Siemens E88CC X Mullard E88CC NOS Tubes

Please,can someone help me to choose between the Siemens and Mullard NOS Tubes,to replace the originals tubes of my Sonic Frontiers Line2?

If it were me/and I loved my pre/ and I could afford it / I would love to buy both sets/ and "play".
In my Line 2 I've replaced only back two tubes with two NOS Siemens CCa (7308). Very dinamic with larger soundstage, transparent & detailed with extended higs,
no grain at all.
I have a Sonic Frontiers SFP-1 and have tried both of these tubes in it. The Mullard's did not work for me at all. Keep in mind there are MANY different Mullard's. These were 1960s vintage and branded Mullard. There were two problems, one was they were soft sounding (very tuby). The other, and much larger problem, was that one of them buzzed severely. These tubes had been tested and were supposed to be top notch (ultra low noise). I sent them back, and tried the Siemens. The Siemens was great, big open soundstage, very transparent. I really loved the Siemens. These were 1970s vintage, gold pin. The Mullards went back, and were reported as good tubes. The seller still charged me nothing for the exchange--great great service in my opinion. I called Sonic Frontiers and asked them about the problem I had. They said in the SFP-1 even the signature they quit using Mullard's because of this noise (buzzing) problem. They recommended that I stay away from Mullard's, that they had nothing but problems with them. I know this is quite contrary to what I had previously heard about Mullard's, but I figure Sonic Frontiers has more experience with Mullard's in their gear than anyone else. Hope that helps.
try asking the guy at vintage tube services. i have some of his tubes on the way....he offers a money back guarntee. something i have not found from any of the other tube dealers. i found his site through another post on audiogon. the post stated that you really never see his tubes for resale here....interesting point.

i know it did not totally pertain to your question....but a new direction.
You also might try the Bugle Boy's, can find them in Ebay at times for between $30.00 and $60.00 (used)for 4. In my ARC they do sound the best, just a thought.........