"Running-in" preamp tubes?

Phantasmagoria

watch where you point that sabre
Tung-Sol RI 12AX7's:

I never really liked them ..they sounded pretty thin/compressed in the mids (not very open) & thin/over-trebly on top in both my other amps (and were banished to my parts drawer lol) ...however they did seem to have a deeper, tighter bottom end & more headroom than most of the other current production stuff.

I recently put one in the V1 of my new Randall T2HL (replacing the stock Ruby) & it was kind of a compromise..the Ruby sounded more open in the mids/crunchy and had a sweeter/rounder top end, but the Tung_sol was cleaner/deeper & punchier sounding....although pretty stiff/hard edged & not really 'juicy' or crunchy at all..

Then, after playing a gig on Saturday (first one with the Randall) with the amp well cranked for an hour and a half, I noticed (back at home), that the amp sounded...WAY, WAY fuller, fatter, sweeter/wetter & super-open/crunchy...like a different amp almost. In fact it sounded amazing..

At first I thought ..maybe I had a stronger speaker-cable connection after reconnecting it at home or the tubes were maybe sitting better in their sockets or something after an hours worth of high volume vibration, but it sounded the same even after I re-sat the tubes in their sockets/rocked them around & re-did the head/cab connection a number of times.. (I'd done this a few times before with the stock tubes in there too...so I know they were pretty well seated right through actually..).

I can only conclude that the "opening-up" of this amp was due to the 'running in" of the tubes, or more specifically ...the Tung Sol in V1 (since I'd cranked the amp quite often before with the Ruby V1 in there) ...something I'd never really given much thought to before or experienced so drastically/dramatically.

Is this something anyone else has experienced with the Tung Sol RI's? That they open up like hell after a good run-in?

I know it's never happened with my other V1 tubes (JJ's/Shuguangs) which have all sounded pretty much the same as when they first went in..
 
Re: "Running-in" preamp tubes?

Well, I've never broken in pre tubes, power tubes, maybe yes.
I do know one thing- when I gig, as the night progresses, my amps sound better, don't know if it's the extended time turned on, heating up those power tubes, or, if it's an aural illusion(ear fatigue), but, it does seem to sound better the longer it's turned on- the same with all my amps Marshall, Laney, Fender.
 
Re: "Running-in" preamp tubes?

I've been a big fan of the TS 12ax7 and never thought they sounded thin, just very full to my ears... but it is all so system-dependent that debating it is just pointless.

Back to your situation: see how it sounds next time right off after you power it on. If it's back sounding thin and all that then Marvar's theory might be right....
 
Re: "Running-in" preamp tubes?

No, it's still sounding the way it did right after the gig (last Saturday) and I've played it every day since.. (so hopefully it stays this way lol.)

...the biggest difference is that the mids have really opened up and the 'feel' is different, still super tight/punchy but not as stiff/hard-edged as before...more 'chewy' I guess the term is..
 
Re: "Running-in" preamp tubes?

Well, I've never broken in pre tubes, power tubes, maybe yes.
I do know one thing- when I gig, as the night progresses, my amps sound better, don't know if it's the extended time turned on, heating up those power tubes, or, if it's an aural illusion(ear fatigue), but, it does seem to sound better the longer it's turned on- the same with all my amps Marshall, Laney, Fender.

Yeah...true...but I think that has to do with the output tubes warming up or something...

What I'm talking about is after the gig (ie...the next day...and every day since...)
 
Re: "Running-in" preamp tubes?

Capacitors can require 50-80 hours of 'On' time to develop, so it's possible that is in the equation.
 
Re: "Running-in" preamp tubes?

Really? Could be that then I guess...good to know. I'm not sure what it was, but whatever happened (and something definitely did), happened during the gig on Saturday ...and that was really the first time I'd run it cranked for so long (our hour & a half long set). I've had some loud 15-20 minute jams with the volume up at home but this was the first time gigging it for a longer stretch..
 
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