Don Sachs Owners Thread

@ptrck887 

I just went through the tube roll exercise.  I got my DS with 4 Shuguang and a Sylvania 6X5gt rectifier. 
 

I asked an old audiophile friend some tube recommendations since we have similar tastes for our system.  Top recommendation was the Tung Sol round/oval black plates.  Those were out of my price league right now.  Next were Ken Rad vt-231, 50’s Sylvania 6sn7w, 5692 RCA. 
 

I was in talks with Brent Jesse for some Ken Rad vt-231 clear glass.  Then I was gifted with Ken Rad 6sn7 188-5 date code 8-43.  They didn’t have the vt-231 or 6sn7 designation and only say Ken Rad.  I installed them in the input stage and left the Shuguang in the output.  From the start, bass was improved and had more detail.  As they warmed up more music snapped into focus and there was more separation and layering.  By the second day, the KR bloomed but the bottom end seemed tubby(?).  Did some research what to roll in the output stage.  I wasn’t able to find much info about tubes for the output but did find a post about one audiophile using 7N7 with an adapter.  From what I gathered, the 7N7 is a drop-in replacement with the adapter.  Supposedly, all 7N7 were manufactured by Sylvania.  National Union did make some and are very rare.  The construction of the short and tall  7N7 are similar to the Bad Boys/Chrome Domes.  Think one even suggested similar the the 6sn7w.  With the 7N7 in the output, everything got refined. More micro-details, lower noise floor, more solid bass.  Took the KR to another level.  I do wonder what the KRvt-231 would sound but for now am very happy.  As the 7N7 warm up/break-in more, I’ll report back if they will stay.  From what gathered, Sylvania’s can sound bright in some systems. 
 

If those Ken Rad's are in fact from 1943 then they are the same tube as the VT-231's which was the designation for Military tubes.  Same tubes different badging. That would make them 6SN7GT's for normal sales channels. The fact that replacing the other pair of Chinese tubes with any good quality NOS tube improved things is not a surprise.  I found the Shuguang's that came with my DS2 and the Linlai's to be a big disappointment. 

@jackd what Linlai tubes did you have? I find the Linlai elite tubes to sound better than the nos ken rad vt231, now will they last as long is another question.

invalid and @jackd, IME your system is no stronger than the weakest link. OTOH, music is very personal, so weakest link is subjective. So, reviews of tubes are going to vary based upon the neutrality of the system, and the predilections of the user. I tend to error on the side of neutrality, or what I perceive as neutrality. I judge neutrality based upon music without electrical power as once you introduce electricity there is no way to actually know how an electric guitar or synthesizer is supposed to sound. OTOH, with a neutral system you, if you know cymbals for instance, you can determine the manufacturer. I don't know cymbals, but those who do can differentiate on neutral systems I'm told. Anyway, old tubes, 6SN7, or 7N7s historically have been disappointing in my system. The E-6SN7s by Linlai sound pretty good. 1964 and older 6H8C Soviet tubes sound the best. The DS2 has various output capacitors. Mine had V-Caps, ODAMs, bypassed with CuFT's, which are very transparent, aka accurate. All of this will impact the sound of the tubes. Ultimately what I like may not be worth anything to someone looking for different attributes and neither of us is wrong because music is personal. I know nothing about newer versions of Vandersteen speakers, but older ones buried details, IME, but while I hate that about them, others love it, neither is right or wrong, we are just listening in ways that appeal to us. The end result is pretty hedonistic IMO, so what another wants is subjective and is therefore only right or wrong in the ears of the particular listener matters. That said, the 1964 and prior 6H8C tubes with the square getter, IME are awesome. I haven't revisited my NOS tubes since several critical upgrades have been made to my system, but I am not expecting any surprises. This opinion was worth every cent you paid for it.

I’ll have to check out the 6H8C and try some time. 
 

I’m really liking these Ken Rads.  The 7N7 Sylvania I’m still trying to figure out if I like the Shuguang more in the output.  The Sylvania seem the be neutral or what I call transparent since a lot more detail is coming through.  More noticeable than the Shuguang.  The 7N7 can sound a bit forward with some recordings.  I don’t want to say they sound bright but the highs seem to be tipped a bit too much. 
 

I then did a test where I turned the gain for each channel one click lower.  Seems all the info I heard before is still there but the highs aren’t tipped to where it can sound bright.  
 

I don’t know much about the gain controls.  The instructions from Don says to start at full throttle so that’s where I put them. Are the gain knobs used for impedance matching?   Are others leaving at full throttle or do you lower to fine tune?  My OCD wants me to crank it back to full since that’s what Don recommended and I feel like I’m limiting what is going through.