Tuesday, November 9, 2021

Boss CH-1 (Digital Version) Mods

Ah the downtrodden Boss CH-1.  It was a exciting pre-show purchase for me a 20 something circa winter 2003.  Having grown up on a healthy dose of lush chorus from Nirvana to The Police, I was looking to recreate those tones.  I'm sure my heart was set on a Electro Harmonix Small Clone or Poly Chorus, but the lowly Guitar Center at the time only had the Boss.  It did the job, but as time went on (17 years now), as I read the bashing of it on various guitar forums, and as I played friends' Poly Choruses, I realized the damn thing didn't do all I wanted it to.  I wanted the wacky quick modulation.  

First mod attempt

I found some great mods online for altering the delay time from flanger to more extreme chorus by changing 47pf cap on the C10 cap to a lower or higher value, up to 100pf.  Unfortunately, upon opening my chorus (bought in 2003) I realized it was made of all surface mount components, which are a bitch to try to mod (not recommended).  Not only that, but upon close inspection, I realized the whole circuit is different with a very different chip powering the delay.  They really should have just named my pedal a CH-2 or something.  After a lot of searching and research, it turns out Boss' schematic refers to it as a CH-1T(Taiwan?).  It really helps when trying to search for it.  I guess Boss decided to go with the new layout sometime after 2001.  That said, I'm not sure I really hear much differences in the old to new models.  But the old analog mods will not work on this newer model.  So after more searching I came across a great blog that had a newer digital mod. Here:  https://proto-schlock.blogspot.com/2013/04/boss-ch-1-mod-digital-version.html?m=1
Here's the new schematic in case you can't find it.

This guy changed the value or the R63 resistor to around 1.8K.  He also had some other interesting mods which I will get into later.  I didn't want to be too invasive to my pedal, so I opted to add a 8.2K resistor in parallel to the original 15K to cut the total resistance value to around 5.3K. Worked great!  Wacky quick modulation galore!  However, I got greedy and tried poking around at the circuit to find what controlled the delay time on the chip.  I had some luck with the R43 resistor, but dropped the pedal in doing so.  The modded, very small resistor pictured above snapped off.  Upon many failed attempts, I finally settled on bridging the connection for 0 resistance.  I got even quicker modulation up to 99% of the rate control knob.  However it folds in on itself at the very last 1% maxed position to cancel out the movement.

So, here's the disclaimer* DON'T TRY TO MOD THESE SUPER SMALL COMPONENTS UNLESS YOU'RE WILLING TO DESTROY YOUR PEDAL OR UNLESS YOU HAVE THE PROPER TOOLS AND SKILLS.  Seriously this was a pain to mod.  I think bridging the resistor ended up being easier in the end.  Maybe next time just a small dab of solder over the resistor.

Now another mod I see a lot of people attempt is adding vibrato to a chorus pedal.  They are in fact the same circuits but with chorus, it adds the dry guitar signal.  Where as vibrato is just the modulated signal only.  So, if you have a stereo chorus (two outputs) like my CH-1, usually you can just add a jack plug connected to nothing into the output B or second output (usually) This will make the pedal send the second output dry signal to nothing.  Muting it, turning your main output to the amp into vibrato.  Hope this helps some people!  If anyone figures out a safe why to mod the delay time to flanging and deeper chorus, let me know.  Here's a quick video sample. (of the earlier mod plus vibrato)

Wednesday, August 18, 2021

Replacing a Digitech Whammy Knob and Rotary Selector

DOH!!!  Why a plastic shaft!?!?!

        So..... you knocked the knob off your Digitech Whammy?  When I did, I thought it would be a cheap fix with a some sort of simple potentiometer.  While the fix itself was easy, it was not super cheap.  All and all it set me back at least $20 just for a little knob I probably kicked off during a show.  You'll most likely need two things special ordered along with all your average soldering and pedal tools.

These are what you'll need and what will set you back the most. (Almost like Digitech wants you to spend more on repairs.)   

  • Rotary encoder with 24 pulses with a 15mm shaft. (ebay seems to be the only place to find these.  Type those exact words into ebay.  Probably $15 for a set of two.  Might as well pick up an extra considering the shaft is plastic and it'll break again.  
  • #4
    7/64" Allen wrench (Not a common size in most sets.  As hard as I tried to buy locally, Amazon was the only place that had one)

You'll also need your basic soldering iron, solder, solder braid (to remove the old solder), a screwdriver, wrench and possibly wire cutters or pliers.

