Technical Notes Index
Return to 'Reproduction of 78rpm
records'.
Home
PREAMPLIFIER CIRCUIT FOR EQUALIZATION OF 78rpm RECORDS (and older microgrooves)
I enclose two gifs of the main circuit, and the feedback loop. I'm afraid the image quality is less than perfect: they were taken from a photocopy of a hand-drawn circuit, which I scanned (using my fax machine!) and converted to a gif. However I think you will be able to read all the component values, which is what matters. As far as I know all the components are still readily available, except that one or two electrolytic capacitor values are no longer made - just use the next highest.
Revised version of feedback loop with modern components
No warranty is expressed or implied as to the suitability of this circuit for this or any other purpose. I regret I can't offer technical support or answer technical questions about this circuit.