg
I don't think it will make a blind bit of difference whether the sockets are 'star' wired or 'daisy chained'. If you are concerned, then plug in the unit that draws the most current into the socket nearest the circuit breaker, and those items that draw the least current into sockets farthest from the breaker.
For my part I'm not really saying it does make a difference, I'm just surprised that the Russ Andrews unit doesn't follow the wiring method he recommends for his distribution blocks.
For my part I'm not really saying it does make a difference, I'm just surprised that the Russ Andrews unit doesn't follow the wiring method he recommends for his distribution blocks.
Yes, it does seem a bit odd.
I'm a little intrigued as to the use of two transformers. Do they have 115V secondaries and so are wired in series?
RothwellAudio
28-09-2017, 15:12
You need a gland on that cable.
Indeed.
Yes, it does seem a bit odd.
I'm a little intrigued as to the use of two transformers. Do they have 115V secondaries and so are wired in series?More likely in parallel to double the power handling. The 3kw unit is twice the width of the 1.5kw unit, which suggest the larger one may be just 2 of the smaller ones in parallel.
Sent from my SM-G930F using Tapatalk
Yes, they could well be the case. My own is just one big transformer but I believe the 5000VA unit is two transformers stacked.
For those so concerned, I have now fitted the cable strain relief!
going off topic,mark did you ever find a spare set of defraction rings for the yammys?
Sorry, got distracted, forgot - I’ll have a look (may need reminding). I’m sure I’ve seen something (I’ve got a LOT of ‘stuff’ - unfinished projects, part built projects, prototypes, models etc).
no worries i'll give you a shot in a few days,if you find anything else i may be interested in let me know :)
Hmm... plugged the BMU into the system last night and had a brief listen. To be honest, I was a bit underwhelmed and thought the sound may have been a touch more 'vivid' without it. Perhaps I was just feeling jaded and it was too late to do any A/B comparisons - will listen some more over the weekend (the noise floor did seem extremely low).
Hmm... plugged the BMU into the system last night and had a brief listen. To be honest, I was a bit underwhelmed and thought the sound may have been a touch more 'vivid' without it. Perhaps I was just feeling jaded and it was too late to do any A/B comparisons - will listen some more over the weekend (the noise floor did seem extremely low).
It seems to be taken for granted that these things make an improvement but when I tried one I was not keen on the change it made to the sound.
In what way exactly Martin?
Perceived dynamics were reduced, sound was a bit 'sat on', there was a weird echo/reverb effect in the bass. Not huge changes, very small in fact, but they were there.
I persisted with it, but when I took it out of the system the improvement was immediate and obvious.
Perceived dynamics were reduced, sound was a bit 'sat on', there was a weird echo/reverb effect in the bass. Not huge changes, very small in fact, but they were there.
I persisted with it, but when I took it out of the system the improvement was immediate and obvious.
What was the VA rating of the transformer?
Stratmangler
29-09-2017, 16:56
No idea, sorry.
Have you got a device name/model number?
I think it depends on the system you have, and to some extent on the quality of your mains supply.
I think it depends on the system you have, and to some extent on the quality of your mains supply.
That was the one I tried.
There was also the BMU Ali built that was slotted into a high end set up at NEBO. Everyone there, pretty much, declared that it improved the sound. The only change I heard was that weird echo thing on the bass. However after a couple of minutes of music I couldn't hear it anymore. So I am deffo in the minority with this. Cloth ears, I suppose.
Did you notice the 'bass echo effect' with both units?
That was the one I tried.
There was also the BMU Ali built that was slotted into a high end set up at NEBO. Everyone there, pretty much, declared that it improved the sound. The only change I heard was that weird echo thing on the bass. However after a couple of minutes of music I couldn't hear it anymore. So I am deffo in the minority with this. Cloth ears, I suppose.
For me, the BMU just helped make more difficult music more intelligible to me. None of my sources in the workroom are top rank in any shape or form, but I do listen basically near field and a heck of a lot on headphones too and applying the old Linn-remnant 'tune dem' parameters, I felt the BMU worked for me. I even used your Krell with it and it took the load with ease... (Krells of the era of yours and later need a clean mains and I remember the positive difference an RA mains strip made to expensive Krell-based setups in central London - anything to clean up the daytime 'noise' a bit).
Well I have now done some A/B comparisons, level matched, and the BMU is really surprisingly better. I have now concluded that my ‘less vivid’ comment relates to the structure of the soundstage which is less upfront but also more expansive and more tightly focussed (powerfully so on piano). What I find most surprising is that the noise floor does sound quite clearly to be lower - I say surprising because this is via vinyl. Admittedly I’m using a very low noise phonostage and my turntable has extremely low self generated noise - but even then I am surprised how much the noise floor can be lowered and increased detail, filigree and nuance can be revealed!
