Tag Archives | tone

Introducing Limelight True Power Bypass

Coldcraft Effects is proud to announce our latest update to the exceptionally clever True Power™ Bypass system: Limelight™ Bypass

The Limelight™ system simultaneously allows momentary bypass and standard latching bypass without the need to switch between exclusive modes.  Operation is simple and intuitive.  If the footswitch is held for 1 second or longer when enabling the effect, it responds as a momentary switch, turning off upon release.  Otherwise it is latching.

Other key features include:

  • True Power™ bypass – should the pedal lose power, it reverts to true bypass.  This includes the EchoVerberator, which has a buffered bypass with trails when powered.
  • Quiet, reliable relay bypass –
  • Opto-FET muting – silent
  • π-filtered power – no noise gets in, or out.
  • Sophisticated Reverse and AC Power Protection

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Big Muff Tone Control Alternative

I haven’t posted much in a while, mostly because I have been very busy building pedals and introducing new products.  So here’s a little snippet I’ve been working with for a while.  The Electro Harmonix Big Muff Pi uses a very simple tone control to mix between a high pass and a low pass filter.   This arrangement of filters lets you get a wide range of EQ curves from flat to scooped depending on the values use, and allows the pot to function as a tilt control.  It cuts bass as it adds treble and vice versa.

This style of control has been used on lots of other effects as well, such as the Boss DS-1 for example.  While toying with it, I realized that in some circuits, I prefer the bass response of the tone at Noon and would rather have it not cut bass when adding treble.  By adding 1 resistor and shorting pins 1 and 2 of the pot you can do just this.

Big Muff Alt

In the alternative configuration, R4 controls the fixed mix of the low pass path.  A good starting point would be to make R4 half of the original tone pot value.  Reducing the value of the tone pot will increase the amount of treble in the lowest setting, but leave the maximum fixed (when pin 2 is shorted to pin 3).  R4 could be made a trimpot internally to tweak the bass mix as well.

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New Retailer – Tone Factor!

Tone Factor, one the of the premier online retailers, is adding our entire line to their stock.  It’ll take a while to get all out new offerings to them, but you can check out what they already have here.

New Pedal Previews

A quick preview of what’s dropping in late June.  These 5 new Coldcraft Flavors will be available in limited quantities direct from our online store, as well as our newest dealer, Tone Factor.  A few details left to finalize (including a few names), but the important stuff is the following,

EchoVerb Compression Preamp Distortion

EchoVerb

  • Parallel Reverb & Echo Machine
  • Warm, Organic sound
  • Repeats, Time, Reverb Mix, Master Mix & Level

Studio Preamp/Compressor (Unnamed)

  • Discrete, Studio Channel Strip-in-a-Box
  • Compressor with Input Level, Limiter Threshold and Ratio
  • Dual Response & Frequency Control
  • Downward Expanding Gate

Distortion (Unnamed)

  • Classic Amp-style Distortion
  • Gain, Tone & Volume
  • Compression, Presence & Voice Trimmers

IC Fuzz (Unnamed)

  • Thick, Saturated Gain with Gate
  • Sustain, Tone, Volume
  • Tone Boost & Mid EQ Trimmers
  • Shape Trimmer controls low end “Tightness”

Fiesta Fuzz MkII Mini

  • Simplified version of the Flagship Fiesta MkII
  • Thick, hybrid-vintage style Fuzz
  • Fuzz, Bias, Volume Controls
  • 2-way OD/Fuzz Switch

IC Fuzz Fiesta Fuzz Mini

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The Case Against True Bypass – Revisited

You’ve seen this argument many, many times.  Hopefully, my peers who have written about this before me have convinced you that the revered 3PDT stomp switch, the “True Bypass with LED” savior is really just a bad idea.  Mechanical parts fail, and they fail way before electronic components.  Things wear out and its just how it works.  When it comes to signal switching in electronics, electronically controlled relays present a much more robust solution than simple mechanical stomps.

So dig this, the more complicated the mechanical switch, the more moving parts it has, and the lower the mechanical life expectancy should be.  The best of the best Single-Pole Carling Switches are rated at 100,000 cycles.  You can bet your ass that a run-of-the mill triple-pole switch comes doesn’t even come close.  Possibly within factor of 5, maybe 10 of that, meaning 10,000 cycles. Total shit.  And that’s a statistical figure, with a BIG spread because in the real world, shit breaks, a lot.

Now dig, the Panasonic TQ2-5V relay used in Coldcraft products, and by many colleagues in the music business is rated at 10^8 to (10^7 minimum) cycles.  That’s 10,000,000 activations, MINIMUM.  The MOMENTARY single-pole switch used to activate the relay will wear out before the relay gives up on you.  Unfortunately, relays can still cause switch POP, or audible clicking when used, but luckily, the same logic controls that switch the relay can be used to silence or quiet the switching action.  This is the basis of our bypass system and others including the Jack Deville-designed “Clickless True Bypass” now available at Mammoth Electronics.

Now the problem of reliability has been solved, dare I say its been obliterated.  However, there’s one more thing to consider, and that is Contact Voltage.

