Not in principle, but all the opamps I have experience with in onboard bass preamps happen to be PDIP. Are there any particular SMD ones you would suggest for this application?
Here's a screen shot, I don't have the schematic but would like one too. They put several of these in one or more of his basses but they were designed from scratch together not a retrofit. I'm sure this isn't new to you but it's cool and fits the thread.
Back in the 80s I designed, etched and fit a Baxandall into my Peavey Foundation and ran +-15 volts on the floor, 5532 opamps. I tinkered with it too many times and screwed it up. I then had kids and but it back to passive but no tone control. I got a matching Peavey TNT130 with great tone controls. I also have Ashly graphic and PEQ EQs I bought cheap. I just retired and should pick it back up.
I did get small circuit boards for SE to balanced buffers with the intent to mount them on the pots and run two channels to the Ashly gear.
Some descriptions and photos but no schematics
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There's been plenty of discussion on both that new pedal and various iterations of Alembic "filter' preamps on Talkbass, for instance: https://www.talkbass.com/threads/multi-coils-filter-type-preamps-a-one-stop-archival-thread.1592738/
Consensus is that something like Craig Anderton's ancient Super Tone Control along with a modified summing/mixing circuit would get you quite close. PedalPCB sells a clone PCB, which I have no experience with. Personally, I've moved on to simpler Sallen-Key resonant LPFs, as Alembic also has done in many cases. These used to be a PITA for DIYers for a variety of reasons, but things have gotten much easier in the last few years.
MusicMan Stingray 3-band preamp - Addendum
One thing I forgot to mention above is yet another quirk of this circuit: the heavy load it may present to both opamp stages. With the controls on full boost, the first stage sees a load that falls from ~3k @ 100 Hz to ~1k @ 3 kHz and to ~600R @ 10 kHz. With the controls on full cut, the second stage sees ~2.8k @ 100 Hz, ~900R @ 3 kHz and ~500R @ 10 kHz. While what happens at 10 kHz may not be too relevant due to the sharp roll-off after resonance, I mention the values at 3 kHz because that's where the resonant peak is, so high distortion there will probably be audible.
The datasheet of the TL062 doesn't provide any THD data and any specs where a load is mentioned, it's 10k, so clearly it isn't design to drive difficult loads. Don't get me wrong, this may very well be intentional and the distortion may be part of the particular sound the designers were after (they could have eased the load by simply using pots of a higher value and they didn't), but it's something to be aware of.
Which brings me to another opamp to add to the list of post #2: the TLE206x (datasheet). I haven't used it in this application but I have as a headphone amp (it's one of the popular choices for the O2 headphone amp), it's specified for high current drive into loads as low as 100R and it has a very low supply current of 0.28 mA / amp, so it looks like a good option where heavy loads are a concern. Maximum output swing is typically ~1.5 V below rails depending on the load but the supply range goes up to 38 V, so it can be used in 18 V systems, and it's also available as single, dual and quad and in SMD versions.
One thing I forgot to mention above is yet another quirk of this circuit: the heavy load it may present to both opamp stages. With the controls on full boost, the first stage sees a load that falls from ~3k @ 100 Hz to ~1k @ 3 kHz and to ~600R @ 10 kHz. With the controls on full cut, the second stage sees ~2.8k @ 100 Hz, ~900R @ 3 kHz and ~500R @ 10 kHz. While what happens at 10 kHz may not be too relevant due to the sharp roll-off after resonance, I mention the values at 3 kHz because that's where the resonant peak is, so high distortion there will probably be audible.
The datasheet of the TL062 doesn't provide any THD data and any specs where a load is mentioned, it's 10k, so clearly it isn't design to drive difficult loads. Don't get me wrong, this may very well be intentional and the distortion may be part of the particular sound the designers were after (they could have eased the load by simply using pots of a higher value and they didn't), but it's something to be aware of.
