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Post by antigua on Feb 9, 2019 4:20:15 GMT -5
 This is the first DiMarzio blade pickup I've tested, so I'm not sure what design aspects are particular to this pickup versus all the rest of their product line, but one interesting thing is that they continue their practice of winding the two coils to the same number of turns, but with different gauges of wire, so even though both coils who near identical inductance, the coil nearer to the guitar's neck shows 3.8k ohms resistance, while the coil nearer to the bridge shows 5.0k ohms. From a technical standpoint, I can't conceive of any tangible benefits from their doing this, except maybe to make it more difficult to use DC resistance as a means of comparing this pickup to a competitor's. Since I haven't measured many other Strat sized blade humbuckers, to pick another popular Strat sized humbucker as a point of comparison, the Little '59... the Chopper is very comparable the Little '59 neck pickup in particular, 5.9 henries for the Chopper, 5.6 henries for the Little '59 neck. The Little '59 bridge pickup is a lot hotter than either at 8.3 henries. It's interesting that while the inductance between the Chopper and Little 59 neck are similar, the DC resistance of the Little 59 is 9.82k, which comes close to the DC resistance of the Chopper's green-white coil. This tells me that of the two wire gauges involved, the Little 59 neck's two coils use the thinner gauge of wire. Regarding the resonant peak, for some unknown reason, the Chopper has a lower intrinsic capacitance than the Little 59 neck, so the Chopper's loaded resonant peak is about 2.4kHz to the Litt'e 59's 2.1kHz. When split (to the coil nearer to the neck) the loaded peak rises to 3.21kHz, while splitting the Little '59 neck brings it's loaded peak to 2.9kHz, so overall the Chopper is a tad brighter than the '59 neck, series or split. Since the Chopper is intended to be a bridge pickup and the Little '59 in question is a neck pickup, it's sort of apples and oranges. The Little '59 bridge pickup is a lot hotter than the Chopper or the Little 59 neck, at 8.3 henries. The most directly comparable Strat bridge pickup I've measured is the Seymour Duncan SSL-5, which has the same loaded resonant peak of 2.36kHz. To my ears, I feel the Chopper and SSL-5 sound very much alike in situ, aside from the fact that the Chopper is noiseless and the SSL-5 is noisy. I also really like the sound of the Chopper split to single coil (it splits to the coil near to the neck), I think it's especially "Stratty" compared to, for example, a tapped SSL-5. The loaded resonant peak of 3.2kHz is far below average for a Strat pickup, but nevertheless it doesn't sound as dark to my ears as a typical Strat pickup with an equally low resonant peak (think Texas Special bridge pickup), and I suspect the reason is because the Q factor is very low, which rounds off the treble response at resonance, as a result of having steel in the coil cores instead of less conductive AlNiCo. I've noticed something similar with the cheap steel and ceramic pickups that come stock in import Strats; they don't sound nearly as dark as you would guess based on the inductance and the loaded resonant peak, but they too have a low Q factor due to the steel pole pieces. I've observed a similar effect with Fender Jazzmasters and Jaguars, which come stock with 1meg pots, as well as Strats with Texas Specials; rolling back the tone control, say to "8" or "9", so as to reduce the Q factor, actually makes them sound clearer, as compared to "full open". Also something very surprising to me, comparing the Gauss strength of these rails pickups to the magnetic strength of the Little 59, the top of the steel blade actually measures about 100 Gauss weaker than the Little 59's screw heads, but at a distance of 8mm (double thick cardboard), where the magnetic fields are more diffuse, the Little 59 shows about 20% to 25% less magnetic strength, ~40G to ~50G. Speaking of blade pickups and magnetic fields, a unique think about blade pickups is that because the magnetic field is homogeneous across their face, none of the guitar string's side-to-side string movement is incorporated into the output signal, but it should be noted that even when a pickup has discrete pole pieces, the side-to-side movement accounts for only a tiny parts of the signal. The more narrow the pole piece, the greater the contribution will be. A Seymour Duncan Quarter Pound's pole pieces are so wide that they might as well be a rail pickup. tl;dr: a noiseless SSL-5 that splits well.DiMarzio Chopper DP184BK #1
- DC Resistance: 8.88K ohms (RB 3.82k, GW 5.03k)
- Measured L: 5.898H (RB 2.115H, GW 2.144H)
- Calculated C: 231pF (241 - 10) (RB 640pF, GW 632pF)
- Gauss: 500G (ceramic between steel blades)
DiMarzio Chopper DP184BK #2
- DC Resistance: 8.86K ohms (RB 3.83k, GW 5.03k)
- Measured L: 5.915H (RB 2.132H, GW 2.159H)
- Calculated C: 221pF (231 - 10)
- Gauss: 500G (ceramic between steel blades)
DiMarzio Chopper DP184BK #3
- DC Resistance: 8.85k ohms (RB 3.81k, GW 5.02k)
- Measured L: 5.904H (RB 2.112H, GW 2.153H)
- Calculated C: 221pF (231 - 10)
- Gauss: 500G (ceramic between steel blades)
#1 unloaded: dV: 3.7dB f: 4.22kHz (black)
#1 loaded (200k & 470pF): dV: 0.7dB f: 2.36kHz (blue)
#2 unloaded: dV: 3.9dB f: 4.31kHz (red)
#2 loaded (200k & 470pF): dV: 0.7dB f: 2.36kHz (green)
#3 unloaded: dV: 3.9dB f: 4.31kHz (pink)
#3 loaded (200k & 470pF): dV: 0.7dB f: 2.36kHz (gray)
 #1 unloaded: dV: 3.7dB f: 4.22kHz (black)
#1 loaded (200k & 470pF): dV: 0.7dB f: 2.36kHz (blue)
RB unloaded: dV: 2.6dB f: 3.76kHz (red)
RB loaded (200k & 470pF): dV: 2.8dB f: 3.21kHz (green)
GW unloaded: dV: 4.4dB f: 4.52kHz (pink)
GW loaded (200k & 470pF): dV: 2.6dB f: 3.28kHz (black)   |
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Post by pyrroz on Feb 9, 2019 8:21:02 GMT -5
nice pup, i have it in my strat in the neck. I'd like a little more clarity in there, but it copes well with fast track 2 in the bridge.
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yanyan
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Post by yanyan on Nov 30, 2019 10:17:06 GMT -5
This is the first DiMarzio blade pickup I've tested I actually requested this pickup along with the Fast Track 1 and 2 on August 3, 2018! Thanks for this analysis! I cannot write on the same technical level as the forum regulars, so i'll comment on a user level. I've found that the Fast Track set (1, 2, and Chopper) sound more and more like fatter single coils the closer the pickups are moved towards the strings. Just recently i had them about 3-5mm away from the strings (didn't take exact measurements), which was the closest i've ever set them, and they sounded too bright. A funny thing was, coil split mode sounded like it had more bass than series! Another thing i found interesting in the case of the Fast Track 2 is that Dimarzio describes it as a single coil sized version of the Super 3 when they sound nowhere near alike, at least in my experience. |
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yanyan
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Post by yanyan on Dec 14, 2019 3:07:16 GMT -5
I wrote to Dimarzio asking if they make available inductance and resonant peak figures of their pickups, specifically the Fast Track 1, Chopper, and Fast Track 2. They provided this information:
Fast Track 1 2.37H 5.65KHz
Chopper 5.74H 3.62KHz
Fast Track 2 9.26H 2.15KHZ
Regarding the Chopper, their inductance figure is lower than that from antigua's analysis. Resonant peak is probably loaded, but with how much capacitance i can't tell.
When testing for loaded resonant peak, 200k refers to a 200k Ohm resistance, right? Does that represent a volume control?
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Post by antigua on Dec 14, 2019 13:35:28 GMT -5
I wrote to Dimarzio asking if they make available inductance and resonant peak figures of their pickups, specifically the Fast Track 1, Chopper, and Fast Track 2. They provided this information: Fast Track 1 2.37H 5.65KHz Chopper 5.74H 3.62KHz Fast Track 2 9.26H 2.15KHZ Regarding the Chopper, their inductance figure is lower than that from antigua's analysis. Resonant peak is probably loaded, but with how much capacitance i can't tell. When testing for loaded resonant peak, 200k refers to a 200k Ohm resistance, right? Does that represent a volume control? Im impressed that they offered the numbers you requested. I'm really surprised that the Fast Track 1 and 2 are so far apart. My measurement of 5.9H is pretty close to their measure of 5.7H, I would say that's within margin for error. There's a right and a wrong way to measure inductance and peak frequency, so it's kind of important that it be disclosed how they're measured. The inductance, if measured with a meter, has to ensure that the meter is able, and configured to, cope with a high series resistance, such as a DE-5000 set to series resistance, and the test frequency has to be very low in order to prevent eddy currents from being factored into the inductance measurement. IIRC with both the DE-5000 and the Extech have a default of 1kHz and parallel resistance, so if someone forgets or doesn't know to configure the meter correctly, they will get invalid values and not know it. In the case of the resonant peak, there will be some amount of testing capacitance in the probes and devices, that capacitance has to be determined so that it can be accounted for. In my test setups the capacitance was as high as 20pF and as low as 10pF. To get the true resonant peak, in theory you have to re-calculate the true resonant peak from the known inductance and capacitance, where the capacitance is less the amount of testing capacitance. To be honest, I didn't do that, my resonant peak values include 10 or 20pF test capacitance, because it's a lot of work and the unloaded resonant is largely irrelevant by itself. The actual peak resonance will be about 250Hz to 500Hz greater, with that 10 to 20pF taken off. We could assume that DiMarzio's testing equipment has a sum capacitance of 10 to 20pF, we can wonder if they accounted for it, but we dont really know. Further complicating things is that the lead wires are usually still attached, and that alone will add 50 top 100pF to the total. Their absolute resonant peak for the Chopper is a lot lower than mine, though, which suggests more capacitance in the test scenario. 200k refers to 200k ohms parallel resistance. Note that it only affects the Q and not the peak frequency though. |
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Post by reTrEaD on Dec 14, 2019 13:35:29 GMT -5
When testing for loaded resonant peak, 200k refers to a 200k Ohm resistance, right? Does that represent a volume control? The 200k Ω represents a 500k Ω volume pot, a 500k Ω tone pot, and a 1M Ω amplifier input, all in parallel. Technically, the wide-open tone pot also has a capacitor in series with it. We could model that as a vector sum of the tone pot's resistance and the reactance of the capacitor. But the capacitive reactance (roughly 3.4k Ω @ 1000Hz) is so low that we don't bother and just use the resistance of the tone pot. |
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yanyan
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Post by yanyan on Dec 16, 2019 9:27:39 GMT -5
Perhaps this might give some insight into how Dimarzio does their testing. In this old Dimarzio catalog i have (probably circa 1990-1995), there is a footnote that says:
"Test conditions: Pickup installed at normal height in solid-body guitar; "A" string picked, others muted; RMS (AC) voltage into a 100Kohm impedance measured 350 milliseconds after initial pick attack."
Obviously "normal height" is ambiguous, and their testing methods might have changed over the years.
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Post by antigua on Dec 17, 2019 1:24:13 GMT -5
Perhaps this might give some insight into how Dimarzio does their testing. In this old Dimarzio catalog i have (probably circa 1990-1995), there is a footnote that says: "Test conditions: Pickup installed at normal height in solid-body guitar; "A" string picked, others muted; RMS (AC) voltage into a 100Kohm impedance measured 350 milliseconds after initial pick attack." Obviously "normal height" is ambiguous, and their testing methods might have changed over the years. That's interesting. This more than I've ever seen mentioned. As you say, there is no such thing as a normal height, and height directly factors into the output voltage, so this is more or less an admission that the values are somewhat random. Other factors include, how thick the A string is, where the pickup is place, and how hard the string is plucked. It's safe to assume that they didn't use one particular solid body guitar, either. Having provided these mV values for pickups over the past thirty years, it's very unlikely that they would keep all of these variables the same over time, especially if it doesn't appear that they cared much about them in the first place. Those are small details, all of them can make a big difference. |
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yanyan
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Post by yanyan on Dec 18, 2019 1:49:18 GMT -5
That's interesting. This more than I've ever seen mentioned. As you say, there is no such thing as a normal height, and height directly factors into the output voltage, so this is more or less an admission that the values are somewhat random. Other factors include, how thick the A string is, where the pickup is place, and how hard the string is plucked. It's safe to assume that they didn't use one particular solid body guitar, either. Having provided these mV values for pickups over the past thirty years, it's very unlikely that they would keep all of these variables the same over time, especially if it doesn't appear that they cared much about them in the first place. Those are small details, all of them can make a big difference. Oh yeah, i overlooked string gauge, pick attack, and pickup position! Nice catch. I'm thinking even the string tuning would matter, length of pickup leads, etc. It's entirely possible though that they have a sort of test harness for pickups. It might not even be a guitar. I'm imagining a wooden jig with a row of tuning pegs on one end and a bridge (or row of anchor posts, i suppose it wouldn't matter) on the other end, and a height-adjustable mount for a pickup that can be moved to simulate neck, middle, and bridge positions. As an aside, i noticed that you don't mention output voltage in your pickup analyses. Is this because it's actually subject to many variables that are guaranteed to give different readings? |
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Post by antigua on Dec 18, 2019 3:37:40 GMT -5
As an aside, i noticed that you don't mention output voltage in your pickup analyses. Is this because it's actually subject to many variables that are guaranteed to give different readings? The output is dependent on the input. It's possible to create a standard input so as to get a standard output, but it would be very specialized. A function generator would have to power an air coil of exact specifications, at some fixed frequency, maybe 135Hz, something that avoids mains frequencies, at some fixed voltage, maybe 10 volts, and the coil would have to be set in some fixed position relative to the pickup. It could be done, but it would be a fair amount of work, and it's possible to infer the output from the inductance. All that is really missing is some data that defines the relative output difference by form factor, for example, suppose a Strat pickup, a Filter'tron and PAF are all 3 henries, what is their voltage output difference for a given input? If that is determined, we could back fill output voltage values for some given input voltage. |
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yanyan
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Post by yanyan on Dec 18, 2019 5:16:04 GMT -5
The output is dependent on the input. It's possible to create a standard input so as to get a standard output, but it would be very specialized. A function generator would have to power an air coil of exact specifications, at some fixed frequency, maybe 135Hz, something that avoids mains frequencies, at some fixed voltage, maybe 10 volts, and the coil would have to be set in some fixed position relative to the pickup. It could be done, but it would be a fair amount of work, and it's possible to infer the output from the inductance. All that is really missing is some data that defines the relative output difference by form factor, for example, suppose a Strat pickup, a Filter'tron and PAF are all 3 henries, what is their voltage output difference for a given input? If that is determined, we could back fill output voltage values for some given input voltage. Some heavy concepts here, but i'm trying my best to understand. Could it be that Dimarzio's test conditions are used to arrive at the advertised output voltages of their pickups? Meaning that given, "Test conditions: Pickup installed at normal height in solid-body guitar; "A" string picked, others muted; RMS (AC) voltage into a 100Kohm impedance measured 350 milliseconds after initial pick attack." The advertised voltage is the output for the given input produced by following these instructions? So it wouldn't be a peak or max voltage as i used to think... |
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Post by antigua on Dec 19, 2019 17:40:30 GMT -5
The output is dependent on the input. It's possible to create a standard input so as to get a standard output, but it would be very specialized. A function generator would have to power an air coil of exact specifications, at some fixed frequency, maybe 135Hz, something that avoids mains frequencies, at some fixed voltage, maybe 10 volts, and the coil would have to be set in some fixed position relative to the pickup. It could be done, but it would be a fair amount of work, and it's possible to infer the output from the inductance. All that is really missing is some data that defines the relative output difference by form factor, for example, suppose a Strat pickup, a Filter'tron and PAF are all 3 henries, what is their voltage output difference for a given input? If that is determined, we could back fill output voltage values for some given input voltage. Some heavy concepts here, but i'm trying my best to understand. Could it be that Dimarzio's test conditions are used to arrive at the advertised output voltages of their pickups? Meaning that given, "Test conditions: Pickup installed at normal height in solid-body guitar; "A" string picked, others muted; RMS (AC) voltage into a 100Kohm impedance measured 350 milliseconds after initial pick attack." The advertised voltage is the output for the given input produced by following these instructions? So it wouldn't be a peak or max voltage as i used to think... Their description of the test leaves a lot of questions unanswered. They aren't accountable to anybody except the customer, if they dont provide fine detail, its very likely that there is no finer detail to be had. |
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Post by straylight on Jan 10, 2020 20:39:53 GMT -5
The 200k Ω represents a 500k Ω volume pot, a 500k Ω tone pot, and a 1M Ω amplifier input, all in parallel. Technically, the wide-open tone pot also has a capacitor in series with it. We could model that as a vector sum of the tone pot's resistance and the reactance of the capacitor. But the capacitive reactance (roughly 3.4k Ω @ 1000Hz) is so low that we don't bother and just use the resistance of the tone pot.
Thanks for that, I knew the tone capacitor made little difference with 500k between it and earth compared to just a 500k resistance, and I wasn't seeing a difference between a full replica of a the components and the 200kΩ and 470pF dummy load, both in real-world testing and in *spice but i couldn't quite articulate why.
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Post by sumitagarwal on Feb 24, 2024 13:49:13 GMT -5
Thanks for this detailed review and measurements!
I found a couple of interesting things here... one is that the overall induction to resistance ratio on these single-coil-sized humbucking pickups seems to be far higher (.67) versus the comparisons you made looking at resistance and induction for both traditional fender and PAF-type pickups.
The other, probably more interesting, thing here is that the coupling factor with these tightly-packed coils is HUGE. Based on your measurements that's 38% higher induction in series than would be expected by just adding the individual coils' resistances
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Post by sumitagarwal on Mar 6, 2024 20:04:03 GMT -5
Since there isn't a separate thread about the similar DiMarzio Cruisers I figure here might be as good of a place as any to drop info I got from DiMarzio. According to them, both the neck and bridge Cruisers have an inductance of only 1.38H! Goes a long way to explain why people find them so anemic, and is significantly below even lower output Strat single coils. Also antigua are you still adding data to your table at www.echoesofmars.com/pickup_data/viewer/ ? I didn't see the Fast Track data in there so I assume you're not |
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Post by antigua on Mar 7, 2024 0:52:47 GMT -5
Since there isn't a separate thread about the similar DiMarzio Cruisers I figure here might be as good of a place as any to drop info I got from DiMarzio. According to them, both the neck and bridge Cruisers have an inductance of only 1.38H! Goes a long way to explain why people find them so anemic, and is significantly below even lower output Strat single coils. Also antigua are you still adding data to your table at www.echoesofmars.com/pickup_data/viewer/ ? I didn't see the Fast Track data in there so I assume you're not I forgot to add it, but I will. It's a bit of a pain to add because I have to edit the spreadsheet, then export it as a CSV file and upload it to the web server. |
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Post by sumitagarwal on Mar 7, 2024 7:35:26 GMT -5
Since there isn't a separate thread about the similar DiMarzio Cruisers I figure here might be as good of a place as any to drop info I got from DiMarzio. According to them, both the neck and bridge Cruisers have an inductance of only 1.38H! Goes a long way to explain why people find them so anemic, and is significantly below even lower output Strat single coils. Also antigua are you still adding data to your table at www.echoesofmars.com/pickup_data/viewer/ ? I didn't see the Fast Track data in there so I assume you're not I forgot to add it, but I will. It's a bit of a pain to add because I have to edit the spreadsheet, then export it as a CSV file and upload it to the web server. Ah, yea that does sound cumbersome. Maybe it'd be easier to export it all into a Google Sheet and simply publish that? It's such an incredibly valuable resource. Nothing else exists quite like it, except for the Guitar Pickup Database which is smaller and is missing inductance values for many of the entries. Also, got a little more data from DiMarzio: DP425 Satch Track: 4.85H and a peak of 3.57Khz Cruiser peaks: 6.28Khz neck 5.06KHz bridge I think that puts the Fast Track 1 closest to the classic Strat wheelhouse, with the Cruiser Bridge a significant step "cooler" than vintage and the Satch Track a significant step "hotter" than vintage. Feels like there's a gap there where there should be some other models closer in spec to the Fast Track 1. Still, I feel like I could imagine putting together a guitar with a Cruiser Bridge in the neck slot, a Fast Track 1 in the middle slot, and a Satch Track in the bridge slot. |
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