I have a Loft Model 450 delay/flanger (single rack unit) that I picked up recently that is a little sick. It works in flange mode, but not in delay mode... I get dry signal passing, just no delays. It's probably a long shot, but I'm wondering if anyone would have a schematic available for this thing?
From poking around inside, it seems a few components have been removed. It looks like around four components have been snipped out from around the NE572 compandor IC (from their lead spacings, my guess is two resistors and two caps).
Also there's some funkyness going on with the signal mix knob (normally mixes the ratio of dry signal to flanged/delayed signal in the output) which I think is related to the above missing components... In delay mode, it seems like it's "mixing" properly between the dry and wet signal: turn it all the way dry and you get nice, loud, dry signal and as you turn towards wet it gets gradually quieter until you reach 100% wet where there's silence (the delay isn't working, remember, so no wet signal is actally being passed). In flange mode it's another story. The flanged signal does diminish as you turn the mix towards dry and does increase as you turn it toward wet (so far so good). The dry signal, however, is always present, even when turned to 100% wet. It seems in flange mode, the signal mix is just turning the flange level up and down, but leaving the dry signal constantly on.
It would appear to me that the issue is with how the signals are mixing in the output section (no delay reaching the output, dry signal always on in flange mode) and I'm guessing the removed components around the compander are the culprit. The problem is, as these components were removed before I got the unit, I have no way of telling what's supposed to go there. Obviously a schematic would be ideal, but I guess that'll be hard to come by.
Any other ideas? It really is a beautiful unit; very nicely made inside, nice PCB work and good components, and it really does produce some fantastic flanging sounds. I'd love to get the delay side up and running too...
From poking around inside, it seems a few components have been removed. It looks like around four components have been snipped out from around the NE572 compandor IC (from their lead spacings, my guess is two resistors and two caps).
Also there's some funkyness going on with the signal mix knob (normally mixes the ratio of dry signal to flanged/delayed signal in the output) which I think is related to the above missing components... In delay mode, it seems like it's "mixing" properly between the dry and wet signal: turn it all the way dry and you get nice, loud, dry signal and as you turn towards wet it gets gradually quieter until you reach 100% wet where there's silence (the delay isn't working, remember, so no wet signal is actally being passed). In flange mode it's another story. The flanged signal does diminish as you turn the mix towards dry and does increase as you turn it toward wet (so far so good). The dry signal, however, is always present, even when turned to 100% wet. It seems in flange mode, the signal mix is just turning the flange level up and down, but leaving the dry signal constantly on.
It would appear to me that the issue is with how the signals are mixing in the output section (no delay reaching the output, dry signal always on in flange mode) and I'm guessing the removed components around the compander are the culprit. The problem is, as these components were removed before I got the unit, I have no way of telling what's supposed to go there. Obviously a schematic would be ideal, but I guess that'll be hard to come by.
Any other ideas? It really is a beautiful unit; very nicely made inside, nice PCB work and good components, and it really does produce some fantastic flanging sounds. I'd love to get the delay side up and running too...