HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Please don't post, use a carrier.

What you hear is what you hear Macca.

Sorry to butt in, but have you thought of trying an NVA amp or at least the speaker cables just to make sure?

It wont make any difference, the BMU should be working in his system, its not, ce la vie!

I have thought about different VA sizes and the difference they make in the music. I got some more 1000va last week and ordered a 500va and 2000va to do some tests. 500va definitely inferior, 2000va to my ears no different to the 1000va, so I think I have optimum in the 1000va. I just wish I could get people to actually understand that they don't add up the VA of all their hi-fi and then say I need that, it is classic forum misunderstanding of what VA is and how transformers work. You add up your system power supplies to 5000va and the 1000va would still be more than enough for the job.

Does the higher VA rated toroid offer lower impedance?

In theory yes but that is important in amplifier circuits, but seems less important in a BMU beyond a certain level. I have explained before that basically the same power amp circuit can run with 30va in an AP10 and over 600va in a pair of A80's, and the musical improvements are obvious. There is no obvious musical improvement between 1000 and 2000va in a BMU.

Any idea why this is? I'm assuming you did the comparison with your 'best' bits of kit?

Reality is reality, it is what it is. Differences using the BMU show with all the amps. Even a AP10 gains from it at about the same level as a pair of A80s. The reason I presume is because an amp has a power supply ac to dc so is not just a transformer. A BMU is just a transformer.

One BMU sent out this week has been damaged in transit. The back panel has a big semi circular crack in it. It is going to be subject to an insurance claim but it seems a waste to scrap it as as long as you don't look at the back panel it is fine.

This is the damage



£300 by paypal gift

Hi Doc
I am interested in buying this BMU. Is it on a 30 day return basis and any warranty.
Regards Badger.