I’m working on a phono pre upgrade and am looking for the best capacitors.
I’m searching for (2) 0.1uF/400V and (6) 1uF/400V caps. I have the DigiKey references, etc. but am not sure of which products to consider outside of the specs. Is anybody hip to this kind of stuff? Thanks!
A large number of manufacturers of high quality audio in recent years utilize WIMA as their choice. I use them as well for a number of signal path and decoupling purposes.
http://www.humblehomemadehifi.com/Cap.html
I recently rebuilt my speaker crossover with Sonicaps Gen 1 and Miflex KPCU-01 600VDC bypass on the tweeter. Very nice!
What Pre are you upgrading, and what is in it?
It’s a DIY phono tube stage kit…here is a shot of one that is identical to mine, but has better caps. I’ve recently invested in better valves, and just want to keep going with the project a little bit further…I’m solid state outside of this.
Ummm, anything? 
Sorry. Part of the deal is that the best thing would be to try different ones if you can afford it. It’s a bit like putting different components into a system - they may both be “good”, and you may like both - but you may end up liking one Clearly over the other in the context of the application. Best way to know.
I haven’t gotten the sense over time that swapping out parts or drivers of the same spec/values always works, especially if the designer Knew What He Was Doing. Sometimes a better part was not chosen - not because it was more costly - but because the first one just worked better, and/or the difference wasn’t worth it.
Having blathered on about that - with regard to Caps in particular - whether they are the best sonic choice or not, usually better sounds “better”. 
or at least Different.
Thanks, Mr. badbeef. I do appreciate it, and agree with everything you’ve said. I need to crack mine open and take a look at the variety of caps installed. I don’t seem to have a record of those parts from many years ago.
I do think that if possible, it is best not to get precious about it, and try stuff. Especially if it is not a central piece in your system.
Soldering technique and solder also potentially matters.
Little Cardas tents for my gear.
First, are the caps in a coupling role (signal through and blocking DC) or filtering AC/noise as part of the power supply?
Second, are the existing caps electrolytic or film? Film are generally more costly, but in a power supply, they can improve the dynamics of the music due to lower ESR.
When you say “excellent caps” are you prepared to spend $50 each (roughly) on Audio Note or Mundorf? I have used them in DACs and a phono stage, all in kits from ANK Kits.
Consider Modwright Truth-M and Truth-T. Truth-M in particular is available in 1uF. The difference is metallized polypropylene vs. teflon. Dan developed these specifically for the Modwright reference series. They are so good he sells them separately. I own a Modwright PH 150 phono stage that utilizes his Truth caps and it sounds terrific.
Thanks for the feedback, gents. I’m looking into your suggestions.
It turns out that my phono pre is a Hagerman DIY kit called the Cornet2. It’s like 10+ years old.
The suggestions from the builder for cap upgrades are Audience Auricap XO .1µF / 400V and the Audience Auricap XO 1µF / 400V.
I think the Auricap XO are a great suggestion. I’ve used their previous versions as coupling caps in a DIY tube amp and still have a pair in my speaker crossovers, in parallel with the tweeters. I just bought a pair of the XO caps (2.2 mF @200v) to replace the older Auricaps. I’m almost finished a “somewhat extreme” rebuild of the crossovers (numerous phases) and can assure you that capacitors are another important element in changing/improving the sound quality. As @brett66 pointed out, the capacitor test info is great and has helped me for many years. A final point - break-in/burn-in is a factor, especially with better parts and systems, so be patient for hearing changes if you proceed.
How much are you willing to pay for caps? You can look at sites such as PartsExpress; PartsConnexion (has full price ranges); Madisound (look at on sale page); Triode Electronics; Meniscus Audio; or the big on line guys.
