Model T - 001

[Jolly]

Hey Everybody!

I've had a change in plans for my next self amplified guitar project. I was going to use high voltage tubes but between a few design setbacks and several safety concerns, I decided to shelf that idea for now. On to the plan for the replacement project. First of all I'm going to consider this instrument the serial number 1 of my building career. It's actually my 5th build but it's going to be the first right handed one so someone other than me can finally play it.

Here are my main goals with this build:

Solidify a Design/Tooling

Showcase Detroit

Outstanding Electrical Craftmanship 

Eco Friendly Finish

Here's the inspiration:

I'm going to lean into the vintage look and feel but obviously this isn't going to be a replica by any means. I'm going to use as many vintage inspired materials and construction methods as possible for the "feel" but there's a few modern technologies I simply can't avoid. I'm not going to do any "relicing" but I really like the general color and sheen of this particular image.

Here's the Tentative Specs:

• Amp - 12U7 Pre Amp Tube, 12K5 Power Tube, 35mW nominal power output
• Power Supply - 4X 18650 Rechargeable Lithium ion Batteries, 14.8V at 3000 mAh
• Electronics - Still working on this one. I'm on the fence between a normal tele neck pickup and a firebird neck pickup… All of the controls will be the same as a standard tele.
• Body - Reclaimed Pine, Reclaimed Maple Top
• Neck - Sourced from Sound Guitar Works (It's ordered!)

A few changes from above, the fretboard will be Richlite and the frets are stainless

The Wood:

Here's where its at now. The maple top is from a staircase and the pine core is a 2X4, both from various deconstructed house's around Detroit. The pine is likely pre 1940's based on the dimensions/saw marks. I don't have a way to date the maple other than layers of paint… it's also old.

The Design:

I've shuffled around where and how to fit all the components many times at this point but I think I've finally settled in on a layout. The detailed design isn't done yet, but I just ordered a bunch of amp and battery components to measure and start test fitting.

The top cover is going to protect the tubes. You'll also be able to access the power switch through it. The slots are to vent heat and to get a look at the hot glass

The bottom cover is going to be hinged, or magnetic, or something easy to access. It's going to house the battery compartment and many auxiliary amp components.

 

Wish me luck!

[Bizman62]

There's something very fascinating seeing someone tinker with electrickery! To me it's magic, similar to how the magicians make a ball disappear from under a cup and reappear under another cup, and when they raise the first cup where the ball should have been there's a lemon and under the second cup where the ball was found there's now an orange. But it's fascinating!

The 18650 batteries look like a good option for longevity as they're not brand specific. Will there be a built-in charger that can be used simultaneously to power the guitar while the batteries are recharging?

[Jolly]

On 2/11/2022 at 2:42 AM, Bizman62 said:

The 18650 batteries look like a good option for longevity as they're not brand specific. Will there be a built-in charger that can be used simultaneously to power the guitar while the batteries are recharging?

That’s the idea! They also have quite a bit more capacity then the drill battery I used in the first build and the particular 18650 cells I ordered have a cool, simple/vintage look to them. I was having a hard time finding a spot to put the drill battery that looked good so this change really opened up some design possibilities. I'm not confident enough in my circuit designing capabilities to charge lithium ion yet. For now I'm going to use this.

Speaking of circuit design, I recently gave digital note taking a try and came up with this. It's more notes than a finished layout/schematic but it should give something to go off of to start selecting components and such. My list of "essential" features got a little out of hand, but I think most of the things I've tried to include add some real expanded functionality. I tried to start this design from the user interface I wanted and worked backwards from there.

Amp Controls
    • On/Off/On Toggle Switch (Clean/Off/Overdrive)
    • Optional Foot Switch (Clean/Overdrive)

Output Jacks
    • Effect Loop (Off = Passive Output)
    • Foot Switch
    • Auxiliary Speaker (cuts onboard speaker)
    • Headphones (cuts onboard speaker, adds resistor between signal and ground)

If anyone has any questions or ideas for improvement let me know! 

I've got plenty of electrical things to figure out while I wait for the neck to ship but all the supplies to finish it have arrived. 

[Jolly]

I've finally made some progress!

I glued the 2x4 body blank together with Titebond. This was all from a single reclaimed stud, but its old enough that each section has a different thickness. I aligned the outward faces to be flat as possible to preserve the most character.

The neck arrived several months back; the quality/workmanship looks great and is exactly what I ordered but...  it was immediately clear that the look was off for my original finish plan. I've been wanting to try roasted maple and Richlite for awhile but it certainly doesn't look "vintage", lesson learned I guess. I feel like sometimes a project will "speak" to you and it was clear almost right away that this was the right wood/color scheme.

The top is going to be maple from the same stair tread as the original plan, just the painted side instead of the wood side. I'm going to attempt to leave the wood as rough as practical while still making a comfortable guitar. The painters tape is a rough idea of the headstock shape plan, I think I'm basically going to leave it square. I think it goes along with the rough/industrial look I'm after.

