I would like to make a change to my loudness circuit, so that it is available beyond the mid point of my volume control. I am using a 23 Step attenuator, so I can tap in pretty much any ware in the range. Can I just move the tap further up the range? or even to the ground lug?
This modification is on a HH Scott LK-72 Tube Integrated.
Before and after, mods in red.
This modification is on a HH Scott LK-72 Tube Integrated.
Before and after, mods in red.
circuit 2 works as a LPF on the 12AX7 for lows while cutting the treble response slightly.
circuit 1 is correct.
if this was a solid state circuit, #2 would do absolutely nothing as the op amp would just drive the load changes effortlessly
circuit 1 is correct.
if this was a solid state circuit, #2 would do absolutely nothing as the op amp would just drive the load changes effortlessly
Thank you. Do you have any advice for how to alter the circuit? So that I maintain the functionality of the first diagram, but throughout the volume range.
on your stepped attenuator, the loudness tap is at the 40% max Vout level.
I would try moving this up to 40 -70% and try that. this will affect the loudness boost levels at low volume so you will have to listen at several positions
some effect of the loudness switch will be seen at full volume as the effect is added at the 40% tap
I would try moving this up to 40 -70% and try that. this will affect the loudness boost levels at low volume so you will have to listen at several positions
some effect of the loudness switch will be seen at full volume as the effect is added at the 40% tap
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Thank you, I will try moving it around on the attenuator. See if I can find a sweet spot.
I have been troubled by how the factory pot works. It seems from about 55-70% the volume does not increase at all. But then it jumps rapidly.
It is probably just the pot and nothing to do with the Loudness circuit.
I have been troubled by how the factory pot works. It seems from about 55-70% the volume does not increase at all. But then it jumps rapidly.
It is probably just the pot and nothing to do with the Loudness circuit.
The loudness is meant to increase the low and high frequencies at low volumes, as the human hearing has lower sensitivity for these when listening at low volumes. If this effect is wanted at all settings of the volume contol, then it is much better to do this correction with the tone controls, just turn up the bass and treble controls to suit you.
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