Small blind PAF test

[ecmalmo]

Cheers! Perhaps some of you would like to help out with this small experiment I’m doing. The dropbox link below contains 3 mp3 recordings of ”PAF style” pickups with pretty similar inductance measurements. The same guitar, amp, speaker impulse etc was used throughout.

www.dropbox.com/scl/fo/5z9qj3ilocnimsnc9kt46/h?rlkey=mq9ixxbntzmijmff6or85mtme&dl=0

Can you hear any differences (in timbre/tone, not playing)? Please describe.
How would you subjectively rank them sound wise? Most to least appealing.

If I’ll get any responses I’ll post the brands and specs in a few days or so.

[gckelloch]

Only thing I would say is #3 sounds like the low side of the pickup is closer to the strings so the note fundamentals are a hair stronger. There is likely some difference in all the heights, but that's the only thing that sounds a bit different...and it's very slight if at all. Cool sound, BTW. Distortion can make it harder to judge, though.

[ecmalmo]

Dec 27, 2023 19:13:03 GMT -5 gckelloch said:

Only thing I would say is #3 sounds like the low side of the pickup is closer to the strings so the note fundamentals are a hair stronger. There is likely some difference in all the heights, but that's the only thing that sounds a bit different...and it's very slight if at all. Cool sound, BTW. Distortion can make it harder to judge, though.

Interesting. Thanks for listening! I did measure pickup height at bass and treble side so that factor should actually be identical.

[gckelloch]

Even ~10% height difference can be audible. That can easily be less than 0.5mm. It's very hard to get heights within such a small range by measuring up to a flexible string. I'd bet they were all a bit different, and that's what I'm hearing.

[ecmalmo]

Dec 28, 2023 4:22:28 GMT -5 gckelloch said:

Even ~10% height difference can be audible. That can easily be less than 0.5mm. It's very hard to get heights within such a small range by measuring up to a flexible string. I'd bet they were all a bit different, and that's what I'm hearing.

I measured it with a string height gauge with .25 mm precision.

[gckelloch]

Assuming the coil height isn't it, and the total coil winds are virtually the same, then it could be that the pickup has more winds closer to the strings. It could also be from a different tilt to coils. Two-height screw HB's don't necessarily hang at the same angle for various reasons.

[ecmalmo]

I added 2 more clips just for fun. Same rules apply.

[ecmalmo]

Dec 28, 2023 7:24:31 GMT -5 gckelloch said:

Assuming the coil height isn't it, and the total coil winds are virtually the same, then it could be that the pickup has more winds closer to the strings. It could also be from a different tilt to coils. Two-height screw HB's don't necessarily hang at the same angle for various reasons.

I would say the specs of the different sets are fairly similar but not identical. I would place them in the same category If I was selling pickups.

[gckelloch]

It gets very hard to delineate when the inductance is less than ~10%. The resonant freq may be different, but it can be too close to tell. It can be even harder when there are lots of generated harmonics in the res freq range, which may be the case with your clip.

Considering all that, clip 5 sounds a bit more open and chimney to me than 4. I'd guess it's the lower inductance of the two.

Nice playing and ideas. Really upbeat vibe. What type of amp and speaker cab or digital sim is that? Offhand, I'd say JCM800 and V30's, but I could be way off.

[ecmalmo]

Dec 28, 2023 18:30:30 GMT -5 gckelloch said:

It gets very hard to delineate when the inductance is less than ~10%. The resonant freq may be different, but it can be too close to tell. It can be even harder when there are lots of generated harmonics in the res freq range, which may be the case with your clip.

Considering all that, clip 5 sounds a bit more open and chimney to me than 4. I'd guess it's the lower inductance of the two.

Nice playing and ideas. Really upbeat vibe. What type of amp and speaker cab or digital sim is that? Offhand, I'd say JCM800 and V30's, but I could be way off.

Not hearing much difference is definitly a legitimate reply. I didn’t choose the music to make it easy. It’s just some things a rock band would play. And you would think various makes of ”PAF” pickups would make some difference based on the marketing copy right…😊
I will say that the ”feel” can differ quite a bit when playing with the different sets, but whatever that is doesn’t come through much in the recordings.

