Rectifier Tubes


Hi all, can anyone tell me why I hear so much of a change in my amplifier's sound (Coincident Frankensteins; 6em7 driver tube, 300b output tube) when I change the rectifier tube? 

I just got the following message from a tube vendor:

"Further, rectifier tubes (5U4) don't pass or amplify any sort of signal so our policy of no returns for tone especially applies to rectifiers. Changing a rectifier tube shouldn't change the tone of your amplifier at all, not even a little bit. This is why many high end amplifiers have solid state rectifiers. "

They actually did authorize a return (I was returning because the tubes were distorting, not because of tone), so I'm not gathering ammo for a fight.  I'd just like to understand why my experience is so different from this (presumably highly knowledgeable) individual's beliefs.

Thanks.
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Showing 1 response by brownsfan

I have a deep respect for those who have electrical engineering backgrounds.  They bring so much to this forum!   I do not have a background in electrical engineering, so I tend to make judgments based on empirical evaluation rather than first principle considerations.  But based on my simplistic empiricism,  I am amazed that anyone with normal hearing, especially a tube vendor, would dispute that different rectifiers, and here I mean different brands of the same type rectifier as well as different types of rectifiers, can have a profound effect on how a component sounds.  For all I know all of this may be limited to differences in sag or rise times.   I'd love it if all rectifier differences could be attributed to measurables.  I will say that I have noticed some pieces are more influenced by tube rolling than others.  Perhaps Erik's comment is relevant to that phenomenon.