Originally Posted by zwack
And there is music! I temporary hooked it up to my computer using some old RCA connectors, just for testing. Sound is a bit thin, but that could well be coming from the computer's soundcard. When I finished the build I will be using my left-over Rega DAC in combination with my CD-pro transport. I have a good feeling that the Rega-CD-pro combination will sound better.
I still have a question about the tubes:
- I'm currently using 12FM6 tubes. At the time I ordered them I was not aware of the tube matching service at Beezar. The ones I got are from Raytheon & Tung-Sol and rated 90 and 85 Whatever that stands for. On both boxes "RCA Side HS" written, assuming that they where produced in the same factory. Are the tubes close enough matched?
Probably. "Millett" tubes were only made by four manufacturers: GE, RCA, Tung Sol, and Sylvania. So, no matter what the original tube box says, or the painted-on tube label, it's one of those manufacturers that made it.
As for the notations on the top of the Beezar tube boxes, I've always intended to document this thoroughly, but it's one of those things that you never quite get around to doing:
Top Left - tube box or tube label mfr
Top Right - tube tester reading
Middle - tube designation
Bottom Left - "real" mfr
Bottom Middle - getter type
Bottom Right - plate type (graphical representation)
"RCA Side HS" - (I'm assuming this was on the bottom) means RCA was the mfr and the getters are Horse-Shoe type mounted on the side of the plates.
Unfortunately, we need to state that you didn't order a kit. Tubes are completely matched according to test, mfr, and construction with tubes that come with a kit. I try to do my best if someone orders tubes separately and they don't pay for matching. In the case of 12FM6's, those tubes are very scarce. Beezar may represent the largest stock in the world right now, but that's still only about a hundred. In your case, the painted-on labels for the tubes have little to do with the actual mfr. Not seeing/remembering the boxes specifically at this point, it sounds like I gave you two RCA-manufactured tubes with identical construction that are 90 and 85 tested output. That's within 10%, so they should be pretty good.
Not to be outrageously self-serving, tubes are not like opamps. Every one may sound different. You are encouraged to buy as many as you like (not just from me) so that you can experience the differences. You never know when you might find that golden tube that does everything just as you want it to.
Edited by tomb - 7/20/13 at 7:21pm