What the F is Contact Voltage?

Well, anytime there is a mechanical connection, there is a resistance present because the connection is imperfect.  Maybe the surfaces are rough, possibly oxidized, corroded or just don’t make great contact.  When a voltage is applied across the contact (AKA your guitar signal), the resistance creates a voltage drop across it, known as the Contact Voltage.  We already know that relays are sealed from the outside dirty world (read: your dirty shoes, beer-soaked bar floors, and worse).  The contacts inside the Panasonic relays are made of Ag and Au (Silver and Copper), two of the most conductive metals in town.  Contact Voltages inside a relay will be very, very small, but what else is involved?

Jacks.

Yes, every pedal has 2 jacks, and requires 2 plugs.  So lets say you have a modest pedalboard of 10 true bypass pedals.  If you were in the know, and purchased effects from VFE Pedals, Dr Scientist Sounds, and the like (that includes Coldcraft…), your pedals have relay-based bypass.  Minimal contact voltages inside the relays.  Ok, so back to the MATH.  2 Jacks, 2 Plugs, 1 DPDT bypass connection (2 contacts), 10 pedals.  That’s 80 contacts using a mechanical stomp switch!

80!

What I am getting at here is that’s an awful lot of places where your signal can degrade.  80!  It really only takes one faulty, dirty or otherwise weak connection to wreak havoc on a passive guitar signal.  So lets do some more MATH.  Suppose a typical mechanical connection is 10 ohms of contact resistance.  10 ohms is tiny, minuscule.  No one even uses a 10 ohm resistor when building pedals because its basically a jumper.

Now dig, 80 mechanical connections X 10 ohms = 800 ohms!  800 ohms is basically 1K ohm, and that can be a big deal on a passive guitar signal.  And this is all assuming there are no problem children, err, dirty, broken, intermittent contacts.  And don’t even get me started if you’re using one of those fancy programmable switchers.  You should just give it another factor of 2-4x.

Now for the punchline.  Say you have a buffer.  Doesn’t really matter if its an Op-Amp or Discrete, you just have one.  A buffer is any preamp/active element that presents the guitar with an ideal input impedance (resistance) and provides a lower, more ideal output impedance for driving heavier loads.  Put that buffer after the guitar, (or some where in the middle of the pedals even).  The output of that buffer will have no problem handling an extra 1k ohm on its output.  Hell, it was designed to do this.

Here’s a nice, tidy example of an Op-Amp based buffer.  This is my Micro Buffer/Splitter design that I have been selling for almost two years as a pre-built mono buffer, or a DIY project.  Personally, I think this buffer sound best AFTER all drive and fuzz pedals, but before any modulation or time-based effects.  That’s just my opinion anyway, your ears may tell you otherwise.  It can be configured as a splitter, mono or stereo buffer depending on how you populate the jumpers (J1, J2, etc). Micro Buffer Schematic

There are many other interesting products out there such as the Cornish LD-2 which is a discrete, bootstrapped design, as well as the Visual Sound Pure Tone, which is another Op Amp buffer.  You can read an argument from Pete Cornish against True Bypass here, and another here from Andrew Barta of Tech 21 NYC.

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4-Way Hum-Free Strat Wiring

After the post on my 4-way Tele wiring scheme, someone asked how I would prefer to wire up a 3-pickup strat.  Not really being a strat-guy I tried to come up with something unorthodox using the same 4-way switch as my Tele wiring.  Traditional Fender wiring for the Strat gives the following options,

  1. Bridge (No Tone)
  2. Bridge/Middle (Tone 1)
  3. Middle (Tone 1)
  4. Middle/Neck (Tone 1+2)
  5. Neck (Tone 2)

Now, my 2nd guitar growing up was a Strat-style, so I am quite familiar with the ice pick bridge that comes from the lack of tone control.  I’m also not a big fan of hum, so after spending some time brainstorming, I came up with the following 4-way wiring scheme for a 3 single-coil Strat.

4way Strat Wiring

I’ve opted for a Master Tone control, and a Master Bass control, as used by Leo Fender when he designed the G&L Legacy.  The Legacy was Leo’s final say on the Strat-style guitar.  You may also notice that this wiring includes an extra cap to ground (C3).  I have not tried out this wiring yet, but it would seem to me that it would be quite smooth, without the ice-pick that annoyed me so much.  The bass control would definitely keep the guitar from sounding muddy.

On to the pickup combinations.  What I’ve done here is only used 2-pickup combinations, either in series or parallel, and always with the bridge pickup.  The combination of the bridge with either the neck or middle should work to balance out the highs and lows for a full sound.  In my experience with the Tele parallel/series, I would expect the series settings to be slightly louder and warmer, whereas the parallel combinations would be brighter and punchier.

One last caveat.  To achieve true, hum-cancelling operation, you must use/wire reverse wound, reverse polarity Middle/Neck pickups relative to the Bridge pickup.  You may see this used on a parts-caster in the near future.  Actually, its the refinished body of the Strat I mentioned.

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