[Harp-L] Honey Tone design flaw, and fix.

[G <gigs@xxxxxxxxxxxxxxx>]

Hi there,
  I love my Honey Tone amp for practicing, and jamming.  Its small light
and portable, and I take it with me when I go away to use with a mic, or
plug in my walkman instead of forking out for a boombox.    So I was a bit
upset when it accidentally fell off my 3' high bedside table onto its head,
and simply stopped working.

I bought a second one, and while waiting fixed the broken one. 
Sod's law being what it is, the new one suffered the same fate.  Now
they're both working and a matching pair.  There's a design flaw that means
if you drop it on its head with a guitar lead plugged in, even from a low
height, it will break, no question.  I thought other HoneyTone owners would
be interested in why this happens and how to fix it.

The 1/4" jack has a plastic thread that cannot handle the force of the amp
falling onto it.   Like all the HoneyTone components, the 1/4" jack is PCB
mounted.   So are the 3 POT controls O/drive, Tone & Volume.   
  When the 1/4" jack is forced into the amp from being dropped, it takes
the PCB with it, and theres little in the way to stop this happening.
However the three POTs are securely fixed to the casing with metal threads
- so they do not let go of the casing, yet they're soldered into the PCB
just as solidly, something has to give.  What gives are the Overdrive and
Tone POTs, they get torn in half, making them for all intents and purposes
useless.

Two things save the Volume pot from getting torn apart.  First the only
screw securing the PCB to the casing is underneath the Volume POT, which is
where the PCB pivots slightly.   Secondly the volume POT is double ganged
with an on/off switch, which stops the POT from being snapped in half.
Although both my amps are slightly noisey when you adjust the volume, so I
suspect they're cracked.  If they do eventually die,  I'll have to replace
the POT, and cut the casing to install an on/off switch.

Considering the 1/4" jack has a plastic thread, I'm wondering why there
isn't a second screw under the 1/4" jack securing the PCB to the case,
which would stop this from ever happening.  This is the design flaw.

There is a strut from the casing underneath the 1/4" jack, which only has a
tiny plastic nipple that slotted into the PCB.  This snapped off easily
with the force of the fall.  And the strut is too thin to screw anything
into.  Whatever repair I came up with will have to be able to take the full
force of another fall.

I've replaced the broken POTs, I couldn't find a match to what Dan Electro
use, and didn't particularly want to use the same thing after seeing the
aftermath.  So I bought 9mm square POTs.  I had to solder on extentions to
their legs to fit them into the PCB holes.  The good thing about this is if
the PCB does get ripped away again, it'll only disconnect the extensions
from the POTs, and they can be resoldered relatively easily.  

However the new POT shanks are different to the HoneyTone's, so the silver
knobs don't fit.  I bought two sets of black knobs which look distinctive,
and can be screwed solidly in place, regardless of the shank design.

I couldn't find replacement 1/4" PCB mounted jacks (locally) that would
fit, let alone one with a metal thread.  A case mounted 1/4" jack won't fit
due to the circuit board.  I could recover enough of the jack's thread to
wind the screw back on to stop the jack wobbling about, but it will not
take the force of another fall, the thread would be completely removed.  

I had to find a way to secure the PCB to the casing underneath the jack.

For the last month I've puzzled over how to install a screw into the PCB to
the case that could take the impact of a fall and stop the PCB moving, let
alone ripping the POTS out of the PCB again.   

I spent some time considering the option of taking the circuit and speaker,
removing all PCB mounted jacks, pots and LED, and replacing the lot with
case mounted components, and installing the whole thing into a small home
made wood cabinet.  It was going to be time consuming, and the resulting
amp would be bulkier.  

Today I found a solution to screwing the PCB to the case under the 1/4"
jack.   I superglued a block of plastic to case, in such a way the existing
strut will take any downward force. Drilled a new hole through the PCB
where theres no circuit to worry about straight through into the plastic
block.  Then used a self tapping Hohner diatonic reedplate screw (MS or
handmade, or Lee Oskar all work).  

I've now replaced the POTs and installed the additional screw to both my
HoneyTone amps.   I'm not game to drop them to see if it holds, but its
definitely more secure than just relying on the 1/4" jack's plastic thread
- theres no movement like there was before.

For people who have working HoneyTones, it may be worth your while taking
it apart, supergluing a block of plastic 19mm high (case to PCB) by 10mm x
10mm into the corner of the strut on the left side (with the back off
looking at the PCB), carefully drilling a hole through the PCB into the
plastic.  You can use a self tapping screw from an old diatonic harmonica
(Lee Oskars, and Hohner handmades and MS diatos have self tapping screws)
to secured the PCB down, and save yourself the trouble of having to buy a
new one, or replacing the POTs after a minor fall.

A side note, I didn't find any A100k (log) POTs for the overdrive that
would fit, so I settled for A50k (log) POT. The result is I have a lot more
control over the distortion which I'd normally never take more than half
way, if that - making the overdrive more useful for harp.

The overdrive POT is A100k Log, but can be simply be shorted if you don't
want/need it.  The tone POT is B100k linear.  The volume pot is A55k Log,
and double ganged with an on/off switch - I'm ignorant where to find a
replacement.  But in considering the idea of transplanting the entire
circuit into a wood cabinet with external jacks, pots and LED, I'd just use
an on/off switch in its stead.

Another side note.  I bought my first HoneyTone a few years ago, the
battery compartment had two pieces of metal which were meant to contact the
battery terminals.  These eventually failed in a fustrating kind of way, so
in the end I tore them out, and used my rotary tools and files to cut away
the extra plastic, then wired in a 9volt battery clip.  I'm glad to say my
new HoneyTone has came with a 9volt battery clip.

Not exactly your custom Meteor amp, but I use my HoneyTone almost every
day... both of them now, used with stereo output they sound pretty good.  :)

Cheers,
-- G.