Capacitor


Dear friends I am interested to upgrade my caps in the tube preamp from Audio theta tin foil 3uf200VDC to Miflex1uf 240VDC copper foil what are your thoughts will reducing the value to 1uf affect the bass and frequency response or should I go with a higher value than 3uf  
jasbirnandra
I have been doing capacitor upgrades for some time now i,especially coupling capacitors in dacs, preamplifiers 
and loudspeakers . The best capacitor for detail  is without question the VH audio CUTF  -Copper foil Teflon it only goes up to 
2 uf I believe , as a main Cap ,my best combination is
for main cap Jupiter Waxed paper Copper foil ,which inside a amp is good to at least 160+ degrees ,no more bees wax. Use  up to 3% of the VH audio CUTF bypass capacitors , they are pretty expensive and room in m any cases is an issue ,I just installed this in my Coda CSIB integrated , and helped a friend in his Loudspeaker this is better then the Duelund cast  capacitors 
at much lower cost they do need a solid 400 hours to fully open up 
But a fantastic combination ,and my preamplifier now is in another league sounding . If you email me I can send you a couple pics to show scale,size.
What I forgot to mention the Duelund are a great capacitors way too  much $$
and huge, they  are top notch caps great detail and depth ,just slightly better the the Jupiter in layering ,but the Jupiter Copper foil has great overall balance, and much less $$ ,they are within a % point or two of each other 
detail on top is very good on both  ,but the VH Audio CUTF  is the best of the best in that 
dept by adding between 2-3% in the VH as a bypass cap the best of both worlds
if you have  a capacitor you need 2 uf or under the VH audio are pretty neutral 
slightly to the warm side but very big and for a pr of 1 uf for example around $1k.
greatness  cost $$.
Jupiters will be here with me in 2 days can some one explain how many hours of burn in will open the cap and what should I expect in the sound  in the process of burn in to stay on track and not discard the caps
Prior to burn in, I generally hear what I'd describe as an uptight sound, lack of transparency, also, excessive attack , attenuated decay. I'm not going to generalize about tonality, timbre. For sure you'll know when they reach burned in state, often the change comes on in what seems an instant. Suddenly you'll hear an opening up, could also be called blooming of sound. I'm sure the burn in process is slow and ongoing, but almost without exception, the last bit happens in just an instant. Many say 100 hours is usual for the process, I hate to say any particular hours, expectation bias sets in with a set amount of hours. I'd say anywhere between 75 and 200 hours should get you most of the way there.
I usually don't even bother listening anymore prior to 75 hours or so, why suffer the burn in if you don't have to. You may be tempted to come to conclusions prior to burn in if you have to suffer through disappointing sound for too long. If new to cap swaps you may want to hear at least occasionally during burn in to evaluate before and after burn in sound.