Thanks! It’s a snippet of a song from a band I play with. Recorded direct via a short cable into a di box and DAW running a Softtube amp simulation plugin modeling a Marshall plexi, then an IR loader plugin using Celestion Heritage G12H30 55hz impulses.

[gckelloch]

They feel different, huh? I suppose that's either from the dynamic envelope due to flux strength at a given distance, and/or the way the amp reacts dynamically to the freq response.

So, I at least got the Marshall sound right, if not the model. Granted, a V30 is pretty different than a G12H30-55Hz. I do prefer a 55Hz cone. Maybe that's why I liked your sound so much. I bought a Weber "Legacy" 55Hz 4x12 Soldano cab IR I like a lot. Don't know how it was mic'd and the proximity effect is very strong, but it sounds pretty nice with the bass reduced. I think it has less ~3kHz than the Heritage 55Hz. Might not be the same cone. There are a few 55Hz cone types available.

[ecmalmo]

Dec 29, 2023 0:26:32 GMT -5 gckelloch said:

They feel different, huh? I suppose that's either from the dynamic envelope due to flux strength at a given distance, and/or the way the amp reacts dynamically to the freq response.

I would call it something like "stiffness". Some feel like they have a more immediate, stiff attack and firm bass response, while others feel more spongy and you are tempted to dig in more. I think it has to do with the magnet type, since it doesnt seem to correlate with high output level of the raw line signal measued as LUFS-I.

[JohnH]

I think they all sound very good, but its hard for me to notice a difference in the pickups because the tones seem to be dominated by the amp overdrive and its all in about the same range of drive. That may well be the tone that most would wish to get with these pickups, but a crystal clean, or at most a slightly break-up tone with some chords and picking and different dynamic levels might reveal more.

[ecmalmo]

Dec 29, 2023 14:56:17 GMT -5 JohnH said:

I think they all sound very good, but its hard for me to notice a difference in the pickups because the tones seem to be dominated by the amp overdrive and its all in about the same range of drive. That may well be the tone that most would wish to get with these pickups, but a crystal clean, or at most a slightly break-up tone with some chords and picking and different dynamic levels might reveal more.

I added the clean line signal for each of the clips for reference in the folder. It's not a sound anyone would use so it kind of goes against the purpose of finding practical differences, but it might be interesting. I find that the clips I like best with processing are the same I like raw.

[JohnH]

Thanks for posting those, so I did some stuff:


I brought all the clean clips into Audacity, and put them each to a separate track. One thing I noticed is how well synced they all the were, All 5 together played perfectly in time, like 5 players together.


Then I took the first 3 sec riff of each one and put them end-to-end to get a quick side-by side 1, 2, 3, 4, 5 comparison.

So my impression was, all of a similar family of tones, with 1 and 2 being very similar, 3 being a bit lighter in tone and 4 being a bit thicker. 5 was also thicker but not as much as 4.

Does that impression correspond with anything IRL?


Then I got some frequency plots:

5 traces, focussing on 100 to 2000 hz, key at the bottom:




On this kind of plot, just look at the peaks, since that's where the notes and harmonics are.

The ones where I heard the greatest difference, 3 and 4, are the green and orange traces.


So will you now reveal what you have there?

[gckelloch]

It still sounds like 3 is the lowest inductance with the clean clips. Maybe 2 is next, and I do think some coils might be bunched more up on the bobbins than others if it's not the actual coil height, and/or flux strength, and/or possibly the magnet permeability drawing the flux lines down more through the center of the pickups. I assume the pole screws are all at the same heights.

Much of the differences in the freq plot could be from picking variances. There doesn't seem to be any real consistency that indicates any file has more or less of anything, and the resonant peaks are likely up about an octave where we can't see them.

[ecmalmo]

OK so the reveal then. These are the specs for each set and my thougths.

