Fender Hot Rod Deville Makes Funny Noises!

Matt from My Twilight Pilot told me that his wonderful Fender Hot Rod DeVille had developed some strange noises.  The volume control was really too sensitive, no low end audio, audio clipping, and we were experiencing some general shakes, rattles, and rolls.  Could the Unbrokenstring Crew help?

Finally, an appropriate warning label…

This brand new tube chart clearly shows that this is one of the wonderful reproduction units from Fender.

Service literature is easy to get from Fender for this model.

The treble tone cap was replaced with a silver mica unit (already installed.)

The bass tone cap on the right was replaced with the orange film cap on the left.  The larger size buys us some reliability as the internal dielectric is a little thicker, a good then when operating at a plate voltage of 350 volts.  The mid-range tone capacitor was also replaced with another orange CDE cap of the proper value.

The tone stack capacitors are now soldered in.  The leads will be trimmed and the rosin flux will be cleaned off.

When the signal generator was swept through the audio range, a mechanical rattle was heard in the vicinity of the reverb tank.  I’ll loosen the reverb tank and do the test again.  This thing IS loud!

A quick check of the electrical connections shows that everything is as it should be.  But the rattle remains!

The loudspeakers are a little loose, but no rattle here.

Aha!  It’s the bottom of the baffle board.  All the bolts were loose.  Here they are re-torqued to about 5 ft-lbs.

A fresh set of output tubes were run for four hours and re-biased per Fender specs.  A 12AY7 was installed in the first preamp.  This tube has lower gain than the 12AX7 used at the factory.  This change gives a little more ‘spread’ to the volume control, increasing its usefulness.

This is a view seldom seen unless you are in the business!  Nice lead dress.

To do the full-power tests, the window is opened and the amp is turned around.  Yes, this is VERY LOUD!  And quiet when it should be.  My job here is done.

Support this local band!

Thanks for reading all the way to the end!

Contact – David Latchaw EE
Cell – 281-636-8626

How Gibson Les Pauls Lose Their GForce Tuners

I own several old Gibson guitars , so I am only passively interested in, and mildly amused at, the flame war over the self-tuning GForce system included on new Les Paul guitars.

Jacob of The Unbrokenstring Crew said “The Internet is where nuance goes off to die.” Like most topics of discussion, the flame wars over the Gibson GForce system has devolved into a bipolar, binary love/hate relationship. Perhaps, someone actually thought about the situation, and decided that they would sell more guitars WITHOUT the GForce system installed. To that end, our local national guitar retailer has received some interesting tool in the mail.

These blocks of steel have nylon alignment pins that fit in the factory tuner holes used by the GForce system. The small holes are where the headstock will be drilled for manual tuners of various makes and models.  The Klouson holes are in the wrong place, so we are only installing Grover tuners for now.

Here is the back of a Les Paul headstock with the GForce system removed. Except for the indentations in the wood where the printed circuit board traces were, you would never know that they were there… more or less…

The GForce tuner assemblies were removed from the headstock. These are to be returned to the Global Headquarters of the National Guitar Retail Chain when we are through.

Perhaps they will salvage the rechargeable batteries, or maybe they will be used for spares as these fail in the future on other guitars. Hey, it could happen!

The nylon alignment pins hold the template in place. Drilling a hole and installing new manual tuners is straight-forward.

Grover tuners, anyone?

How about some locking Grover tuners?

For the purists, here are some Klusons on an older guitar.

I will not weigh in on the flame war over the deployment of the GForce system. But now you can go to a retail outlet and find a 2015 Les Paul that does not have the GForce system installed. We’ll see how this decision plays out over the coming years.

Thanks for reading all the way to the bottom!

Contact – David Latchaw EE
Cell – 281-636-8626