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
With tube amps you are good with output caps from .47uf to 2.2uf.  If you want a more holographic image I suggest two cap brands.  
- VH Audio Odams 
- Duelund CAST CuSn - tinned copper version 


What do you think of the Audyn, miflex or the Rike Audio Q cap if you have heard them.
I need 4 caps and the brand mentioned above are going to cost a lot. 
No doubt that the cost can escalate with having to acquire 4 capacitors depending on the particular one chosen (Interior space is a consideration as some capacitors are large). I can absolutely vouch for Duelund CAST Copper  foil capacitors. 

 Put them in my Speaker's crossover (Only required 1 per speaker) and as output coupling capacitors in my DAC. This was grannyring's suggestion to me years ago.   Simply superb sound quality outcome in both instances. Worth every single penny to do so.
Charles 
If cost is the issue, then consider a smaller value VH Audio Odam. Perhaps a 1.0 uf. In the end if these are still too costly for you, then a Miflex will be better than the others you mention. Yes, I have used all the caps you mentioned.

Please be aware that the Miflex caps are huge and may not fit easily based on the value you decide on. Check for fit first.  Simply look up the dimensions and make a mock up using a properly cut and rolled piece of paper or thin card stock.