Anyone know the circuits in the Seymour Duncan and Dimarzio active pups?

[Alan0354]

Anyone has the Seymour Duncan and Dimarzio circuit diagrams of their active pups?

[David Schwab]

DiMarzio doesn't make any active pickups. I have no idea what's in the Duncans, but this is supposed to be an EMG 81.

[Alan0354]

DiMarzio doesn't make any active pickups. I have no idea what's in the Duncans, but this is supposed to be an EMG 81.

[ATTACH=CONFIG]15971[/ATTACH]

Thanks, do you mean SD is the same design as EMG that has a stagged coil and use an opamp to sum the two to cancel the noise?

[frankfalbo]

Our preamp is not like the EMG. If you want ours though, you can buy the Blackouts Modular Preamp. It essentially contains our neck and bridge preamp. The Blackouts Modular Preamp

[big_teee]

Our preamp is not like the EMG. If you want ours though, you can buy the Blackouts Modular Preamp. It essentially contains our neck and bridge preamp. The Blackouts Modular Preamp

Any way to make that work with both pickups on a 4 Pot LP?
T

[frankfalbo]

Yeah of course. The pot has it's own dedicated terminal for in and out. It doesn't prewire the signal into the pot. So you just jump one preamp out directly into the volume pot, and the other over to the other volume pot.

[big_teee]

Yeah of course. The pot has it's own dedicated terminal for in and out. It doesn't prewire the signal into the pot. So you just jump one preamp out directly into the volume pot, and the other over to the other volume pot.

A very Novel Idea in Deed.
So I would like to try one with some vintage type Strat coils.
I run 5.8k, 6.1k, and 6.5k, N,M,B.
Do you have any sound clips similar to that?
To me that makes a lot more sense to incorp. with the blackout than just the plain ol Liberator.
T

[frankfalbo]

Bear in mind the preamp is intended to act like a humbucker in itself. The signal from one coil comes in out of phase and is inverted when summed, thus cancelling more hum. A single coil wired into one half of the preamp will hum. Also one of the coils is loaded. So pretend one coil has a low value pot on it. It's darker sounding than the other one. Together it makes up the expected sound, but separately only one of the coils (represented by the white wire in our schematic) is "flat" sounding.

[big_teee]

Bear in mind the preamp is intended to act like a humbucker in itself. The signal from one coil comes in out of phase and is inverted when summed, thus cancelling more hum. A single coil wired into one half of the preamp will hum. Also one of the coils is loaded. So pretend one coil has a low value pot on it. It's darker sounding than the other one. Together it makes up the expected sound, but separately only one of the coils (represented by the white wire in our schematic) is "flat" sounding.

I just thought it was a regular preamp.
I know Nothing on the Subject.
Sorry
T

[Alan0354]

Our preamp is not like the EMG. If you want ours though, you can buy the Blackouts Modular Preamp. It essentially contains our neck and bridge preamp. The Blackouts Modular Preamp

So the strat size one is not a hum cancelling pup like EMG. How about the Livewire pups?

[Alan0354]

Bear in mind the preamp is intended to act like a humbucker in itself. The signal from one coil comes in out of phase and is inverted when summed, thus cancelling more hum. A single coil wired into one half of the preamp will hum. Also one of the coils is loaded. So pretend one coil has a low value pot on it. It's darker sounding than the other one. Together it makes up the expected sound, but separately only one of the coils (represented by the white wire in our schematic) is "flat" sounding.

You lost me on this, Are you talking about the Blackout that already has two coil so you just have preamp for each coil separately and sum together later?

But for single coil Blackout, you only have one coil, there will be no cancelling no matter how you play with the preamp. It that true then that the single coil Blackout has hum like any other single coil?

[Mike Sulzer]

Bear in mind the preamp is intended to act like a humbucker in itself. The signal from one coil comes in out of phase and is inverted when summed, thus cancelling more hum. A single coil wired into one half of the preamp will hum. Also one of the coils is loaded. So pretend one coil has a low value pot on it. It's darker sounding than the other one. Together it makes up the expected sound, but separately only one of the coils (represented by the white wire in our schematic) is "flat" sounding.