Bigman80
29-09-2017, 22:27
"Filigree" used twice in one day on this forum. Well done good sir!
Sent from my EVA-L09 using Tapatalk
Ali Tait
29-09-2017, 23:35
Well I have now done some A/B comparisons, level matched, and the BMU is really surprisingly better. I have now concluded that my ‘less vivid’ comment relates to the structure of the soundstage which is less upfront but also more expansive and more tightly focussed (powerfully so on piano). What I find most surprising is that the noise floor does sound quite clearly to be lower - I say surprising because this is via vinyl. Admittedly I’m using a very low noise phonostage and my turntable has extremely low self generated noise - but even then I am surprised how much the noise floor can be lowered and increased detail, filigree and nuance can be revealed!
You don't notice the noise until it's gone. :-)
It wasn't broken or malfunctioning at all, and hum was only audible from about 12 inches from the unit. It changed the sound I just did not like the change.
I know I am in a minority of one although IIRC someone else tried one and reported no change at all.
What was the VA rating of the transformer?
That would have been 1000VA.
As an update on transformer hum. When all my gear is turned on the BMU does produce an audible, but low level, hum (mechanical, not through the speakers) However, the rest of the transformers are really quiet - practically silent (even more so than with the 2000VA unit I tried).
sweet now your happy can you have a look for those defraction rings please,please pretty please??? :D
https://i.imgur.com/OwBhMkGl.jpg
Blends seamlessly into any rooms decor ;).
(Note, with cable gland)
Could run a power station with that cable
You should see the size of the cable that feeds the Belkin P30 mains conditioner. It must be at least 1/2" in diameter.
A lot of that cable in the picture is speaker hookup, you need a lot for my speakers.
A lot of that cable in the picture is speaker hookup, you need a lot for my speakers.
Van Damme 4mm2?
Yeah, some is, Tour Grade Black (to the woofers). The rest is Linn K400 which is also massive. Essentially there are three runs of speaker cable. The mains cables are all various varieties of Belden.
walpurgis
30-09-2017, 18:05
I've tweaked the photo, so things are easier to make out.
http://i68.tinypic.com/17679j.jpg
So still quite confusing then ;).
sweet now your happy can you have a look for those defraction rings please,please pretty please??? :D
Ok, have found something. Not quite all of it, but most of it.
marvelous!
so what have you found? i'll pm you my phone number to save cluttering up this thread.
sq225917
01-10-2017, 19:45
Lol, nothing like a bit of aerial to litter the floor after the mains treatment....
Most of it is speaker cable - not much one can do about it as it's from the speaker closest to the amps. If you just mean speaker cable in general as an aerial - well that's an endemic issue and not really relevant to the mains treatment.
rubber duck
02-10-2017, 14:16
Isn't it better to separate power cables from signal cables?
walpurgis
02-10-2017, 14:17
Isn't it better to separate power cables from signal cables?
Where possible. And to keep signal cables away from mains transformers.
The mains cables cross the signal cables at angles approximating ninety degrees and all the signal cables are speaker only, no low-level stuff. Not that any of this is relevant to the thread though....
I'll be interested in your thoughts once you have put some listening hours in Mark.
Ammonite Audio
03-10-2017, 16:48
I've bought the smaller 2kW BMU from Airlink, and it seems to be doing pretty much what Mark has reported. Imagine your system on a really 'good day' - that's what it does here. Initially it made the system sound 'sluggish' but after a few hours that seems to have given way to a lovely, organic and realistic sound. For £270 + VAT it's a bargain, being not only relatively cheap, but beautifully built and finished (the photos on Airlink's website don't do the finish justice).
Mine is very neatly built but pretty industrial [emoji4] - I knew what I was getting though.
I’ve had a bit more of a listen and the effect on some recordings is really profound. I’ve just listened to the recent rerelease of Dead Can Dance’s live album ‘Toward The Within’ and the sense of focus, tonal density and texture is quite stunning! an amazing sense of focus.
Ammonite Audio
04-10-2017, 21:01
That's pretty much what I'm experiencing. Extra bass depth is the most immediate impression, but as you say tones and textures are also so much better reproduced, along with acoustic cues from the recording venue. The BMU brings a beauty to the sound of my system that otherwise only exists at certain optimum times of the day or night. I'm struggling to find any negatives - that initial perception of 'sluggishness' is not borne out by extended listening.
That 3 o'clock in the morning sound every hour of the day. :thumbsup:
An essential part of my systems 'infrastructure' and the best thing I've done with it in years.
I wonder what/if there's any difference between the standard and conditioning units.Have to agree with previous post's ref SQ improvements.
