I found a pair of RCA 5963 for a decent price.
After reading a bit it seems like they should be a suitable replacment for the 12AU7.
Searched the thread and I couldn't find any comments on them.
Will they work?
To be honest, they've always been my favorite tubes in a low-voltage, 12AU7 circuit (like the original SOHA). They generally have everything a 12AU7 has, but operate at a much lower plate voltage.* I think they were originally made for WWII walkie-talkies, which needed lower voltage tubes to operate with the batteries at hand. The data sheets say 67.5V is the typical operating plate voltage. That's not too far from the Starving Student's operating voltage at the plates.
* The closer a tube operates at its data sheet operating voltage, the more linear its response (better its performance).
I'm a noob (very much so) and i've been trying to figure this out for an hour or so, and i can't seem to understand. Here's the thing. I thought i'd built a starving student (12au7 version), and it would be great if you guys could explain to me why these schematics http://diyforums.org/SSMH/variants/SSMH-12AU7.gif show 8 pins on the tubes, where as 12au7 have 9. What am i not getting?
Thanks in advance
It's very nice of you to suggest, but it wouldn't as much fun. The whole point of the exercise, i find, is the challenge of it. To be honest i thought about buying it (i saw it a few days ago), but i'd rather try on my own. I'll keep that in mind as a plan b though.
Also, Fred is shipping from Australia. It's a beautiful little board, I may buy another, but you've gotta wait at least a week (usually more) to receive it in the states.
I finished my SS with the PCB of Fred. Sounds good and fairly happy with it. But fairly is not 100%. Because I have a slight hum on my can's. This isn't bothersome when playing music, but during silent parts it's noticable.
The volume of the hum doesn't change when using the pot meter. Most likely a grounding issue. But I think my grounding is pretty OK, but there is alway room for improvment. Any clue on where to look/improve? Help is greatly appreciated
I totally rewired it, with shielded cables. works flawlessly right now. Now enjoying the AMP with a internal odac.