Matched Tubes Quicksilver Line Pre

I just ordered a couple 12AT7’s for my Quicksilver Line Pre and I don’t believe I requested a matched pair. I emailed seller and asked him to make sure they were before USPS picked them up, but he did not respond.hmmmmmm

How important is this? Surely if I had remembered I would have requested it in the beginning. The fact that there is no bias adjustment tells me it is not an issue.


Any thoughts by someone WITH ACTUAL EXPERIENCE on this issue?


Thank you in advance,




Preamp tubes like the 12A*7, 6S*7,6922/6DJ8/ECC88 don’t really require matching because the amplification factor/mu of each triode half is usually very close and current draw varies little between these small-signal tubes.

I have that same preamp.  If the 2 tubes are the same brand it should be fine!

If you don't use military grade tubes you'll be replacing tubes every 3-4 months.


That's hogwash! I've been using the same tubes for over 7 years and I  never needed to replace them! Low voltage preamp tubes last for years!

@yogiboy  whatever you say. You can ask Mike, I had several discussions with him about it. Or don’t. 

@gochurchgo Really?

TUBES Your preamp is shipped with J.J. 12AT7s, which we feel provide the best sound, and have a life span of many thousands of hours. The J.J. 12AT7 is a new design and provides superior performance to new old stock 12AT7s. The Chinese also have a redesigned 12AT7 which provides very good performance

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I had that preamp for several years.

1. Matching not important or beneficial.

2. Military grade not important.



These tubes will last a long time as long as you don't leave the pre on crazy hours every day, etc.

@hilde45  You moved on to a different pre.....Why? what did you get and why? and what changes did you notice? Any regrets?

@tonydennison A friend loaned me a very nicely built preamp based on the 6SN7 tube. I compared it agains the QS Linestage for months. Back and forth, all kinds of music, with both tube amps and class A solid state in the mix. Over and over, the 6SN7 tube had more body, bloom, space, and a bigger soundstage. It was really not even close for me. I had upgraded my QS linestage with really good caps, too, so it was hard to let it go, but my ears want what they want. A local buyer took it off my hands for a fair price and I gave him all my tubes — including some very nice NOS tubes. No tube for the QS linestage could make a difference against the 6SN7 tube — for me.

I hope I never hear a 6SN7 Pre....LOL

I will hopefully be happy with what I least for a while.🤣