Tube DIY Asylum

Posted by tubesforever (A) on June 19, 2005 at 22:41:40

In Reply to: E88CC posted by Meister on June 19, 2005 at 13:09:51:

Today I purchased some Amperex Buggle Boy 6DJ8 tubes and some Siemens 6DJ8 tubes to roll next. I am not sure about the Amperex but I hear the Siemens is very neutral and somewhat more linear than other brands. If I cannot get the sound I am after, then it is time to make sure my cartridge is loaded optimally.

I am very intrigued about the 12AU7 tubes. 30% less power than the 12AX7. But I hear they may make a nice cascode preamp circuit. I have heard others comment about the 6CG7 as well. I do not know if this would require extensive reworking of my preamp or not....

I also purchased 4 12BZ7 tubes, GE Models. The seller says these are up to 30% more power than the 12AX7 so I may be willing to modify my circuit to get the higher gain. Then I can buy a low powered moving coil cartridge which is my future plan, and run it without a step up converter.

Here is the description of the 12BZ7's....

"From an audiophile's private collection, here is a remarkable NOS NIB matched QUAD of GE LONG CURVED BLACK PLATE 12BZ7 preamp and guitar amp tubes MADE IN USA in the 1950's or '60's. These are direct plug-in "big brother" replacements for the venerable 12AX7's. Three are labeled/boxed "GE" and the fourth is labeled/boxed "Zenith". It was actually made by GE (common practice back in the good old tube days). They have the SAME amplification factor (100), higher plate power dissipation ratings, can handle more power and therefore can be run at a lower percentage of their full capability which means their dynamic range is significantly better than 12AX7's in a similar circuit. My SAMS tube substitution handbook says that 12BZ7’s are great substitutes for 12AX7’s! All tested EXCELLENT on a TV-7B/U military tube tester."

I am hoping these will sound nice, if not, I will provide them to one of my Guitar playing buddies.....

Cheers.