MagneQuest/Peerless Forum Welcome! Need support, you got it. Or share your ideas and experiences.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ MagneQuest/Peerless Forum ]

---

[ Alert Moderator ]

---

RE: Best sounding amp I own - I Second that

Posted by Jim Doyle (A) on October 14, 2011 at 14:57:00

In Reply to: RE: Best sounding amp I own - I Second that posted by mqracing on October 12, 2011 at 18:44:23:

The 6V6 as a triode driver is a 20ma affair. I believe that Tango had an IT part in their catalog that was precisely built for 6V6 - everyone was using it about 15 years ago. It was either the NC-16 or NC-20... Nonetheless, the 6V6 is a very sweet and clean sounding tube.

Direct coupled amps are really only for people who know what they are doing... Because one tube sets bias conditions for it's neighbor - it's very easy to blow things up when stuff goes wrong (tube out of socket, dead filament, anything). Too easy to destroy something with that topology.. Ontop of that, you are always dealing with a 700-900V supply due to one tubes plate being tied to anothers grid.. So even the PSU becomes hairy and expensive... The Welborne DRD amps use this topology - I'd be anxious to hear about in-field reliability... :)

Nonetheless, direct coupling the first two stages is safe and inexpensive.. LC coupling the Komuru driver sounds every bit as good
as IT coupling on my 845... Cheaper too - but I'd already bought my interstage transformers but I did listen and audition out an LC coupled amp on that driver and it was awesome!

I'd also lower the total gain of the Komuro stage.. It has 20*8 mu = 160.. You could sub out the 6J5 (mu 20) for something
around 10 - using a 76, 6P5 - which is what I do. Omitting the cathode bypass cap on the first will also reduce the net gain... In my implementation, the driver gain is 64 - which is perfect for a 300B or
LV 845 and a 2V input. You might find other ways to modify the net gain - for instance using perhaps the 71A rather than the 6V6. One of the very nice thing about the 6V6 / 76 combination is that the resistor complement needed to set bias is very straight forward - 47K, 470 ohms, 4.7K ohms.. :)

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

Parts Connexion

---

[ 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 ]

---