Good amp for Sennheiser HD 598? (from PC)

The Indeed G2 hybrid headphone amp I bought on Ebay arrived from China today, fitted with a 6N22 tube and IRF510 mosfet.

After a few hours of burning in, I conclude that going from:

Imac >> Nuforce UDAC 2 >> Sennheiser HD598

to

Imac >> Nuforce UDAC 2 >> Indeed G2 hybrid tube amp >> Sennheiser HD598 

makes a HUGE improvement.

Yes, the HD598's have 50 ohm impedance so even an Ipod can raise sound pressure on the HD598's to ear damaging levels. However, the amp lifts the sound of the headphones to a whole new level adding detail, clarity, impact, bass, bass extension, ...

Hybrid tube amp = Highly recommended for use with HD598! 

Tell me please, do you hear any noise coming out of HD598 when plugged into u-DAC2?   Like when not playing any music, and just having the u-DAC2 at low volume level, like 9-10 o'clock?   The noise im talking about is high pitched (about 12 khz) constant buzz, very silent, but people say its present. Can you hear it?  

Also, in which ways does u-DAC2 improve sound compared to just plugging your headphones into sound card?  Does it make it louder?  Clearer?  More bass? Is it a noticeable difference?    Do you hear any channel imbalance when listening trough u-DAC2?

Sorry for asking so many questions, but i was about to buy u-DAC2 when my friend told me they had some faults.

I have Sennheiser HD558 modded to 598.

That NAD is overkill for the 598, not even sure if it has a headphone output. Anyways the UDAC2 can also feed a real headphone amp (UDAC is essentially just a DAC with a good potentiometer), but that should do well for just the 598. Hold the amp upgrade until you get another headphone and if at that point the UDAC2 seems like it might need a little help.

I'm going to buy HRT Music Streamer II / II+ and Indeed G2 to use with my 598's...

As soon as I can make the decision what models to buy :)

(Can I hear the difference between II / II+ with 598's -> is II+ worth the extra dough, and what tube, 6922/6N11/6N23P, would best suite my taste. 598's are just a little too bright for me)

Quote:

Originally Posted by dogilainen 

I'm going to buy HRT Music Streamer II / II+ and Indeed G2 to use with my 598's...

 

As soon as I can make the decision what models to buy :)

 

(Can I hear the difference between II / II+ with 598's -> is II+ worth the extra dough, and what tube, 6922/6N11/6N23P, would best suite my taste. 598's are just a little too bright for me)

I was thinking about buying a tube amp as well for my HD558, because after modding them to 598's I also find them a bit too bright and a bit too "difficult" to listen to for a long time. Its really not a typical Senn sound.  Its more like a sound for showing off, it makes a great first impression with details and clarity, but in 20-30 mins it becomes almost painful.  My old Senn headphones were always cranked up at high volumes, but I often find myself listening to HD558 at really silent volume levels.

A pure tube amp may have difficulty coping with the current needed to drive low impedance headphones like the 558/598. I would recommend either a solid state or hybrid (e.g. tube with mosfets in output stage) amp. 

Quote:

Originally Posted by Bacci 

A pure tube amp may have difficulty coping with the current needed to drive low impedance headphones like the 558/598. I would recommend either a solid state or hybrid (e.g. tube with mosfets in output stage) amp. 

 Duh, I thought all Indeed G2 amps are hybrid!