Do new tubes undergo break-in like other devices?


I just put a new pair of Mullard Ecc34 (should be 6sn7s) tubes in the r/l inputs on my BAT VK60. These are the 2 most importants positions for BAT amps.

Part of it sounds wonderful...back of the soundstage, instrument separation, dynamics, articulation in the bass. Oh, and much queiter.

However, I don't think they have as much gain, I have to turn up the volume some on the preamp, and the bass is much lower vs the other parts. Kind of like a new power cord...needs time to open up. I can deal with the gain, not sure about the bass. This may just be a system matching thing, works great for some, not for me.

Is it break-in related?
128x128jfrech
I was using some early russian 6sn7's bought from upscale audio. The positively smoked the stock sovteks from the start. I do have about 1.5 years on the russians...

Sounds like a little patience is in order here. Thanks for the info!
I've found tubes need break-in but not to the extent of components such as amps, cables and speakers. Tubes go through the same sonic character changes during break-in as other components, but I've found they do so much faster.
A new power cord needs time to open up?????!!

What does this mean? How does it open up? I didn't know powercords "opened up"...

I'm not going to a DBT zone or saying wires don't matter. I just want to know what to listen for if I buy a superpowercord...how long I should wait for it to open up before I decide that it didn't matter.

Do wall outlets need time to "open up" too?
everything "opens up" and breaks-in. this crazyness goes onto the tip-toes and other tweaks. man, your stand should also break-in...

listen more more more more to realize he...he...!!!
Ok...here is what I heard...less than 30 hours on the tubes...

These are awesome sounding, and in the right system, you'll love em. If you are looking for more air, detail, quietness, these will do it for you. The bass was a little less for me, and that's a weak point in my system before the tubes went in. A single VK60 is a little underpowered for my room size and WP 6's.

Everything else I loved. The bass was more detailed, more tuneful, just less of it.