Balanced power for Hifi or not

[simon g]

Whatever the benefits of a BMU, I can't see how they'd provide any surge protection which was the OPs first question.

 

[KevinF]

Caution is healthy when we are dealing with mains electricity. As with much else, there are safe ways to do things and ways that are not safe.

A safe BMU, like the Russ Andrews one mentioned by George47 earlier in this thread, will among other features have a double-pole circuit breaker/switch. The review that George refers to not only mentions both the circuit breaker and a thermal cutout, but both elements are visible in the accompanying photographs.

Commercial balanced mains units are available from a number of UK vendors. They include (and this is neither an exhaustive or necessarily recommended list ):

https://www.airaudio.co.uk/brands/air-audio-services/ac-2k-balanced-mains-transformer/
https://airlinktransformers.com/category/balanced-power-supply
https://quiescent.co.uk/product/t500va-4-balanced-output/
http://www.britishaudio.co.uk/pureseries.htm
https://nvahifi.co.uk/collections/mains/products/nva-balanced-mains-unit-bmu-1kva

Wammers may find the fourth of the links above to be particularly informative, since it was written by Ben Duncan about the BMUs he designed for domestic hifi use (although they could just as effectively be deployed in studios).

Duncan, for those here that don't recognise the name, is a polymath with the design of hundreds of audio circuits to his credit, collaboration with multiple manufacturers and studios, and responsibility for the design and implementation of grounding schemes for the performance stages at Glastonbury and other venues.

And, speaking of studios, here is a link to a piece by Mike Valentine on his *journey* with balanced mains: http://www.michaelvalentinestudio.com/hi_fi/bmu_conditioners/index.php

Two personal observations from me now:

1. Having evaluated several BMUs and recently reviewed in print two of them, I can state with considerable confidence that, rated output for rated output, we do indeed get what we pay for; BMUs that are cheap compared to others with the same rating can disappoint. They trim cost by using poor quality core material, and as a result cannot achieve their rated output and more often than not suffer badly from mechanical hum.

2. Mains pollution of the kinds mitigated by a BMU is very setting dependent. Try before buying.

 

[Psilonaught]

I tried an airlink balanced unit for a few days. It was noisy and made no audible difference to my ears. I returned it

 

[RobsterD]

Was going down the Airlink balanced tranny route but some of this has piqued my interest an off the grid solution we’re looking at the bigger option for work - might nick it
https://bluettipower.co.uk/pages/bluetti-ac300-b300

 

[newlash09]

They are expensive 😜. In my opinion their solar powered one makes sense.

There are a lot of folks in my place using pure sine wave online Ups to power their audios. They claim very clean power, however the batteries if maintenance free, have to be replaced every 30 months. But I haven't tried one yet.

 

[Rayymondo]

I had a balanced supply (Airlink) for my kit - when I had Naim kit I wanted to stop the intrusive hum from its linear power supplies. It reduced it, but did not eliminate it. The solution for me was to switch to Chord Electronics and Linn, which use switched mode PSUs. There was no longer any benefit from using the balanced supply (at least none I could hear) so I no longer use it. Airlink is very good company and if you have problems with buzzing transformers then its products can help.

I don't have any experience or knowledge of balanced supplies but this piqued my interest. When I recently used a Perreaux amp there was a very audible hum from the transformer, this was greatly reduced when I added a Furutech Flux-50 NCF inline power filtering unit that "eliminates many common problems caused by contaminated electrical power lines." I have also used Linn amps with no hum and my current Crayon CIA-1T is silent in use - this also uses a switch mode power supply.

 

[Nopiano]

They are expensive 😜. In my opinion their solar powered one makes sense.

There are a lot of folks in my place using pure sine wave online Ups to power their audios. They claim very clean power, however the batteries if maintenance free, have to be replaced every 30 months. But I haven't tried one yet.

I somehow think that replacing what you already have might be the safest route. I can imagine that your mains quality may well be poorer than many of us enjoy in the UK, so a bit of help can only improve things. But balanced mains seems to be a solution to a problem very few actually have, and with a considerable cost to achieve it safely too.

 

[newlash09]

I somehow think that replacing what you already have might be the safest route. I can imagine that your mains quality may well be poorer than many of us enjoy in the UK, so a bit of help can only improve things. But balanced mains seems to be a solution to a problem very few actually have, and with a considerable cost to achieve it safely too.

Thanks sir 😀..

Iam still exploring available options as the newer regenerators are way beyond budget. Not to mention the shunyata stuff like everest etc.. Which will demand a kidney in exchange 🤣🤣.

But with my sparse understanding of electronics, I will definitely not attempt trying balanced BMU's at the moment.

 

[Nestor Turton]

@savvypaul contributes to this forum for NVA who make this - he may be able to add some useful info.

https://nvahifi.co.uk/products/nva-balanced-mains-unit-bmu-1kva

 

[Ergot]

I used a balanced power conditioner in my system, I didn’t die and nothing exploded. I was however living in a property that could have been the posterchild for noisy mains with every conceivable nightmare scenario (dimmers, halogen, multiple fridge, coffee machine, etc etc) and it did remove all mains noise as well as providing a single on/off switch for my entire setup. I kinda miss it to be honest.