Author Topic: amz buffer questions  (Read 1389 times)

ninjadave7

amz buffer questions
« 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!
david L

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Re: amz buffer questions
« Reply #1 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.
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ninjadave7

Re: amz buffer questions
« Reply #2 on: April 19, 2010, 11:22:33 AM »
sweet, i'll try those suggestions, thanks!
david L

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Re: amz buffer questions
« Reply #3 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.
MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...