[Huskerbryce]

I recently added 4 Deulund Cast-pio pure silver foil .022uf bypass caps to both the tweeter and mid circuit of my Oticas.  Both circuits were already bypassed with miflex Kpcu-01 .1uf copper foils (tweeter) and miflex .47uf (mid), but I wanted to try the deulund silvers.  I used alligator clips to start but found it mechanical sounding.  So I temporarily twisted a 2 ft copper speaker wire around the caps on the board and stretched it out in front of the Oticas.  I could then easily attach the caps to the wire by alligator clipping the stripped copper around the capacitor leads.  The difference between the miflex and deulund was very slight.  For a few days I liked the miflex.  For another couple days I liked the deulund.  I could not decide what if any was better.  I didnt want to wait weeks for “burn in” so what I did was parallel the silver foils to the copper foils and piggyback both into the circuit.  Basically I made a hybrib copper/silver foil bypass cap.  It sounded amazing before and it sounds amazing after.   I cannot say “yes” it sounds amazing so add deulund silvers.  Nor can I say “dont” add them cause it didn't do anything.  Nothing drastically improved sound but I wont recommend against it.  To me, it was additive and not subtractive.   However, unless you have nothing better to spend your money on, maybe consider putting your money into other upgrades first.  🤷🏼‍♂️

[TRADERXFAN]

I don't get how you are including the big clip wago into the crossover circuit to test bypass caps... what is plugging into what, there?

It seems like signal would be passed through the connector on those...

Also make sure to break in the caps you are testing before you judge... I dont do this myself but seems like comments have been made about some oil caps taking hundreds of hours... sounds like in for quite the job!

[Tyson]

I've gotten to the point that I only consider bypass caps with copper or silver foil.  Especially if the main cap uses tin or aluminum foil (the vast majority).  Bypass caps are a way to get a little bit of that 'copper flavor".

[allensound]

I don't get how you are including the big clip wago into the crossover circuit to test bypass caps... what is plugging into what, there?

It seems like signal would be passed through the connector on those...

My thought was I'd twist a piece of bare copper wire on each end of the main capacitor to run in parallel with the bypass cap.  Those bare copper ends would each go into a separate wago connector, to which I would then insert the bypass capacitor...

Not sure if that makes sense in words...here's a little drawing where I tried to illustrate with copper wires twisted to each end of the main capacitor running into two separate wagos....

That said, I think I may be digging the idea of just having some wooden clothes pins and clamping the leads that way.

Also make sure to break in the caps you are testing before you judge... I dont do this myself but seems like comments have been made about some oil caps taking hundreds of hours... sounds like in for quite the job!

Definitely - I'll be doing some long-term burn in on all of the things I tinker with

Another (crazy?) question - should I strip the tin off the capacitor leads before twisting them together and soldering the connection?  It seems like if you go through all the trouble of buying all these high end capacitors and whatnot, that you would want to squeeze every little drop of goodness out of them? 

[Hobbsmeerkat]

Try these. https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/940C30S1K-F?qs=wE98CiVmOw5ePFogrQjHvA%3D%3D

Considering they're a standard poly cap I don't really see there being huge differences between it and the Gen3 Sonicap or JB JFX caps I've already tried, esp. at 0.01uF where it's also going to have less influence than the more typical 0.1uF values.
A rating of 3000V is pretty wild to see though.

From what I remember of my testing a year ago, metalized polycaps as bypassed don't do much to influence the sound of the main cap, they mostly just improve clarity, but may influence soundstage to a small degree.

To influence the tonality of the main caps, you need caps with different metals, like copper, silver, silver plated copper, tinned copper, gold, etc.
The higher end caps also really need burn in.
I remember when I was burning in the Duelund JDM Copper it did some listening and the soundstage was flat as cardboard until about 400 hours, especially compared to the Gen 3 and JB caps.

I recently got my hands on the CAST-PIO copper, and might get some Tinned Copper to compare against.

Personally, I'm not a big fan of the silver-based caps, as I've found they tended to come off as a bit gritty or grainy, but I'm sure there are some speakers/applications where they might be better suited. but I do have a burned-in pair I can test with at any point

[mkrawcz]

I recently got my hands on the CAST-PIO copper

I just swapped out the coupling caps in my ANK tube DAC with these and they’re pretty much the best.