Upgrading coupling caps - which ones first?

Sounds good re the change to 1 uF.  As you may already have calculated, in conjunction with the amp's 70K input impedance that will result in a 3 db bandwidth extending down to 2.3 Hz, and only about 6.5 degrees of phase shift at 20 Hz.

Based on that and on the values you supplied, and without knowing anything further about the design of the amp, what seems likely to be the most optimal prioritization would be doing that pair of caps first, then the 0.47 uF caps, then the 0.1 uF caps.

Good luck.  Regards,
-- Al
  

The best place to start is your source as the whole system will benefit! ! Start with your dac's output caps. Please let me know what brand they are and what sound change or difference you want. I am very versed on what various caps sound like in dac's and amps being a chronic cap roller:)

Dont  try to change too much, but rather start here and give it time to settle into your system and mind. Some caps sound fuller, some warmer, some darker, some more focused on the upper mids and highs etc... 

I support the concept of  beginning at the upstream  position  (source) and then progressively moving  down the audio signal pathway. Replacing the  output  coupling capacitors in my DAC yielded more impact than changing the  input  coupling  caps in my amplifier. Now I'll admit that changing the  single tweeter cap in my speaker's crossover was a very noticeable  upgrade without question. I used Duelund CAST in the DAC and speaker and Jupiter copper foil in my amplifier. I can recommend  either brand enthusiastically.
Charles,

Please let us know in what way you would like to change the sound. Those dac output caps will have a big impact on your overall sound. 

So far I've been playing around with the .47uF output caps on the amp and right now I am trying to decide which ones are going in there permanently.  After that I will target the DAC.  So far I have tried Jupiter copper foils, Clarity MR, Mundorf Silver Oil, and of course the stock Nichicon polyester film caps. 

Surprisingly the stock Nichicons have a lot going for them.  They have a clear, wide open sound with the best bass of the bunch, and extended highs that seem tipped up and can be a bit thin sounding and on the shrill side at times.

The Mundorfs have an extremely smooth sound that is very musical, and are a tiny bit darker with a smaller soundstage in direct comparison with the Nichicon.

When I first installed the Jupiter, the imaging was what I noticed first.  It is more pinpoint but at the same time the sound was a bit closed in.  After a few days I reinstalled them for a second evaluation and they seemed to have opened up.  Their presentation is similar to Mundorf but not as smooth, and bass is not up to the levels of the Nichicon.

I am a big fan of Clarity TC caps in the power supply so I was eager to hear the MRs in coupling duty.  The first impression of these caps are that they are clear and have a big sound to them.  They don't quite have the smoothness of the Mundorf, they are instead more neutral and true to the source it seems.

These caps were all burned in for a week with a tuner on the speaker output of an old amp connected to a dummy load.  I'm not sure if they still need to be run in some more but I could swear that the Jupiters sound different now then when I had first installed them.

So what I've discovered is that all these caps do some things great but not everything.  Based on what I've heard so far, the ideal cap would have the bass slam and transparent open sound of the stock caps, combined with the smooth liquid highs of the Mundorfs.  Does such a cap exist?  We will see.  I can only imagine the can of worms I am opening up once I start with the DAC.  Why can't I leave well enough alone!?