Ammonite Audio
05-10-2017, 09:03
I wonder what/if there's any difference between the standard and conditioning units.Have to agree with previous post's ref SQ improvements.
I’ve always found that inline mains ‘filtering’ such as in the conditioning units always imposes a penalty in terms of dynamics and musical flow. So, I’d hazard that the difference between conditioning and standard Airlink BMUs is firstly unnecessarily increased cost, and secondly relatively anodyne (but maybe superficially ‘sweeter’) sound presentation. Just my experience and opinion, of course.
As above, I too have yet to hear any kind of mains filtering/ conditioning that doesn’t reduce the dynamic ‘swing’ of the music.
Inside picture of mine,can't tell if anything has been added.
Ammonite Audio
05-10-2017, 10:57
Inside picture of mine,can't tell if anything has been added.
You can see the inline filter built into the back of the IEC inlet. There's also a transient suppressor of some sort (the black disc thing).
farflungstar
05-10-2017, 11:02
I use one for the Vida and the Truth but wouldn't for power amps. My amps are wired direct to their own 30amp spur.
You can see the inline filter built into the back of the IEC inlet. There's also a transient suppressor of some sort (the black disc thing).
And the blue disc-shaped item near the IEC inlet filter might be a VDR.
The inside of mine:
https://i.imgur.com/hPSl4B2l.jpg
Wakefield Turntables
05-10-2017, 20:00
Mark, just had a flick through this thread with great interest. I own a P10 regenerator, granted, not the same thing but dosen't a decent power supply to your kit sound great!
Ammonite Audio
06-10-2017, 06:52
Mark, just had a flick through this thread with great interest. I own a P10 regenerator, granted, not the same thing but dosen't a decent power supply to your kit sound great!
Indeed - a decent supply is the foundation to any system sounding at its best. I used to have a PS Audio P5, and I have a distinct feeling that one of these BMUs brings far more to the party in terms of beautiful sound and musicality, at a tiny fraction of the cost (and box size, for that matter). Add to that, unlike a P5/P10 a BMU consumes hardly any extra electricity, and there is very little (eg pretty much nothing) to go wrong ;)
Yes, as Hugo says, there is nothing really to age or go wrong.
Andy, yes, it is most beneficial :). However, as you also point out, fundamentally different to the approach taken with your PS Audio unit.
-------------
In the picture above, of my unit, you can clearly see the large NTC (the black disc component on top of the transformer) used to limit inrush current when the unit is first turned on. last night I tried removing it from the circuit (very easy to do). Unfortunately I quickly found out that the inrush current of a 3000VA transformer is more than sufficient to trip the circuit breaker on my main fuse box! So, after a quick visit to the cellar to reset the fuse box I reinstalled the component and calm was restored - no harm done :).
You can see the inline filter built into the back of the IEC inlet. There's also a transient suppressor of some sort (the black disc thing).
So would these additions have any effect on sq ?
Ammonite Audio
07-10-2017, 11:50
So would these additions have any effect on sq ?
I think so, particularly the inline IEC filter. I wouldn’t advocate pulling your BPS apart yourself to replace the inline filter with a plain IEC connector though - if you feel like experimenting with removing the filter components, such work should only be done by a competent (in the electrical safety sense) person.
See Mark’s post above regarding the black disc component, which is needed to limit initial current rush when the unit is switched on.
I used to be an M & E service engineer working on control panels and equipment up to 415v,so swapping the IEC shouldn't pose a problem.
Get rid of the IEC filter, but don’t worry about the MOV disc, I would keep that there...
I wonder if the NTC wouldn’t be better replaced with a soft start module like Avondale Audio supply?
Blueflash
31-10-2017, 21:19
Yes, as Hugo says, there is nothing really to age or go wrong.
Andy, yes, it is most beneficial :). However, as you also point out, fundamentally different to the approach taken with your PS Audio unit.
-------------
In the picture above, of my unit, you can clearly see the large NTC (the black disc component on top of the transformer) used to limit inrush current when the unit is first turned on. last night I tried removing it from the circuit (very easy to do). Unfortunately I quickly found out that the inrush current of a 3000VA transformer is more than sufficient to trip the circuit breaker on my main fuse box! So, after a quick visit to the cellar to reset the fuse box I reinstalled the component and calm was restored - no harm done :).
I changed the circuit breaker in the fuse box to a "D" type which is used for starting electric motors, then you can remove the NTC.
I think, on balance, I would rather leave the NTC in place.
Radford Revival
02-11-2017, 09:10
I changed the circuit breaker in the fuse box to a "D" type which is used for starting electric motors, then you can remove the NTC.
:stalks:
Prooooobably not the best idea in a house!
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