Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tube DIY Asylum ]

---

[ Alert Moderator ]

---

RE: Ping: Michael Samra - 6P3S-E Data

Posted by Triode_Kingdom (A) on March 14, 2015 at 13:37:01

In Reply to: RE: Ping: Michael Samra - 6P3S-E Data posted by Michael Samra on March 14, 2015 at 13:13:18:

"...the 6P3S-E which is the 6L6GB"

Well, this was a major surprise, but what you've said above (which is something I've also believed for a long time) doesn't appear to be true. I just finished an initial test with the 6L6GBs, and their performance in this amplifier is almost identical to the 7355s. They deliver *exactly* the same output power as the 7355s - 25W on the nose. In fact, the only reason I won't say they're identical is that distortion is better. The output stage I posted now does less than 0.1% THD at 4W output (I'm using 4W as a convenient standard for comparison at the moment).

So, I guess I need to ask how you arrived at the conclusion that the 6P3S-E is equivalent to the 6L6? I know this is a common belief around the Web, but have you verified it for yourself?

OK, I think at least one more test is needed at this point. I'll try the 6P3S-Es at higher voltage/dissipation by temporarily changing the amp to fixed bias. That will raise the effective anode voltage from about +350 to +385. I should be able to see if there's a trend toward better performance at that point. Maybe an adjustment to the feedback circuit is also in order.

About balance, all these pairs other than the 7355s have been graded for Gm on my Hickok and for idling current in a test fixture at +400V. The HK also allows balancing AC currents for minimum IMD, which I've done each time I tried a new pair of tubes.

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---