Quote:
Originally Posted by onespecial  im a LONG time reader but first time post-er here so i may have posted this in the wrong area.
im looking to try a few things that i have read about on a MXL 9000 tube mic.
i am new to modding but i will have a friend who is good with a soldering gun.
does anyone know where i can look for a circuit diagram for this mic?
i'd like to swap the transformer but i don't know what to order.
Kevin at K and K said he would help but he didn't know anything about this mic either.
any advice or places to look for advice would be greatly appreciated.
--jason |
Here is a link to a schematc and some info on the MXL9000. This mic is nice because it is a plate follower circuit that drives a 12at7 tube. Easy upgrade would be an NOS tube. A 12at7 or 6072a would be a good choice. This mic has some feedback 9pf plate to grid that helps control the 67 style capsule.
If you look at the classic circuits (C12, C24, Elam 251) and compare them to this schematic you will see the circuit is basicaly the same with increased filtering. Keep the B+ filtering and make the circuit more simple. Copy 1/2 of the C24 for a simple and elegant plate follower circuit.
Transformers:
Cinemag 2480: Bright clear better than stock.
Jensen DB transformer not as bright more expensive.
Haufe T14/1: nice transformer saturates early.
AMI T14 copy of the early C12 C60 transformer more color historically accurate.
Capsules:
Adk Vienna: bright edge terminated
Adk Hamburg: Darker
Dont waste a dual membrane capsule on this mic unless you add the multi pattern circuit and a 9 position pattern power supply.
Capacitor:
C6 and C6a should be replaced with a single film capacitor 1UF 250v.
Link to schematic:
MXL 9000 Exposed I hope this helps