I measured inductance at 100 Hz with a Uni-T UT612

Gauss is measured by touching the two middle screw poles with the gaussmeter probe and noting the highest reading.

1
Bridge: Gibson 57 Classic +
Cover: Unplated nickel silver (aftermarket)
L: 5.1
DCR: 8.2k
Q @ 1000: 2.12
Gauss: 312 (Alnico 2)

Neck: Gibson 57 Classic
Cover: Unplated nickel silver (aftermarket)
L:4.9
DCR:8k
Q @ 1000: 2.13
Gauss: 260 (Alnico 2)

Subjective:
My least favorite. Seems to be missing something in the upper midrage/lower treble. Kind of a nasal low mid focused sound. The neck pickup is a bit too woolly.
A friend of mine liked this set the best however, as it sounded warm.
Pro-Q over the first two sections tells me there is slightly less happening around 4-5 KHz on the raw line signal compared to the other bridge pickups.
Feel is very spongy - soft and unfocused.
This set is the loudest when comparing the recorded line signals with LUFS-I (-20.8), probably due to the neck pickup being the hottest of the bunch.
I installed covers on and wax potted these, originally they were uncovered.

2
Bridge: Own wind (5000 screw, 5200 slug, 42 AWG PE)
Cover: Unplated nickel silver (aftermarket)
L: 4.9
DCR: 8k
Q @ 1000: 2.17
Gauss: 280 (Alnico 4)

Neck: Own wind (4600 screw, 4800 slug, 42 AWG PE)
Cover: Unplated nickel silver (aftermarket)
L:4.2
DCR:7.3k
Q @ 1000: 2.06
Gauss: 220 (Alnico 4)

Subjective:
My favorite set. I made them with "vintage correct" components like plain enamel wire and the expensive machined retainer bars, but ABS bobbins so they withstand wax potting. The bridge seems well balanced with a decent bite without being too stident in the treble. Possibly the neck pickup is a bit weak, but raising it slightly would probably fix that. Feel is "medium" - not as spongy as the Gibsons.

3
Bridge: Seymour Duncan SH-1b 59
Cover: Plated nickel silver
L: 5.1
DCR: 8.1k
Q @ 1000: 2.18
Gauss: 340 (Alnico 5)

Neck: Seymour Duncan SH-1n 59
Cover: Plated nickel silver
L:4.2
DCR:7.5k
Q @ 1000: 2.00
Gauss: 310 (Alnico 5)

Subjective:
In a way this is the most impressive set. It has the strongest resonance, even with a plated cover, and retains a lot of treble. The neck pickup is big and bassy but still has presence.
The strong resonance makes them a bit harsh in the bridge but backing off the tone helps. The neck pickup is too big sounding IMO.
The feel is very stiff with a fast attack and lots of firm bass.

4
Bridge: Amber Spirit of 59 (bridge)
Cover: Plated nickel silver
L: 5.4
DCR: 8.4k
Q @ 1000: 2.33
Gauss: 300 (Alnico 4)

Neck: Amber Spirit of 59 (neck)
Cover: Plated nickel silver
L: 4.6
DCR: 7.2k
Q @ 1000: 2.29
Gauss: 230 (Alnico 4)

Subjective:
The original pickups of the guitar. A nice sounding set, very close to set 2. Maybe the bridge is a tiny bit congested. Very nice "exclusive" looking pickups and labeling. The cover screw holes are countersunk in a way I've never seen before.
I had to wax pot these myself as we rehearse loud with lots of gain and they come un-potted. This is the least loud recording according to LUFS-I (-22.8).
Feel is a little bit tighter than set 2 but not as stiff as set 3 or 5.

5
Bridge: Own wind (5500 screw, 5700 slug, 42 AWG Poly)
Cover: Brushed nickel silver
L: 5.5
DCR: 8.6k
Q @ 1000: 2.41
Gauss: 320 (Alnico 5)

Neck: Own wind (4900 screw, 5000 slug, 42 AWG Poly)
Cover: Brushed nickel silver
L:4.4
DCR:7.6k
Q @ 1000: 2.27
Gauss: 380 (Alnico 5)

Subjective:
This set stands out the most spec wise. I made it as a "hotter" variant with lots of winds and strong magnets, but still using 42 AWG and alnico.
I feel the output is greater and the treble a tiny bit muted compared to set 2 for example. Still better presence than the Gibson bridge pickup.

