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Audere noise cancelling preamp-single coils without the hum

#21
A Rickenbacker 4003 may be a good test instrument. Although not RW/RP from the factory, some people have removed the magnet from the bridge pickup and flipped it over and reversed the phase to cancel hum when used with the neck pickup. I've done this modification on my 4001 and it definitely helps, though the cancellation is not perfect.

Also, is reverse winding actually important, or is reversing the polarity sufficient?
 
#22
12bass said:
A Rickenbacker 4003 may be a good test instrument. Although not RW/RP from the factory, some people have removed the magnet from the bridge pickup and flipped it over and reversed the phase to cancel hum when used with the neck pickup. I've done this modification on my 4001 and it definitely helps, though the cancellation is not perfect.

Also, is reverse winding actually important, or is reversing the polarity sufficient?
Click to expand...

lakland/hanson doesnt reverse wind their jazz pickups. just reverse polarity.
 
#23
From what I gather, reverse winding is electrically/magnetically the same. Do the electrons care which way the wire is wrapped? The relevant factor is to swap magnetic and electrical polarity. Are pickup manufacturers actually winding in opposite directions for hum cancellation, or merely reversing the polarity of magnets and output wires?
 
#24
For an ideal coil of 1 layer setting in free space it of course it will not mater.
Very technically it can matter if you have a multiple layer coil but I would say not important at audio frequencies.
But when you have a "significant" capacitance coupling to a conductive object then it can start to mater which side you consider ground and hot.

So the 2 cases are often not equal at the high frequency end of the pickup's response especially if a pickup includes some shielding.

Yes many winders only reverse the wires but IMO it is easier to do a more "ideal" test then to wonder if this side effect was important.
 
#25
BUMP... thinking of getting this bad boy for my Squier VM Jazz... I already have an Audere 4 band Pro that I LOVE! My past shielding jobs were awful & this bass could use some noise reduction for sure. I'll probably change the pickups to the Nordstrand NJ5F because its my ONLY single coil bass. I gotta admit, I really like the sound of the Duncans & Audere though.

If these can really crush hum it would be so sweet!
 
#29
Are pickup manufacturers actually winding in opposite directions for hum cancellation, or merely reversing the polarity of magnets and output wires?
Click to expand...

I can't speak for other manufacturers, but our two in-house wound RWRP J4 single-coil offerings are both a true reverse wound coil set.


this 'preamp' sounds like a cool idea applied in an equally cool way

all the best,

R
 
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#30
like audere alluded to, what happens if you "cheat" and just flip the wires rather than winding the other way is that if you have fender-type pickups the windings right against the magnets become the hot end, and the magnets themselves become really noisy if you touch them.
 
#31
Just had one installed on my 2001 MIM jazz. Terrific preamp. Very neutral sound with eq flat, dead quiet and accurately reproduces essential tone of my SD Antiquities. The eq is very useable. Dave Meadows was VERY quick to answer some questions I had about the preamp during the installation--including at times of the day/night I wouldn't normally expect a response at all!
 
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#32
David Meadows is a genius and a great guy to work with too. I'm a big fan and have installed his regular preamps in 4 basses. Latest project is pictured here (4 big singles, two of which are under a MM cover). This bass will use the noiseless product so that each of the 4 coils can be used in any combination in addition to the naturally noise cancelling combinations. I'll post clips if I can get my son to help me out with that part. Am also working with David on use of the noise sensor system by itself (without active tone controls) in a Tele guitar which is our latest charity project (the bass below is a new toy for me).

IMG_0178 crop.jpg
 
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#33
I finished up this bass today. Have had several Pro-Z models and one Classic - Audere is pretty much the only preamp I use. Tried the noiseless version this time and am blown away. Even though I feel like I know and trust David Meadows, I'm a born skeptic, so I ordered mine with a bypass switch in order to A/B compare. It works exactly as advertised - all the tone without the hum. This one is a custom setup that's a little more complicated because I'm using 4 pickups. There are two noise sensor phantom coils and two noise cancellation modules (one set for each pair of coils) and one 4 band Classic pre.

IMG_0242.JPG


IMG_0240.JPG


IMG_0250.JPG
 
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#35
nice!

