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Tube Mic Preamplifiers

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Power Supply

48v 2a supply


47µfd 35v caps
better electorlytic
Film

Use quality film caps (they will be large) or use low leakage el caps like Nichicon KL series. No need to match 47 or 100 uf, the tolerance variations will only affect the sub 20hz frequencies. Above the R/C roll offs the cap's ESR might vary a tiny bit but won't make any difference. Matching the CMRR of the active front end is what affects that spec.

Microphone	Voltage Specified (volts)	Current Draw (mA)
Sennheiser MKH800	48	3
Sennheiser MHK40	48	2
Neumann U87	48	0.8
Neumann U89	48	0.8
Neumann KM100	48	2
Neumann KSM140	48	2
Neumann KSM150	48	2
Neumann TLM50	48	2
Neumann TLM170	48	2
Neumann SM69	48	0.8
Neumann USM69	48	2 x 0.7
Neumann KU 81 I	48	2 x 0.7
Neumann RSM 19	48	2 x 1.9
AKG C414B ULS	9	2
AKG C414B TL II	9	2
AKG C426	9	2
AKG C3000	9	2
AKG C460	9	1
AKG C480	48	2
AKG SE300B**	9	2
AKG C522MS	9	2 x 1.5
AKG C535	9	1
AKG C568	9	1
AKG C451EB	9	5
AKG C451E (old)	9	10
B & K 4007S	48	3.5
Shure KSM32	48	4.65
Shure KSM4	48	5.4
Shure VP88	9	2 x 1.3
Shure SM-81	9	1.2
Crown PCC-170	12	4
Earthworks - all	48	10
Beyer - most	48	3 - 5
Schoeps - most	48	4