tube upgrade for first sound


Has anyone been able to improve on the stock tubes in the First Sound preamps? I was thinking about trying the Russian 6H23. Any thoughts? thanks
84audio
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I've also gone through two sets of the EH tubes. But I want to know why they are not working.
hi dan. i tried it (the extreme version) across my entire system (pc, ic, tube pins etc). At first things were bright and forward, but with continued use, that feature resolved and i was left with increased clarity, articulation, and speed - yet i dont think any harshness or glare was introduced. Like every other maneuver that increases these aspects, the system should be "up for" increased exposure and transparency. Overall i think well balanced systems would benefit more than those with underlying tendency towards stridency - "more is not always more." As i recall, your system with the FS (and rowland was it?) would not have this issue....

Having said all that, overall i did hear a real benefit. whether it was $149's worth or not is a case by case individual decison, but I would say yes for me. They offer a money back guarantee, so it might be worth a spin.