Attenuating Unbalanced to Balanced Signal. Instrument level to Mic Level

[steveyjennings]

I would use a microphone transformer 10k in 600ohms centre tapped or lower. Attenuate the 10k in as appropriate or active buffer. I’ve done this lots of times and it doesn’t introduce noise. Choose best quality you can afford, place in an ally earthed box.

 

[abbey road d enfer]

or steal one from a shure sm58, place in an ally earthed box.

The SM58 xfmr is a 25:200 ohms type.
It's hard to interface with line level.

 

[steveyjennings]

The SM58 xfmr is a 25:200 ohms type.
It's hard to interface with line level.

I beg your pardon you are quite right. The transformers I used where 10k to 600 centre tapped.