An Engineer’s Tips For Selecting Your First Guitar

A guilty pleasure of mine is to sit in the ‘acoustic room’ at a national chain guitar store and play expensive guitars.  When I was growing up, we had no real opportunity to see and hear, even less to touch and play, expensive guitars. Nowadays, it’s easy to have unfettered access to so many models and price ranges of guitars.

This weekend, I was camped out in the acoustic room, confirming that my playing skills were equally poor on an expensive guitar as they were on an inexpensive guitar.  Four ladies were shopping for a musical instrument.  The ten year old played flute and clarinet, but her asthma caused her to consider another instrument.  Her six year old little sister enjoyed playing with ukeleles.  Mom watched her daughters go through the overwhelming selection of instruments.  Grandma, who was apparently bank-rolling the whole enterprise, glanced nervously at the price tags.

Mom walked past me as I was playing a few scales.  She turned and asked if I worked here.  “No,” I replied, “but could I help you?”

“My daughter is shopping for guitar or ukelele.  She plays in the school band but wants to consider another instrument.  How do we find the right guitar?”

So the conversation that followed was the genesis of this blog post.

Three Criteria For Selecting Your First Guitar

Guitars come in many sizes, shapes, styles, sounds, colors, and technologies.  For a beginner, guidance from a music teacher, price and playability are significant criteria to apply when choosing a particular guitar.  Let’s set aside everything that makes a guitar what it is EXCEPT those parts that touch the string e.g. tuners, the nut, the fingerboard and frets, and the saddle.  Let’s also look at ergonomics e.g. size and shape of the guitar, and derive some selection criteria that may be of use when choosing a guitar or ukelele.

Tuner and Nut

Loosen and tighten each string.  Does the pitch of the string change smoothly, or does the tuning ‘jump’ suddenly?  Does the string ‘pop’ or squeak when moving through the nut?  Jumps and pops can be corrected by a luthier, but we want to purchase an instrument that works from the outset and does not need additional work ‘out of the box.’ (Image credit:

Fretboard and Frets

every note
Play an open string, then play each note in sequence moving in half steps up the entire fretboard.  Does each note sound clear and crisp?  Is there a buzz or muffled sound?  Is the note played a the twelfth fret exactly one octave above the open string?  Buzzing and muffled sounds from any string, or intonation problems, can be corrected by a luthier, but again, why pay money for a guitar with a problem?  (Image credit:


Barre all six strings at once with one finger.  Can you hold all the strings down WITHOUT using the thumb of your fretting hand in a vise-like grip?  Or do you have to whip out the ‘Kung Fu’ vise grip to hold all the strings down?  Holding all the strings down is easy with a ukelele, but can be difficult with a guitar, particularly a steel-stringed guitar.  (Image credit:

Hint – Hold the body of the guitar against your body firmly with the elbow of your plucking arm (right elbow if you are playing right-handed.)  Now pull back against the strings with your fretting hand and execute the barre without using the thumb of the fretting hand.  Sounds odd, doesn’t it?  No, you won’t break the guitar in half.  A common bad habit among guitar players is to grasp the neck so tightly that your hand aches after ten minutes of playing.  Pushing the neck of the guitar forward, by pulling the body back towards you will lessen the load on your fretting hand.  Try it!  The longer you can practice without tiring your hands, the better and more-motivated a player you will become!

Now that your thumb can take a break, is the width, string spacing, and curvature of the finger board compatible with the construction of your barre index finger?  Every individual has a unique fingerprint.  By extension, I would assert that everyone has a slightly different internal construction of their hands.  The location and size of the knuckles, tendons, muscles, and scars becomes relevant when making a barre.  Does this guitar allow you to hold down every string so that they ring clearly when played?  For a beginner, this will require some experimentation even with an easy-to-play guitar.  If you find the guitar that is easy to barre, you are well on your way to choosing a good guitar.


