Tubes can be noisy and microphonic, they can also be expired, they do not last forever. As for the 12AT7 i would recommend NOS Sylvania Gold Brand with Gold Pins - this is amazing tube with moderate price for a NOS. A tube phono stage owner must have a bunch of backup tubes, an issue like this is one of the reason i would never use a tube phono stage myself. But when i’ve been using a tube amp i quickly realized than some nice NOS tubes (like those Telefunken, Sylvania, Matsushita) are always better than any new tubes, the difference is sound is huge. So it’s always an open question, endless tube rolling.
Phono Cart Impedance Question
I have a little bit of hiss through my 6 ohm, 0.28mV cart but only at a volume pushing the upper end of my listening volume...and it's only audible before I drop the needle, and even then not from the listening position. I realize I therefore likely have a "non problem"!
But I still have a generic question on to the sensitivity of producing hiss as it relates to cartridge impedance alone. If one kept all other cart specs identical (including output of course) would you expect hiss to go up or down at the same volume and system gain if I used an 8 ohm or 12 ohm cart instead? It seems like the hiss would likely go up just like moving to a higher impedance speaker under the same gain setup but perhaps I'm looking at this incorrectly? I realize moving to a slightly output cart could very well reduce the hiss.
Thoughts? Sorry if this is a ridiculously obvious question and answer.
But I still have a generic question on to the sensitivity of producing hiss as it relates to cartridge impedance alone. If one kept all other cart specs identical (including output of course) would you expect hiss to go up or down at the same volume and system gain if I used an 8 ohm or 12 ohm cart instead? It seems like the hiss would likely go up just like moving to a higher impedance speaker under the same gain setup but perhaps I'm looking at this incorrectly? I realize moving to a slightly output cart could very well reduce the hiss.
Thoughts? Sorry if this is a ridiculously obvious question and answer.
Showing 2 responses by chakster
If you really want to learn more about tubes you’d better read Tube Assylum forum, some folks like are crazy about tubes and tried almost everything and they are not sellers. I spent a year on this forum just reading and making notes. If you’re in America then vintage Sylvania Gold Brand (Gold Pins) 12at7WA is superb even compared to my Telefunken ecc801s. The best tubes are NOS Military Grade, they last much longer, they are stable, low microphonic and very quiet. None of the new 12AT7 or 12AX7 can beat them. Tube rolling is fun, but very expensive. Look for NOS tubes, save for NOS tubes. I don’t know much about 12AX7, used Soviet tubes in my Luxman amp for a short time, but 12AT7 was in my WLM Minueta amp for many years and i’ve been looking for cheaper alternative of Telefunken ecc801 (very expensive), i found Sylvania 12at7WA and Matsushita 12at7WA (gold pins) amazingly good. |