somethingtron

[Billy Bones]

I'm looking to wind something "filtertrony."

I don't have the best ears. looking at the different specs I've come across, I've seen everything from 3000 turns per coil using 42 ending up around to 4k(together) to 4000 turns ending up around 8k.

In my own experiments last night,

3000 turns of 42 gave me a reading of 2.2k
4000 turns gave me a reading of 2.9 and
4500 turns gave me a reading of 3.3

I read that Chet Atkins had his loaded up to something like 7.4k, but I don't know how many turns that was.

I have really enjoyed playing through milder pickups lately so that I can the my tubes do the breaking up. When we're talking about the difference between 4 and 8k I would think that is enough difference that they wouldn't both sound like Filtertrons.

My question is - What is it that makes a filtertron sound like a filtertron? The biggest thing I can find is that it's wound a little lower than a PAF and keeping more of the highs, and obviously it has 12 pole pieces.

Are there other things that play into the sound as much as those two or am I going to end up somewhere in the right neighborhood this way.

Using an Alnico V bar.

Billy Bones

[Peter Naglitsch]

IIRC the magnet is 1/4" thick. Double the thicknes of standard HB magnets. That is one part that makes a Filtertron sound the way it does. Another thing is the 12 screw poles. That has some significant influense. The DC resistance is traditionally in the 4.5 Kohms range for the coils in series (once again IIRC). But there were a Country Gentleman released in late 70's that had 8K filtertron pickups. But a traditional Filtertron pickup is somewere between 4 and 5K.

[David King]

Aren't the magnets also A-3s?

[soundmasterg]

The baseplates of my newly installed TV Jones filtertrons were brass. Pickups were around 4k-4.5k and sound fabulous. I can get you AC resistance, DCR, Q, and Inductance readings if you want.

Greg

[bill raymond]

FilterTrons

I believe the original filtertrons used 42 gauge wire and, as stated, DCR in the 4-4.5 kOhm range. Chet had his bridge pickup rewound by Shot Jackson to the higher--as I recall, about 7.8 kOhms. I am only guessing that Jackson used 43 gauge wire; the later Gretsch filtertrons used 43 gauge and were wound to somewhere in the 8 kOhm range (again, IIRC). Chet used the standard 4-4.5 kOhm supertron in the neck position. Somewhere on the internet there are winding specifications for the filtertrons in their various incarnations--I think it was a Brazilian site. If I can find the link (it's been some time ago) I'll post it.

[bill raymond]

Post Scriptum

I can't locate the link I mentioned above. Perhaps the page no longer exists. I'm out of town at present, but when I get back home I'll check to see if I still have a copy of the data in my files somewhere. It was a spreadsheet with wire diameters specified in metric and number of turns. Perhaps I can post the chart somewhere if I can find it.

I might add that the original magnets were AlNiCo of some sort, probably V, but later pickups (the Baldwin era of Gretsch guitars) used ceramic magnets.

I should also add that Clint Searcy has rewound a later era Filtertron (ca. 8kOhms DCR) and reports that the wire used was 45 gauge.

[Clint Searcy]

Hi Gang,

I wanted to try to fix some misinformation I am responsible for. Many years ago I posted an article on the web about some Gretsch FilterTron pickups. In that article I stated that some of the Japanese made TilterTrons in the 90's used 45AWG magnet wire. After some discussion with Bill Raymond I decided to go back over my notes from all those years ago and look up where I got that information. After much scrutiny I decided that my information was not conclusive so I wrote to Gretsch and asked them if they ever used 45AWG wire for the 1990's FilterTron. Here is the answer I got from Jeff Krause at Fender.

Hello Clint,

Thanks for writing in. According to our techs, the wire is #42. Your guitar was made “pre Fender”, so it could have been #43. I hope this will help you out.



Best Regards,



Jeff Krause

Fender Musical Instruments Corporation

Consumer Relations Department

So in the end I don't think 45AWG was ever used and I'm posting this here to try to correct my error.

Clint

[salvarsan]

Bobbin dimensions

Does anyone have the inside bobbin dimensions
such as core length and width, distance between
the flats, and flat width?

-drh

[BillScheltema]

Hi guys,

Im wondering if anyone has the bobbin sizes available, Im doing a new guitar model and wouldn't mind trying my hand at some trons.
I have a few guys planning to order so I want to make them available outside of TV Joneses versions. Thanks, Bill

[jonson]

Hi guys,

Im wondering if anyone has the bobbin sizes available, Im doing a new guitar model and wouldn't mind trying my hand at some trons.
I have a few guys planning to order so I want to make them available outside of TV Joneses versions. Thanks, Bill
[ATTACH=CONFIG]26774[/ATTACH][ATTACH=CONFIG]26775[/ATTACH]

Angela Instruments has the bobbins, baseplates and covers for them Bill. All you gotta do is source your magnets they do need to be thicker and slightly narrower than a bucker mag.

[BillScheltema]

Thanks Jonson. Are they close to vintage spec would you know.

[jonson]

Can't say that Bill they are just on my list of suppliers and spotted their stock a while ago.

[BillScheltema]

Heres a thought I had about the filtertron cloning and dealing with thinner A5 bar mags.
What if the 1st bar mag sat where it would normally go with a 1/8" shim to keep it high then place another on the underside of the baseplate?

Filtertron-Model.pdf

[jonson]

That may be interessting Bill and gives you the chance of changing the distance between them to see if it has any effects. the pain has always been narrowing the 1/2 inch mags down to just under the 12mm width instead of the 12.7mm to align the polescrews in the cover. The last set I did on a Billy Bo I cloned I used just the thickest bucker mags I could find and wound them to about 4.5k and that is a unique non paffy sound.

[BillScheltema]

I think so too. Plus you can swap out the lower may easier to a different value. I think that even keeping the upper bar directly on the baseplate without the 1/8" wood spacer Ans the lower bar directly on the other side would work too.