Sennheiser HD600

I neglected to mention that I do have the upgraded Cardas cables.

Well, in that case I am willing to go out an a limb and guess that upgrading to Cardas cables is almost certainly not what you are looking for. I use an older Headroom home headphone amp that I like, but must admit that I haven't compared it to anything else and am not familiar with what you're using. So, apologies, no use when it comes to your actual question. Best of luck.

If you find the HD600 thin, then barring upstream issues (your current amp is probably good enough to drive the HD600 reasonably), there's a good chance you're in the camp that greatly prefers the HD650. I'm in that camp. They have more & tighter bass, more weight to the presentation, lass treble energy, and are overall smoother with less grain. I find that despite the "darker" signature they're actually MORE resolving than the HD600.

On cables - with the HD650, I found the Zu Mobius cable best - better dynamics, better bass, and returns all the "airiness" that I thought was exclusive to the HD600. With the HD600, the Cardas was a good match - the Cardas does smooth things out a bit, but still I prefer the HD650 w/ stock cord over an HD600 w/ Cardas.

The HD600/HD650 headphones, more so than most even many higher priced headphones, respond to source, and especially to a quality vinyl setup.

On amps - well there's a whole word out there. Best I've heard was a headamp Gilmore Dynamic Reference for SS, and a Singlepower SDS (best sounding amp I've heard, though Singlepower & its owner went REAL bad those last few years) and Eddie-Current Zana Deux for tubes. There's new options I haven't tried (Beta 22, new Eddie-Currents, TTVJ Millet tubes/transformers) that should be spectacular.

Agree with Mulveling's comparison and assessment on HD600 vs. HD650. I may also add that the HD650 is harmonically richer, and more body to the sound. The HD600 is more neutral. I prefer the HD600 listening to analog front end, and HD650 with digital front end. My own conclusion is that the HD650 was voiced to compensate for the thinness of digital sound.

I've also come to the conclusion that the HD600 mates best with Cardas cable, and the HD650 with Zu Mobius. I had done some comparison with various cables available on the market about 4 years ago. But there have been several new players out on the market these days. I have just obtained a Stefan Art cable. I have been listening to it with my HD650, but have not spent time to compare it with other cables.

Every year, there seems to be a slew of new headphone amps on the market. I've lost track of what's popular today. I have 3 headphone amps, two tube amps (EL84s and 2A3s)from Consonance/Opera Audio (China), and one hybrid amp from Rudistor (Italy).

The Rudistor has the most balanced sound, The EL84-based amp is the warmest, most tubey sounding amp. The 2A3-based amp is just a complete different animal. I am still trying to figure out how to describe the sound.

So my recommendation would be to try a tube amp. And if you look around www.Head-Fi.org, there are many offerings out there. But for under $500, I think Chinese amps will be hard to beat. They do sound drastically different with NOS tubes.

Best yet, check out the "local meet" section of Head-Fi.org. I started the headphone craze by visiting these meets so I could listen to various headphones and amps to find something that I like.

FrankC

hd600 LOVES a good tube amp