Break in period for tube amp. How long?

Capacitors should not be an issue with a "new" tube preamp; guess I was daydreaming and thinking of tubed preamps that have been unused for a long time....those should be checked out a by a tech before putting into service.

A friend and I fired up an Audio Research PH3 tubed phono stage that had been unused for round 8 years. It came up OK and sounded pretty good. Problem is there is an audible buzzing noise coming out of both speakers; we shut it down immediately after listening for ten minutes. It goes to the shop next for a complete inspection with cap and tube upgrade.

if it sounds awful, it isn't a break-in situation.

Hello. Probably one week, most likely two or three...I had the same experience on purchasing a new ARC SP9MkIII pre-amp some years ago - having heard a used MkII with great results, I could not believe how 'awful' the new MkIII sounded straight out of the box - after a week it was a good, and after a month it was perfect. I've been recently auditioning tube power amps as potential replacements for an ARC D125. The shop, Audio Connection in Sydney, Australia, has a great choice, so much so that their demos are virtually unused - this meant a Jadis Defy 7 and an ARC VS110 both sounded 'awful' in exactly the way you've described. Congested and harsh. The store suggested a few weeks before they would at their best - in the meantime I'm meant to 'use my imagination' during auditions! Hooking up used amps to the same system saw much smoother results. Good luck. Rob.

It's funny, but when I bought my first Jadis, I experienced EXACTLY the same thing you are going through. Awful, and I do mean awful. Congested, constricted, constipated, absolutely no extension in the bass or treble, and a harsh, irritable midrange. You want to talk about buyer's regret?!? I had it like never before or since. It's one thing to insert a component and hear little or no improvement. It's quite another to buy something you auditioned carefully, spent more than you ever have for, and come home and have it be day and night inferior to the mid fi components I had in the house.

Despite the absolute heartache that only someone who has experienced can empathize with, I soldiered on, and let it run in. The fact is, it wasn't anything noble I did, I had little recourse in getting a return from a dealer I kind of sold my soul to the Devil for to buy in the first place (breaking one of my life mantras - You lay down with dogs, you get up with fleas). And, a truly ugly duckling to beautiful swan story it turned out to be. Was it the tubes? Maybe. But, how much the capacitors, resitors, wire, etc. also had to run in I cannot say.

I do know that after about 50 hours, I was beginning to calm down. And, things just kept getting better and better and better. I looked up one night, three months after my purchase, and was getting the absolute best sound I have ever gotten. I was in a near nirvana state. Happy in having persevered the initial out of the box performance, that again, was truly awful.

Not that this is the case always, as a bad speaker - amplifier, or preamplifier - amplifier interface, or broken component could be the issue. But, in your case, as your Nagras are replacing another pair, I would tell you to just hold on and try to be patient enough to give the new babies a full chance to run in before you make a final judgement. Unless something in those amplifiers is broken, and the odds that the same thing in a pair of mono amps would be broken in both is kind of small.

After my experience, anyone who tries to tell me that "the component doesn't break - in, you become 'used to it'" has an impossible task in trying to get me to buy that.

Trelja, thank you for sharing your experience. You described exactly how I felt. Well now, after about 25 hrs the VPA's are opening up......the best yet to come I'm sure, as you suggest.