My favourite test to perform when looking at an analog delay unit is the self-oscillation test. It’s a really good way of hearing the sound of the device itself.
It involves just plugging in an output and turning up the feedback. You can then play with the delay time controls to see what tones and textures you can get out of it.
So, here’s a compilation of self-oscillation tests of some of the gear I’ve tested so far, you can find the full test videos for each unit on the channel too.
Intro - 0:12
Boss DM-1000 - 0:40
Echoman EM-150 - 1:04
Evans AE205R - 2:06
JHS MX-99 - 2:59
Monacor EEM-1200 - 3:21
Melos DE-1 - 4:38
Yamaha E1005 - 5:30
Altai EC-500 - 6:32