headphone amp question

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.

I agree that Head-fi has deteriorated in recent years to the point that it is impenetrable unless you keep track of members who have something of value to say and ignore those who are just running up their post count.

FYI, I have owned a lot of headphone amps in the last six years, including amps from Luxman, Meier, Woo, Singlepower, Blue Circle, and Original. I have also attended meets and have heard amps from Ray Samuels, Burson, TTVJ, and Decware.

Headphones like Sennheisers have a fairly high impedance. I have found that OTL headphone amps offer the best sound quality. If you like Sennheisers and can afford an OTL from Woo or Decware, you will get amazing sound quality...liquid, full mid-range with no sacrifices in terms of bass. FYI, I enjoyed my Sennheiser HD650s much more out of my Singlepower Extreme, an OTL tube amp, than out of my Luxman P1-u, one of the best solid state amps on the market with a retail price of $3,000.

So for high impedance cans, go with an OTL, as their performance is amazing and they are often less expensive than transformer-coupled amps. If, on the other hand, you plan to switch to low impedance cans from Grado, Audeze, or JH Audio IEMs, a transformer-coupled tube amp or a solid state amp would be a better choice.