Take the casing apart by removing the top allen screws then remove the two screws with the screwdriver next to the "midi in".  With a little gentle sliding up and away from the "midi in" jack the top should come off with the board.   By now you should see picture #2.  Next we'll unscrew the washer holding the broken pot.  The top board will come loose.  Picture #3 at the bottom shows the 5 solder points we want to de-solder.  Honestly this is the hardest part.  Don't heat the points too long.  Use solder braid to lift the old solder.  You might need wire cutters or pliers if the old rotary encoder is stubborn to come out.  After the old broken rotary encoder is out, pop in the new one and solder it in.  (If the new rotary encoder has small metal tabs on the top sides like mine did in up top in picture#4, you may have to snip those off to fit it flush to the enclosure.) Then put everything back together.  Hopefully you didn't loose the original knob like I did and yours looks totally original.  My orange knob was all I had on hand at the time.  I'll have to get something better in the future.  Hopefully this helps you bypass Digitech customer support and shipping.  Good luck out there.  
What a looker...

Tuesday, June 1, 2021

Volume Pedal Mod Revisited (Switchable Minimum Volume/Volume Off)

 So with the prospects of once again being a supporting guitarist for Don Matsuo this July, I found myself pondering the volume pedal mod I did years ago where I physically stopped the minimum volume the pedal had to control the gain on my amp.  I don't know what to expect with this gig, despite this being my second go around.  Would I need a gain control, or a volume pedal?  I also got tired of pulling out the screwdriver each time I wanted volume swells on my lap steel.  So, the solution for me was clear.  Create resistance to ground on a switch.  I measured 1.55K on my multimeter as the resistance on my minimum volume with the previous mod.  So the idea, was to put a combo of resistors to equal 1.55K that could be added between the volume pot of the pedal and ground, as well as to be taken away (switchable).  After contemplating drilling a new switch hole, I realized I never used the tuner output.  I actually really have no use for it.  So that was my mounting hole.  Also 100% reversible. 

So, (1.)I de-soldered the tuner jack, and the ground wire (grey) from the board.  (2.) Soldered the pot ground (same grey wire) to the middle switch lug. The tuner jack left me some holes to run wires through!  (3.) Ran a new wire from one side of the switch to the original ground board connection.  (4.) Ran my resistors (1.55K) from that same lug to the opposite lug on the switch.  

 After doing this, I found there are a few pedals on the market that do this same thing with a variable resistance pot, such as the new Ernie Ball MVP.  I did my approach, because I didn't want the potential for the knob to get bumped or moved.  I wanted a quick on-the-fly switch to change the function of my pedal.  For me, this is the perfect volume pedal.  (Also there's a treble bleed mod in there as well) 

Here's a quick clip of it. 

Sunday, April 11, 2021

New Split 7 Inch Out in July With Big Guest Stars

I know....It's been a while.  It's trange how things line up and how lucky I've been the last year.  Even though some people have these ridiculous superstitions about the calendar year number, the end of 2020 was a productive and musically rewarding one.  A band I play in and record (Born Shit Stirrers) decided to finally put some music down on recording after being inspired and cheered on by Mike Watt after being on the Watt From Pedro Show.  I think a lot of us felt in a suspended state, unsure of what to do in the future.  I certainly felt very uncreative around March of 2020.  The kind and wise words from Watt really got me out of my funk for sure,  "You're out there on the ocean all alone on a boat."  "What are you gonna do?" "Tell the wind which way to blow?"  In other words, make do with what you got and adapt to the situation.  Watt also always ends his radio show with "keep your powder dry".  Kind of an always be ready mantra of the revolutionary war.   
Not only was he the kick in the pants we needed, but he also was kind enough to add his bass to our tracks.  It's got to be one of the biggest musical moments of my life for me to play on the same tracks as a hero of mine.  I'm really proud of how everything turned out and came together, even though I'm probably going to hell for the lyrics.  
Watt wasn't alone either as a guest star.  We were lucky enough to have Joe King(Joe Queer) from The Queers and Reverend Nørb from Boris the Sprinkler grace us with their vocal stylings.  The songs will come out on a split 7 inch in July on Serial Bowl Records in the UK with friends from another semi-local band in Kumamoto Japan, Led Zep Vietcong.  The album names were definitely inspired by the crappy company I was working for last year and our sexual frustrations in lock-down.   I know July is a ways away, so here is a track to wet your beak to until then.  A cover, believe it or not about Richard Gere and a gerbil.  Written by geniuses from Salem/Portland Oregon, The Bumble Bees   

Enjoy!  ~Lum