Boutique caps in oil... reliable?

you might take a look at the Vandersteen high pass. There are 3 models in relatively small form factor boxes. As you go up the line cap quality improves. All have battery bias to keep the caps formed. I use a Teflon model w my Treo  / sub 3 system and the M7 amps have a built in HP filter. As i am sure you might surmise, beware creating a tanking circuit…. You can see a picture of some of the internals on the Vandy website.

Best to you - keep after the DIY projects, they sharpen the mind and tge ear.

• I was planning a DIY high pass but instead recently added a Marchand XM46 XLR Passive Line Level Balanced Crossover between my preamp/buffer and my amplifiers, which rolls off my main speakers at about 45Hz.  I cannot hear any noise or other ill effects from having the Marchand crossover in my system, but it does result in improved bass.

Thanks for the recommendations. The complexity for me is not the high pass filter. It’s a circuit that works on the AVR’s 12V trigger and lets me integrate the sub into both the Anthem AVR and Luxman Integrated.  I think I pretty much have it figured out, but need to shop for nice sounding caps to use.

@charles1dad Thanks I had no idea you were considering AN when you bought your Yamamoto. And did a bit of reading on the Abbas site he credits Andy Grove from AN UK for a lot of his background knowledge and the George Slawa of Sw1x is his protege. A small incestuous design world I have to say I love manufacturers sharing ideas like that. Apologies to @erik_squires for the thread hijack and please create a thread for your Abbas Dac impressions Charles.

The only oil caps that I’ve seen leak (I’m sure there are others) was Jensen oil caps. The Jensen copper foil paper and oil were notorious for leaking within 5-10 years. I never really cared for their sound anyway but after replacing one after another for people I definitely wouldn’t recommend them. Some leaked within 2 years.
V-Caps are amazing and never seen a problem with them. I’ve also seen most Vitamin Q caps still working even at 15-20 years. Not that they sound great but they are good cheap oil caps.
Of course it’s all about the cost you want to put into equipment and sound taste.