Loving this thread - new to tubes and learning all the time. I got a couple of Sovtek 6H30Pi, installed them and used them for a good many hours but was really unimpressed. The sound was flat and un-engaging. I was coming from stock tubes - is there any internal setting I need to change to make these tubes work?
Haha funny thing here what's happening. The 6sn7 for me is the best upgrade for this dac. And I have here quite some tubes laying and tested personal on the dac. My rectifier is spot on and linlai elite 274b would never change. So now for the pre tubes, I also tried the stock 6h6; there good, yes, for the money and good quality but just as is.. Good for stock I think.
Before the 6sn7 I use now I used for long time the 12bh7 from Full music and they are typical tube sound; warmish and great emotional full bodied sound I get from these tubes. Some soul into the music. Which I like.
Then I tried the EH 6h30pi gold pin, because everybody (and also Garry) where very excited about these tubes. Well short story short; they aren't, everything is just to much, dynamic allover, it's good if you want that or searching for it but it lacks the emotional feeling and sound. Just hearing everything without soul.. Not my taste. I would say to much audiophile or something like that. It's not good for listening for long time..
Then the 6sn7, I tried vt-231 Jan/rca NOS from around year 60 or something. It was good but not in greatness, audio image was lacking, its just sitting in the speaker and doesn't want to come out..
Then a message came and I definitely got to try the 6sn7 Nanjing 6h8c from the year 1958 and holy crap. Everything is here, stereo image is enormous with a good dynamic without loosing soul and emotion in the music. It's exactly what I want. For sure I needed to cut some holes in the top cover and some converters but yeah works like a charm!
So basically this dac can get you really to your taste but you need to look and search for the right tube and it takes someong time to get. Put some effort in it.. Now I have brand new ones EH 6h30pi gold lying in the box for doing nothing.. Sadly but he atleast I know now. The caps are standard mundorf Supreme and bypass Cornell Dubilier 940c 3000vdc 0,01. I recently upgraded to the mk3 deluxe motherboard and background is even more quite then the previous mk3. Still needs some playing hours to burn in time, but always Garry does a very good job. Hope the 4499 is here soon. Cheers!
Edit: best for budget go for stocks, if you want the typical warmish tube sound, switch the switch from 6v to 12v and use 12bh7. If you want best dynamic and you love punchy sound go for 6h30pi. Otherwise best and you love the old sound from the 6sn7 tubes, consider this and try several brands. I use rca output on low gain like Garry mentioned in his manuals. There is quite some difference in the output gain for the tubes look for manual.
) and totally another to be tuned for a particular set of tubes. For my mp-d2 mk3 I am using Genelax 6922 .... so far so good ...