Took the plunge on Sennheiser HD 650

[McCrutchy]

Originally Posted by pentatonic

Well they are 300 ohms so an amp (or good audio card with amp) might be necessary for optimal sound. But they are efficient at 103 dB. Rule of thumb is the higher the impedance the harder it is to drive. Are there restocking fees at Amazon if it doesn't work out as I believe you will need and want an amp (doesn't need to be a $500 unit) For the longest time I was listening to my now sold AKG K340 electrostats and volume was there but it's not until I started using my vintage receiver to power them that I realized how awesome they could sound with an amp.

Just to clarify, would I need an amp with the A/V receiver as well?

Also, can you recommend any low-priced ones (<$200 perhaps)?