Elrog 300B vs Takatsuki 300B tubes

07-07-15: Brownsfan
My power company will not address the issue unless the voltage is outside of 120 V plus or minus 5%.

That is the standard in the USA for household AC, as measured at the service entrance. The upper limit of that range corresponds to 126 volts.

With due respect to George, I must admit to some skepticism about the requirement of 122V max. I would expect that the designs of the power supplies in equipment marketed in the USA would in most cases be targeted to supply optimal DC voltages to the tubes and circuits for an AC input of exactly 120V. And I find it hard to believe that an increase of 1.67% from that figure would be the upper limit of acceptability.

Also, I don't see how a statement as specific as "over 122V AC is a game changer for these or any other 300B tubes" can be defined in such a universal manner, apparently with applicability to all 300B-based designs, given that I would expect significant variation among different designs in the +/- tolerances of the transformers and other components in their power supplies. Not to mention in how hard the tubes are driven.

Best regards,
-- Al

Thanks Al! I'm going to leave this discussion to you guys who actually know something. I will allow you and George to dialogue until a meeting of the informed minds occurs, at which point, I will act accordingly. I just don't want to start burning through 300Bs.

Once again, you are a priceless AG resource Al!

Hi Al,
You raise a valid point regarding the narrow recommended range for AC power.For sake of argument do you believe using a variac and keeping the AC between say 115-120 to go "easier" on the Elrog 300b(to enhance tube life) is reasonable?
Thanks,
Charles,

Bill (Brownsfan), thanks very much for the nice words.

Charles, I suppose it would be reasonable to try that experimentally with an inexpensive variac, perhaps purchased used at eBay, but it wouldn't surprise me if the result was degraded sound quality. Due to both the effects on the amp's sonics of the lower voltage and the effects of the variac itself.

Best regards,
-- Al

Al,
I had exactly the same concern regarding variacs. I spent $1K having dedicated lines run to the room, and who knows how much on PCs. Now I'm supposed to run everything through a cheap variac? I'm also concerned about limiting current. Don't really want to throttle down the juice! On the other hand, one of the PS audio regenerators used might be a reasonable investment. I just know that not everyone likes these, especially for power amps. So even that is an expensive experimental question. I much prefer the do nothing option, but I won't be happy if I am buying new 300Bs 6 times a year.

With respect to my nice words, my parents raised me right. Sometimes the children need to remain silent while the adults converse. Its been too long since my college physics course. Electrons are important to organic chemists too, but we are interested in pushing them from one nucleus to another, not pushing them through a bunch of wires and circuits.