tube mic design (opinions ?) + high value resistors

[garyk]

Last year I built the "Royer" mic (mod) using an ADK 51 mic and the 5840 sub-min tube. Sounds very good, used a Cinemag output transformer.

I have acquired a Peluso double sided C12 type capsule to make another mic, but wondered which circuit/schematic to try this time.

Most of the diagrams for set ups like the elaM250 or the C12 use very high value resistors (eg 60m- 100m - 150m).

So: two questions:

a) any suggestions for the best schematic, tube, tranny, etc, for this capsule?
Could be anything from the 5840 to EF86, 12AY7 ..etc...anyone tried the nuvistors?

Might be good to try to emulate the C12 or the elaM250?

b) where to get these high value resistors (not available here in Australia?)

Thanks

Gary

 

[cliffforrest]

Resistors

Farnell should stock them, or you can use a string of 10M 5% film resistors.

 

[garyk]

yup.. but @ 150m thats a LOT of resistor strings to chuck into a little mic casing ...

 

[cliffforrest]

Well, theyare available eg

http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?Nr=AND(avl%3auk,searchDiscon_uk%3aN)&Ntx=mode%20matchpartial&N=4294730713&in_dim_search=1&name=SiteStandard&forwardingPage=line&R=2477799&callingPage=/jsp/search/search.jsp&BV_SessionID=@@@@0933770793.1174153587@@@@&BV_EngineID=ccccaddkgiedmlhcefeceeldgondhgl.0&cacheID=ukie

but I don't know how easy down under.