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DIY Stompboxes => Building your own stompbox => Topic started by: ninjadave7 on April 17, 2010, 08:20:45 PM

Title: amz buffer questions
Post by: ninjadave7 on April 17, 2010, 08:20:45 PM
a couple questions:

i built the amz jfet buffer, upped the resistors on the input so i'd have a 1M input, used a J201 jfet, all on vero and running at 18v.  even using short leads, the buffer actually cleans up the signal a little (there was a bit more dirt in it before i buffered), and its noticeably brighter than the dry signal.  is the cleaner sound normal?  is there a way to take off a bit of the brightness?

also, i have built the opamp buffer on amz, but it was breaking up when i hit it hard.  can i run the opamp buffer at 18v also, and give myself headroom?

thanks!
Title: Re: amz buffer questions
Post by: GibsonGM on April 18, 2010, 05:07:23 PM
High input impedance will make a signal appear brighter, since less is shunted to ground via input capacitance.  You might try DECREASING the input impedance a little, to warm up the sound, if you like, by lowering the input resistance.  Increase input cap for a bassier sound; you can tweak a little to 'tune' the buffer.

As long as the IC and caps are rated at better than 18V, sure, you'll get more headroom.
Title: Re: amz buffer questions
Post by: ninjadave7 on April 19, 2010, 11:22:33 AM
sweet, i'll try those suggestions, thanks!
Title: Re: amz buffer questions
Post by: GibsonGM on April 20, 2010, 10:48:19 AM
No problem man.
Oh, you might be able to tweak and bias the JFET buffer to run at a little lower voltage, and be "less clean", BTW.  Didn't occur to me when I read your post, lol.