Testing Trannies, got to be a better way....

[guavatone]

I made this geofx.com inspired test plate for testing some old UTC's and DI experimentation. I want to test with preamps too.

Can I just run a line out of my console to get a good idea what the XFMRs sound like? I used a mic since they are 600ohm mic xfmrs for this and it was a pain in the but.

I'm thinking of ading some 3p3t switches and more xlrs to AB quickly.

 

[ziller]

I'm trying to something similar. What I've been doing, which may be all wrong :? , is run a line out of my comp (using a signal generator program) into my console. Then, since I don't have balanced outs, output a signal to a DI box then out of that into the transformer.

I then set the signal generator to output a series of freq, and measured the input and output of the transformer. I'm hoping to plot a graph to check the freq response. I haven't gotten to far yet... One problem I'm having is I'm only able to get down to about 4mA output from the DI, not quite mic level.

A couple of things I'm unsure about is if the output of the XFMR needs a dummy load on the secondary winding. Also, the input voltage to the XFMR varies with freq, and I'm not sure if I should keep setting back to a common input voltage, or if the change is a result of the transformer itself, and should be included in the response.

 

[guavatone]

hmm, I'm hoping CJ "the xfmr wizard" would chime in. He could help us both out I'm sure.

Yeah, I was thinking there were 2 issues about the console output; impedance and level. The DI solves the impedance issue and the level issue might be solved by a pot or resistor network.

The DI idea bothers me because - it will impart its own sonic characteristics to the path. Maybe all ccan be resolved with resistors.

The other question is how the XFMR output gets to the preamp. Maybe a Fetboy channel would be good for a simple uncolored sound.

 

[CJ]

Maybe a chunk of wood with some mini clip leads attached.

I don't see a way around soldering some wires.

Doing A/B tests is a real nightmare, becuase then, you have to wire up two or more transformers.
Who want's to do that when they could be breaking out the saw?
:razz: