I believe all you had to do was connect the meter to the speaker out of the amp. Can't vouch for their accuracy. I have an RS LED model somewhere.
Also have a Heathkit AD1701 (LED) that can connect via speaker or line level. I think that Onkyo used to make a large "component" sized VU meter. Watch on EBAY. If you are just looking for a light show you could pick up an old o-scope on EBAY, hook it up and play Pink Floyd DSOTM.
Also have a Heathkit AD1701 (LED) that can connect via speaker or line level. I think that Onkyo used to make a large "component" sized VU meter. Watch on EBAY. If you are just looking for a light show you could pick up an old o-scope on EBAY, hook it up and play Pink Floyd DSOTM.