Do preamp tubes have break-in period?

[JLagoon]

Do they?

If I'm not mistaken, they do have break-in period, not just power tubes.

I put a new set of preamp tubes in my TriAxis on last Saturday, and the TriAxis sounded brighter tonight in rehearsal. The new preamp tube set is supposed to sound brighter in mid frequency.

Thoughts?

Thanks!

 

[Gearjoneser]

Re: Do preamp tubes have break-in period?

I don't think so. They're small, like a component, so I don't think they have a break in process, other than being burned in and tested at the factory before they're boxed up. Any change in tone is a result of using a different pre tube.

Power tubes usually sound really bold when you first install them, then mellow a bit after a month or two......but in a good way.

 

[JLagoon]

Re: Do preamp tubes have break-in period?

Well, the new tubes sounded different between last Saturday and tonight. I don't know what really happened, but the mid frequency of the TriAxis sounded brighter in a very noticeable way; it's almost like adding a mid hump on an eq.

 

[Gearjoneser]

Re: Do preamp tubes have break-in period?

You may have heard them turned up and really noticed the difference between the old ones and new ones. What were the old ones, and new ones?
I'm a bit of a tube nut, and have swapped dozens of pre tubes in and out of my amps, in listening tests. Then, I normally pick the one that makes the amp break up just the way I like it, and leave'em. They all accentuate different frequencies in a different way, so sometimes a pre tube will sound great in one amp, and sound thin in another.

 

[JLagoon]

Re: Do preamp tubes have break-in period?

The old ones were high gain set by JJ, and the new ones are gold pin set by JJ.

MmMMMm......

 

[Jeff_H]

Re: Do preamp tubes have break-in period?

Pre-amp tubes are "burned in" for several hundred hours when they are matched and graded. I've not ever noticed a "break in period" with them. Over the course of years there may be small losses of tone, but it's so subtle most of us miss it.

It's probably your perception of the new tone more than anything. You may have to adjust your favorite amp setting to account for the different tone the new tubes bring, as each tube, even within the same brand and type all have a slightly unique tone.