Active pickup build

[Prostheta]

Sounds good! What are your observations on this version?

[nakedzen]

I'd say more low mids, midrange in general, smoother more subdued top end.

[henrim]

Good stuff! While it's of course the most important thing how the pickup fits in to a mix, I think it would be nice to hear isolated guitar tracks. Like a back to back comparison of the different design stages.

[Prostheta]

Agreed. In general the TL071 when run as a buffer without any sort of filtering will do a number of things to a basic pickup. Primarily it eliminates load on the coil, however as to the exact physics of this I am not the expert. This being said, a pickup that is heavily loaded becomes muddy and indistinct. "Smear-y" I guess I would say. A basic unity buffer allows a pickup to sound as it does naturally without losses from parallel resistances, cable capacitance creating a LPF that wools up the treble. That sort of thing. They also seem to reduce the tendency of the pickup to be prone to extraneous noise, especially when run as a pure differential amplifier without reference to ground.

The negative commentary that many people repeat about actives is based around them hearing pickups without the artifacts that passive have, which a lot of us have become used to, and our equipment have grown up around. Fishman Fluence are great, however I think the HF Tilt is a drastically under-mentioned option for those that think actives have too much high end. It's simply that passive circuits commonly lose a lot of that and we are blissfully unaware.

If it's adding clarity to the low mids, that's worth the price of entry alone. When that range gets smushed, everything gets messy and sounds "cheap".

[nakedzen]

1 hour ago, henrim said:

Good stuff! While it's of course the most important thing how the pickup fits in to a mix, I think it would be nice to hear isolated guitar tracks. Like a back to back comparison of the different design stages.

I can try and put together something like that. Differences are much more apparent in a mix though, I can barely make out any difference on soloed tracks between pickups.

[nakedzen]

Here's the comparison between three pickups evolution.

LM4250: Supermassive Black Hole (Alnico 5) - Dark Matter Halo (lower wound, ceramic) - Tidal Disruption (alnico 5, blade pickup)

TL071H: Supermassive Black Hole (Alnico 5) - Dark Matter Halo (lower wound, ceramic) - Tidal Disruption (alnico 5, blade pickup)

EMG 81

Difference is pretty clear in the highs, much less harsh with the TL071.

 

[Prostheta]

It's a shame that people don't use underwound pickups as much for metal. They lose out on so much touch sensitivity and punch. Sounds good. I presume that was double-tracked?

[nakedzen]

Most of those are a bit on the high side. DMH is lower wind count. Two tracks panned 90% yeah.

[nakedzen]

Full mix comparison

 

[henrim]

Thanks!

On 10/27/2023 at 5:17 PM, nakedzen said:

I can try and put together something like that. Differences are much more apparent in a mix though, I can barely make out any difference on soloed tracks between pickups.

As I see it isolated tracks make it easier to hear how much difference there is between the pickups. Subtle nuances and such. Mix is of course better for finding out what they really sound like. E.g. I'm not a big fan of the ceramic alone but in the mix it cuts through nicely. Anyways 81 is rather flat and mushy compared to any of yours.

[nakedzen]

7-string build and some bad playing. Interesting how it sounds very similar to the Alnico 6-string version, even though it has different pole pieces and ceramic magnet.

The 6-string version had a nasty honky mid bump with identical pole screws on both bobbins, this doesn't. Maybe it's the larger geometry. Something with different pole screws on the 6-string changes the magnetic field enough to get rid of the honk.

 

[Prostheta]

Sounds like a longer scale as well? There's so many variables that go into a design. Sounds nice and tight though. EQ'ed out that would work really nicely.

[nakedzen]

Good ears it's 27" scale. Thanks for checking!

[nakedzen]

Dum dum dummm. First very small batch of production underway.

 

[Prostheta]

Very cool. I've half been considering whether to make a small batch of balanced preamps to fit onto the rear of existing commercial pickups because of the stray earth noise we seem to get in Finnish electrics. EMGs and Fluence are dead silent, but I get noise even with basic passive humbuckers.

[nakedzen]

3 hours ago, Prostheta said:

Very cool. I've half been considering whether to make a small batch of balanced preamps to fit onto the rear of existing commercial pickups because of the stray earth noise we seem to get in Finnish electrics. EMGs and Fluence are dead silent, but I get noise even with basic passive humbuckers.

That sounds cool. Maybe put some sort of screw in connector for the wires to make them easily removable?

[Prostheta]

I haven't put a lot of thought into it, since I know that my resources are stretched fairly thinly right now, what with building the CNC. It would be a great way to modernise my #1 Ibanez, however it might make just as much sense to have a preamp in the cavity instead. It's just super cramped, what with being an HSH configuration and a thin body S.

[Prostheta]

In fact, look at what EMG do with their "Retro Active" pickups. This to me looks like a standard pickup with an external preamp bolted onto the rear as I proposed.

https://www.emgpickups.com/guitar/fat-55-set.html

[Prostheta]

 

[nakedzen]

Yeah that's where I got my idea for this build. But eventually decided on the sandwich-style instead since it's much cleaner looking than just screwing the board on the back, imho.

[Prostheta]

I don't hate it. If anything I like the idea of being able to use common existing components without modifying them for this sort of retrofit. There's a sizeable difference between the bobbin screw spacing of my TBH-11 and APH-1N. That's probably why Rob mentions that the bridge pickup preamp has a small "bump" as this implies both preamps have different levels of gain. More or less unity for the neck ("fingerboard" as he calls it) and a slightly hotter bridge. Did he also mention some sort of op-amp used specifically for pickups in that video?

"There isn't a custom op-amp made for a pickup until this one", nice grammar butchery.

The death of the LM-4250 might mean that EMG had their hand forced to move to a different op-amp, so maybe this is what he meant even though this is not what he said. It might simply be the same LM-4250 topology but remade enough not to need any sort of licensing to TI or whoever. More than likely it's an op-amp custom-made with ultra-low current consumption with frequency performance comparable to that of the LM4250 with the Iset resistor hard-wired internally. The shots of the preamp in production shows something like 3-4 SMD resistors and four SMD chip capacitors, so I'd almost put money on this being the same preamp as used in the 81 or maybe the X series, however that preamp differed. Maybe it was only a different Iset value to improve frequency range and reduce compression in-circuit.

Speculation anyway. I think an 81 preamp circuit built around a TL071 or OPA1655 would be fine.

[nakedzen]

First small batch done!

 

[Prostheta]

Looks like I'll have to be changing the name on the headstocks of my guitars. 

[nakedzen]

Lol. Sorry. Lumi has been in the name of all of my companies since 2014.

I did consider using my name as the pickup company name, but honestly, who does that? 

[Prostheta]

I'm not bothered really. It's far too ubiquitous to claim or trademark. It just means I need to do some actual thinking to find a unique identifier!