See attached. At bottom-left this circuit uses 1/2 of a 6DJ8 for purpose I don't really understand. Can one of you smart people explain it to me?
That stage has x -1 gain and feeds R16, the inverting input of the balanced amplifier.
It is fed by the input signal from the preamp, which also goes to R11, the non-inverting amplifier input.
This is internally a balanced amplifier, with an internal single-ended to balanced converter (the x -1 gain stage).
But it only accepts inputs from unbalanced sources.
This topology was used by Bill in all of his early ARC amplifiers.
It is fed by the input signal from the preamp, which also goes to R11, the non-inverting amplifier input.
This is internally a balanced amplifier, with an internal single-ended to balanced converter (the x -1 gain stage).
But it only accepts inputs from unbalanced sources.
This topology was used by Bill in all of his early ARC amplifiers.
Ahh, thank you so much rayma! Is there an inherent benefit in having internally balanced designs?
Typically, ‘differential’ (improperly referred to as, balanced) circuits:
1) Suppress even order distortion products.
2) Feature twice the slew-rate of a single-ended version of the same circuit.
3) Reduce the dynamic loading of the power supply rails.
‘Balanced’, properly refers to the impedance terms of the signal interconnection between powered component boxes (preamp, power amp, DAC, etc.), for the purpose of common-mode noise rejection across the interconnection.
1) Suppress even order distortion products.
2) Feature twice the slew-rate of a single-ended version of the same circuit.
3) Reduce the dynamic loading of the power supply rails.
‘Balanced’, properly refers to the impedance terms of the signal interconnection between powered component boxes (preamp, power amp, DAC, etc.), for the purpose of common-mode noise rejection across the interconnection.
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