Tape Project Forum

Tape Machines => Tape Tech => Topic started by: johnsonad on April 13, 2010, 03:53:58 AM

Title: NAB EQ filter values
Post by: johnsonad on April 13, 2010, 03:53:58 AM

Hello,

I'm trying to find out the filter values to use in applying the NAB 7.5/15 IPS curve.  Could someone tell me the values for the bass pole, bass zero, treble pole and treble zero?  Or, just the right resistor and capacitor values to apply the curve.

Thank you,

Aaron

Title: Re: NAB EQ filter values
Post by: stellavox on April 13, 2010, 05:24:41 AM

Hi Aaron,

If you are going to use active feedback, for the highs you could start with 22nf or so in series with a 5K pot.  For the lows, try taming the head bumps by dampening them with a parallel value around 200K.

For passive feedback, look in the Bottlehead website for Doc's tape mods to the Seduction preamp. Again, I'd suggest using a pot to aid in in "tweaking" the HF response. 

And good luck!

Charles

Title: Re: NAB EQ filter values
Post by: microstrip on April 26, 2010, 10:12:23 AM

Hi Aron,

Application note AND8177D from ON semiconductor for the NE5534 has some data on values for RIAA and NAB equalization - see

http://www.onsemi.com/pub_link/Collateral/AND8177-D.PDF

regards
Francisco