Mutt90 Dog Ear - 50's spec - Gerg's buddy

[muttley]

Here goes people. A few days ago gerg ordered up a Dog ear p90 style for his buddy who is planning on dropping it into a Chibson that is on the way to him from somewhere in Asialand,

The spec is to get close to the vintage p90's of the 50's. A few PM's later we came up with this spec.

Nickle baseplate. (The best for tone on p90's imho)
Forbon handmade bobbin (Gibson used both these and later plexi clear bobbins in the early days)
42 AWG wire.
Wound to around 7.5K (Slightly underwound)
Alnico V
Braided pull back wire
Counter clockwise wound south up polarity. (P90 standard)
Nickel Fillister head slugs (Traditional)
Lightly potted. (Its going to be a mostly recording guitar. Heavey potting may stop microphonics and help avoid feedback problems but it can also kill a lot of subtle tone)
Oh, and a black cover.

Gerg then ordered up a similar Mutt*Pup in soap bar for his SG bridge pocket (What a guy). I'll cover that in another thread.

I have been waiting on a few parts that I didnt have and the post has been slow here for some reason, By 3pm they still hadnt arrived. Still the bobbins are the first thing to do on both these Mutt*Pups so I cracked on today and made a start. Hopefully tomorrow postie will bring GAS mail.

Since the bobbins are to be the same for both I took a bit of time to make up some p90 Forbon bobbins today.

First thing is to accurately mark out and cut the flatwork to size. These have to be dead on or the pole pieces dont line up with the holes on the cover. I make em up in batches and today made up six sets as I have an order for a matched set of soap bar from elsewhere. Six bobbins should keep me in bobbins for now.

Gerg_p90_bobbin_1.jpg

Gerg_p90_bobbin_2.jpg

Once the flatwoek is cut to size and the pole spacings are set, the rest of the pole positions can be drilled out on my mini pillar drill. They must be cock on.. so I drill them in pairs.

Gerg_p90_bobbin_4.jpg

I make up the maple spacers in batches as well. It improves accuracey and is also quicker. Once they are cut to size the 50mm spacing is drilled out and then I stick them on a couple of penny nails to stack them up while I shape the ends.


bobbins and some winding...

Gerg_p90_bobbin_7.jpg

Finally the bobbins flatwork is glued to the spacers, The final drilling out will be done once the glue sets tomorrow. I use a good epoxy on fibre bobbins. The flatwork and spacers are lined up with the pilot holes and clamped up in sets and left overnight. Just like little Xwing fighters....

Gerg_p90_bobbin_9.jpg

Tommorow the final shaping of the bobbins and some winding to be done...

More to follow.

[Greg_L]

Fuck yeah, thanks Mutt!

[muttley]

Still no post yet but progress on the bobbins.

First thing to do is check em over and check the holes line up by just pegging a few pole pieces in there...

Gerg_p90_bobbin_14.jpg

Gerg_p90_bobbin_13.jpg

Next I can drill out all the pole piece holes now that I know everything lines up

Gerg_p90_bobbin_11.jpg

Finally shape the corners and clean them up before winding. The slightest snag will break the wire and thats a no no....

Gerg_p90_bobbin_10.jpg

I will dip these in some shellac to seal them off and then onto the winder. Video to follow soon...

Stay tuned.

[Greg_L]

[muttley]

I'll be honest Ive held fire on winding gergs bobbins for the p90's because I've been waiting for the nickle baseplates to arrive. I wanted to be absolutely sure thy would fit nice nd snug. Even a fraction of a milimetre off can futz things up. I was out buying more wire this morning and when I returned postie had been. Waiting for me was GAS mail with all the stuff I have been waiting on.

So, test fitting th bobbins before winding is done.

gerg_p90_bobbin_fitting_test.jpg

One of the bobbins has been put aside to test fit as I go... All is good...

gerg_p90_baseplate.jpg

The baseplate fits like a Glove. I am breaking out the winder and the video cam right now. All systems go. They should be winging their way to you early next week..


Oh, and I scored some really old vintage formvar wire at the suppliers this morning. This stuff is rare as rocking horse shit.. Its been a good day.

Formvar.jpg

[Greg_L]

Fanfuckingtastic!

I was talking to the guys last night about your pickups. Everyone can't wait to hear it.

We're still waiting on the guitar to arrive from the Orient, so you will probably beat them here.

[muttley]

Yeh, maybe. But you will get your Mutt90 oapbar too...

[Greg_L]

Yeh, maybe. But you will get your Mutt90 oapbar too...

Awesome. I'll give you sound clips of that thing ASAP.

[muttley]

No problem mate. Lets get the thing done first...

[muttley]

Last night I had a chance to wind up several of the Mutt90 bobbins detailed above.

Here's gergs dog ear bobbin.

[BBvideo=640,360]https://youtu.be/eUJShC_e5yc[/BBvideo]

[ido1957]

Wow - Once you mentioned in the video you were guiding it, I kept thinking you would rip a hole in your finger guiding that wire. Anyhoo, fascinating video, never realized the effort and skill it takes to make a pickup. Thanks for sharing - very cool

[muttley]

You do end up with slight callouses from the wire but nothing compared to the 56-14 strings I use...

Seriously though you have a hair trigger control over the wire as it snaps easier than a a hair. It takes a very light and sensitive touch but once you get it it is pretty straightforward. My hands are pretty tough after many years on the bench though...

[Greg_L]

Awesome Mutt! It's so cool to watch this happen. I'm gonna pass that vid along to my homeboy.

[rayc]

Impressive - and I enjoyed the music too. I'll go lookin'.
The live compilation on utub is cool - a little more energetic/frenetic than the recording - good vibe too.

[muttley]

I'm gonna assemble the dogear Mutt90 today.

First thing is to gather the parts

gerg_p90_assembly-parts.jpg

The pull back braided wire is then soldered to the base plate. Smoe early p90's had a solder tag attached to the baseplate to take the ground. I dont like that idea and as this is going over the pond I want a nice solid ground joint.

gerg_p90_baseplate_sheild.jpg

The magnets and spacer are put in place ready to be screwed to the coil and ready for soldering up and potting. In this case I will be lightly potting as modern amps handle microphonic squeal better than they used to and too much potting can take a lot away from the tone. In any case gerg tells me this will mostly be a recording axe so it can be manageed better than in a live setting. It can always be heavily potted later... The magenets are lined up with both have the south edge faceing in. Traditional for p90's. I use a bit of double sided tape to hold them in place at final assemby. As you can see they dont want to stay where they are supposed to...

Gerg_p90_bobbin_magnets_stos.jpg

More shortly after potting... The wax is heating up right now... Stay tuned

[Greg_L]

Yes! Awesome.

[muttley]

So it's all together and we were aiming for 7.5K (ish) or slightly above.

Came out at..............

gerg_p90_impedance.jpg

This will be on the way later this week. I'm just waiting for some more cloth tape to arrive as the bobbin needs to have a final wrap of cloth tape to vintage spec before its done.

Tones to follow hopefuylly)

[Greg_L]

That's perfect Mutt! Thanks!
I'm not in a huge hurry on that one as the guitar is nowhere even near here yet. You wanna build my soapbar and just send them together? My soapbar will go in as soon as it hits my mailbox.

[Minerman]

Awesome Mutt!!!! Very cool indeed, I still haven't forgotten about your p'ups dude, maybe in another week or so I may have you make a set for one of my Gibsons with the quick-connect plugs I mentioned...

[Greg_L]

Sound clips here:
viewtopic.php?f=25&t=56&p=18797#p18797