Don’t get me started on 6V / 7V tubes…
Haha!
I’m going to go with the factory tubes for as long as it takes for me to understand the sound and understand what areas of it, if any, I’d like to change. 
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Great thread!
I have had a bunch of Pass Preamps / Amps over the past 6+ months; Pass X150.8, X250.8, XA30.5, X2.5, XP10, XP20, and most recently XP12 and HPA-1; In the way back an X250.5 paired with X2.5 and then a BAT VK51;
I really like Pass gear, Nelson Pass’s contributions to the DIY community, the company, etc. Great stuff; Sort of in parallel to my experimentation with the more current Pass gear, I dipped a toe in the Luxman waters…started with a 507uX integrated, then 509X (stunning and wonderful, and despite my love for the Pass gear, I had no choice but to part ways with the X250.8/XP12 combo as the Lux had bettered in all the ways important to me);
Somewhere in the above machinations, I landed a new PS Audio DSD with Bridge II, and quickly realized what an incredible piece this baby is; Prior to this DAC I had a Meitner MA1 (V1 and V2–did the upgrade myself), Exogal Comet +, Ayre Codex;
Current system is:
PS Audio DSD w/ Bridge II (latest update to fix the DSD pops…works 100% perfectly and I love it with Roon)
Luxman M-900U amp;
Dynaudio Contour 60 speakers;
IsoTek Aquarius Evo III conditioner;
Transparent Audio PC; mix of other Wireworld PC’s; Wireworld Silver Eclipse 6 speaker cables; AQ XLR cables
…enter the BHK.
Stock tubes were fairly noisy and presented lots of very irritating pops/ticks when changing volume and especially at the attenuator transition points, a real nasty DC pulse that made the meters on the amp jump; I went to Upscale Audio and got Genalex Gold Lion Premium matched 12AU7; that did the trick. No more noise. the other bit of noise, the gentle hiss from tweeters and midrange is livable;
The BHK sounds notably better than the PS DSD direct to Lux; I only have about 24 hours on the new tubes and the PRE only about 125 ; I have used the HPA-1 also and will update later about comparisons, but looking forward to more time on this wonderful sounding BHK!
I agree with the above mention about “personalities”; Indeed there are differences, some nicer some not so much; The final “AHA” which is brought out by micro scale (I have found that us audiophiles generally agree on macro performance) adjustment, is ultimately dependent on individual, and hence, subjective tastes. In our audiophile realm, the micro world is where we live and breath, I think…just my 0.02;
Cheers and happy Friday the 13th!
PS: really admire the forum here and philosophy of PS Audio. Good Stuff.
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Thanks for the tube recommendation! My BHK only has about 80 hours on it so I figure it’s not burnt in yet, in a few months once I get to understand it’s signature I know I won’t be able to resist trying out some tube options.
@audiopacer , this may be slightly OT, but can you describe any differences between the 250.5 and 250.8?