The plan for the front hardware is to look like a regular telecaster. I have a few electronic tricks up my sleeve, but for the most part I want the controls to match an off the shelf tele. I'm going to use an oval speaker to leave room for a neck pickup.

The back is going to get one large control cavity route. I'm not entirely settled on the electronics going in it yet, but the shape shown overlaps with the pickguard. I'm going to route both out as deep as possible to create open area for the "speaker cab". Speaking of electronics, I've totally reimagined that facet of this build as well. The power amp will still be tube, but I've just ordered a odd assortment of solid state electronics to string together into a pre amp. 

[Jolly]

Had some quality help working an a color scheme/finish plan!

I tried out a few different methods for the back finish on scrap and ended up coating it with a thick layer of water based grain filler. The only prep I did was scraping off glue residue and brushing off the dirt. I did this before any machining to help preserve the look/character of the rough 2x4's.

After coating the back I flipped the blank over and milled the top of the blank flat. I originally glued the blank with the back side as flat as possible so this step removed all of the irregularity from the original 2x4's and made a gluing surface for the top.

While we were at it we flattened the top as well. Again wanting to preserve the layered paint character, all of the machining had to be on the joint side of the blank. To add to the fun, absolutely nothing was flat or square. The front center of the stair tread had a noticeable dip worn into it! We clamped it at the edges as lightly as practical to avoid warping the blank and took very light passes. We contemplated using a plane or thickness sander, but along with the wonky shape this blank still has some nails stuck in it!

I cut out the headstock shape on the bandsaw along with some finish shaping with a sander. I didn't keep a great record of the exact schedule, but experimented by feel with a rotating cycle of burnishing, sanding, and coats of linseed oil.

I used a 2x4 scrap that I had test coated with linseed oil for most of my burnishing attempts. I think it added a bit of lubrication/coating that worked pretty well. This was my first dive into burnishing wood but I think it will become a regular tool in my finishing kit. I'm still forming my opinion if it does anything to the hardness or feel of the wood, but I certainly think it slowed down the oil absorption. I think this may extend to stain/other finishes as well. 

This was also my first attempt at an oil finish neck. I'm very drawn to natural finishes, or at least ones with minimal harsh chemicals. Again, still waiting to see the final product but pretty sure this will also become one of my go to finishes.

After several coats of oil I moved on to the headstock decal. Waterslide decals are not compatible with oil finished, so I applied several layers of Zinsser shellac. After applying the decal I layered on more shellac. Right now its curing, I'll probably flat sand it after a few more days and maybe do one more oil coat to blend anything that ended up funky. I've also been experimenting with nanoceramic coatings. They don't stick well to oily surfaces but I'm thinking about spraying a layer right after the oil, maybe they'll "sink in" and cure with it?

I've been scheming and testing things for the amp alongside the woodwork. I've been trying to balance tonal options with simple controls. For looks, I don't want to add anything to the front that you wouldn't see on a stock Telecaster. I have the power amp pretty well figured out, but I still haven't settled on some controls/features.

From a players perspective, anyone have any ideas about the following?

• Neck Pickup - If I include a neck pickup I have to make compromises on the speaker and it will likely use up the selector switch. That being said, It would offer an additional base sound with no additional electronics, and perhaps make it a slightly more useful "normal" guitar.
• Overdrive - I think it would be pretty cool to have a built in distortion pedal type function. The last one I build can accomplish this with the selector switch, but its a little clunky. I currently have the power switch on a push pull pot, but that's one option to activate it. 
• Reverb - I've been playing around with a karaoke machine echo chip. I think it adds some "thickness" to an obviously size limited sound, but it will undoubtedly add complexity.  I'm also not sure I have the control room to manipulate it?

[Bizman62]

19 minutes ago, Jolly said:

From a players perspective, anyone have any ideas about the following?

If space is an issue, one single pickup might be the better option. You can alter the sound quite a lot by just changing the strumming/picking location. Using the volume and tone pots add even more variations.

My Blackstar Fly amp has Gain, Overdrive, Volume, EQ and Delay (level and time), six AA batteries and a 3" speaker in a 17x12x10 box - and of course a 6 mm jack for input and two 3 mm jacks for line in and headphones, and a power supply input and an extra speaker (RJ11) jack. This video shows shows that there's quite a lot of empty space inside: https://youtu.be/6DjLFJude7E. A tube amp requires more space but I guess the effects used in the Fly wouldn't take too much space.

 

[Charlie H 72]

Could you use a 4 (or 5) way switch to turn the power on, freeing up both pots for effects (overdrive & verb?) not sure how the wiring would work out, but worth a try 

or

use two push pull or push push pots to select pickups (which gives you an option to combine in series/parallel as well) and then the switch is free to operate amp settings

Edited March 26, 2023 by Charlie H 72