headphone amp

There is no real need to spend that much on a headphone amp to get good sound. I own both Grado RS-1 and Sennhiezer 650HD.

If you need just an amp (no remote) the Gilmore Lite from headamp.com will do the trick for $400. They also sell "better" amps too. If you want a tube amp the brand Single Power is worth checking out.

Also benchmark's DAC1 has a good headphone amp too. It could also upgrade your system's DAC depending in what you own and start at $1000.

"If you want a tube amp the brand Single Power is worth checking out."

NO do not even think of Singlepower! Please read all the threads on head-fi.org about Mikhail's dangerous shoddy engineering and fraudulent business practices. He has disappeared, leaving many customers out $$$ and equipment. While his amps once commanded a stellar reputation, he has been exposed as a fraud and crook.
Don't buy any used Singlepower amps either unless you are an engineer and can redo the wiring.

Do not buy Singlepower! He ripped me off for $6K on the last amp i got from him. they are also hit & miss on the used market. (mostly miss) The remarks "fraud and crook" are being to nice IMO. Stick with offerings from Headroom or Headamp, or Woo Audio.
Lots of info on www.head-fi.org or www.head-case.org

That is pretty sad to hear about Singlepower. I had one of their amps about 10 years ago and thought it was pretty good... Sorry to hear so many people got screwed! Hopefully you paid with a Credit Card and could stop payment.

Headamp always seemed to be more geared toward the Grado band and Headroom always seemed to favor Sennheizer (very general and IMO). I have owned a few Headroom amps and a few Headamp amps and they all were pretty good. I felt that Headamps were better buys but I have not heard Headroom's newest line.

I would argue that you look for an amp to drive the Sennheizers well. Most anything that can drive the Sennheizers will drive the Grados with ease. Keep in mind the Grados are 30 ohms while 650s are 300 ohms. But some amps may be better suited for Grado because of impedance matching.

I heard the woo amps at RMAF and they were very impressive.