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RE: 6SN7 circuit

Posted by sideliner on March 27, 2017 at 07:19:11:
That's a nice circuit. I had looked at the Blue Velvet some time back and considered building it, but alas my system gain is such that I don't need to run a preamp - well at least for now. The only thing that I'm a bit hesitant about, is that the input tube is running into a 11.2K impedance as presented by the next stage.

The effective load for the first stage is at 3K which is kind of low. The 15dB of NFB will cancel distortion at the second stage but the input tube has only the degenerative current feedback from the unbypassed Rk to do some HD reduction. This may, or may not be enough (I'm just thinking out loud here, not saying that this is actually the case). I'm wondering if a bit of cathode feedback at the input tube might be of some benefit.