02-09-2015, 07:06 AM
Not sure if the links work anymore, but I posted a bit about different configurations and had a screenshot or two here: http://www.ampegv4.com/forum/viewtopic.p...5061#p5061
I at least simulated the curve of where the default mid frequency is cut/boosted, corresponding with bass/treble pot settings, when modding the two treble side cap values (note that there are two caps for the high frequency range to work normally).
Stock is 470pf/4.7nf, but I also simulated 330pf/3.3nf, 220pf/2.2nf, and 150pf/1.5nf. I forget which ones I did and didn't audition with solder.
Per that post, I may have landed at 150pf/1.5nf, but I don't remember anymore if it stayed that way or if I settled on 220pf/2.2n.
I do find again and again that ~600hz is where I like a midrange cut to be centered for guitar amps run clean and with pedals for dirt. That is the center of the mid frequency cut when you boost the bass and the treble with 150pf/1.5n combo, more or less.
FYI, if the rest of the tone stack is left stock:
470pf/4.7nf = ~325hz (similar to most blackface fender deluxe/twin/princeton)
330pf/3.3nf = ~400hz
220pf/2.2nf = ~475hz (very similar to a stock blackface *Super Reverb*)
150pf/1.5nf = ~575hz
The things I like most about shifting the mid frequency center point higher are:
A) The sound retains more of the fat low-mids, to the ears
B) 'Boosting' the treble control does more in the 3khz+ range, while the resulting mid scoop still cuts a good dose of 1k and 2k, which the stock arrangement preserves/restores far more of 1k and 2k frequencies. The stock arrangement made it harder to set the treble control to suitably clarity but not fatiguing to the ears, with a guitar, IMO.
Stock, 300hz is a frequency you can control with the active mid control anyhow, so it seems redundant to have the baxandall controls centered rather close to that frequency too, IMO.
Likewise, 330pf/3.3nf seems too much like stock to be a noteworthy shift, but if one is really happy with the stock arrangement and doesn't ever find the EQ a little hard to dial in, it may be a good place to start if curious about other options.
The resistor between the wiper of the mid and treble pot has some affect on the midrange frequency in the baxandall, but far less than the caps.
I at least simulated the curve of where the default mid frequency is cut/boosted, corresponding with bass/treble pot settings, when modding the two treble side cap values (note that there are two caps for the high frequency range to work normally).
Stock is 470pf/4.7nf, but I also simulated 330pf/3.3nf, 220pf/2.2nf, and 150pf/1.5nf. I forget which ones I did and didn't audition with solder.
Per that post, I may have landed at 150pf/1.5nf, but I don't remember anymore if it stayed that way or if I settled on 220pf/2.2n.
I do find again and again that ~600hz is where I like a midrange cut to be centered for guitar amps run clean and with pedals for dirt. That is the center of the mid frequency cut when you boost the bass and the treble with 150pf/1.5n combo, more or less.
FYI, if the rest of the tone stack is left stock:
470pf/4.7nf = ~325hz (similar to most blackface fender deluxe/twin/princeton)
330pf/3.3nf = ~400hz
220pf/2.2nf = ~475hz (very similar to a stock blackface *Super Reverb*)
150pf/1.5nf = ~575hz
The things I like most about shifting the mid frequency center point higher are:
A) The sound retains more of the fat low-mids, to the ears
B) 'Boosting' the treble control does more in the 3khz+ range, while the resulting mid scoop still cuts a good dose of 1k and 2k, which the stock arrangement preserves/restores far more of 1k and 2k frequencies. The stock arrangement made it harder to set the treble control to suitably clarity but not fatiguing to the ears, with a guitar, IMO.
Stock, 300hz is a frequency you can control with the active mid control anyhow, so it seems redundant to have the baxandall controls centered rather close to that frequency too, IMO.
Likewise, 330pf/3.3nf seems too much like stock to be a noteworthy shift, but if one is really happy with the stock arrangement and doesn't ever find the EQ a little hard to dial in, it may be a good place to start if curious about other options.
The resistor between the wiper of the mid and treble pot has some affect on the midrange frequency in the baxandall, but far less than the caps.