Retirement integrated amp for a “fiscal conservative”

@ezstreams Congratulations on your retirement, welcome to the club. It is off golf season for me currently, so I am listening to my system about 12 hours a day, some critically, some background as I browse forums and sometimes post, like now, but it is a wonderful life.

Looks like I am much more productive than @wsrrsw , I get half of my nothing to do done at the end of the day. 

Plenty of wonderful suggestions in here, I am sure you would enjoy many of the recommendations given, and you will never know what an Accuphase or Coda integrated will sound like in your system until you try it, but I wouldn’t be so anxious to replace what you have based on the possibility of a few future tube replacements. Knowing what I know, which is half as much as half of the people in here: 

First: I can’t speak to your integrated exactly, but I have the Primaluna EVO 400 pre, and I can tell you changing the tubes to older ones (NOS) from the ones supplied radically transformed it- it is not the same pre-amp at all. From memory I can’t confirm that the bass went from a bloaty ponderous flab to the tight defined tuneful bass I have now, but I recall resolution and clarity being transformative- I could put the stock tubes back in and compare just the bass if you are interested, but then this is a pre and not an amp so I don’t know if that information would translate. As some have stated in here call a reputable tube seller (mentioned in this thread) and get some advice- they might even give you re-buy back if it doesn’t work out.

Second: I didn’t see cables mentioned- but I skimmed the last 2 pages and didn't check your original post again, so I may have missed it- but you can get much better bass with upgrading your power cables/interconnects, so that may be an option. 

Lastly, don’t think solid state amps are problem free- I have had issues and repairs with everyone I have ever owned- everything has a life. Even the reported wonderful, bullet-proof, efficient, and environmentally friendly class D amps- my Nord NC500’s went through both of the power supplies in 4 years- tubes can last longer than that.

@ezstreams On the PL HP (had one) it’s only the two inside pre tubes (3/4) you need to ungrade for something fancier to alter sound.

@mclinnguy  Half ot nothing. Who would have thunk? Please don’t overdo it!

@mclinnguy thank you for your observations. If it’s not imposing, I would appreciate you testing to see if the NOS preamp tubes you now use did tighten the bass on your system (your system A looks and I’m sure sounds fantastic!). If you can only swap tube positions 3 and 4 as @wsrrsw suggests, that would be an extremely useful test (at least for me). 
I really don’t want to go down the cable rabbit hole right now. I currently have mid level Audioquest and Morrow cables throughout (fiscal conservative 😂). 
Again, thank you both for your time and thoughts. 

@ezstreams

Thank you- actually the system has changed so much this year -the amp I am using right now isn’t even listed in my virtual system yet.

It has been a while since I tested tube rollin’ in the EVO400 myself, so no worries, I needed a good excuse to experience the differences again.

Quick answer: Yes, absolutely the bass tightened up with my RCA Cleartops over the Primaluna stock 12AU7’s.

I still have the Prima Luna OEM 12AU7’s in the carrier spots on the sides (#1 and 6 spots) and I left in the 1960’s Mazda/Brussells f33 rectifiers for all listening. (I think that is what they are ) And RCA Cleartops in the middle 4 spots. I listened to Buddy Guy’s - Blues Singer ’Lucy Mae Blues’ and ’I love the Life I Live’ which have always had a little loose sounding bass to my ears, and I recall it being quite bloomy in the past. I also listened to one of my favourite basstest tracks Holly Cole Train Song. Didn’t touch volume, or anything else, just turned off the pre amp, let it cool a bit, and changed tubes.

First I put in all 4 Primaluna 12AU7’s back in the middle 4 spots- Buddy Guy sounded MUCH louder, and fuller everywhere, and the bass bloomier/less tight- I had an urge to turn it down, I only lasted 5 seconds but clearly obvious-I quickly changed to Holly Cole. Surprisingly I didn’t notice this as much, I believe it was a little looser, would need to go back and forth again to be sure, but after I heard the additional sibilance in her voice it was hard to focus on the bass again!

I put in just the middle 2 RCA’s as suggested, and yes bass became much tighter and controlled- and the loudness I experienced was gone. And just as important Holly’s voice sounded less sibilant.

Putting back in the other 2 RCA’s in #2 and #5 positions to have all 4 back in front, bass was leaner again, but minimally so, perhaps half as much as the middle positions? so Warren was correct in the middle two positions made the most difference.

Now I am wondering if bass, while a little fuller and bloomier with the mix of RCA and PrimaLuna OEM’s compared to all 4 RCA’s might have been more even-keeled? Hmmm, would need more testing to determine a preference personally, but your question is answered and my curiousity satisfied.

As always, my system my ears, and this is with a Zavfino Silver Dart power cable into the back of this EVO400: YMMV- this is my result- pretty obvious actually.

And these RCA Cleartops are the only 12AU7 tubes I have experimented with so far. I planned to get more but after getting these felt the improvement was good enough, and decided to do other things first. Bugle Boys, Telefunkens may be nicer, and for your concerns tighter still in the bass, I don’t know. But Brent Jessee has these RCA Cleartops for just $39 each- so you could get all 4 for the price of one Telefunken!

Whereas a "rabbit-hole" powercord that could tighten up the bass this much would cost many multiples of this, methinks, so a tube experiment would be good bang for the buck.

@ezstreams Please read this on Agon Seeking a Warm 12AX7 Tube for Preamp. Tube rolling can have nice benefits.