The feel is big and tight, similar to set 3 but with less treble and bite overall and less bass in the neck position.

Conclusion:

Overall the differences are really small in the recordings, absolutely not worth the effort from that perspective. Some small eq in post will have a much bigger impact. The "feel" difference might be placebo or psychoacoustics, but I find it's pretty consistent and it might still be worth swapping if you got the budget and don't bond with some pickups from how they respond and feel more than how they sound recorded.

One measurement I can't make sense of is the Q @1khz. I can't really relate it to what I'm hearing as a strong vs weak resonance.

Another thing to note: The SD and Gibson bridge pickups in my opinion sound the most different but they measure almost identical except for the magnet type and strength.

This is the long suffering guitar. My Maybach Lester, now getting some double creams for looks mostly...

[gckelloch]

Shows to go how little small inductance differences make. I'd say the reason I thought 5 sounded brighter than 4 is mainly because of the higher Gauss A5 magnets, but the permeability might play a part as well. I used the neck pickup section of the clips to compare the high-end. I did not know you switched to the neck at the end, but it's obvious now when I listen back. I'd pick 4 over 5 though because I prefer the softer attack.

[JohnH]

Nice looking guitar!

I'll plot out those charts to pick up 1000 to 5000hz, to see if it reveals anything about the resonant peaks. It's a lot about the cable capacitance in this case. How long is the cable?

[ecmalmo]

Dec 31, 2023 6:11:24 GMT -5 JohnH said:

Nice looking guitar!

I'll plot out those charts to pick up 1000 to 5000hz, to see if it reveals anything about the resonant peaks. It's a lot about the cable capacitance in this case. How long is the cable?

Thanks! Its like 2 meters, I can measure the C of it when I get home.

[ecmalmo]

The cable measures at 214 pF and it’s actually 2.75 meters so about 9 feet. It’s some expensive low capacitance cable I got on a roll and use to make my own cables from.

[JohnH]

Here's the plots as before this time covering the range 1000 to 5000 Hz:








Not sure what can be deduced there! But, if we're looking at pickups with L in the range 4.2H to 5.4H, with capacitance of 214pF (cable) plus allow 100pF (windings) plus allow 100pF (amp input and general guitar wiring), then we are looking for treble resonance in the 'ball park' range 3400Hz to 3800Hz.

[ms]

Dec 31, 2023 15:38:49 GMT -5 JohnH said:

Here's the plots as before this time covering the range 1000 to 5000 Hz:








Not sure what can be deduced there! But, if we're looking at pickups with L in the range 4.2H to 5.4H, with capacitance of 214pF (cable) plus allow 100pF (windings) plus allow 100pF (amp input and general guitar wiring), then we are looking for treble resonance in the 'ball park' range 3400Hz to 3800Hz.

This is quite a bit higher than usual for humbuckers in this inductance range.  I am wondering if preferences might be different with a higher capacitance cable, giving a somewhat thicker (and more common) sound.

[JohnH]

Jan 1, 2024 7:03:32 GMT -5 ms said:

Dec 31, 2023 15:38:49 GMT -5 JohnH said:

Here's the plots as before this time covering the range 1000 to 5000 Hz:








Not sure what can be deduced there! But, if we're looking at pickups with L in the range 4.2H to 5.4H, with capacitance of 214pF (cable) plus allow 100pF (windings) plus allow 100pF (amp input and general guitar wiring), then we are looking for treble resonance in the 'ball park' range 3400Hz to 3800Hz.

This is quite a bit higher than usual for humbuckers in this inductance range.  I am wondering if preferences might be different with a higher capacitance cable, giving a somewhat thicker (and more common) sound.

