Spring Reverb CIrcuits

[gstopp at fibermux.com]

     I've used normal op-amps (i.e. 1458 etc.) back in the days when all I 
     cared about was raw sound and getting stuff to work at all. It worked 
     OK but I do remember some hiss. Probably if I still had these around 
     I'd be shocked at what I used to think was an acceptable noise level!
     
     I remember Craig Anderton had a PAIA kit called "Hot Springs" - 
     anybody ever build these? John? Any advice? Are the schematics still 
     around?
     
     I think if I were to have a sudden craving for another spring reverb, 
     I'd probably try to duplicate the Moog 905 Reverberation Unit from the 
     original modular schematics. Four transistors plus various resistors 
     and caps, line level input. For some reason I like the timbre of that 
     module. I suppose some experimentation with finding the proper 
     transistors would be needed, but at least there's only four of them. 
     Also this circuit did produce some noticable noise which may be a 
     reason to try something with newer (low noise) parts if that's your 
     goal.
     
     I have heard (can't remember where) that the Accutronics spring units 
     come in different models, with different transducer impedances. Is 
     this true, anybody? Also I seem to remember that some tanks had a 
     sticker on them with a humorous comment about the place of 
     manufacture.
     
     Anyway not really an answer but my 0.02...
     
     - Gene
     gstopp at fibermux.com


______________________________ Reply Separator _________________________________
Subject: Spring Reverb CIrcuits
Author:  "A.S.P." <ms20 at serv.net> at ccrelayout
Date:    11/26/96 4:03 PM


I'm on the lookout for a good generic spring reverb driver circuit, now 
that I have an 18" Accutronics box.
     
I found one in an old book of electronic circuits.  It basically has a two 
watt amp IC (LM 377) pumping audio into the reverb, then two stages of low 
noise preamping (LM387) at the other end.  I think this is a good way to 
go, but would be interested in what any of you gurus and veterans might 
have to offer.