The current issue of "Audio Critic" #28? has a short review of headrooms little amp. They said price was 159.00 so I'm not sure if this was the upgrade. Anyway it received a high recommendation.
They were surprised at the low cost and quality of the unit.
The Audio Critic is hard to find but Barnes & Noble should have it.
Tyl should know of this review since He probably loaned it to the mag.