Henke has provided the raw data as well, see link above.
But, just in theory: if my EMG GZR sounds more “present” (might be more “aggressive”) than the DiMarzio, what could be the reason?
Remember: I exchanged the pots already, which did change the sound (I think), but it sounds even more “harmonic” now.
The only thing I did not change on the Dimarzio setup is the capacitor, which is the TAD Cap Orange Drop 47nF (of course - as somebody made fun of it AND it’s orange!).
Again, it’s not an issue, as both basses sound absolutely great. I am just wondering, cause of all the statements about the DiMarzio.
So, I’m not getting my soldering iron and dremel as of now, except when there is a very good reason ^^
That’s just the same data, it’s not a graph of the pickup output vs frequency.
To be really specific, what they are doing here is measuring the frequency response of the pickup as a filter as they sweep a signal through it via transmitting it from a coil placed atop the pickup. This is complicated as they also are including the tone filter and volume attenuator circuit in the instrument as well at various values (which is why there is more than one line). In this case, since a pickup is both a coil and has resistance, it acts as a filter in this test.
The results are measuring the shape and amplitude of the resonant peak of the collective, combined filter circuit - pickup, pots, and cap - across the range of the reference signal. In other words, this is how much the pickup is affecting the reference signal.
This will absolutely be somewhat indicative of pickup tonal qualities but not entirely, and I’m not sure how to interpret it. If this were synthesis I would say some of these things are extremely bad filters
I found the circuit of the preamp built in to the EMG’s and it’s interesting. It’s a traditional opamp based preamp but it’s amplifying the signal differential and not the individual pickup output. The pickup is not wired in series or parallel but instead each of the halves are feeding one opamp input and it’s amplifying the difference, which is how it gets the hum canceling.
There’s also multiple filters which are, basically, shaping the tone.
anyway @howard you’re right to say that on an active onboard system, the active electronics shapes the sound by itself and is not always designed to be linear
The X series of pickups from EMG have a preamp soldered into the pickup, I think their “normal” active pickups just have a circuit. I think, could be wrong but I know the X has a preamp.
I thought it was also pretty cool in overall function - it discards the primary signal from each pickup coil as it is amplifying the difference between them, which is what removes the coil hum from each. Since I assume they must be phase-reversed, this works.
pretty sure they are all preamps, not sure what other electronics you would use there. It’s not like the coils are charged. The diagram I saw was from an EMG81:
