Day To Day Ear Fatigue

[vibratoking]

...EL84s are my favorites so I'll always be using them but I've noticed that some days everything is cool and the highs don't register as piercing to me and others I question how I could take it the day prior. ...

I understand where you're coming from, but what I was really talking about was perceived brightness and not necessarily the texture of the clipping, more of the stridency of notes. I can actually confirm the change in capacitors over a long break in though. ...

Starting to squrim, are you? I won't beat this to death and please don't take this personally. I'll just mention that these two statements aren't consistent IMO. Could be I don't understand words like piercing, texture of clipping, stridency, etc... My basic comment is you have stated that you have day-to-day hearing issues or amp issues, yet you don't suffer from any of that over the long periods of time it takes for capacitors to break-in. I'm pretty sure Sozo loves that type of thinking since they have never provided ANY data to prove their assertion. I know I have never experienced day to day changes. That's about all I can compare because my memory for audio is not trustworthy over longer periods. I have never distinctly heard a noticeable difference after the "break-in" period. Personally or via a recording.

It might be that you are hearing voltage fluctuations. This was discussed in a recent thread. I can't say I've ever heard it and my wall voltage fluctuates between 118VAC to 128VAC. I've tested it with a Variac and I couldn't hear it there either, but you might want to conduct that test to see what you hear.

[Blackburn]

No worries.

I did a back to back comparison today. Like I said, some will feel the way they do and not much will change that. I'm just reporting my experience with a newly built amp and one that's quite older with a good deal of time on it, both damn near identical in parts, tubes, etc. Same cab used as well. I could be wrong.

As for the stridency and piercing statements, they are referenced to discomfort of the treble notes when registered. Some days I don't feel bothered. Others are different. Like I said, maybe atmospheric pressure? The weather has been seasonably strange round here.

I'd define texture of clipping by things like note separation and clarity. That doesn't really change day to day to me, just the level of brightness I can stand.

[Structo]

Another thing to consider is the usually high tolerance of capacitor values.

Most electrolytics are up around 15-20% tolerance, not to mention plastic caps which hover around 5% tolerance.

So if you have two otherwise identical amps, there is more of a difference between them than you might at first think.

If carbon composition resistors are used, it's common knowledge that they drift in value over time, usually upwards.

Also if tubes are new, the top end frequency response is known to fall off.
Probably more so with new production tube.

This is particularly true of power tubes.

Not to mention if a new speaker is being used for the first time with the new amp.
So after the magic number of 100 hours, it may just be things settling down a bit more or more accurately, wearing out.

So things do change over time but, I'm not sure I would call it breaking in.

[vibratoking]

Tom - all good points, but this discussion was started regarding hearing the amp differently from day to day . I clouded the discussion by mentioning that I thought it would be impossible to hear capacitor break-in if the way you hear the amp changes on a daily basis.