Mic cable XLR to phono

So, let me see if I understand correctly:  you have a normal, balanced XLR cable (XLR on both ends), that when one end is hooked up to your mic and the other end is hooked up to a device with an XLR connection (as a low-impedance mic input on a mixer), the sound level is as it should be.  However, you have another unbalanced cable that has an XLR on one end and a 1/4" (tip/sleeve) plug on the other, and when you hook a mic to the XLR end and the 1/4" plug into what I am assuming is a high impedance input, the signal level is lower ... do I have it right?  If so, then I don't think there's any problem with your unbalanced cable, but you do have an impedance mismatch when using the unbalanced cable, because you are taking a low-impedance microphone and plugging it into a high-impedance input.  In addition, most high-impedance inputs are designed to handle a line-level signal, and a microphone puts out a much lower signal than what the input expects.  So, you get a sharp drop in volume.  If you had a high-impedance microphone and plugged it into the high-impedance input, then you would get the kind of signal level you are expecting, but you won't get it with a low-impedance mic.  XLR inputs, on the other hand, tend (in general) to be low-impedance, low-level inputs designed for microphones, and so that's why your low-impedance mics through a standard XLR mic cable have good levels.  There are exceptions to all of this, however, as it really depends on the device you are hooking the mics up to, but the best way to know what's what is to look at the device specs and see what the various inputs are rated for - then you know for sure.  Hope that helps a little!

fireberd


An instrument input, such as guitar, bass, etc is an unbalanced "high impedence" input, however "instrument level" is about the same level as a microphone.  So that should not be an issue. 

Yep, I meant to mention "instrument-level" but forgot.  It all depends on the device - I have a mixer that has dedicated "instrument-level" inputs that will handle a guitar/bass signal just fine.  But, if I plug a guitar/bass into an Aux input, which is expecting a line-level signal, then I get a substantial drop in volume.  There are also 1/4" inputs on the mixer channels which can accept either a high- or low-impedance input, but I have never tried plugging a guitar/bass into those to see what happens.  Geez, no wonder people are confused when they first start working with this stuff!

you are missing your transformer.