Headphone amp advice

Sharky, GK 1-J foto: I have it, but haven't uploaded pics to my virtual system yet. It is an unassuming black box, weight ca 200 grams, size 12 cm deep x 9 wide x 5 high. It has two output jacks and a volume knob in front (can used balaned h-phone cable, or 1-2 standard h-phones) and 2 x rca inputs and power adaptor input at the back.

Ptmconsulting: wish you good luck with the building. Now that my Jade has become housewarm, there is absolutely no going back. The OTL sound was a bit bleak at first, but I'm warming to it, or vise versa. I guess most good h-phone tube amps will take you there.

Note also, I can use the Jade with my small active speakers, Sony SRS Z500, with good results (these are single-driver speakers, well designed). This is a bonus for me, since headphones are headphones, to put it that way.

Possibly, small passive single-driver speakers would sound even better, if the Jade and similar tube headphone amps are able to drive them. The GK can drive my bookshelf Royd "The Sorcerer" speakers to a listenable level, the Jade cannot, but the 2-way Royds are a fairly heavy load.

GK 1-J picture, now uploaded to my mobile system.

I am very satisfied with my new headphone amp Audiotailor Jade. Great sound. It can drive headphones excellently, and even drive small active speakers to new heights. See Jade thread at headfi:
http://www.head-fi.org/forums/f5/review-audiotailor-jade-vacuum-tube-headphone-amplifier-389381/

We are soon ten years after - and the Jade has served me well for all these years. If you can find it, buy it. Or at least take a listen. It has a remarkably clear, coherent and musical sound, especially with NOS tubes (1 Telefunken driver, 1 RCA output). It has the marvellous full-scale clarity of OTL. It drives my desktop active speakers (Sony single drivers) very well, and headphones sound great, especially after I modified my AKG 701 to run balanced (using both outputs on the Jade).