Rolling Mullard 6DJ8 into GE 5670 Application

I’ll be interested in your results. I have an amp that uses 6DJ8. I am currently using WE 396A with an adapter. I have never tried the Mullards.

I will say that I’ve found the red tip Russian 6N5P to be a pretty good option you might roll in sometime.

Jerry

there are many many many 6dj8’s and equivalents... it was a popular tube, used in many applications, consumer, commercial and military, and was made all around the world up to the point where tubes were supplanted with solid state devices in the 80's and 90's

if the tube is in fact in the audio circuit of the op’s dac in a meaningful way as @lewm mentions, there will be many many different sonic presentations available through rolling different 6dj8’s

i still have hundreds (no exaggeration) of old stock 6dj8 variant tubes, made in usa, uk, holland, hungary, japan, india, slovakia, russia and so on... as i used conrad johnson linestages for many years, and they exclusively ran that tube in their better models for 20 years

Based on the additional info it sounds like you’re on the right path. My system tends to be bright and I’ve avoided any silver in my interconnects to correct that problem. The tube “ Sound “ description on the Brent Jesse site is extremely accurate. My pre uses 12AU7’s and the sonic change is very similar to the E88CC change in my power amp. I was fortunate enough to be in your position some years back and nos tubes were not at astronomical prices. My experience with the German tubes is an improvement across the entire spectrum and that appealed to me. It has also been a plus to have a selection to roll with. I recently tried some KT 150’s for the first time and after some break in, wasn’t feeling it. So I rolled in the hottest rectifier tube I had ( a Mullard ). Now I had too much bass , so I changed the E88CC from a Tekefunken to Amperex to bump up the treble. In retrospect I’ve managed to be able to really tune my systems sound by tube rolling, but like stated above I acquired a bunch of tubes. It’s been a pricey but fun experience. Unfortunately I’ve had to attend Tube Addicts Anonymous after my wife saw my credit card charges. 😆 But seriously, Happy Hunting and good luck, Mike. 

 Buell, from your post I gather you may have either substituted for a 12AU7 or rolled 12AU7s. Which is it?

The adapter was delivered last night and I was able to do the tube swap this morning.  It definitely sounds different and my initial response was positive, but I'm becoming less impressed as time goes on.  I'll give it a few weeks and then switch back and see how it feels.