Tube Amp, Preamp upgrades -- what did you do that improved your units?


Hi folks,
If you upgraded a point-to-point wired tube amp or preamp, what did you upgrade?
I assume capacitors, but was there anything else which you upgraded that made a genuine difference for the sound?
I am looking into improving the caps in my Quicksilver stuff, but before doing that, I am curious if there's anything in addition to caps which I should consider.
Thanks.
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Wow. The Odams never sound congested in the over 20 units I placed them in. In audio it seems nothing is ever absolute. We get that. I know Jeff at Sonic Craft likes the Miflex. The Jupiter copper caps sound better, but he no longer sells them. He will push what he carries and that makes sense. He told me the Miflex sounded as good or better than the Jupiter copper foils for less money so I tried them. I just cannot agree. They are too forward sounding in the electronics and crossovers I placed them in. The Odams were the best of the lot. Just my opinion.

Some like that forward, front row perspective and that is a subjective preference for sure. This is why nothing is absolute. Builders have sonic preferences just like the rest of us.

The one thing I find strange however is the congested comment on the Odams. I have never heard it. No other comment I have heard or read suggests this either. This is an outlier opinion that has me scratching my head my a little 🤓. However, I greatly respect Aric and his builds.  He does great work and that is a fact! 
@grannyring With regards to Jeff selling what he carries- it’s just the opposite. He carries what customers want and expressed to me that even though he believes the KFPMs to sound better than the KPCUs, he has sold over 2,000 KPCUs and about 66 KFPMs. He keeps up with what there is demand for and is a stand up guy. I just wanted to address that point, the rest with regards to caps is opinion. All that matters is that you enjoy the music! Thank you for the kind words, and respect :-)
Agreed. My point is vs Jupiter caps and those are not being carried for other reasons beyond what we want as I understand it.


Jeff at Sonic Craft is a great guy and I have learned a great deal from him. Big plus for the industry! I will try the other Miflex caps based on your comments here. I have only tried the KPCUs based on Jeff’s suggestion.
Yes Solen Fast caps are made in France. They could very well be used by QS. They are the very definition of modest quality…at best. Dull and flat sounding compared to the better ones mentioned here. Used by many builders because they are very low cost. Some builders do have real cost constraints to contend with. 
I agree with granny again.  Miflex are really great caps but they are forward (not harsh though) in their presentation.  I've never heard an ODAM sound congested.  At the risk of sounding VCap biased, maybe the Odam was revealing something in the source component?  

I also love the British made ClarityCap.  I like them (personally) a touch more than Audyn's higher end stuff.  The good to best ClarityCaps can sound holographic and surreal while being pretty neutral.  

Auricaps are great on a budget. 

Mundorfs are overall great caps. I just like the other options for my taste. 

If you really want to experiment, you could buy the Musical Paradise preamp, which allows you to roll coupling caps as the unit uses binding posts (like speaker posts) for coupling caps!  Very cool.  I picked one up for $500 and use I to test out cap sounds.  I know, though, that the results are a skewed by the circuit too, yet this preamp has a fairly simple design.