Burns Tri-Sonic magnets

[Mick Bailey]

The original Tri-Sonics were made with two magnets, whilst the copies/reissues have a single magnet. What's the reason for having two magnets? All I can think of is that the smaller magnets could be used in their Dual-Sonic pickups without having to stock different magnet sizes.

[Helmholtz]

In this article by Bernd Meiser (being a knowledgeable EE and GITEC board member) the author states the the original patent showed a single block magnet while production PUs used 2 smaller magnets for availability reasons:
https://www.gitarrebass.de/workshops...reble-booster/

From the point of physics there shouldn't be a difference in performance if magnet material and strength are the same.

Some more info: https://dsgb.net/faqs/trisonics/

[Mick Bailey]

Thanks - I hadn't seen the Bernd Meiser article. I have some Korean-made copies that I'm intending to rewind as per the originals and also reduce the overall height to get the dimensions more accurate.

[soundmasterg]

Thanks - I hadn't seen the Bernd Meiser article. I have some Korean-made copies that I'm intending to rewind as per the originals and also reduce the overall height to get the dimensions more accurate.

Are you going to wind them as air coils like the original Tri-Sonics or did the Korean ones use bobbins? The most accurate Tri-Sonic clones I know of are the Adesons, and I believe he even uses the original machines that Burns used to wind the air coils.

Greg

[Mick Bailey]

I'm going to wind them as air coils, so some work to do to make a collapsible former. They currently have bobbins and don't actually sound bad, but I'd like to use them as the basis for experiment.

[soundmasterg]

The air coils with collapsible formers look like an interesting way to make pickups, though a little more work than with bobbins. Will be interested to see and hear what you end up with!

[dsgb]

Hi gents. First post... I found this forum linked from here:

https://guitarnuts2.proboards.com/th...ance-lcr-meter

while researching capacitance of guitar pickups for a forthcoming YouTube video on the electromagnetic characteristics of (in particular) Tri-Sonic pickups.

What started as an idea to demonstrate how to measure the DC resistance and inductance of the pickups in circuit then calculate the values out of circuit has increased in scope somewhat. The challenge is how to package and make theory accessible to a general audience.

It was curious to see my FAQ/primer on Tri-Sonic pickups referenced in an earlier post. Thanks.

I made a three part removable former from PTFE to wind a vintage style bobbinless Tri-Sonic pickup using rudimentary equipment in this video on Tri-Sonic pickups:

https://youtu.be/JXJux4IDfsE

Doug

[Mick Bailey]

Hi Doug, and welcome to the forum.

I've followed your work for a good while, initially from the Red Special forum as it used to be, sadly now pretty much abandoned. My own Red Special build stalled in September due to a string of bad luck but hopefully will get back on track. I decided to build the hardware as Brian did by hand and using his original 3-piece bridge design with the bolt-on side cheeks (and black wrinkle finished). I hadn't appreciated just how laborious this would be - endless hours of filing and checking. The Korean pickups are still on my bench unaltered. Mainly because of indecision whether to rewind these with an air coil and modify the covers, to locate an original set, or buy a set of custom-made replicas.

Something that you may clarify - in the Red Special book Brian refers to potting the pickups with Araldite, yet the photographs of the pickups show unpotted coils. Was it just the original home-made pickups that were potted?

[dsgb]

Hi Doug, and welcome to the forum.

Something that you may clarify - in the Red Special book Brian refers to potting the pickups with Araldite, yet the photographs of the pickups show unpotted coils. Was it just the original home-made pickups that were potted?

Hi Mick.

I thought your name rang a bell! Hello once again. Were you the guy with vintage 1960s blockboard that sent me a picture so I could determine the width of the core softwood battens? If so, I lost the image file! The old Red Special forum is dead and getting spam posts which is a shame. All the action happens on the Facebook Red Special group but large social media groups aren't for me so I keep out of it.

A quick aside. I'm down a properly good rabbit hole now. Looking at buying a PicoScope 2204A and using the third party software by Adam 'Hexamer' to conduct Bode plots on a few of my Tri-Sonic pickups in and out of circuit. That should look cool on video but not sure how many people are nerdy enough to appreciate it. Also, I'm unlikely use the PicoScope system much in the future so even GBP100-200 is challenging to justify for this project/investigation.

https://www.picotech.com/support/viewtopic.php?t=14311

You guys are probably very familiar with the supporting information on this but here is what I've been reading so far:

http://www.planetz.com/wp-content/up..._Technique.pdf
https://guitarnuts2.proboards.com/th...nse-calculator
http://www.buildyourguitar.com/resources/lemme/
https://guitarnuts2.proboards.com/th...pickups

To answer your question, coincidentally, I was just thinking about the araldite potting at the weekend when responding to a question from a user commenting on my YouTube Tri-Sonics video. Brian completely encapsulated the NECK pickup with epoxy resin and Ade Turner of Adeson did the same on all his retail sets. He made me a replacement full "original BM spec" set in 2022 if I recall correctly which must have been one of the last customer sets he ever made. It is this set that is pictured on my website FAQ (link below). He fully encapsulated that neck pickup with standard black epoxy resin electronics potting compound.

Greg Fryer stated that he covered/smeared the BRIDGE pickup in araldite and it kind of looks a bit crusty in Greg's photograph but it can't have head the same treatment as the neck which necessarily required a lot more araldite because he completely removed the steel base plate. At one point, Ade Turner fitted non-ferromagnetic base plates, presumably to avoid using so much Araldite but I guess even that alloy was sufficiently EM reflective to color the tone differently to Brian's original set and he resumed the full epoxy potting.

The middle pickup was left as the original cotton tape wound coil. Greg filled the middle and bridge with wax to reduce microphonic feedback. Again, Ade Turner did that too. That's the limit of our understanding because, other than for minor working repairs done by Nigel Knight of KAT, nobody else has ever dismantled or worked on the pickups in Brian's original Red Special.

https://fryerguitars.com/red-special-restoration-1998/

I paraphrased Greg's information in the FAQ on my website so I'm keen to make sure that I have done so accurately.

https://dsgb.net/faqs/trisonics/

Hope this helps?

Doug

[Mick Bailey]

Yes, it was my blockboard. I was intending to send you a sample, but a family death completely derailed things. I subsequently loaned the board out to an acquaintance who was going to get it replicated true to the original material, composition and size but I never saw him or the board again. I may still have the pictures and dimensions - I'll take a look.

A friend in the joinery business who was working professionally through the 50s and 60s told me that blockboard varied a lot between manufacturers and anything I had may not have been the same as Brian used. Some had only one good face, some two, and there was what he referred to as 'paint grade' with filler, staining or discolouration. The number of plies also varied for the face boards. The voids within the timber infill also varied. I'd resigned myself to constructing boards. I now have a decent planer/thicknesses so that will help.

The information on potting is really useful as well as interesting historically. I think Arladite has changed over the years - the regular long-cure product never seems to completely cure and the surface remains slightly sticky. I've tried it a number of times for potting transformers and small coils but never been satisfied with the result compared to JB Weld. Arladite used to cure really hard at one time without the sticky surface. I think it's now one product that I wouldn't be inclined to use for pickups.

[soundmasterg]

He made me a replacement full "original BM spec" set in 2022 if I recall correctly which must have been one of the last customer sets he ever made. It is this set that is pictured on my website FAQ (link below). He fully encapsulated that neck pickup with standard black epoxy resin electronics potting compound.
Doug

Did Ade Turner pass away? I have a set he made for me in the early 2000's but I haven't put it into a guitar yet. I noticed his site is no longer active.

Greg