my homemade BPSSC

[ludkokanta]

What about the core then?

Air, diamagnetic, paramagnetic or ferromagnetic?

bpssc is air, kinman and dimarzio are iron slugs (slightly ferromagnatic) I think.....

[madzub]

what exactly are you asking?

[ludkokanta]

what would be the best core for a homemade bpssc?

My tremolo cavity is tight so I'd put a smaller noise sensing coil under the springs.

So, I'm thinking I need the iron core to increase the "negative hum inductivity"?

[madzub]

the bpssc doesn't go IN the tremolo cavity, it goes OVER the cavity, encased inside the cover. The larger the loop, the fewer turns you need, resulting in less windings, which gives less alteration to the tone.

I think that increasing the inductance would alter the tone quite a bit, dulling your high end unless compensated for by using brighter pickups.

[ludkokanta]

If its a thin shred guitar there is not much room between the cover and springs.

Also, how come kinman and dimarzio use metal slugs (to increse inductance on a small dummy coil) and still sound bright?

My coil would be 3,5" x 1,5"

[Alan0354]

I pickup this old post by accident. I did a little experiment, I don't think it even come close to the cancelling effect of a true humbucker. It is very position dependent. I look at the signal with the scope, the two signals ( from the pup and the air coil) vary at different position, sometime one is bigger than the one or the other. Also, I don't think the frequency response of the two are the same. The signal pup is very high inductance and the higher harmonics are not as strong where the low impedance coil seems to have more higher harmonics. they don't cancel out. Yes, you can make the low 60Hz cancel out well, but the buzzing ( high harmonics) is very position dependent.

[Mike Sulzer]

I pickup this old post by accident. I did a little experiment, I don't think it even come close to the cancelling effect of a true humbucker. It is very position dependent. I look at the signal with the scope, the two signals ( from the pup and the air coil) vary at different position, sometime one is bigger than the one or the other. Also, I don't think the frequency response of the two are the same. The signal pup is very high inductance and the higher harmonics are not as strong where the low impedance coil seems to have more higher harmonics. they don't cancel out. Yes, you can make the low 60Hz cancel out well, but the buzzing ( high harmonics) is very position dependent.

The different inductance values should not matter: they just go in series and add, and so if the two coils have the same sensitivity to magnetic hum signals, they should cancel anyway. Combined with different capacitance values, it would make a difference at very high frequencies. I suspect that introducing adjustments is a slippery slope, and that one is better off getting the sensitivity right without any adjustment in a completely passive system, and just accepting the fact that it is not perfect. The coil is just too big to work really well in any case.

[David Schwab]

The coil is just too big to work really well in any case.

I haven't heard one in person, but all the audio demos I have heard sound very good. It cancels most of he hum and doesn't step on the tone of the pickup.

It would probably be a little quieter if he wasn't sitting right next to the amp.

[Mike Sulzer]

I haven't heard one in person, but all the audio demos I have heard sound very good. It cancels most of he hum and doesn't step on the tone of the pickup.

It would probably be a little quieter if he wasn't sitting right next to the amp.

The amount of hum cancellation at the beginning of the video is really not all that much. This is a promotional video intended to sell a product, a product which will work better or worse in different circumstances. Do you think the video shows, best, typical, or worst performance?

[David Schwab]

Another video. It's hard to hear the hum until about 1:05 when he has the amp cranked.

Most of the reviews I have seen at various forums are favorable, and say that with vintage output pickups you get about a 70% reduction in hum. Hotter pickups seem to work better.

[Kindly Killer]

I just made myself a coil and a PCB following the patent info. I'm wondering exactly how Suhr stuffs it into the body. Has anyone either seen a production body with the coil around the pickups or done a DIY version they're happy with? Where do you put the coil? I made mine with AWG30 so it's a little thick to attach to the back of the guitar. I have some AWG36 on the way to do my other strat and I will have enough to redo this one if it doesn't work out, but it seems tidier all around to put it under the pickguard.

[Alan0354]

The amount of hum cancellation at the beginning of the video is really not all that much. This is a promotional video intended to sell a product, a product which will work better or worse in different circumstances. Do you think the video shows, best, typical, or worst performance?

It is very position dependent. You have position that don't do a thing and one or two position that is even worst. The point is there are a lot more position that is better and you can easily find one to stand and play. But from the demo, it does change the sound, it is not exactly the same.

I am experimenting noise cancelling and you really has to have the cancelling coil very much the same and at the very close proximity like the big humbucker to really have true noise cancelling, all the others are hit and miss and you still have to find a sweet spot. For two to three hundred dollars, they can keep it. That must be the reason it is not popular at all. Not to mention it does not work for guitar with reverse winding in the middle. The kicker is it definitely sound different with it in vs out as shown clearly in the demo. Yes, you can argue that it does improve from the Dimarzio Areas, but don't say it is the answer for the single coil. If people nitpick about CTS pots and tear drop caps, this is a huge difference in comparison.

BTW, I did experiment with shielding of the flat cancelling coil, I tried wrapping even the whole thing and it does not make a dent of a difference. I just left the bare coil on the back plastic plate totally unshielded.

[Kindly Killer]

The one I made did pretty well just hanging off a disembodied pickguard, but when I put it in my test guitar (mostly hollowed out with a router for things just like this) it barely made any difference. I'm in the middle of implementing something else now.

[Mike Sulzer]

It is very position dependent. You have position that don't do a thing and one or two position that is even worst. The point is there are a lot more position that is better and you can easily find one to stand and play. But from the demo, it does change the sound, it is not exactly the same.

I am experimenting noise cancelling and you really has to have the cancelling coil very much the same and at the very close proximity like the big humbucker to really have true noise cancelling, all the others are hit and miss and you still have to find a sweet spot. For two to three hundred dollars, they can keep it. That must be the reason it is not popular at all. Not to mention it does not work for guitar with reverse winding in the middle. The kicker is it definitely sound different with it in vs out as shown clearly in the demo. Yes, you can argue that it does improve from the Dimarzio Areas, but don't say it is the answer for the single coil. If people nitpick about CTS pots and tear drop caps, this is a huge difference in comparison.

BTW, I did experiment with shielding of the flat cancelling coil, I tried wrapping even the whole thing and it does not make a dent of a difference. I just left the bare coil on the back plastic plate totally unshielded.

Position dependent just means that it is not canceling very well.

The inductance is low (.02 H in the patent), and so electrostatic shielding should not make a lot of difference, but I guess if you want to get everything theoretically right...

That adjustment circuit in the patent seems pretty useless. What you need most is a way to adjust the sensitivity to match the range of different sensitivities of different pickups. Both of the two adjustments are frequency dependent. It sort of looks like an attempt to resonate the circuit at about 8 KHz and then adjust the Q and the high frequency attenuation. This is not what is needed, and I suspect that this is not what is in the product in any case.

[bassetrox]

DIY BPSCC tutorial

Hi there guys, I'm putting a simple tutorial together on how to DIY one of these things as I attempt the project myself. If you're interested, or if you guys who've done it can give me any valuable input, take a look at Experiments |

Cheers,