Negative feedback options.

[hdahs]

Just wondering if there is an appreciable difference between a 47K on the 4ohm tap, and a 100K on the 8 ohm tap? I've read that the 100k brings more gain and mids, but at the expense of some smoothness.

Any favorite combinations?

Thanks

[toner]

I don't know how those exact values compare from experience but 100k / 8 ohms will have less NFB than 47k / 4 ohms so your description makes sense (more gain). Feedback doubles when going from 4 ohms to 16 ohms with the same resistor.

I like the stock 47k / 8 ohms in a plexi for classic rock. For me, it's a good balance of tightness and cleanness without being too clean like JTM 45 values. I can see where people wanting higher gain and sustain would prefer less NFB though.

[stef]

I
I like the stock 47k / 8 ohms in a plexi for classic rock.

me too
100k/4 (stock 70's nfb) made my cranked amp unstable, prone to too much feedback and noise

[Roe]

depends on tubes, voltages, guitar, etc. best thing is to use a resistor in series with a pot. try 12k + 100k pot at 4ohms

[Winslet]

welcome to all,

nice forum keep up