OT, but as sexy as all that copper foil is, if you want something that shields every bit as well but takes a fraction of the time to do and will never peel up, look at the Invalid Link Removed:

Invalid Link Removed
one 5 second coat sprayed in a control cavity will dry in like two minutes and have something like 20 or 30 Ohms measured DC resistance from one end to the other (way more than good enough for shielding purposes). do a second coat and you get down to single-digit resistances across even large cavities.

i'll never bother with expensive, tedious foil or messy, slow-drying, electrically inferior graphite brush-on paint again.
 
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#36
walterw said:
nice!

OT, but as sexy as all that copper foil is, if you want something that shields every bit as well but takes a fraction of the time to do and will never peel up, look at the Invalid Link Removed:

Invalid Link Removed
one 5 second coat sprayed in a control cavity will dry in like two minutes and have something like 20 or 30 Ohms measured DC resistance from one end to the other (way more than good enough for shielding purposes). do a second coat and you get down to single-digit resistances across even large cavities.

i'll never bother with expensive, tedious foil or messy, slow-drying, electrically inferior graphite brush-on paint again.
Click to expand...

Isn't it more work to tape off the finish than to paint the cavities with a brush or put foil tape on? The foil is a TV task for me, so I don't mind. A professional full time builder would want a more efficient process than what I do.
 
#37
Doner Designs said:
Isn't it more work to tape off the finish than to paint the cavities with a brush or put foil tape on? The foil is a TV task for me, so I don't mind. A professional full time builder would want a more efficient process than what I do.
Click to expand...

Oh lord no. I am pretty quick with tape at this point but I can fully shield a bass in 30 minutes with paint and most of that is letting the paint dry for 10 minutes between coats. It takes minutes to tape off a body with paper and tape and a few minutes more to blast away. I do my pickguard and pickup surrounds while the paint dries. Much faster and much more professional looking.

I can definitely relate to tape being a TV task. When I first started shielding basses I found myself doing one almost each week. Friday nights were re-runs of Lockup and aluminum tape in a Fender... it got a little ridiculous at one point because even my friends made fun of my Friday nights.

@Tunaman I am sure you are well past a decision at this point but your shielding jobs will never have an effect on 60hz noise (i.e. single coil hum.) Shielding only reduces RF interference.
 
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#38
DiabolusInMusic said:
Oh lord no. I am pretty quick with tape at this point but I can fully shield a bass in 30 minutes with paint and most of that is letting the paint dry for 10 minutes between coats. It takes minutes to tape off a body with paper and tape and a few minutes more to blast away. I do my pickguard and pickup surrounds while the paint dries. Much faster and much more professional looking.

I can definitely relate to tape being a TV task. When I first started shielding basses I found myself doing one almost each week. Friday nights were re-runs of Lockup and aluminum tape in a Fender... it got a little ridiculous at one point because even my friends made fun of my Friday nights.

@Tunaman I am sure you are well past a decision at this point but your shielding jobs will never have an effect on 60hz noise (i.e. single coil hum.) Shielding only reduces RF interference.
Click to expand...

I can think of plenty of worse ways to spend a Friday night. :-)
 
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#39
Doner Designs said:
Custom NC rig here, ready for installation. It may look like a rats nest when installed, so here is a clean picture. It's complex because it's being fed by 6 separate coils, three with Alnico 5 magnets and three with Alnico 3.

View attachment 708267

View attachment 708789
Click to expand...

Hello Steve. That bass looks like it's going to be great, but let me ask: will it have a passive mode?

Just kidding! ;)

Good luck with the build. Your photos of the Doner Designs basses always show impeccable work.

Best,

Snaxster
 
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#40
DiabolusInMusic said:
@Tunaman I am sure you are well past a decision at this point but your shielding jobs will never have an effect on 60hz noise (i.e. single coil hum.) Shielding only reduces RF interference.
Click to expand...

I sold that MIM jazz & a VM jazz with Auderes a while ago. My new MIA J Standard is really quiet & if its loud because of bad outlets I just run in the middle. I do all my EQ changes at my feet & at amp. I do like the Audere though if I could have gotten em quieter.
 

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