This is somewhat confusing. "Humbucker" implies the cancellation of magnetic fields, mostly of electrical power line origin, thus 60 Hz and harmonics. A preamp does not do that; coils that detect the interfering fields with opposite polarity are required. However, you can in addition cancel hum from electrical fields by using a differential amplifier. I assume that this is what you are doing, as I believe EMG does. Also, I described a 3 op amp instrumentation amp for doing that in the string sampling discussion.

When you load the two coils differently, you lose the cancellation of the higher harmonics. In environments with a lot of buzzing from, for example, high current switching such as light dimmers, this can be a problem. I have been surprised that designers are willing to lose some hum rejection, especially when active circuits are involved, since it seems just a matter of frequency response that can be achieved easily by other means in an active circuit. However, when you consider the string sampling issue, altering the gain of one coil at the higher frequencies can partially prevent the cancellation of higher string harmonics on the wrapped strings. This could be part of the reason for the popularity of making the coils with different responses.

[frankfalbo]

...for single coil Blackout, you only have one coil, there will be no cancelling no matter how you play with the preamp. It that true then that the single coil Blackout has hum like any other single coil?

Blackout and EMG single coils are stacks under the cover. There are two coils. The BMP-1 that we now have available separate from the pickup is intended for a 2 humbucker guitar (side-by-side). It will work on a stack but you'd want to make sure the top coil was not the loaded coil. I'll repeat this is not the intended design, and not the same preamp topology we use in our single coil Blackouts.

[frankfalbo]

This is somewhat confusing. "Humbucker" implies the cancellation of magnetic fields, mostly of electrical power line origin, thus 60 Hz and harmonics. A preamp does not do that; coils that detect the interfering fields with opposite polarity are required. However, you can in addition cancel hum from electrical fields by using a differential amplifier. I assume that this is what you are doing, as I believe EMG does.

Sorry to have confused you. I'm using the term humbucker affectionately like a nickname. "Noisebucker" would be more apt. But we feel we have some significant benevits vs. the EMG circuit. Our noise level is improved by 12-14dB while also freeing up more headroom up top. So the noise at rest is 12dB quieter, but the increased headroom means that at some point when the EMG preamp clips, having a hard limiting effect on the signal, the Blackouts do not clip and therefore something could be said about the signal to noise ratio, but it's only apt once the EMG preamp clips. It clips the attack (call it peak?) of almost any moderately picked note, and clips what you could loosely refer to as "RMS" under medium-to-hard playing. Many players run the EMG's at 18 volts, but the headroom of Blackouts at 9v is equal to or higher than the EMG at 18.

When you load the two coils differently, you lose the cancellation of the higher harmonics. In environments with a lot of buzzing from, for example, high current switching such as light dimmers, this can be a problem. I have been surprised that designers are willing to lose some hum rejection, especially when active circuits are involved, since it seems just a matter of frequency response that can be achieved easily by other means in an active circuit. However, when you consider the string sampling issue, altering the gain of one coil at the higher frequencies can partially prevent the cancellation of higher string harmonics on the wrapped strings. This could be part of the reason for the popularity of making the coils with different responses.

The hows and whys of our preamp are proprietary. I can't disclose various secrets, but like everything else we talk about here (vintage pickups, Wal bass pickups, etc) anyone can buy one and reverse engineer it. I don't want to "Mike Sulzer" this thing across three pages, so I'll say what I can and hope to move on.

The preamp is quiet. The resonant peak of a coil is pretty narrow, and narrowest at the peak. The at rest noise received within the peak area is not proportionately reduced by the amount the dB reduction the peak undergoes in the loaded coil. One way to think of this is that if the resonant peak of a coil was responsible for substantially more noise than the surrounding frequencies, the self noise of a single coil would be dominated by peak frequency of the coil. That's not how we hear it. In other words, you'd see a meaningful spike in noise at the peak frequency. It's just not really an issue. You don't "lose the cancellation of higher harmonics" as you say. You may affect it, but you do not lose it. That's where I say it is not proportionate. An 8dB flattening of the peak does not equal an 8dB increase in noise in the shape of the gap between the two peaks.

[David Schwab]

EMG say they also load each coil differently.