Which brings me to another opamp to add to the list of post #2: the TLE206x (datasheet). I haven't used it in this application but I have as a headphone amp (it's one of the popular choices for the O2 headphone amp), it's specified for high current drive into loads as low as 100R and it has a very low supply current of 0.28 mA / amp, so it looks like a good option where heavy loads are a concern. Maximum output swing is typically ~1.5 V below rails depending on the load but the supply range goes up to 38 V, so it can be used in 18 V systems, and it's also available as single, dual and quad and in SMD versions.
MusicMan Stingray 3-band preamp - mods
I already mentioned above some of the things one may want to tweak, like the high-pass filter Fc and the pickup loading. As an example, here I'll replace the 8n2 caps with 12n, which as mentioned lowers the Fc to ~37 Hz, and replace the 2n2 cap with a 330p and add an 82k resistor in parallel with it, which moves the resonant peak to ~5 kHz with a height of ~3 dB. You can adjust to taste, of course.
Another thing you may want to do is increase the boost / cut range of the mids control, and/or generally tweak the EQ. Here I'll quote from the 1980 National Semiconductor Audio & Radio Handbook (free download from TI, highly recommended), section 2.14.9 - Midrange control, where they describe a 3-band EQ:
"Any two of the controls appreciably loads the third. The equations that result from a detailed analysis of Figure 2.14.18 become so complex that they are useless for design. So, as is true with much of real-world engineering, design is accomplished by empirical (i.e., trial-and-error) methods."
And from Douglas Self, Small Signal Audio Design (also highly recommended), Three-band Baxandall EQ in one stage (page 433 of the 2nd edition):
"The drawback is that cramming all this functionality into one stage requires some compromises on control interaction and maximum boost/cut."
So, after lots of trial-and-error, I've come up with a couple of examples of what can be done. First I tried tweaking the component values without changing the circuit topology (so no PCB surgery needed if you're modding an existing one) and the best I could do was set the boost/cut range for all three bands to +/-12 dB at 40 Hz, ~600 Hz (my preferred mids frequency for bass if I can only have one, YMMV) and 10 kHz, sim file attached (MMS-3B-tweak.asc). The filter and pickup loading tweaks above are also included. For convenience there are two .step directives, you Ctrl-right click on them and select "Comment" or "SPICE directive" to use one or the other and show bass + treble or mids. I've set the plots to the same range as I used for the original for easier comparison:
A nice side-effect of this is that now the worst case load on the opamp stages is a bit lighter: for the first stage ~3.1k @ 100 Hz, ~1.7k @ 3 kHz and ~1.2k @ 10 kHz and for the second stage ~2.8k @ 100 Hz, ~1.5k @ 3 kHz and ~1k @ 10 kHz.
Since there's still significant interaction between bands and the mids bell is very broad, I then tried using Douglas Self's topology (fig. 15.31 in the reference above), which is different in that the treble wiper branch connects to the negative input through the mids wiper cap, see schematic below. It's a small change and the same number of components, but there's much better band independence, allows for a broader boost/cut range of +/-15 dB and gives a much more focused mids control, sim file attached (MMS-3B-alt.asc):
Here the worst case load for the first stage is ~2.4k @ 100 Hz, ~1.2k @ 3 kHz and ~730 @ 10 kHz and for the second stage ~2.1k @ 100 Hz, ~1k @ 3 kHz and ~600 @ 10 kHz.
In case the load is still a concern with the opamp you want to use, I also attach MMS-3B-alt100.asc, which uses 100k pots and gives pretty much the same response (not shown), but the worst case load increases for the first stage to ~4.9k @ 100 Hz, ~2.5k @ 3 kHz and ~1.4k @ 10 kHz and for the second stage to ~4k @ 100 Hz, ~2k @ 3 kHz and ~1.1k @ 10 kHz.