Earlier, we discussed holding the guitar body.  Some guitar bodies are thin, such as solid-body electric guitars and jazz acoustics.  Others are made thinner but are otherwise normal acoustic or classical guitars.  Likewise, some guitars are intentionally scaled smaller to accommodate children and youth, and people with small frames.  My wife plays a smaller guitar whenever possible.  In my case, I prefer thinner bodies to compensate for my big gut.  Some guitars, particularly solid body electrics, are best played standing up.  Find what is comfortable while at the same time allowing you to easily reach all the strings and frets with both hands.  Pass on any guitar that places a sharp edge or corner on your arm or leg or makes you reach uncomfortably.  (Image credit: and


Our young musician picked out a nylon-stringed classical guitar, in 7/8ths size. The guitar only cost about $139 but was an excellent instrument which passed all of our criteria above, had a very pleasant voice, and was easy to play. Everyone, including the six year old, was enthusiastic. Grandma was particularly happy to make this moderate expenditure, and had no problems purchasing a bag and a tuner for her granddaughter’s new guitar. I recommended a good teacher in her part of town, plus we exchanged email addresses so that I could send some more links and supplementary material about practicing, guitar music theory, and caring for her new instrument. Life Is Good!!

Thanks for reading all the way to the bottom.

CONTACT – David Latchaw EE


Fender Hot Rod Deville Combo Workmanship Problems

The more this amp was played, the stranger it sounded and the worse the noise from the speaker became. What’s up with that? The Unbrokenstring Crew to the rescue!

A quick walk-around the amp revealed a nice nameplate with ‘just the right amount’ of road wear and mojo. See the mojo?

Removing the covers reveals a straight-ahead circuit board layout, with the tube sockets on another circuit board.  The input jacks had been replaced along with a few other components.

Removing the knobs and potentiometer nuts allows us to pivot the main circuit board downward so that we can work on it. The first order of business is to look for any workmanship issues, because this amp was built during the time when the factory transitioned from an assembly process using conventional solder to one using lead-free solder.

This is not factory soldering, but some later repair work. This solder joint will get reworked.

Flexing the circuit board in the vicinity of this ribbon cable results in a terrible racket from the loudspeaker. Something’s wrong here!

Following the cable, we found an unsoldered joint on one of the tube sockets. This is a factory workmanship problem.

After the missing solder joint was restored, the amp was still noisy. I captured some of the noise waveform on the oscilloscope display here.

Further troubleshooting revealed that the tone caps were noisy. Here are some new ones, right from Mouser.  The Orange Drop capacitors on the left are the correct value.  The darker capacitors on the right are epoxy dipped silver mica, very stable and will withstand the full working plate voltage in that part of the circuit.

C7 is the capacitor associated with the treble control.

C6 is part of the mid-range tone control.  C5 is part of the bass tone control.

C18 is in series with the volume control, was noisy, was the wrong value, and is now replaced.  This amp is VERY well behaved now.

Jacob jacks the Epi Les Paul into the amp to run it through its paces.  This is an amazing combo amplifier!

Jeff picks up his amp wearing his special T-shirt. Only musicians will get it.

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE

Vintage Electro-Harmonix Memory Man Pedal Refurb

A good friend of UnbrokenString wanted this unit checked out. After some years of dis-use, it was time for this pedal to get ‘back into the loop’ as it were…

One never sees this style of construction anymore.  The sheet metal box has given way in favor of the die-cast boxes used today.  An attached AC cord is almost never seen on pedals, but the DC power adapter, or 9v battery, has taken its place.  This is a piece of history!

These are the in/out jacks and an AC power switch.

No set screws here, but rather the D-shaped holes in the knobs are lined with metal to toughen them up.

This foot switch needs a little attention. The nut is a thin locking ring, and absorbs the entire pressure of the foot when the switch is ‘stomped.’

The printed circuit board is single-sided, with jumper wires installed as-needed to complete the circuity.

The CMOS logic and the delay line are socketed.

The ubiquitous 1458 dual operational amplifier makes an appearance in this circuit.

Let’s straighten out that stomp switch. In this picture, I’ve used some hard plastic sheets to protect the face of the pedal from the sharp edges found on the jaws of my pliers. Those sharp edges are necessary to get a good grip on the jammed knurled nut.

This is when I’m glad I have that hard plastic in place, or I’d really be making a mess of things.  The knurled nut is coming off for the last time.  It’s headed into the recycle bin as the threads are ruined.

For cleanup duties, I really like the Gibson guitar polish. No matter how delicate the finish, the polish seems to clean and condition any surface without leaving a detectable residue behind. It makes sense that something made for guitars that cost more than my car would be good stuff.

A larger nut and washer spread out the pressure applied on the stomp switch.

If you ever get a chance to fool around with one of these, you will delight in the cool sounds and effects of which it is capable. I was honored to be able to recondition this unit and spend some quality time with it cabled between my guitar and amp. Highly recommended!!

Thanks for reading all the way to the bottom!

CONTACT – David Latchaw EE