. . . ohhh, so they are MC9011s? I just did a cursory read on them--interesting amps. Anyway, Mac is calling the two 12AX7s the signal tubes for the amp. Which is not what I would call a "preamp tube" (I would call a preamp tube a tube in the preamp) but I guess it doesn't matter what you call it. I wonder what the 12AT7s are for? Inputs or drivers into the ss section? |
OP I’m 75, until last year, I thought rectifiers were rectifiers, nothing to do with the sound. My friend had a new Phono Preamp built by .... she included new 'broken in' tubes as well as some spare used tubes. We listened here, changed tubes, small subtle differences, ’prefer’ not ’better’ differences. changed rectifier, holy smokes was I surprised how easy it was to hear the difference. ’better’ was obvious. |
@elliottbnewcombjr Im also under the impression that a rectifier is a rectifier, so now I’m curious as to what you have found by switching rectifier tubes and what your are now using that make the difference. I have McIntosh MC30s and have been using NOS RCAs. Let me know. Thanks. |
I read a lengthy comparison written years ago about 12AX7s and the writer felt that the 5751 gave a more engaging presentation. The 5751 is a lower gain, quieter version of the 12AX7. So I tried a Sylvania black triple mica NOS and I agree with him. I find I lose interest in the music easily, even with a $275 12AX7, compared with the 5751. With the 5751 in my 300B integrated amp, I can’t stop listening. Have to force myself to get up and walk away. And I don’t notice any difference in gain. |
GE Black Plate 5751 are great tubes and I've used them a lot over the years. Late 60's Mazda 12ax7 WA silver plate however are the finest small sig tubes I've iused in my current preamp. Have run through Amperex, Tele, Brimar, Mullard & I find the Mazdas are legit - right in my lane. Just my opinion. |
