|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
63.246.168.59
In Reply to: question for triode kingdom... posted by Vinnie on April 7, 2007 at 06:32:03:
nt
Follow Ups:
Hi TK,Thanks for sharing your amp schema... Curious about your choice of 6BL7 in srpp. Have your tried a similar noval in that position in "breadboard stage", lest's say a 5687? How do they compare?
Two factors influenced the choice for the SRPP (in addition to usual criteria like availability, sonics, etc.). First, I simply prefer US-made octals. That's especially true when the output stage is a classic triode like the 211 or 845. Second, there's a concern in this circuit regarding heater/cathode breakdown voltage. I initially used a 6SN7 in this position, but was worried about reliability because of its 90V rating. The 6BL7 is rated for 200V, and I know from experience in high-power RF applications that it will handle much more. Of course, I could have added a floating filament transformer, but I decided there wasn't much to gain. The 6BL7 has a very nice and open sound in this circuit, a quality that I attribute in part to the higher than usual B+.
Hi TK,
Yeah, and the 5687 has 100V max. That's neat reactor follower driver stage. I've seen it in a similar SE 845 amp but the mu follower input stage is the one using a choke on its cathode. Thanks again.
This post is made possible by the generous support of people like you and our sponsors: