Best headphone amp for classical music CDs?


I am listening to classical music CDs on Sennheiser HD700s through the headphone jack of the Marantz CD6006. I am pretty happy with the sound--the built-in DAC/headphone amp on the Marantz are good. Question: would a separate headphone amp (not DAC) make it better? In particular, I have been considering the Burson Audio Soloist SL MK2 and the Graham Slee Novo.

Please let me know which of these you think would be better or whether neither of these would really improve on the Marantz sound.
shostakovich
The HD700s are not the easiest thing to drive. would suggest something with at least 30-50 watts per channel into 8 ohms. with the impedence of the sennheisers you may be able to get a few watts output.

would also suggest you take the plunge and buy the least expensive denafrips DAC. it will blow away the chip set in your Marantz.

Happy listening.
 
The impedance ranges from 150 to 380, but sensitivity is 105 dB. So an amp that is fine with the impedance range and get clean 0.5 to 2 watts?. Did I get this wrong?.

If you are using the single ended converting them to balanced will help.
Since headphone amps that have balanced outputs can put out a lot of power compared to single ended, in my limited experience.

Check out the Audio-gd gear, Kingwa specs them across the wattage across impedance range for both balanced and single ended outputs, class type and also have measurements for you to look at.

In my opinion try going for Class A for sure, with headphones you will notice distortion much easily.
I recently purchased a Rupert Neve RPHP headphone amp....I am using it with Grado RS2e and it is a great amp...  it drives my 600 Beyers pretty well too.

https://rupertneve.com/products/rnhp-headphone-amplifier/

Fantastic amp,  detail retrieval is excellent, dead quiet.  Best $500 I have spent on audio in a long time.