Headphone amps


I like to listen to music at night - my wife likes to sleep - I can't understand why she does this with so much good music to hear. Headphones have been a blessing for maintaining peace given our somewhat different nocturnal patterns. I'm soon getting a new integrated amp without a headphone jack, so I will require a little amp for the headphones. Please provide recommendations for headphone amps that you have used and loved. I like to listen to jazz and classical at night. I'm using a FMJ 23 as a source and I tend to like tube sound. I have Sennheiser HD 600 headphones.
johnrob
The microZotl works just fine with the Senns (my second HP rig), but may be a little laid back for some. The 650 is better. Hard to find the micro used, but they do turn up on Head-fi occassionally. Cheaper than the RKV for sure.
Danlib1,
I compared it to the Antique Sound Labs MG Head DT OTL mk III (say that fast 3 times) and the Grado RA-1. I preferred it over these two with the stock tubes. The Woo sounds even better with the Mullard tubes as well. IMHO, I don't think you can beat it for under $500.

I also used it as a preamp for a month while I was between preamps. Although it didn't embarass itself, sounding quite sweet at times, I wouldn't recommend it as such. It was a bit noisy and limited operationally for my preamp tastes. I had just sold my BAT VK-31SE, so it is quite a step down from that, as one would expect.

As for customer service, I wouldn't say they are the best either. The unit comes with no manual or power cord. If you buy direct from Woo Audio, they e-mail you a 2 page manual, which tells you there is no power cord. I haven't had any service issues, so I cannot comment on their response. It did take 3 weeks after my order to receive my unit. So overall, I wouldn't say that customer service is their fortay. They do make a good sounding head amp though.

Cheers,
John
I am currently using the same source and phones in my office setup, and can readily endorse the microZOTL. I do agree that it is a touch more laid-back than some SS amps I have heard (Headroom). Nonetheless, I find this to be a good match with the Ring DAC of the Arcam, which I find to be very detailed, yet forward. Good luck - a great headphone setup can amaze and engoss you.
I third the Earmax. Relatively inexpensive OTL tube amp, small and portable, and a very impressive sound with the Sennheisers.
To all,

Thanks for the ideas. I look forward to further research; however, it appears that auditioning some of these units prior to purchase might not be possible since they are mail-order. It does appear that several of the little amps have been endorsed by several people and will likely sound better than my existing, but soon to be eliminated, amp.

John