One thing that I wanted to point out was that a lot of the above bands mentioned produced better sounding music than various CD issues would have us believe. Joy Division LP's sound fine as do the first couple PIL records. In fact if you have Metal Box by PIL(3 x 45 RPM records) then you have one heaping pile o' sonic goodness! However, with many of these bands the CD issues have been terrible transfers. I find it too bad that so much energy is spent into transferring what I consider inferior music because it's "audiophile" approved. There is a ton of horrid jazz and boring classical that make any audio show you go to a truly pain giving experience.
I think it's great that the Clash have gotten enough "classic" status to have gotten remastered into better sounding CD's. It sure would be nice if there were more activity like that happening. Things like the Amphetamine Reptile catalog(Cows, Helmet, God Bullies etc) have never been well represented digitally. Again, some of the LP's sound great so it ain't the low budget recordings. There have been some decently recorded music with cheap equipment. See Steve Albini's comments concerning this.
It's the quality of the CD's mastering that make so many of us go around in circles trying to wring more sound out of them.
While I got into punk to escape the sort of music Rainchild is recommending above, it's actually pleasing to me to hear him recommending various rock music and not the usual "audiofool" suspects except for that Floyd. Man, I lived through that in the 70's and while I won't diss the utter genius of that record, I can't hear it without my sphincter clenching. Still I'd rather hear someone talking about listening to the Chili Peppers or Scorpion's than Belafonte or the ugh, Weavers.
My test discs include Boredoms "Super Roots 7" and "Pop Tatari", Spiritualized's "Ladies and Gentleman", Can "Monster Movie", Butthole Surfers "Locust Abortion Technician" (talk about wringing a lot of sound out of recording on 8 tracks in your kitchen), Pere Ubu's "Modern Dance", Velvet Underground's "Sister Ray" (a real test of resolution in your system), and Nurse with Wound's "Sylvie and Babs" and Radiohead's "Kid A". There's plenty of other underground discs that have various well recorded sounds to hear since some had good masters or have been remastered decently.
Like you Seanbaik, I have some long in the tooth digital that I'm in the process of researching to upgrade. Do I get a DAC? And like you I want a sound that's not too harsh in the upper registers(like I said those digital punk masters can be less than steller) but capturing the necessary dynamics and attack.
Of course my system is all tubes except for the CD Player. My system was solid state but that has changed over time. And I ain't never looking back.
I'm thinking of taking steaksters advice and trying some ERS paper in my CDP (Micromega Stage).
