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GEO A/B/Y box.....questions


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9/8/1999 12:22 PM
jason
 GEO A/B/Y box.....questions
Has anyone built this yet. I suddenly find myself in need of one and am thinking of building this. How important is chip selection (does it need to be an LM 833 or will an equivalent work).  
 
Any comments or suggestions appreciated.  
 
Thanks,  
 
jason
  
9/8/1999 2:43 PM
R.G.
In my proto, the biggest difference chips made was in drive capability. The LM833 will happily drive a 600 ohm load. The lower the impedance the chip will drive, the better it will control the primary inductance of the transformer(s) and the lower the bass is extended. Other opamps will work, the tone, especially in the bass may (or may not, depending on details) be changed.  
 
 
 
I suggest socketing it, and swapping.
 
9/8/1999 6:56 PM
roger
Jason, go to http://www.jensen-transformers.com/ for lots of info on transformers and interfacing with audio circuits. Jensen has numerous schematics online and the A/B/Y is basically one of these with switching:  
 
 
 
http://www.jensen-transformers.com/as/as014.pdf  
 
 
 
Rog
  

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