i created the "SE"upgrade for initially the North American distributor: Globe Audio Distributors, then it was installed at the factory after most existing pre "SE" capitole, prestige and prima dac were upgraded in the field ,most in Canada at Globe and also at the tech in Arizona. The caps in the kit were Sonicap platinums, a silver composite/teflon film and foil cap. Careful listening experiments revealed unanimous overall improvement over the rel cap tft. Lesson # 1, all caps that are film and foil teflon do not sound the same. V caps performance according to 1 high profile boutique tube manufacturer were similar quality improvement over hovland musicap but different than the sonicap platinums. Sonicraft does not have any more of this value of cap. I have a dozen pair or so in storage,as well as the damping/mounting pads. We tried many nos 6021w but went back to the phillips jan and cryoed them,most upgraded and earl factory "se"will have these tubes except some of the early units that were upgraded in the field. Never did as careful, controlled listening tests on different tubes, consistency and supply being in favor of the jan philipps . Cryo tubesĀ make a difference if you have a well sorted system with excellent cables(and yes good cryoed cables allow you to hear the difference more easily cryoed tubes make). It does the same thing ;sounds more resolved and refined, quieter, more relaxed,more involving 3d halograph sound. Cryoing tubes is not cheap so if was not worth the expenditure, we would not have done it. Everything in that "se"upgrade kit, made a difference. Also all caps were matched as well as tubes were tested/matched after cryo for symmetrical gain/noise /microphony. I produced the kits along with a well known high end audio tech/designer. Globe Audio distributed to their dealers and the initial factory production of "se". Did have some good results ourselves with sylvania gold 6021w and the few close friends with them. I think a Mark 1 Capitole has the same sylvania golds 15 years now, i'll check on that next time in Canada.