Transformer Break-in

[BLT]

Has anyone done a study on the break-in time for transformers made by the 4 or 5 major transformer manufacturers used on this forum?

[Cantplay]

I would guess its more related to the number of heat cycles than total run time.

John

[rooster]

Ha, that would be so subjective, wouldn't it? All I can do here is repeat what MM has said consistently, that "it takes approximately 40 hours of play time for an OT to break in".

That said, I am rebuilding some large diaphragm recording mics that use transformers on their output. Knowing what Sergio of MM has said about OTs, I am currently burning in the new transformers 5 hours a day till I hit 40 hours. Whether a mic transformer is comparable to an amp OT I dunno, but WTF, you know? FWIW, I can tell you that the very first hour made a huge difference in the mics top end and overall presence - but that could have been other components and not the tranny at all as it was a complete rebuild.

In regards to replacing OTs in my amps with new off the shelf varieties, my experience has shown 20 minutes to be the 'noticeable difference moment'. Now, it may be that subtle things are changing as the tranny approaches 40 hours, but I am pretty sure I wouldn't be able to quantify those changes.

One last thing, chasing OTs is not fun on the wallet.

[printer2]

Subjective is right. I can not see what would change in the transformer to cause any change. Do a distortion sweep when first new and after a given period of time. Set up two identical transformers in a circuit with an A/B switch and listen for any difference. Then run one transformer for a length of time and then do the A/B comparison again with the 'new' transformer.

[VacuumVoodoo]

Put in a 40hrs week of guitar playing. The transformer won't change its characteristics but your chops will improve significantly. That's the point of burning in an OT.

[JazzGuitarGimp]

Put in a 40hrs week of guitar playing. The transformer won't change its characteristics but your chops will improve significantly. That's the point of burning in an OT.

I was thinking down a similar road. Remember when you were a preteen, and a new song that you had never heard came on the raido - and you HATED it? Then, a few weeks later, after hearing the song 10 times a day, you really liked it? I have to wonder if there's at least a little of this going on when companies claim a "break-in" period for their parts. "Make them wait a few weeks before they pass judgement, and they will accept the tone for the golden magic we claim it to be." Not that I'm slamming Mercury: I think they make a superior product, and they are my first choice for transformers.

[VacuumVoodoo]

Well I can't say anything about MM transformers other than I did measure up full characteristics on a couple and can confirm that these were, in fact, transformers.