Dynamic Mic > Guitar Pedal Preamp/Transformer, need some directions here!

[rudeez]

Hey all!
I'm working on this vocal "pedal" for a friend of mine and would need some help as i'm not that familiar with microphones and the whole balanced/unbalanced/impedance thing.
So this friend is a one man band and needs a pedal that has a old dynamic mic going into a filter for a telephone type of sound along with a clean blend.
I've been googling for so many hours and nights now and i just can't wrap my head around it.
He's going to connect this pedal into a Fender Blues JR or similar so the chain will basically be Dynamic Low Z Mic > blend > telephone filter > Amp.
I've been working on a solution using a transfomer, can't remember the number of it but a basic one but just can't get it to sound loud really.
What will i need and how should i do this, should i make a microphone preamp rather then a transformer?
It dosn't really matter if it's a bit noisy and such, were not talking HIFI here as he's a blues artist, altho there can't be issues like feedback and such.
Variable impedance and input level would be great maybe?
Any help and advice would be highly appreciated on this matter!
Thanks!

[bool]

http://sound.westhost.com/project122.htm

The circuit is easy enough to adapt it for a single-supply (battery). The NE5532 will work with a fresh 9V battery just fine.

It may be necessary to change the input caps to 330 or 470nF to preserve more bass.

[rudeez]

Cool! So this by it's own would work you think? What makes this specific preamp stand out for this purpose compared to other JFET preamps and such?
Anyway to make the impedance variable or is that unnecessary?

[bool]

Just wire a 5K pot at the input as a variable resistance and label it "vari-impedance"?

Since you have been asking, I thought you know about this stuff. Mike pres, although simple, do require some previous knowledge to make them useful ...