MCA SP1 mods

[carnold1]

Hi there. I've read most of the old posts about modding this mic (most recent is 2016 I think). There are a lot of text instructions about switching parts and such, but was wondering if anyone had a schematic of the original with the changes notated schematically? The way my brain works, having a schem to guide me works much better than text notes.
Also, yes, I have one of the old ones with through-hole components.
Thanks in advance for any help!!
-c

 

[fsalter]

There you go.

 

[carnold1]

This is awesome. thank you so much

 

[carnold1]

So all the modding is simply based around the JFET and Transistor changes. No changes to the actual EQ of the circuit.

Strange, my component numbers don't line up with that schem at all...

 

[RuudNL]

No changes to the actual EQ of the circuit.

In fact there is no EQ in the whole circuit! Some people think that the 1 nF have an influence on the high frequency response, but since the PNP transistors are driven from a low impedance, the influence of the 1 nF capacitors can be neglected in the audio range.