Cheap DI mod

[sr1200]

So i found these cheap (under $50) DI boxes.  All they have is an XLR 2 1/4" jacks and a ground lift.  Inside is just a single transformer.  Any suggestions on what i could replace the transformer with.  I kinda feel this DI is robbing a little bit of the high end (in a bad way) in comparison to the active DI's I have (i know, nature of the beast) but perhaps someone knows of a "higher end" alternative to whatever is in there.

 

[Meathands]

It depends on whether it's the transformer robbing you of the high end, or the input impedance. I suspect it's the latter--what are you plugging into it? A typical passive DI transformer into a typical mic preamp will only give you about 140k input impedance. If you're plugging something with passive pickups into it you can expect to lose some high end.

That being said, I like a good passive DI for the right purposes. I sell one with the Cinemag CM-DBX transformer, but I've tried the Jensen's, too. They're both quite magnificent. I understand that Sowter and Lundahl make nice ones, but haven't tried em.

 

[wave]

+1 for the Cinemag. They're pretty reasonable price wise. I do like me some Lundahl and Sowter trafos too but they're more expensive.

Dave

 

[joaquins]

as said before, if you have something passive feeding the DI it doesn't get anything better beeing passive, just an phantom powered active would work, because it doesn't have any ground from anywhere else to do a ground loop, but if you have an active output from a bass amp for example you have another ground path across the safty ground of the amp, so you should lift it somewhere, a transformer is the better way of doing this, so the output is low Z so no losses because of the trannie and real ground lift is done which you can't do with phantom powered active ones, and if it's self powered it needs to be transformer output to have real ground lift... to be really floating I mean.

JS

 

[sr1200]

I opened up the little case the TX was in and there was the same kinda non descript, non marked scotch tape wrapped tx's you find in donor mic's lol...  I;ll have to take a look at the cinemag site and see whats available.  (ive used cinemag stuff for all my 312 builds great company to deal with)  I'd love to build something like the Reddi by @ designs.  NY dave one bottle perhaps with an inst. input.

 

[pucho812]

IF you plan a one bottle and solely plan to use it for instruments you can skip the mic transformer. The nice thing with this is you have a nice D.I. that ends up at line level and can go directly into pro tools.

 

[dmp]

I stuck Jensen DB transformers in similar donor DI boxes. I'd say they are nice to have. Different than an active DI, but good. And very easy & ultra reliable in a recording situation.
I have 2 Jensen passive, 2 Bo Hansen Active, and 2 NYD 1 bottle.
But for passive pickups, the NYD is the winner!

 

[okgb]

If tube d.i. a transformer will be [ not that one perhaps ] useful for balancing the output
a simple cathode follower circuit will do the job , but at unity , the NYD will give you gain
I have the Demeter circuit around as well .  Let us know what you find for a psu xfmr if you
go that route , it's something I could use occasionally 

schematic for demter d.i.
http://www.groupdiy.com/index.php?topic=50879.msg645927#msg645927