Calling All Tube Gurus, Poll:Capacitor Rolling vs Tube Rolling

Start with this:

https://forum.audiogon.com/discussions/satisfying-is-not-settling

I have replaced, changed tubes, moved to ’matched sets’, but never an active tube roller, I just don’t want to go there. Never capacitors, oh hell no.

I check tubes in a unit (new or used) with my simple tube tester (how could you live without a tester), then, if it sounds good, leave it alone, listen, enjoy, routinely check them every 6 months.

A short, a weak tube, a blown tube: now research is needed to make a choice, and test what I receive, listen, good, or, listen, nah.

I don’t need instant comparison, some sound great, some just don’t have the degree of involvement I used to get with known content. Just not right.

Nah, well hopefully I bought from a source that accepts returns, at least exchanges.

Sound bad: Brent Jesse (recently sold) had me break them in 1st, in case that made a difference (on, 60 hrs, no signal needed). Nah after that, pick an alternate, Oh Yay, happy days are here again, DONE! (for a while).

IOW, even if not rolling, it’s not always easy.

When I retired my vintage fisher 80az mono blocks (no remote volume), whatever I chose had to sound as good as them. Research, based on an amazing review I chose a Cayin A88T, luckily it sounded very good, then I changed type: 6550 to KT88, they sounded even better to me. Not brand rollling, but type rolling I guess.

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BIAS. Think about bias when changing tubes, you might want to start with a unit that has both safe and easy external bias adjustment and even has bias meters built-in. A few have auto-bias, I don't know more than that.

Later Cayin models have easy external bias, but my speakers are 16 ohm, and the only version that has 16 ohm taps is Mark 1. Sadly, bias is 4 adjustments, internal, no meters, old and shaky, I paid VAS to re-bias for KT88's. I did not hear any difference pre/post bias adjustment, maybe someone else might, just got it put right because I read I should. 

Much easier to do tube rolling, particularly reversing a substitution.  What capacitor(s) are you thinking about changing? One can fundamentally change the sound of a tube amp with a change of coupling capacitor or adding a small capacitor in parallel with the existing coupling capacitor.  Many modern tube amps utilize caps from the likes of Mundorf that sound very different from old school caps like the "Chocolate Drop" caps from companies like Cornell Dublier.  It certainly is worth trying different caps; just don't automatically assume that newer, close tolerance caps are superior; a lot of people, myself included, like the warmer sounding old caps.

On a few different amps I upgraded, I learned later on that I could hear tube changes more -after- making coupling capacitor changes to more transparent ones. With more veiled over and smoothed over caps, could hear tube changes less so.  

Not a cut and dry quick answer for this.  It depends on the piece of gear, what’s in there now for a capacitor and finally the location/function of the capacitor.  Output capacitors on the output of a preamp or dac can have and bigger impact for sure.  If going from a $5 cap to nice copper foil type the improvement can be remarkable and help you hear even more differences and impact when tube rolling.  Once done no need to replace the cap as it ages. One time expense. Just one example.  

Binding post rolling, amp case rolling, roll them feet...who can resist resister rolling? All are somewhat time consuming but hey...you do what you gotta do. I did stick some large Mundorf caps in my speakers (suggested by Pure Audio Project) which is the only cap roll I’ve done and they added something...or should I say "that certain something" and besides, they look cool (open baffles display everything). I have piles of tubes that lead to frequent rolling generally for no logical reason except hey...they're otherwise just stuck in their little boxes with nowhere to go.