Sonic Frontiers Power 1 Tube advise

Hi, Can someone advise replacement tubes for the original Svet 6550's. I'm thinking of using KT88, will this work? which brand ? How about for the 6 pcs 6922 in there, any advise as to what to replace these with?
Replace the 6922's first with 6DJ8"s and you will get fast bottom end with a more musical midrange. Everything seems to come to life. The VALVO's work great in POwer-1's and will make a bigger difference than changing the output tubes. If you do want to change the 6550's than the KT88 is the way to go.
In the Power 1, you can get more midrange bloom with Ei KT90 Type 3. Note we recommend them for the Power 1, but not the Power 2. We have also had a great experience with the Svetlana KT88 in that amp. Smooth and musical. DO NOT use the Tesla KT88. They have been very problematic. Then for even more confusion, there is a Chinese KT88 that looks just like the British classic Gold Lion. They were sold by Gold Dragon for a while, and have been unavailable, though we are supposed to get 100 or so soon. That tube is dependable, and sounds great with the little more extension at the tip top if that is what you want. Valvo never made a 6922. The ones you see being sold everywhere nowadays are older Tesla. We have some Valvo branded 6922 that are the real thing, made in Holland by Philips NV in 1964, but they are very rare.
Wally, I know you're familiar with SFI gear, cause I bought a pair of amps from you. As you might know I also have the whole 3 line of SFI (T3/P3/L3) -and soon in a month or so when I get them- Power 3. I have been using them for few month now and happy with them. But my amps are the 7Bs and speakers are the ML "ReQuest". As you can in another thread, this combination is not perfect particularly in the highs (too edgy specially at high volume). Now, I was thinking to upgrade the tubes in the Line 3 preamp. SFI tech recommends the Valvo ECC88 to replace the Sovtek 6922s. Others recommended the Amperex 7308. Or shall I wait for the amps to come? Also what upgrades would you guys recommend for the Power 3 if any. The same question I would ask the guys of Upscale audio whom I heard some good things about their knowledge on the web.
Hi Mohamed; I'd suggest waiting until you get the Power 3s before you start tube rolling in your pre-amp. I recently got a Power 2, and it is distinctly softer, a bit warmer, and more relaxed than my McCormack DNA-2DX. The Power 2 is supposed to sound much like the Power 3. The P-3 amps may be just what you need to take some of the "bite" out of your solid state amps with ML speakers. I'm enjoying the Power 2, but have no intentions to sell the McCormack-- but then I have warmer Vand. 3Asig. speakers. Cheers. Craig.
On the Power 3, you would be better off changing out one pair of tubes in the Line 3 than changing the tubes in the Power 3's. As I mentioned previously, the Valvo ECC88 and E88CC you see at most every site are actually early production Tesla...and were never made by Valvo. Valvo was a German arm of Philips Holland, the same way Philips Holland bought Amperex in 1955. At some point they had Tesla make these ECC88 tubes for them, but remember this was the cold war, so it was not so cool to have "made in Czechoslovakia" on your product, so it was hidden. An experienced tube head can ID them easy. Does not make it good or bad...and in fact in the Pro 3 I hear they sound quite good. I might suggest though leaving your power 3's and doing the preamp tubes. More predictable, and more effective. You can change just two tubes and get a 10-20% bump in performance.