Sonic Frontier Power 1 Tubes

Could anyone share their experiences with trying different tubes in the Power 1? Any preference on the 6922 and 6550C or KT-88. Music preference consists of Jazz, Blues and Rock. Any input would be great.
I have a Power 2 and prefer the KT-88 tubes.

My preference is based on the power needed to push my speakers. I use the Power 2 to push electrostatic panels in a hybrid speaker. Haven't tried 6922s, but 6550s sounded much "thinner" in my application.

The people at partsconexion, which include the original designer for Sonic Frontiers have packaged upgrades for the SF amps and they all utilize KT-88s.
Thanks for your input. Have you done any of the SF upgrades to your Power 2?
Hi, I used to have a Power 2. My favorite tubes in it for the 6922's were Amperex 6922PQ or Amperex USN 7308, both USA made. Have fun. Mike.
No the only change I've done is rolling the tubes to KT-88s. I live on the west coast and am not ready to ship my "baby" to Ontario and be without for so long.
I have a POWER 1 amp. I have tried the Svetlana KT-88's and pulled them out in favor of the stock Svetlana 6550C tubes. I then e-mailed PartsConnexion about this, and they informed me that I didn't really have Svetlana KT-88s. What I bought was basically Sovtek tubes, made in the Reflektor factory. Apparently, because of some legal issue, REAL Svetlana KT-88's are sold as "SED Winged-C KT-88" tubes. PartsConnexion recommended JJ Tesla KT-88's most highly for the POWER series amps. I have a set arriving tomorrow and will post again with my findings. I haven't tried replacing the 6922's yet, but I plan to try that soon. My inclination is to get Electro-Harmonix gold pins to replace the stock Sovteks. I've considered going the NOS route, but every time I think about it seriously I feel the neon "sucker" sign going on over my head.
I've put in JJ-Tesla KT-88's and I like them a lot. Today, I replaced the stock Sovtek 6922's with EH 6922 Gold Pins and so far I hate them. It sounds like I have blankets on my speakers. Do input tubes require some break in time?

Update... The EH 6922's are sounding better after about 10 hours of use. I'm starting to like them (or am I getting used to them?). The bass response from the get-go has been excellent, but the midband seemed collapsed initially. Today midrange seems much better. Later this week, I'll swap the old Sovtek's back in and we'll see what happens.

After much playing around, I am happy with the EH tubes. They've come around nicely. The main difference between these and the Sovtek's I replaced is bass response.

I've heard that tubes require some break-in time, but this is the first time I really noticed it.