Show Us Your Mojo – Guitar Builds by Chuck Chambers

I wanted to share some pictures of a couple guitars I built using Mojo bodies and pickup kits.  I wound the pickups with your PE wire.  All of the items were top quality and look, play and sound great.  Thanks for providing quality parts and trustworthy service!!!!

Chuck Chambers
Chambers Custom Guitars and Amps

Chuck Chambers / Chambers Custom Guitars and Amps

Show Us Your Mojo Spotlight: Fender ’66 Vibrolux Reverb Cab

Hi George,Just finished the conversion on the Fender ’66 Vibrolux Reverb, thought you might like to see some pics.

It turned out extremely well. Locating and accurately drilling the chassis mounting screw holes was a bit painstaking, but other than that, everything went together smoothly. Thank your cabinet shop for me, they did a great job.

Bill Gruner

Show Us Your… Purple Elephant

The cab came today…looks great and all hooked up with a Scumback H55. Here’s a photo with the Pocket Rocket that I had made for my son, a Trainwreck Rocket circuit amp with miniature tubes.


Soldering 101

There are several types of solder, soldering irons, and iron tips for different applications.  Here we are mainly focusing on guitar and amplifier electronics.  Before learning the technique of soldering it is important to understand what to use for a particular job.

Choosing the Right Soldering Iron (avoid using soldering guns if you can)…..

25-30 Watt Irons
Great for delicate PCB work where less heat is good, though not recommended for hand wired electronics because it can require more time to heat up the bigger solder joints which may damage the component before the solder can melt.
35-40 Watt Irons
Ideal for most guitar and amp electronics, especially the hand wired components.  The higher wattage requires less time to melt the solder joint, so you reduce the risk of overheating the components.
Variable Heat Irons
These are the best because you can adjust the heat to handle almost any job.  You can reduce the heat enough to work on delicate PCB’s, or increase it enough to solder Humbucker covers or any large surface that absorbs heat and makes it difficult to solder.

Choosing the Right Tip…

Chisel Tip (L), Pencil Tip (R)

Chisel Tips – These come in all sizes. They have a flat head which helps to better disperse heat across bigger surfaces.  A small chisel tip is good for most hand wired components that have solderable lugs.  Medium to large sized tips are great where high heat is needed, such as soldering Humbucker covers to a base plate, or soldering directly to a chassis.

Pencil Tips – These are pointed and designed to focus heat directly to one central point.  Pencil tips are ideal for PCB’s or any smaller solder connections.  They can also be great for crammed wiring where a chisel tip won’t reach without burning surrounding wires or components.

Choosing the Right Type of Solder…

This should be pretty self explanatory.  Just use a rosin core solder, like 60/40 or 66/44 which are most common.  The thinner the solder the better it is to work with.  You do not need to use flux with rosin core solder since the rosin is the flux.
Kester ”44” Rosin Core Solder .062 Core 66 Flux 44
Item No. 1000015a***SPECIAL ***

Let the Soldering Begin…

If there has ever been any mysticism or uncertainty about soldering, let us clear it up for you today.  While doing it right means less chance of a bad connection between components, there is nothing about it that should cause apprehension.  Follow these steps, practice practice practice, and commit them to memory.  You’ll be great at soldering in no time.
Step 1: Plug in your soldering iron, and wait for it to reach a good operating temperature.  For most applications, you’ll know you’re good to go when you can melt solder with the tip.
Step 2: Make sure the surfaces of the components are clean and clear of any debris. The only way for soldering to work is if metal is being soldered to metal.  If you are soldering a component to a PCB for example, you may have to scrape a bit of the PCB’s overlay coating from a trace to make a good connection.
Step 3: Secure the components together. More specifically, make sure the components are contacting each other at the point at which the connection should be made, and that they will not move when you apply the iron and solder to them.  This is important because you stand a good chance of creating a cold solder joint if the components move around during soldering.  A cold solder joint occurs when one of the components is heated enough to receive a good solder bond, but the other component is not heated enough due to an aforementioned movement or bad iron placement.  This is a failed solder connection.
A good way to stabilize everything together is through the use of alligator clips or a set of helping hands.

