Idle current is 30mA as shown. Change R5 to vary. The LND150 is a stiff part. It should be very stable no matter how toasted the 340 gets
D1 sets the idle current or the spread between the sources which being a diode is AC bypassed (also with cap, too) for full open loop gain. A lower Vf, more current through the diff stage. A 4148 is good also when the p-channel voltage gain part is less than the turn-on of that VP0550 which offhand is 4.5 volts.
Adjust R4 for offset. It really is differential with both gates at the same potential. As the diff stage is in series, balance of N and P parts should be less of an issue compared to long-tail.
Don't run B+ beyond 50V or +/-25 for when shifted to bi-polar without the front bias.
D1 sets the idle current or the spread between the sources which being a diode is AC bypassed (also with cap, too) for full open loop gain. A lower Vf, more current through the diff stage. A 4148 is good also when the p-channel voltage gain part is less than the turn-on of that VP0550 which offhand is 4.5 volts.
Adjust R4 for offset. It really is differential with both gates at the same potential. As the diff stage is in series, balance of N and P parts should be less of an issue compared to long-tail.
Don't run B+ beyond 50V or +/-25 for when shifted to bi-polar without the front bias.
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Here's another variant that separates DC gain and AC gain. DC gain is set to (R1/R2) such that Vout=0.5*B+ also considering open-loop I-toV value for offset. AC gain is 31dB. I love the roll-off; minimal Bessel for no impulse ringing.
Okay, all you all, make me some great sounding headphone amps... or perfect MM phono preamps. These should be excellent for use with transformers for that vintage 1973 style of discrete circuits (aka Rupert Neve BA184)
Okay, all you all, make me some great sounding headphone amps... or perfect MM phono preamps. These should be excellent for use with transformers for that vintage 1973 style of discrete circuits (aka Rupert Neve BA184)
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Here's a short intro, if you don't "get it". Soundbites: Classic Neve Desks – A Basic Overview
I knew that already 
But today...nobody's making those consoles anyway, NOBODY! because the modern engineers learned how to deal with it using very elaborate software...I asked a friend of mine at some moment: is there any use today for a tape delay?And he said...it's true that you can get some very special sound if you have the right equipment , but i never needed and the new generation doesn't even care about that "old days sound" ...I am only getting payed for new sound with new money...They don't get me gold coins for using 8 track reel to reel...they just pay me with God damn paper...
But today...nobody's making those consoles anyway, NOBODY! because the modern engineers learned how to deal with it using very elaborate software...I asked a friend of mine at some moment: is there any use today for a tape delay?And he said...it's true that you can get some very special sound if you have the right equipment , but i never needed and the new generation doesn't even care about that "old days sound" ...I am only getting payed for new sound with new money...They don't get me gold coins for using 8 track reel to reel...they just pay me with God damn paper...
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Some aspects, like a state variable filter with six(?) opamp channels per band would be expensive to do in discrete. Consoles are amazingly simple, though, and when it's yours and being built by you, does cost really matter?
And then there's the hybrid approach with a modern dynamics control and a wonderfully clean audio path through a vactrol. Put it where it counts.
In the end, it's always analog
And then there's the hybrid approach with a modern dynamics control and a wonderfully clean audio path through a vactrol. Put it where it counts.
In the end, it's always analog
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Not really...If you are into physics, you know that the universe nature is DISCRETE, the same as you can tell apart clear sound levels only on a logarithmic scale, that is why the instruments have clear musical notes:
Website of Wayne Stegall - Analog is Digital
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