Hi folks,
in an interstage coupled two stage tube amp, which kind of negative feedback can be applied? I read that a feedback loop from anode of the second tube to the cathode of the first tube has to be avoided as it is a loop wraped around a transformer coupled stage. So which feedback is to be prefered as the above mentioned often sounds good with cap coupling and is practical.
Thanks, Uwe
in an interstage coupled two stage tube amp, which kind of negative feedback can be applied? I read that a feedback loop from anode of the second tube to the cathode of the first tube has to be avoided as it is a loop wraped around a transformer coupled stage. So which feedback is to be prefered as the above mentioned often sounds good with cap coupling and is practical.
Thanks, Uwe
When the interstage transformer is a good one, with good low and high frequency bandwidth (which is not that difficult to achieve with a 1:1 type), I see no problems applying a feedback loop as phase shifts will be minimal.
You can sooner expect problems with a feedback loop from amplifier output (after the output transformer) back into the amplifier circuit as phase shifts will be larger.
You can sooner expect problems with a feedback loop from amplifier output (after the output transformer) back into the amplifier circuit as phase shifts will be larger.
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