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Re: Anybody built a D. I.?


 
3/16/1999 2:27 PM
Steve M.
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Re: Anybody built a D. I.?
RJH,  
 
Do you have the URL handy?  
 
TIA,  
 
Steve
 
3/16/1999 4:27 PM
Greg
www.jensen-transformers.com/apps.html
 
3/16/1999 4:35 PM
Steve M.
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Thanks!
 
3/16/1999 9:02 PM
Reid Kneeland
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That's the web site that STARTED this thread, BTW.  
 
Also, I looked in my copy of DIY Projects For Guitarists, and there are not one but two DI units there. One (called the IGGY) is very simple.  
 
Reid
 
3/16/1999 10:00 PM
R.G.
Website
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I picked this thread up kinda late. I think that you could use the same circuit I'm using in the Splitter over on GEO. The transformers are 10Kct to 10kct,and although I'm not using the CT, you could bring it out and have the other two terminals for balanced signal.  
 
It uses the Mouser 42TM018, which is only specced to 300Hz. However, that spec is worst case with a significant source impedance, and with DC on the primary winding, all of which cause low pass problems with a transformer. In the splitter, I drive the primary from an opamp output with low source impedance and make sure that there is no DC on the primary. I breadboarded this and it actually turns out -3db at about  
60 Hz, so you're probably fine for guitar, but not bass. The high end was fairly flat out to 18kHz and then rose to a resonance at about 28kHz and dropped off.  
 
The 42TM018 is under $2 as I remember. It's worth a try to see if it meets your needs, I think. The transformer is cheap enough to make the box and connectors the major expenses.
 
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