Ooh the bonniness of valve tape echo! This is used for vocal reverb. Bought on e-bay for £140, a bargain! It should have a cover over the tape loop, but this seems to have gone missing over the years. This was a high-class unit in its day. Far superior to the Watkins Copicat which was really a budget kinda thang. It can be a bit tricky to get the right sound, but it sounds excellent.

[Schematic 1]
[Schematic MKII]

Check out Tim Fletcher and Steve Russell's Selmer Truvoice site for more Selmer delights.