Lastly, to make the tweaking process less painful, I came up with a little "tweaker" simulation where I have the tone control stage only, all resistors and caps parametrized and, since pretty much everything affects at least two if not all bands, the circuit is duplicated so you can plot simultaneously the bass + treble and mids only responses, see attached sim file Baxandall-3B-tweaker.asc. It's has Self's topology but you can easily edit it for the stock one, just take R7/R20 directly to the negative opamp input:
I already mentioned above some of the things one may want to tweak, like the high-pass filter Fc and the pickup loading. As an example, here I'll replace the 8n2 caps with 12n, which as mentioned lowers the Fc to ~37 Hz, and replace the 2n2 cap with a 330p and add an 82k resistor in parallel with it, which moves the resonant peak to ~5 kHz with a height of ~3 dB. You can adjust to taste, of course.
Another thing you may want to do is increase the boost / cut range of the mids control, and/or generally tweak the EQ. Here I'll quote from the 1980 National Semiconductor Audio & Radio Handbook (free download from TI, highly recommended), section 2.14.9 - Midrange control, where they describe a 3-band EQ:
"Any two of the controls appreciably loads the third. The equations that result from a detailed analysis of Figure 2.14.18 become so complex that they are useless for design. So, as is true with much of real-world engineering, design is accomplished by empirical (i.e., trial-and-error) methods."
And from Douglas Self, Small Signal Audio Design (also highly recommended), Three-band Baxandall EQ in one stage (page 433 of the 2nd edition):
"The drawback is that cramming all this functionality into one stage requires some compromises on control interaction and maximum boost/cut."
So, after lots of trial-and-error, I've come up with a couple of examples of what can be done. First I tried tweaking the component values without changing the circuit topology (so no PCB surgery needed if you're modding an existing one) and the best I could do was set the boost/cut range for all three bands to +/-12 dB at 40 Hz, ~600 Hz (my preferred mids frequency for bass if I can only have one, YMMV) and 10 kHz, sim file attached (MMS-3B-tweak.asc). The filter and pickup loading tweaks above are also included. For convenience there are two .step directives, you Ctrl-right click on them and select "Comment" or "SPICE directive" to use one or the other and show bass + treble or mids. I've set the plots to the same range as I used for the original for easier comparison:
A nice side-effect of this is that now the worst case load on the opamp stages is a bit lighter: for the first stage ~3.1k @ 100 Hz, ~1.7k @ 3 kHz and ~1.2k @ 10 kHz and for the second stage ~2.8k @ 100 Hz, ~1.5k @ 3 kHz and ~1k @ 10 kHz.
Since there's still significant interaction between bands and the mids bell is very broad, I then tried using Douglas Self's topology (fig. 15.31 in the reference above), which is different in that the treble wiper branch connects to the negative input through the mids wiper cap, see schematic below. It's a small change and the same number of components, but there's much better band independence, allows for a broader boost/cut range of +/-15 dB and gives a much more focused mids control, sim file attached (MMS-3B-alt.asc):
Here the worst case load for the first stage is ~2.4k @ 100 Hz, ~1.2k @ 3 kHz and ~730 @ 10 kHz and for the second stage ~2.1k @ 100 Hz, ~1k @ 3 kHz and ~600 @ 10 kHz.
In case the load is still a concern with the opamp you want to use, I also attach MMS-3B-alt100.asc, which uses 100k pots and gives pretty much the same response (not shown), but the worst case load increases for the first stage to ~4.9k @ 100 Hz, ~2.5k @ 3 kHz and ~1.4k @ 10 kHz and for the second stage to ~4k @ 100 Hz, ~2k @ 3 kHz and ~1.1k @ 10 kHz.
Lastly, to make the tweaking process less painful, I came up with a little "tweaker" simulation where I have the tone control stage only, all resistors and caps parametrized and, since pretty much everything affects at least two if not all bands, the circuit is duplicated so you can plot simultaneously the bass + treble and mids only responses, see attached sim file Baxandall-3B-tweaker.asc. It's has Self's topology but you can easily edit it for the stock one, just take R7/R20 directly to the negative opamp input:
CORRECTION: In Baxandall-3B-tweaker.asc above, the "Boost" and "Cut" labels are reversed: the wiper going up is a cut and going down is a boost. No big deal but if you were to design a PCB based on it, you might end up with the pots working in the wrong direction... Corrected sim file attached. Sorry!