4 Dec 2013

Yustech bust up a pedal.Did he really? Part I

 









Stop! Don't take out the knobs just yet! Electro-Harmonix Micro Metal Muff Alert!

The owner complaint his pedal ceased to work.Upon holding it he noticed a burnt smell.I didn't noticed such smell when receiving it.The only burning smell I notice is from my L&M that was in the ashtray.Ha ha.So I did the usual open up procedure.No burnt component were visible.So I thought maybe something did at the other side of the board.Just like most pedals the pots here are fastened to the top enclosure with hex nuts while the legs are securely soldered through the PCB.Its a practical way done by most to avoid premature loose pots over time.Loose pots can mean either bad QC or fault.

Common sense dictate I must take out the knob to access the hex nut.To do that I use a technique I call "Two point leverage push". It has nothing to do with push ups nor Brazilian Jujitsu.Its a method using 2 steel rule at opposite side to push the knob upwards.I invented this years ago after watching God of Cookery.Ha Ha.Then the unimaginable happens.Not only out went the knob,it brought along the pot shaft with it as well.It couldn't have happened at a better time.Right in front of the client.Imagine that!Thankfully he understood the situation.

Now,there must be a good rational explaination as to why that happened but before that a bit about my past experiences and findings.I have disassembled various and countless knobs,button and potentiometers ranging from Guitar,Hi-Fi,Amplifiers,Pedals,Kitchen Stove,Toys etc.I successfully bust up my dad fridge when I was 11 and again barely a year after.There was no Youtube back then.Thanks to Macgyver TV Series.People say "get them started young" .So trust me,I know what I'm doing if I have to do it.He he.

As I remember,I have been in this very same situation 4 times for the past 14 years.The first was when I pry open a PLASTIC knob of a Fender amp then sometime later a PLASTIC tone knob from a Strat.The third was a Trace Elliot bass amp mmm...wait a minute,that was my fault.I didn't know there was a grub screw under that green PLASTIC knob.The fourth one I will speak of it 10 years from now.Yes that knob was PLASTIC too.Here we have number five.

Plastic knob analysis.

  • The plastic knob could've been push to far in that it grab the pot knurled or otherwise shaft  tight like a super glue.Any tech in the world will botch the attempt including Mike Mathews himself.
  • The plastic knob could've been made so tight on purpose so that any repairs should be conducted by EHX or EHX appointed service centers only.Monopoly,now that's a board game I used to enjoy playing.Any tech in the world will botch the attempt including EHX them self.But then again they have the parts so they can bust it and replace it and everything will be honky dory.Have they?Will it?
  • The plastic knob could've contracted due to surrounding temperature causing it to grab it too tight.My uneducated scientific guess of course.
  Potentiometer analysis.
  • Unlike most guitar pots CTS,Noble,Alps and Bourns pots I have came to the conclusion that Mike Mathews of EHX has approved the use of cheap inferior quality potentiometer without rivet like shaft  strength..The shaft has fragile grip to the plastic wiper holder.Common sense tells me when Metal put up against Plastic.The former should be stronger than the later.Why buy good ones when the cheapo can do the same.Sound more like Electro-Harmonix shit at work here.Kudos

In part II begins my journey of finding the suitable pot.Will I find it.Its pretty slim but hopefully I will.Guess whose paying for it.None other than yours truly.Though I'm tempted to email bother Mike,I'll let him enjoy his cigar moment for he is a very busy man just like me.


Non authorized tech
yustech

2 comments:

Ijau D. Koceng said...

saya teringat komen ni dlm entri WORM tahun lepas:

"The chassis are made in China but the units are all assembled, and tested in NYC USA. We do not make ICs, transistors, caps resistors boards ect. It would be impossible!"

tak tau la apa jawatan yg dipegang oleh tukang komen ni di EHX, tapi dgn kata lain, dia mengaku

YusTech said...

Saya pun masih ingat.Hehe