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Questions from a Tube Preamp newbie

I have my Rogue RP-5 back from warranty repair and I am loving how it sounds. While at Rogue, they installed 4new JJ 12au7-s tubes. Sounds great. I have some questions.

1. with about 2 hours daily playing, how long do typical preamp tubes last (I have heard Rogue's, like CJ, can be hard on tubes)

2. Do new tubes need broken in? if so, what is normal time frame?

3. Does tube rolling really make a difference on a preamp vs power amp?

4. What is the general concensus on JJ tubes for a preamp? Again, I am really happy with the sound, so I probably won't change. However, I will eventually probably get the itch.

Thanks
aberyclark

Showing 2 responses by mofimadness

mofimadness's avatar
mofimadness
5,597 posts
 
1. Most preamp tubes will last 3000-5000 hours. Some are speced out to 10,000 hours, so there are exceptions.

2. 40-50 hours, there are exceptions.

3. Depends on how the circuit is designed and how the tube(s) are implemented within that circuit. Tube rolling can make a huge difference or none at all.

4. Never been a fan of the JJ tubes.

I have quite a few of the Mullards and have never experienced a premature failure or an increase in noise?  Excellent tube.  The Pvsane tubes are also very, very good.
mofimadness's avatar
mofimadness
5,597 posts
 
I have a lot of the CV4003s from Upscale.  They used to be $35 each for the Platinum Grade.  These are the ones that I've had no problems with.  I've used them in DACs, preamps, phono stages, all over.

I also have several other types of Mullard 12AU7/equiv.
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