Audio Research SP-9 MK II version. The SP9 preamp is known for it's warm, sweet sound and it comes with a phono stage that is worth the money by itself in my opinion. The SP-9 uses two 6DJ8 tubes. The line stage has a beloved Hewlett Packard tube marked Made in Gr. Britain while the phono stage tube has no visible markings. The unit is in perfect working order and will be sure to please. The unit looks great but has light handling marks which can be seen in full sun as noted in pictures. A Cannon hi res camera was used in full sun light to reveal any flaws so that you can buy with confidence!