need schematic for hum cancelling jazz bass pickups

[David King]

Oops! sorry I forgot about the rails and hbs! I'll go taste a 9v battery and repent for my inattention.

[David Schwab]

All those "noiseless" J pickups are either stacked coils or split coils or single string coils with equalized turns*areas.

Not all of them. Both the Joe Barden and my Neo Jazzbuckers are dual rail humbuckers. I also make sidewinders in a J case. But stacks and splits are the most common.

[David King]

All those "noiseless" J pickups are either stacked coils or split coils or single string coils with equalized turns*areas.

[Mike Sulzer]

Hi Mike,
transformer maybe?

No, same problem as a differential amp. The pickup uses the law of magnetic induction to sense the string and hum fields. You need to use the same law to cancel it.

[odyyiannis]

Hi Mike,
transformer maybe?

[Mike Sulzer]

stratoblaster will amplify hum to from a jazz bass single coil, so it's not work for me,

As will any preamp. They all amplify the signal and magnetic hum together. The problem with a sc pickup is that it does not cancel hum from magnetic fields as a humbucker does. No preamp, not even differential input can do that. Magnetic hum must be canceled using two or more coils

[odyyiannis]

Thank you David,
need to do a research and I'll come back.

[David King]

Try this then: LS204

[odyyiannis]

Hi David,
thank you for your replay,
stratoblaster will amplify hum to from a jazz bass single coil, so it's not work for me,
THAT 1510 seems to be nice but 6ma current draw is to high for on board preamp (ideal will be under 1ma).
The devise it's not necessary to be DIP8 package, can be surface mount ether (I can soldered at the back side of pcb board).
Well that's all for now,lets hear a nice song,
dedicated to all forum members.
Johnny Cash - I've Been Everywhere - YouTube

[David King]

THAT 1510 and 1512 seem like they might be of interest if you are looking for an opamp that's still available in a DIP8. The specs are all pretty good until you get to current draw which is a whopping 6ma, about 10 times more than your typical LM442 etc.

[David King]

Welcome to the pickup-maker's ghetto Yiannis,

A buffer schematic with balanced input?

If you don't need the balanced input I'd think just a J-fet stratoblaster might work.

Undoubtedly there are dozens of dual input buffer chips with very low noise, low current draw. The datasheets will supply all the schematics you'll probably ever need.

[odyyiannis]

Hi David,
thank you for answering in my thread and I know that you have the answer to my question,as you mention about it at list two times in your older posts. You see I have spend many hours during last 4 years reading the pickup forum.All the infos I got from all of you help me a lot in my work (I am bass builder since 1992).
I am very grateful to all of you for that knowledges.
I have setup a winding machine and make many tests and came with the results that pickup building its very simple-complicated !!! no final product till now but I like it.
You write that active hum canselling pickups color the sound but I want to give it a try and if I have good results I will post it (I have 6 years experience with on board preamps).

Thank you for your time,
All the best to you and ours,
Yiannis Ioannides.

[David Schwab]

You want a schematic for a pickup? Pickups don't have schematics.

[odyyiannis]

Hello everybody,
new in town,
I need a schematic for hum canselling vintage style jazz bass pickups, I am planing to use it as input stage (buffer) to an existing 3band eq.
I was looking for info in old posts with no lack.
Thank you in advance,

Yiannis Ioannides.