bladerunner
Member
- Joined
- Nov 17, 2005
- Messages
- 10
Hi,
A vocalist friend has asked me if i could make him a combined mic preamp and delay unit for use onstage, and i could really use some help with the design!
For the delay portion of the unit i was planning on using the innards of an old electro-harmonix memoryman delay that i have lying around, which is powered by +24V single-rail AC supply:-
http://mysite.wanadoo-members.co.uk/deltaharmonic/schems/EH_delux_memoryman.gif
(link from murk burnley post - cheers mark!)
Looking at the schematic it seems the 24V AC is then rectified becoming single -15V DC. i hope this is right!!
I would like to ask is any advice or recommendations for a suitable mic preamp circuit that might fit the bill - i suppose ideally the mic pre would run off the same +24V single supply as the MM circuit. although if i was to do something like a very basic version of the green pre, would it then be feasible to run the MM circuit from the - rail of the +/-15V supply?
The unit would always be used with an SM58, so no phantom power is needed...
The input and output of the memoryman is unbalanced instrument-level, so i suppose i would need level/impedence matching between the two circuits... and also would need to add balanced output stage or buffer of some kind - the ultimate output of the unit would be line level via XLR to front of house..
i have some surplus bits lying around which it would be great to incorporate - a sowter 9820c input transformer (API input replacement), and some unidentified input transformers from an old mic mixer (marked 32246F). the sowter transformer is 1+1 : 3.54 but im not sure about the ratio of the other transformers..
any help would be greatly appreciated!
A vocalist friend has asked me if i could make him a combined mic preamp and delay unit for use onstage, and i could really use some help with the design!
For the delay portion of the unit i was planning on using the innards of an old electro-harmonix memoryman delay that i have lying around, which is powered by +24V single-rail AC supply:-
http://mysite.wanadoo-members.co.uk/deltaharmonic/schems/EH_delux_memoryman.gif
(link from murk burnley post - cheers mark!)
Looking at the schematic it seems the 24V AC is then rectified becoming single -15V DC. i hope this is right!!
I would like to ask is any advice or recommendations for a suitable mic preamp circuit that might fit the bill - i suppose ideally the mic pre would run off the same +24V single supply as the MM circuit. although if i was to do something like a very basic version of the green pre, would it then be feasible to run the MM circuit from the - rail of the +/-15V supply?
The unit would always be used with an SM58, so no phantom power is needed...
The input and output of the memoryman is unbalanced instrument-level, so i suppose i would need level/impedence matching between the two circuits... and also would need to add balanced output stage or buffer of some kind - the ultimate output of the unit would be line level via XLR to front of house..
i have some surplus bits lying around which it would be great to incorporate - a sowter 9820c input transformer (API input replacement), and some unidentified input transformers from an old mic mixer (marked 32246F). the sowter transformer is 1+1 : 3.54 but im not sure about the ratio of the other transformers..
any help would be greatly appreciated!