Is it usually better to put the tone controls before an amplifier stage, or at the end of the circuit? Or does it make any difference?
Is it usually better to put the tone controls before an amplifier stage, [yes, if you want EQ there].
or at the end of the circuit? Or does it make any difference
It makes a difference.
I built a Tonemender...and tried it before/after different effects...
If the amp stage is 'clean', the difference of placement before/after may be 'somewhat' less apparent.
The question is not entirely clear. By "amplifier stage", do you mean a power amplifier, or a gain stage?
If you were to dig back some 15 years through archived postings back to the days of alt.guitar and alt.rec.music.makers, when the net was text only and such newsgroups was all we had, you'd find that discussion of pre-EQ vs post-EQ is a well-worn path.
The thing to keep in mind is that tone controls essentially removed content. If the goal is to reduce hiss, then a treble control inserted after a gain stage helps to rein in whatever boosting of noise has taken place in the gain stage? Alternatively, consider that tone controls placed before a gain stage (and I'm going to go out on a limb here and assume you're talking about something with overdrive/distortion properties...call it a hunch :icon_wink: ) can change how close portions of the signal are to clipping. Pre-EQ can therefore change the likelihood of clipping and harmonics coming from some portions of the spectrum and some parts of the fretboard. Neither is really "better", but they have different consequences, the same way a wah before a fuzz produces a different sound than a wah after a fuzz.
Ideally, some sort of tonal shaping before AND after a gain stage is helpful in achieving a broader palette of sounds/tones/feels. That doesn't mean that one needs something like the unit Akai made for a little while, with a 7-band equalizer before AND after the clipping stage. Something as simple as a tunable midrange boost/cut (i.e., you can change where the boost/cut is applied) before any gain stages, followed by the tonestack of your choice after the gain stage, can serve up a pleasing amount of control. I might point out that some older Fender amps had the bass and midrange controls situated earlier in the preamp and the treble control situated one or two gain stages further along. Presumably whatever harmonic contrent was introduced by the extra bass driving the preamp tubes could be trimmed back by a treble control situated later on.
This is actually something I've been thinking about as I'm planning on building a chipamp this summer.
Right now my plan is
Input jack
LBP-1 preamp (with a trim pot set to a certain value)
Aron's simple 3 band EQ (fender stack)
lm3886 poweramp (this will have a potentiometer controlling overall volume)
speaker(s)
I think it should work ok...but I guess we'll see.
Thanks, I think I have all the info I need.