Upscale marks the measurements on the tube boxes they sell you. Just make sure they are somewhere in the same ballpark. Over time your tubes will no longer match as they begin to drift anyway...hence auto-bias kicks in on your amp. I wouldn't obsess unless the measurements were wildly different which I wouldn't expect from the same brand of new release tubes.
Primaluna evo 400 - unmatched tubes
Hi
quick history....i recently borrowed a primaluna evo 100 from the local store and loved it so bought the evo 300 and immediately bought 4 matched KT150's for it, but then 2 weeks later wish i bought the evo 400 ! so my local store let me return the 300 (small restocking fee) and now i have the 400. Sounds like a lot of $$ but I'm thinking this is a lifetime purchase so have justified it that way ;-)
Because I had 4 KT150s that i bought for the evo 300 i decided to buy another 4 so i could fill the 8 tube requirement of the evo 400. I'm driving magnepan .7's so more power the better. By the way the primaluna sounds great with these speakers....I've found a low end i'd never heard even when driving with 150wpc solid state and the sound is very natural, pleasant, and unfatiguing to my ears. The KT150's in my system sound much better than the EL-34's. They sound fuller and more spacious. I sat there last night and kept wanting to play just one more song....they drew me in. The choice of tubes is related to the speaker being driven so the EL-34's may sound better on a different speaker.
Anyhow to the issue......when i installed the 8 tubes in the amp i totally forgot they were actually 2 matched quad sets so in effect i have mixed them up. Will it matter? should i have put in a matched set per channel? Will the autobias feature negate any issues?
The 2 sets were bought from different suppliers but i don't think there would be any different markings as they were both tung-sol branded.
quick history....i recently borrowed a primaluna evo 100 from the local store and loved it so bought the evo 300 and immediately bought 4 matched KT150's for it, but then 2 weeks later wish i bought the evo 400 ! so my local store let me return the 300 (small restocking fee) and now i have the 400. Sounds like a lot of $$ but I'm thinking this is a lifetime purchase so have justified it that way ;-)
Because I had 4 KT150s that i bought for the evo 300 i decided to buy another 4 so i could fill the 8 tube requirement of the evo 400. I'm driving magnepan .7's so more power the better. By the way the primaluna sounds great with these speakers....I've found a low end i'd never heard even when driving with 150wpc solid state and the sound is very natural, pleasant, and unfatiguing to my ears. The KT150's in my system sound much better than the EL-34's. They sound fuller and more spacious. I sat there last night and kept wanting to play just one more song....they drew me in. The choice of tubes is related to the speaker being driven so the EL-34's may sound better on a different speaker.
Anyhow to the issue......when i installed the 8 tubes in the amp i totally forgot they were actually 2 matched quad sets so in effect i have mixed them up. Will it matter? should i have put in a matched set per channel? Will the autobias feature negate any issues?
The 2 sets were bought from different suppliers but i don't think there would be any different markings as they were both tung-sol branded.
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- 18 posts total
- 18 posts total