VK-31 or other BAT preamp upgrade

Mark,

Though I cannot answer your question specifically, I did own a VK-P5 and later a VK-P10SE w/ Super-Pak phono preamps. BAT's phono preamp was based on the 6922 tube. I also have a lot of experience with BAT preamps. I've owned the 31SE. 50SE and 51SE.
IMHO, you will notice a very impressive increase in performance, particularly in the music's weight, rhythm, and soundstage. That's the plus side. The negative is that these caps seem not to last as long as one would like, and they are expensive to replace. Figure $600 just to replace the six-packs. The Super-Paks are much larger caps, so I believe the price would be even more substantial to replace. The six-packs that failed in my 51SE were only 4 years old. BAT says that they should last 5-7 years.

So they definitely improve the sound, but they are high maintenance. Again, this was just my personal opinion. I hope this helps.

Regards,
John

Mark,

Though I cannot answer your question specifically, I did own a VK-P5 and later a VK-P10SE w/ Super-Pak phono preamps. BAT's phono preamp was based on the 6922 tube. I also have a lot of experience with BAT preamps. I've owned the 31SE. 50SE and 51SE.
IMHO, you will notice a very impressive increase in performance, particularly in the music's weight, rhythm, and soundstage. That's the plus side. The negative is that these caps seem not to last as long as one would like, and they are expensive to replace. Figure $600 just to replace the six-packs. The Super-Paks are much larger caps, so I believe the price would be even more substantial. The six-packs that failed in my 51SE were only 4 years old. BAT says that they should last 5-7 years.

So they definitely improve the sound, but they are high maintenance. Again, this was just my personal opinion. I hope this helps.

Regards,
John

Just a comment on the SIX-PAK "life time" issue. The oil capacitors used in the SIX-PAK's really have no wear out mechanism, and their life time is extremely long - probably in decades, certainly not 5 or 7 years. However, some samples may have less than perfect seal, and these with time will develop electrical leakage due to moisture penetration. The percentage of these defective units is small, and their replacement is often covered under warranty.

Even being small in frequency, that is still, of course, a concern, and an inconvenience, and we worked with the factory to address that issue. The factory has redesigned the seal, and since then we have not seen any such failures.

The leakage is only a concern in the output capacitors - the SIX-PAK's or single ones, but not in the SUPER-PAK's.

Balanced Audio

Thanks for the info.
How recent are the factory's capacitor imporvements? My vk-p5 with six pak is about 3 years old.