That's a good point, and sometimes having very low capacitance throws the natural resonance up past the point where guitar strings and guitar speakers are most effective, so a bit more capacitance might make an apparently brighter final sound. But the recordings sound great anyway, its just that the cable can be a significant variable. I used to put buffers in my guitars, untill I figured out that they sounded better with a good normal cable.

[ecmalmo]

I like to have treble ”on tap” so I can brighten up when I roll down the volume. When on full volume I usually roll off the tone until I get something I like.

[ms]

"But the recordings sound great..."

I agree. This is a very good test.

[ecmalmo]

I added another clip (6), clean and dirty, that I just recorded with a new set.

See If you hear anything that stands out. Will reveal soon.

[gckelloch]

More punchy, louder, and maybe higher inductance than most. I compared it to clean 2 and 5 because you wound those. Clean 2 is the weakest, and 5 is in between. I took an average SPL of each clip with the free Voxengo Span FA set so the subtle difference can be seen. Notice how much the high-end rolls off. Hard to say how much the differences in the high-end is the pickup vs how strongly various freq ranges you picked. You can compare the B and N graphs separately to see the differences. The Lowest inductance clips do have relatively less midrange I still don't see any resonance peak where they should be, but there are some bumps up higher.

[ecmalmo]

Thanks a lot! But I'm not sure which graph corresponds to which set as I cant see any captions. Are they in order 1-6 from top to bottom?

For reference I added a clip of a very un-PAF like humbucker set. These are the ceramic monsters 500T and 496R from my Explorer. These are 7.6 H in the bridge and 5.6 H in the neck:

www.dropbox.com/scl/fi/ad5rjuknsrxql2oo20n23/500T_496R.mp3?rlkey=x9lnpjmf536o7dq5fhtqbfq2j&dl=0

www.dropbox.com/scl/fi/u50hhcv9l4gvoarl5460h/500T_496R_clean.mp3?rlkey=sxnp6kur9wxqwo0mkdu6pmciv&dl=0

This is another guitar so it's not a clean comparison, and I had to pad down the linebox for it to not clip then compensate with the gain on the interface, but could be interesting to listen to something way out of spec with the others. 

[JohnH]

This is an aside, but thought I'd post about resonant peaks and why we aren't seeing them clearly:

When we plot pickup tests to give bode-plot sweep responses such as in tests by Antigua or ms, we see the electrical response of the pickups, on it's own or together with a load representing the guitar wiring, based on a consistent frequency input induced by a coil. There is no effect of the actual string vibration, nor of the acoustic performance of the speaker. These tests are very insightful and usually show a smooth curve with a treble peak. We can also generate plots like this by analysis.

But such a loaded test on a PAF usually gives just a very subtle peak, and with a real signal induced by strings, the peak is masked.

GuitarFreak is a spreadsheet loaded with pickup models derived from Antigua's physical tests, and it matches them pretty well using 6 components to represent each pickup, plus the guitar wiring. It also has the math built in to address string vibration, pickup width, position, and vibration harmonics. Here are plots based on a classic '57 with 500k pots, and the low capacitance cable discussd above.




The top blue dashed curve is the electrical response with this load, approximately as would be derived from a bode-plot sweep. You can see a slight peak, but it's very subtle. A higher cable capacitance will bring a stronger peak.

The red jagged line represents an analysis of the real signal output from the guitar, based on strumming across all the strings. I've set it to be with open strings, starting with low E. This spiky line is comparable to the real frequency plots from the tests, except for:

1. the real playing generates hundreds of harmonics, hence very finely-spiked lines. My red plot does 30 harmonics of each string, but to plot them it shifts them each to the nearest semitone (to save data points), so the curve is somewhat cruder and more blocky, but has about the right trend.

2. GF doesn't include the speaker response, which adds a further shaping and fall-off after about 4kHz (actually, I could add that to GF, it's not too hard!)

So now comparing; the red curve is falling off after the last strong peak just above 3Khz. If you look at the real plots posted above, you can kind of see a similar thing, with peaks dropping away after about that frequency, but there's some interpretation needed.

Anyway, I hope that is a bit interesting at least!