headphone amp question

Not sure exactly what the issue is, but if the problem is sound leakage from the Senns, you might consider closed back phones.

I would recommend a Woo 2 or a Decware CSP-2 as an upgrade, or a Schit Valhalla if you want something cheap. Both will make Sennheisers sing. I would avoid solid state.

I don't know much about the ASL headphone amps...but they never gathered much of a following on Head-fi, a sign that you can do better for the same or less money.

You can take a look at the HA-160 or the 160D (with dac and preamp) both have nice synergy with sennheisers.

Maybe you can explain a bit more about your problem.

I think a good solid state amp with your headphones sound good. I think finding a Gilmore Lite is an excellent amp. If you must go tubes then the Little Dot MKIII does a terrific job. Subjectively I prefer the Gilmore Lite but the LDMKIII is hardly a slouch. Plus you can tube roll if that's your choice.

You might want to bring your question over to Head-Fi.org, if you can tolerate the signal/noise ratio of the posts there. There's a whole bunch of great headphone amps that would work well with the 580 as they're not that difficult to drive. It really depends on your budget and expectations/goals. I recently heard Schiit's new Lyr amp with a few different cans and was very impressed. You might also consider upgrading the headphones if headphone listening becomes a priority. There are many options that sound significantly better than 580's to my ears, but certainly always at some significant cost increase. For the $ they are a very good headphone.