Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: g-man on February 09, 2016, 11:51:56 am
-
Deleted
-
Hi G! Long time...
My "educated" answer is yes. As the rotation/arrow goes upward you will have the 250k pot in parallel with the 10k which = 9k6 for the stack loading effect. When the wiper/arrow is all the way down then you are left with the 10k. Either are a bit more than the 6k8 loading from the other stack so you'll end up with slightly more midrange and a bit more gain (slightly less signal loss - depending how you like to say it) also.
-
Deleted
-
Yes it would have to since the tone stack loading is less as the resistance increases. There will be less of a mid notch on the 2nd stack while the 1st one I'd say shouldn't have a mid dip/notch. The higher the value the more "tweedy" the response & increase in signal gain and mids both while lessening the tone stack's affects. The 1st stack can be made to be like the 2nd if you add the additional cap and a small re-wiring of the bass pot and remove the .003uF cap. If you do a tone stack lift by disconnecting the 10k/6k8 say on a switch, then try to implement having a smaller coupling cap going to the next stage to reign in the bass response a bit so your signal doesn't get bass heavy. Start with a .01 or even .005 and it will help keep things tight the more you turn the power up .
-
Fender Blackfaces use 6.8K in the many-tube amps, 15K in the few-tube Champ, and a variable resistor in the models that sport a MID knob. I'd never noticed the 10K but it is clearly the same thinking.
100K Audio taper gives "6.8K" near "4", "15K" near "6", and at "10" takes most of the tone-stack out of action for a non-scoop screaming tone. If you have the hole, just do it. If not, do it temporarily and experiment to find the value which works for you, then solder a fixed resistor.
-
Deleted