[Swelfelo]

As I write this post, I have about three hours of burn in/listening time on my VK-53SE and I am very impressed so far. I am putting the VK-42SE up for sale!

Geoff Poor of BAT had written me that:

"Please take note of the fact your unit will now need significant break-in because of the massive new power supply components. Additionally, the custom transformers (which have replaced the output signal capacitors) will need some burn-in as well. I’ve always enjoyed the process, however, because you can really hear the results."

"The burn-in time requirement varies as to how broken-in your 52SE already was. The typical time required to break in a new BAT 5 series pre-amp approaches 500 hours! I’d guess you’ll notice a smoothing in the upper mids after the first week, while the bass region will extend and get more 'interesting' - revealing more of the texture of different bass instruments. The top octaves will appear to be 'sweeter', with more 'air' on the top. Cymbals will seem more real after a couple of weeks."


I had at least 500 hours of use on my VK-52E so I can say that she was fully broken in. Some differences are immediately apparent with the VK-53SE as against her predecessor--the VK-53SE is simply more dynamic, nimble and the instrumentation seems richer and there is greater low level detail. I can hear that the extension of treble and bass is slightly constrained as I remember them from before, but the core midrange is there. This preamp is a powerful, muscular beast and it is impressive to think that she will only get better over time.

When I sent in the VK-52SE, due to noise three of the tubes were replaced with current production Sovteks from 2014. I had not heard any clicking or other noises before sending in my preamp--so maybe shipping took its toll. Part of me cringed initially when I heard this because I stockpiled a very large supply of rare and expensive 6H30DR pre-1986 tubes with the preconception that they would sound better than the newer, supposedly inferior production--after all the internet said so. Vladimir, BAT's Production Manager, stated that in his opinion, that the sound quality between the new and old tubes was equal, but that the discard rate was substantially higher for the new production. Of course the DR rated tubes have substantially longer life expectancy than the newer ones. If I remember correctly, he said they discard 2/3 of the new tubes to find ones that are acceptable. The discard rate for the older stock is closer to 50%. Ouch--half, if not more, of my very expensive tube inventory might be worthless. Tube rolling is not practical in my configuration so if it ain't broke....

I will revisit this thread after another 60 hours of time with the VK-53SE and report any additional changes I can hear. However, I can already say that there is a marked improvement between the last generation and this preamp. The upgrade was worth every penny and I am happy that I took the plunge.