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RJM Audio

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Discrete op amp modules with bipolar inputs are probably not going to work in the Sapphire. The impedance around the IN+ node is too high and the op amp modules don't have input bias current-cancelling like many bjt ICs do. A module with FET input, on the other hand, should do the trick nicely.
products: Model 995FET-Ticha Discrete Op Amp Updated March 4th, 2014. Model 995FET-Ticha Datasheet and Specifications PDF · Model 995FET-Ticha Purchase Online General Description: 995FET-Ticha Discrete Operational Amplifier The 995FET-Ticha is a high performance discrete operational amplifier ...
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Not in the near term. Want see how people get on with the modules first.
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RJM Audio

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Someone made a mono version of the stereo VSPS board and kindly send me the renders.

For your viewing pleasure.
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Proaudio community forum. Interesting - from a home audio diy perspective - to dip your toe in from time to time to see what's up in a completely alternate universe. 
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There are dozens of discrete op amps available in the 2520 package. So plenty of options for the Sapphire 3.1n boards!
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For my own reference. Tons of info within.
Analogue Audio. Welcome on Samuel Groner's page on analogue audio design. Please choose the section you'd like to visite on the menu to the left after you've read the Terms Of Use and Disclaimer sections below. Terms Of Use. The designs described on these pages are not commercial in any way.
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That's a lot.
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Any op-amp with a input bias current specification in micro-amps probably isn't going to work very well unless you can equalize the impedances "seen" by the + and - inputs.
-ammel68
http://bit.ly/1Kbrfix
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Cheap ... if you want to try. Info here http://bit.ly/1TrWCts

Note that these op amps need a small compensation capacitor across the feedback resistor to avoid overshoot. For Rf 10-20k a 47 to 100 pF capacitor should be fine.
Zen Cart! SGA-SOA-2 kit - Revised version of Samuel Groner's simple yet beautiful sounding SGA-SOA-1Specs  Input offset voltage: < 20 mVInput bias current: -1.1 uAInput voltage noise: 1.5 nV/sqrt(Hz) at 1 kHzCurrent noise density: 0.6 pA/sqrt(Hz) at 1 kHzOpen loop voltage gain: 80 dBGain-bandwidth product: 40 MHz at 10 kHzUnity-gain bandwidth: 15 MHzSlew rate: ±14 V/usOutput
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Sapphire 31n boards are now in stock!
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That's a great .gif!
Op amp compensation techniques two pole single pole loop gain bandwidth
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Will try them in Sapphire 3. Anything I should know?
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A resource for the design and construction of high-fidelity audio equipment.
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RJM Audio is my hi-fi hobby site. I design and build audio equipment, from interconnect cables to headphone amplifiers to voltage regulators though I'm best known for my VSPS and Phonoclone phono preamplifier circuits.
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