Step 4: Is your soldering iron ready?  Here is the key to a proper soldering technique:
  • Touch the iron to the area to be soldered.  Make sure the iron touches all of the components including the PCB if applicable.  This may take a few approaches at different angles before you get it right.
  • A few seconds later, touch the area with solder.  When it begins to melt, move it around the components for even coverage− no globs.
  • When everything is covered, take the solder away while keeping the iron on the area.
  • A few seconds after that, remove the iron while making sure nothing moves in the process.
  • After the solder hardens, give all the components a tug to test the bond.  Nothing should seem loose.
Your process should not deviate from this order.  Apply heat, apply solder, remove solder, and remove heat.  Practice this, and you will become a soldering master.
Now, what’s a good way to insure you’ve soldered properly?  Test it with an Ohm meter. Take a reading with the black probe on one side of the connection, and the red probe on the other side.  A good connection will read 0 to 10 Ohms max.  A connection needing attention will read O.L. (an open circuit) or some high resistance.
Need something to solder?  Try one of our Amp Kits or a Guitar Kit.
Pre-tin your leads with solder before making the connection.  This is most important with stranded wire because the strands need to be completely penetrated with solder in order to make a solid connection.  In summary, tin the wire, tin the part, heat both parts and join them to you will insure a better connection every time.

Click Image to Enlarge
Be careful not to overheat components, especially solderable lugs.  Remember that lugs are an extension of a contact point of a switch, jack, tube socket, or potentiometer. Overheating can make the solder to run down into the contact point causing it to fail or seize. When you see the solder start to “flow” onto the connection, then immediately remove the iron. This will prevent solder from “overflowing” into the contact point.
Always wear eye protection and solder with adequate ventilation. You never want to have solder smoke billowing around your face. Solder smoke is toxic and absolutely bad to breath. Use a fan or something to pull the solder smoke away from you. Also hot solder can fling or spit rosin which may damage surrounding finishes, or injure you, so always wear eye protection and protect the surfaces around your area.

Related Items:

Philips JAN 6080WC OTL Amp Project

Tired of listening to output transformers?  Make your next project an OTL amp using the military-grade Philips JAN 6080WC output tube.  This NOS U.S.A. made tube was subjected to the most rigorous vibration tests for military use, and as a result, should prove to be less microphonic than the Russian versions, and last longer too.

For the low-budget builder, a simple cathode-follower or a common cathode resistor bias will push both sides of the tube in the output section.  This is due to a low plate resistance (280-300Ω), well-matched triodes, and the tube’s ability to pass a lot of current.  These are also great for low impedance headphone drivers in the studio. Compared to other dual-triode configurations, the 6080 is more rugged than the 6AS7G, and much more affordable than the 2A3.
Check out some examples of the 6080/6AS7 used in OTL audio amplifiers:
Then, if you find yourself reminiscing about your days with output transformers, keep our 15W SE transformer in mind.

Related Items

Vacuum Tubes
Amp Kits

Champ Reverb by David Wren

I designed/built from scratch a CHAMP REVERB amp … Fender never had a reverb with the CHAMP.
I installed two 1964 Jensen C8R speakers in the speaker cab.

Thanks again for the great product MOJOTONE builds.
David Wren

DIY Snakeskin Drums

We’re rarely surprised and always impressed with the fascinating ideas our customers come up with AND implement.

Here’s just another primo example.

From Mark W. on Tuesday, March 2:

I purchased some of your snake skin tolex and used it as a drum covering. It looked so good I ordered more for my other drums! Much cheaper to use than regular drum wrap and looks great! Check out the pictures I attached.
Thanks for a great product.

Burgundy Snake Tolex

Amazing job!

(Alligator would also look sweet I’m thinking.)

Check out Mojo’s full selection of tolex and you might be inspired to DIY, too.