Humcancelling system for single coil pickups

27th May 2016:

Youtube demo of humcancelling system 8a:

Soon I will be testing the 2 new versions of my humcancelling system and will have youtube demos of them.

Costs will only be known once the system design is finalised but as a rough estimate I am hopeful that the humcancelling system will sell at between $AUD700-800 plus fitting labour costs. This is an estimate for a handmade version of the system and I am hopeful that this product is something that can be factory made to brings costs much lower.

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15th April 2016: exciting new product under development:(updated info 20th May 2016)

Humcancelling system for Fender Stratocaster® guitars which use the standard 3 single coil pickup format.

(pickups need to be same magnetic polarity, wound in the same direction and wound to approx the same turns count)

16th April 2016 Strat humcancelling system 8a trials with test guitar

16th April 2016 humcancelling system 8a trials with test guitar

 

16th April 2016 Strat humcancelling system 8a trials. Dummy coil is mounted between neck and middle pickups on this test guitar but can also be mounted near 5 way switch in control cavity.

16th April 2016 humcancelling system 8a trials. Dummy coil is mounted between neck and middle pickups on this test guitar but can also be mounted near 5 way switch in control cavity.

In 1989 an active humcancelling system was designed for me by Warren McAlister and for several years I fitted this system to some of my custom made guitars and to some other guitars for customers. This 1989 active system was powered by a 9V battery and used a dummy coil. The system was good but had some drawbacks which needed to be improved: the active sound needed to be closer to the passive pickup sound and the amount of hum reduced was good but not entirely satisfactory. There were also other design issues to improve on.

1989 humcancelling system pcb and 2013 version 1 pcb

Warren McAlister’s 1989 humcancelling system pcbs at bottom and 2013 version 1 pcb part a

In 2011 I began experimenting with developing new versions of the humcancelling system. This has meant experimenting with fresh designs, and to date I have trialled 8 prototype versions of a new improved system.

From 2011 to 2013 I experimented with circuits which were transformer coupled with transistors and/or FETs. The present circuits are using combinations of transistors, FETs and ICs.

My objectives have been to design an active humcancelling system which:

  1. is as close as possible in sound to the normal passive pickup sound
  2. reduces as much 50/60 cycle hum and general noise as possible
  3. is easy to install thus reducing installation labour costs
  4. has extremely long 9V battery life
  5. has easily accessible switching between passive pickup and active system modes via a push/pull pot switch located underneath one of the guitar’s potentiometer controls.
  6. pcb capable of being neatly housed in the guitar’s control cavity rather than requiring a separate routed cavity in the guitar body.
  7. when fitted on Stratocaster® guitars the system can have a ‘level boost’ control in place of the usual 2nd Tone control mounted on the pickguard. In active humcancelling mode this level boost will function to give addition output level for solo or other passages.

Achieving these objectives has proved more elusive and time consuming than first thought, but recent prototypes are showing great promise. More information will be available soon as well as a demo youtube clip when the latest prototype is finalised.

Battery cavity used on many of my custom guitars which had the humcancelling system fitted during the 1990s. This gives easy access for 9V battery changeover.

Battery cavity used on many of my custom guitars which had the humcancelling system fitted during the 1990s. This gives easy access for 9V battery changeover.

Circuits that I have tried for single coil Stratocaster® pickup humcancelling systems since 1989:

  1. Warren McAlister who ran Phase Engineering at Brookvale designed the 1989 humcancelling system, the guitars that these systems were fitted to usually either had a push/pull pot or a rotary switch which selected either active humcancelling system or passive pickup modes.
Warren McAlister humcancelling system 1989

Warren McAlister humcancelling system 1989

When Warren designed this system we were aware of the other humcancelling systems from the 1980s which used a dummy pickup coil and active electronics: the short lived Fender Elite Stratocaster® from 1983 had their own system, John Carruthers in California had also produced a design, as did Chris Kinman in Australia with the ‘Buzz-Bucker’ system which was used on his Stratocaster® style guitars made in Brisbane in the 1980s. Warren McAlister’s design was an improvement on these other humcancelling systems.

For info and specs about the 1983 Fender Elite Stratocaster® please see: http://www.homepages.ed.ac.uk/reimer//elite.htm

2. Colin Bloxsom’s 2000 J-Fet based humcancelling system, this gave a further improvement in the pickup tonality compared to the 1989 system.

Colin Bloxsom JFet humcancelling system circuit approximation

Colin Bloxsom JFet humcancelling system circuit approximation

3. Fryer humcancelling system 9B 2016, this is one of many prototypes that I have been experimenting with since 2011.

Fryer humcancelling system prototype 9B 2016

Fryer humcancelling system prototype 9B 2016

 

Stratocaster® is a registered trademark of Fender Musical Instruments Corporation and Fender Australia Pty Ltd. Fryer Guitars is not affiliated in any way with Fender Musical Instruments Corporation or Fender Australia Pty Ltd.